uwsh manual chapter 12 - controllable pitch propellers · s0600-aa-pro-120 0910-lp-019-9270 30...

S0600-AA-PRO-1200910-LP-019-9270

30 OCTOBER 1998Change 1 Dated 15 November 1999

UNDERWATER SHIP HUSBANDRY MANUAL

CHAPTER 12CONTROLLABLE PITCH PROPELLERS

PUBLISHED BY DIRECTION OF COMMANDER, NAVAL SEA SYSTEMS COMMAND

DISTRIBUTION STATEMENT A: This document has been approved for public release and sale; itsdistribution is unlimited.

REVISION 1

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LIST OF EFFECTIVE PAGES

Date of original pages is: 30 October 1998Date of Change 1 is: 15 November 1999

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Title, A, and B. . . . . . . . . . . . . . . . . . . . . . . . .1Certification Sheet . . . . . . . . . . . . . . . . . . . . .1blank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OFlyleaf-1 (Flyleaf-2 blank) . . . . . . . . . . . . . . .1i through v . . . . . . . . . . . . . . . . . . . . . . . . . . Ovi blank. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ovii through viii . . . . . . . . . . . . . . . . . . . . . . . . .1ix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ox through xiv. . . . . . . . . . . . . . . . . . . . . . . . . .112-1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112-2 through 12-6 . . . . . . . . . . . . . . . . . . . . O12-6A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112-6B blank . . . . . . . . . . . . . . . . . . . . . . . . . .112-7 through 12-15 . . . . . . . . . . . . . . . . . . . O12-16 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112-17 through 12-46 . . . . . . . . . . . . . . . . . . O12-46A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112-46B blank . . . . . . . . . . . . . . . . . . . . . . . . .112-47 through 12-54 . . . . . . . . . . . . . . . . . . O12-55 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112-56 through 12-71 . . . . . . . . . . . . . . . . . . O12-72 blank . . . . . . . . . . . . . . . . . . . . . . . . . O12-73 through 12-81 . . . . . . . . . . . . . . . . . . O12-82 blank . . . . . . . . . . . . . . . . . . . . . . . . . O12-83 through 12-84 . . . . . . . . . . . . . . . . . . O12-84A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112-84B blank . . . . . . . . . . . . . . . . . . . . . . . . .112-85 through 12-90 . . . . . . . . . . . . . . . . . . O12-91 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112-92 through 12-107 . . . . . . . . . . . . . . . . . O12-108 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112-109 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112-110 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OA-1 through A-13 . . . . . . . . . . . . . . . . . . . . . OA-14 blank . . . . . . . . . . . . . . . . . . . . . . . . . . OB-1 through B-22 . . . . . . . . . . . . . . . . . . . . . OB-7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1B-8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OB-9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1

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RECORD OF CHANGESACN/FORMAL

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*CHANGEACN NO.

DATEOF

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ENTEREDBY

TITLE AND/OR BRIEF DESCRIPTION**

*When a formal change supersedes an ACN, draw a line through the ACN number**Only message or letter reference need be cited for ACNs

Flyleaf-1/(Flyleaf-2 blank)

1 11/15/99 Incorporate warning blade bolt installationoperationIncorporate chain hoist cautionMake changes to Hex Bolt ElongationMeasurement Procedure

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TABLE OF CONTENTS

Paragraph Page

SECTION 1 INTRODUCTION 1

12-1.1 GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1

12-1.2 PURPOSE.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1

12-1.3 SCOPE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1

12-1.4 APPLICABILITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1

12-1.5 CONTROLLABLE PITCH PROPELLERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1

SECTION 2 FFG 7 BLADE REMOVAL, RETRIEVAL, AND REPLACEMENT PROCEDURE

12-2.1 REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-5

12-2.2 PROCEDURE SYNOPSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-5

12-2.3 PREPARATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6

12-2.4 SPECIAL TOOLS AND EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6

12-2.5 RIG SHIP’S HULL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-9

12-2.6 ROTATE BLADE TO BE REMOVED INTO THE 12 O'CLOCK POSITION . . . . . 12-11

12-2.7 REMOVE MORGRIP BLADE BOLT CAPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-11

12-2.8 REMOVE MORGRIP BLADE BOLTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-12

12-2.9 BLADE REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-16

12-2.10 BLADE PORT AND BLADE INSPECTION AND PREPARATION. . . . . . . . . . . . 12-20

12-2.11 BLADE INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-23

12-2.12 MORGRIP BOLT INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-28

12-2.13 MEASURE INSTALLED BOLT LENGTH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-30

12-2.14 BOLT CAP INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-30

12-2.15 TEST THE CPP AND PRAIRIE AIR SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . 12-31

12-2.16 FINAL PROCEDURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-31

SECTION 3 FFG 7, DD 963, DDG 993, CG 47, AND DDG 51 CLASS PROPELLER HUB PRAIRIE AIR CHECK VALVE REPAIR

12-3.1 FFG 7 CLASS REPAIR PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-33

12-3.2 DD 963, DDG 993, AND CG 47 CLASS REPAIR PROCEDURE . . . . . . . . . . . . 12-33

12-3.3 DDG 51, CG 47 (CG 66 AND ABOVE), AND MODIFIED EARLIER CLASS SHIPS REPAIR PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-33

SECTION 4 FFG 7 CLASS WATERBORNE BLADE PORT HUB SEAL REPAIR

12-4.1 REFERENCES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-35

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12-4.2 SPECIAL TOOLS AND EQUIPMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-35

12-4.3 REPAIR PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-35

SECTION 5 DD 963, AND CG 47 BLADE REMOVAL, RETRIEVAL, AND REPLACEMENT PROCEDURE

12-5.1 REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-45

12-5.2 PROCEDURE SYNOPSIS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-45

12-5.3 PREPARATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-46


12-5.5 RIG SHIP’S HULL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-49

12-5.6 ROTATE BLADE TO BE REMOVED INTO THE 12 O'CLOCK POSITION. . . . . 12-49

12-5.7 REMOVE MORGRIP BLADE BOLT CAPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-50

12-5.8 REMOVE MORGRIP BLADE BOLTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-51

12-5.9 BLADE REMOVAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-55



12-5.12 MORGRIP BOLT INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-67

12-5.13 MEASURE INSTALLED BOLT LENGTH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-69

12-5.14 BOLT CAP INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-70

12-5.15 TEST THE CPP AND PRAIRIE AIR SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . . 12-70

12-5.16 FINAL PROCEDURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-70

SECTION 6 DD 963, DDG 993, AND CG 47 CLASS WATERBORNE BLADE PORT HUB SEAL REPAIR

12-6.1 REFERENCES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-73


12-6.3 REPAIR PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-73

SECTION 7 DDG 51 "FLEET" TYPE BLADE REMOVAL, RETRIEVAL, AND REPLACEMENT PROCEDURE

12-7.1 REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-83

12-7.2 PROCEDURE SYNOPSIS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-83

12-7.3 PREPARATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-84


12-7.5 RIG SHIP’S HULL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-87

12-7.6 ROTATE BLADE TO BE REMOVED INTO THE 12 O’CLOCK POSITION. . . . . 12-87

12-7.7 REMOVE BLADE BOLTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-88

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12-7.8 BLADE REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-91



12-7.11 BLADE BOLT INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-105

12-7.12 MEASURE INSTALLED BOLT LENGTH. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-108

12-7.13 REMOVE THREE-POINT LIFTING ASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . 12-109

12-7.14 BOLT NYLON PLUG AND SCREW INSTALLATION . . . . . . . . . . . . . . . . . . . . 12-109

12-7.15 TEST THE CPP AND PRAIRIE AIR SYSTEMS . . . . . . . . . . . . . . . . . . . . . . . . 12-109

12-7.16 FINAL PROCEDURES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-109

LIST OF APPENDICES

APPENDIX A MORGRIP BOLT ELONGATION MEASUREMENT PROCEDURE

A-1 TUTORIAL DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

A-1.1 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

A-1.2 PRINCIPLES OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-1

A-1.3 COMPENSATION FOR TEMPERATURE AND SALINITY CHANGES . . . . . . . . . .A-2

A-1.4 POTENTIAL PROBLEM AREAS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-2

A-1.5 OUT-OF-RANGE READINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-4

A-1.6 DIVER TRAINING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-4

A-2 SCOPE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-5

A-3 REFERENCED DOCUMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-6

A-4 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-6

A-4.1 DEFINITIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-6

A-4.2 PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-6

A-4.3 EQUIPMENT AND MATERIALS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-6

A-4.4 POLICY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-9

A-5 PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-9

A-5.1 GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-9

A-5.2 CALIBRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-9

A-5.3 BASELINE DIMENSION MEASUREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-11

A-5.4 UNDERWATER MEASUREMENTS AFTER INSTALLATION. . . . . . . . . . . . . . . .A-11

A-5.5 ELONGATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-12

A-6 EVALUATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-12

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A-6.1 EXAMPLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-12

A-7 RECORDING AND REPORTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-12

A-8 PERSONNEL QUALIFICATION AND CERTIFICATION REQUIREMENTS . . . . .A-13

APPENDIX B HEX SOCKET BOLT ELONGATION MEASUREMENT PROCEDURE

B-1 TUTORIAL DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1

B-1.1 SCOPE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1

B-1.2 INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1

B-1.3 PRINCIPLE OF OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-1

B-1.4 COMPENSATION FOR TEMPERATURE AND SALINITY CHANGES. . . . . . . . . .B-5

B-1.5 OFFSETS DUE TO DIMENSIONAL VARIATIONS . . . . . . . . . . . . . . . . . . . . . . . . .B-5

B-1.6 POTENTIAL PROBLEM AREAS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-6

B-1.7 OUT-OF-RANGE READINGS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-7

B-1.8 DIVER TRAINING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-8

B-2 MEASUREMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-9

B-2.1 SCOPE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-9

B-2.2 BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-9

B-2.3 REFERENCES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-9

B-2.4 PERSONNEL QUALIFICATION AND CERTIFICATION REQUIREMENTS . . . . .B-10

B-2.5 DESCRIPTION OF MEASUREMENT SYSTEM COMPONENTS . . . . . . . . . . . . .B-10

B-2.6 PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-11

B-2.7 MAINTENANCE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-13

B-3 EPOCH II ADDENDUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-13

B-3.1 SCOPE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-15

B-3.2 INSTRUMENT CALIBRATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-16

B-3.3 BASELINE MEASUREMMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-19

B-3.4 IN-PROCESS MEASUREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-20

B-3.5 FINAL LENGTH MEASUREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-21

B-3.6 PERSONNEL QUALIFICATION AND CERTIFICATION REQUIREMENTS . . . . .B-22

APPENDIX C HYDRAULIC INTENSIFIER

APPENDIX D BLADE BOLT CAP WRENCH

APPENDIX E MORGRIP TEMPORARY BOLT HYDRAULIC JACKING SYSTEM

APPENDIX F PROPELLER BLADE LIFTING FIXTURE

APPENDIX G BLADE RIGHTING FIXTURE

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APPENDIX H CENTER POST SLEEVE

APPENDIX I MONOBLOCK PROPELLER PRESERVATION & CPP HUB PRESSURE TEST

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LIST OF ILLUSTRATIONS

Figure Page

12-1 CPP Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-212-2 Top View of Clockwise Rotating Blade. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-312-3 Blade Palm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-412-3A Tugit Lever Hoists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12-6A12-4 Ship’s Hull Rigging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1012-5 Blade Bolt Numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1312-6 Power Head/Morgrip Bolt Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1412-7 Morgrip Bolt Hole Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-1912-8 Righting Fixture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2112-9 Blade Port Inspection Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2212-10 Hydraulic Hose Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-2712-11 Location of Nylok Pellets in the Morgrip Bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3112-12 Prairie Air Check Valve Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3412-13 Blade Port Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3612-14 Shim Requirement Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-4012-14A Tugit Lever Hoists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12-46A12-15 Ship’s Hull Rigging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-5012-16 Blade Bolt Numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-5212-17 Power Head/Morgrip Bolt Assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-5312-18 Morgrip Bolt Hole Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-5812-19 Righting Fixture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6012-20 Blade Port Inspection Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6112-21 Hydraulic Hose Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6612-22 Location of Nylok Pellets in the Morgrip Bolt . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-6912-23 Blade Port Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-7512-24 Shim Requirement Measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-7812-24A Tugit Lever Hoists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12-84A12-25 Blade Rigging Detail, Key Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-8812-26 Blade Rigging Details, Hold Back Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-8912-27 Blade Rigging Details, View at FR 448 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-9012-28 Hex Socket Bolt With Hydraulic Torque Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-9112-29 Blade Bolt Numbering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-9612-30 Blade Bolt Hole Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-9812-31 Righting Fixture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-10012-32 Blade Port Inspection Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-10112-33 Bolt Elongation Measurement Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-10712-34 Blade Bolt and Transducer Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-10712-35 Blade Bolt Plug and Screw Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-110A-1 Bolt Elongation Measurement Tool . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .A-7A-2 Bolt Elongation Measurement Calibration Standard . . . . . . . . . . . . . . . . . . . . . . . .A-7A-3 Bolt Elongation Measurement Inspection Report and Worksheet . . . . . . . . . . . . . .A-8B-1 Bolt Elongation Measurement Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-2B-2 Hex Socket Bolt Elongation Measurement Tool. . . . . . . . . . . . . . . . . . . . . . . . . . . .B-3B-3 Hex Socket Bolt Calibration Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-4B-4 Hex Socket Bolt Baseline and Post-Elongation Measurement Worksheet . . . . . .B-14B-5 Hex Socket Bolt Elongation Measurement During Installation Worksheet. . . . . . .B-15

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B-6 rf Ultrasonic Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-18B-7 Full Wave Rectified Signal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-18

NAVSEA Drawing 6698050 Rev E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .C-1NAVSEA Drawing 6698073 Rev A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .D-1NAVSEA Drawing 6698018 Rev C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .E-1NAVSEA Drawing 6699569 Rev E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .F-1NAVSEA Drawing 6699571 Rev E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-1NAVSEA Drawing 6699590 Rev B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H-1NAVSEA Drawing 6699591 Rev B. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .H-5NAVSEA Drawing 6697839 Rev D. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-1NAVSEA Drawing 6698352 Rev (-) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . J-1NAVSEA Drawing 6698342 Rev (-) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .K-1

LIST OF TABLES

Table Page

12-1 Material To Be Provided by the Repair Activity . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-712-2 FFG 7 Quality Assurance Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-812-3 FFG 7 Class Waterborne Blade Port Hub Seal Repair

Quality Assurance Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-3712-4 Material To Be Provided by the Repair Activity . . . . . . . . . . . . . . . . . . . . . . . . . . 12-4712-5 DD 963, DDG 993, and CG 47 Quality Assurance Points . . . . . . . . . . . . . . . . . . 12-4812-6 DD 963, DDG 993, and CG 47 Class Waterborne Blade Port

Hub Seal Repair Quality Assurance Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-7412-7 Material To Be Provided by the Repair Activity . . . . . . . . . . . . . . . . . . . . . . . . . . 12-8512-8 DDG 51 Quality Assurance Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12-8612-9 Sweeney Tool Fit-Up DDG 51: Right Hand Blade . . . . . . . . . . . . . . . . . . . . . . . . 12-9312-10 Sweeney Tool Fit-Up CG 66 and Higher: Right Hand Blade . . . . . . . . . . . . . . . . 12-94B-1 EPOCH II Initial Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .B-17

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SAFETY SUMMARY

GENERAL SAFETY PRECAUTIONS. Thefollowing general safety precautions supple-ment the specific warnings and cautionsthroughout this chapter. These general pre-cautions are related to the task of underwaterSonar Rubber Dome (SRD) repair. They areprecautions that must be understood and ap-plied before and during work on the SRD. Inaddition to the following precautions, person-nel must be familiar with and observe safetyprecautions set forth in the following publica-tions:

a. Navy Occupational Safety and HealthProgram Manual for Forces Afloat,OPNAVINST 5000.19 (Series)

b. Naval Ships’ Technical Manual(NSTM)

c. Technical/operating manuals forequipment

e. U.S. Navy Diving Manual, Volume I,NAVSEA-0944-LP-001-9010.

Do Not Repair or Adjust Alone.

Do not repair or adjust energized equipmentalone. The presence of a qualified individualcapable of rendering aid is required. Alwaysprotect against grounding hazards and makeadjustments with one hand free and clear ofequipment. Be aware that even after equip-ment has been de-energized, dangerous elec-trical hazards can exist due to capacitorsretaining electrical charges. Circuits must begrounded and capacitors discharged.

Test Equipment.

Make certain electrical test equipment is ingood condition and personnel are familiar withits safe operation. Handheld equipment mustbe grounded, if possible, to prevent shock in-jury. Because some types of equipment can-not be grounded, avoid holding them.

Equipment in Motion.

Remain clear of equipment in motion. A safetywatch will be posted if equipment requires ad-justment while in motion. The safety watchshall have a full view of operations and imme-diate access to controls that are capable ofstopping equipment. If at any time the equip-ment appears to be moving out of control, stopit immediately.

Limit Switches and Interlocks.

Limit switches and interlocks are provided toprotect personnel and equipment. Theyshould not be overridden or modified exceptby an authorized person. Do not dependsolely upon limit switches for protection. Dis-connect power at the power distr ibutionsource before adjusting limit switches if possi-ble.

First Aid.

Attend to all injuries, however slight, by obtain-ing first aid or medical attention immediately.

Resuscitation.

Personnel working with or near high voltageshall be familiar with approved resuscitationmethods. Begin resuscitation immediately ifsomeone is injured and stops breathing. A de-lay could cost the victim’s life. Resuscitationprocedures shall be posted where electricalhazards exist.

Minimizing Relative Motion.

Relative motion is the movement of two ormore objects in relation to each other. Thisposes unique hazards to divers. A commonexample is a group of ships swaying andbouncing against each other because of windand wave action. This motion would easilycrush a diver caught between the two ships.To reduce the hazards of relative motion andto simplify the task, suspend the work platformand rigging from fittings on the ship.

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WARNINGS AND CAUTIONS.

Specific Warnings and Cau-tions appearing in this chapterare summarized below foremphasis and review.

All CPP blade bolt installationoperations require a NAVSEA00C technical representativeon-site (page 12-1).

Rotating the propeller whiledivers are in the vicinity mayresult in serious injury to ordeath of divers. Divers must beclear of the propeller bladesand verify that dive hoses andrigging lines are clear of thepropeller blades. Divers mustbe warned when the propellerwill be rotating (pages 12-11,12-17, 12-18, 12-23, 12-24, 12-25, 12-49, 12-56, 12-57, 12-62,12-63, 12-64, 12-87, 12-95, 12-97, 12-99, 12-103).

The power head must have fullthread engagement with theblade bolt to avoid catastrophicfailure and possible personnelinjury when the bolt is pressur-ized. Ensure seven full turns.Record each power head pres-surization in the log book pro-vided (pages 12-12, 12-28, 12-51, 12-67).

High pressure oil jets can pene-trate the skin. Ensure thatdivers are aware that the powerhead is about to be pressur-ized. Divers should be clear ofthe power head (pages 12-13,12-54).

High pressure oil jets can pene-trate the skin. Divers mustensure that topside personnel

have depressurized the intensi-fier before disconnecting theHP tube (pages 12-15, 12-54).

High pressure oil jets can pene-trate the skin. Ensure that top-side personnel are clear of thevalve opening when depressur-izing the power head (pages12-15, 12-55).

Propel ler blade edges aresharp. Avoid injury while han-dling blades (pages 12-18, 12-25, 12-56, 12-64, 12-95, 12-104).

Rotating the hub with the rig-ging attached poses a serioushazard. Rigging loads will eas-ily be exceeded if the jackinggear pulls against the rigging.Direct communication betweenthe Diving Supervisor and theShip’s Force personnel operat-ing the jacking gear is required(pages 12-18, 12-57, 12-95,12-97).

Divers must not place hands orfingers between the blade palmand hub (page 12-25, 12-64,12-103).

Divers must not place hands orfingers between the blade palmand hub. Follow all safety pre-cautions concerning rotation ofblades (pages 12-26, 12-65,12-104).

Maximum pressure for hydrau-lic temporary bolts is 3,000 psiand must not be exceeded.Serious injury to a diver couldoccur if hydraulic temporarybolts were to fail (pages 12-27,12-66).

High pressure oil jets can pene-trate the skin (pages 12-29, 12-68).

High pressure oil jets can pene-trate the skin. Ensure divers

WARNINGS

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are clear of the valve openingwhen bleeding the power head(pages 12-30, 12-69).

It is essential that all tools andmaterials brought to the under-water job site are accounted forand removed at the completionof the job. Tools and materialsinadvertently left at the job sitecan generate unacceptablenoise and possibly causesevere damage to shipboardcomponents. Locally generatedwork packages shall ensurethat a general tool and materiallog sheet is prepared and main-tained during all UWSH opera-tions (pages 12-6, 12-35, 12-46, 12-73).

Chain twist in the working chainloops of manual chain hoistsand chain falls will cause chainfailure. Chain twist in the work-ing chain loop occurs when thechain has an improper reevethrough the chain sprocketsOR (more often) the runningblock has flipped up andthrough any of the chain loops(see figure 12-3A 12-14A, and12-24A).

All chain hoists and chain fallsissued with NAVSEA SUPSALVUnderwater Ship Husbandryequipment kits have beenchecked for chain twist and thechain hoist/fall has beenloosely two-blocked so that therunning block can not flip overinto the working chain loopsduring shipment.

OPERATORS must ensure thatthe running block is not flipped

over into the chain loops creat-ing chain twist while deployingand rigging the chainhoists/falls.

To check for chain twist in thechain loop:

Hang the hoist from the tophook in a safe, accessible loca-tion. Tighten the hoist until lessthen one foot of separationexists between the hoist bodyand the running block. Theshort throw allows for mucheasier visual detection of twistin the individual chain reeves.Confirm that none of the chainlengths running from the work-ing chain sprocket to the run-ning chain sprocket (chainreeves) have any twist causedby the running block beingflipped over and through theloop of the chain. If ANY chaintwist is detected, flip the run-ning block back through thechain loop until the twist isremoved. If ANY twist can notbe removed by flipping the run-ning block, the hoist chainMUST be removed from thehoist body and re-reeve exer-cising care not to twist thechain during installation (pages12-6A, 12-46A, and 12-84A).

Before removing the blade boltcaps, measures must be takenfor oil containment and abate-ment in accordance with localSenior Officer Present Afloat(SOPA) Manuals and referencec. of section 12-2.1, Require-ments (page 12-11).

Hydraulic fluid pressure mustnot exceed 37,500 psi. Exceed-ing 37,500 psi may damagepower head or intensifier(pages 12-15, 12-29, 12-54,

CAUTIONS

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12-68).

Blade edges are easily dam-aged. Do not strike bladeedges with air cylinders, tools,or other equipment (pages 12-18, 12-56, 12-95).

Careless use of tools or equip-ment may nick or gouge theshaft and propeller and causenoise or cavitation problems.Extreme care must be taken toensure that the propeller bladeand shaft are not damaged(pages 12-18, 12-57, 12-95).

Ensure that new O-rings areused for all installations (pages12-20, 12-23, 12-59, 12-62, 12-99, 12-102).

Divers must verify that the sus-

pended blade is clear of thehub in order to ensure that nodamage is done to the propellerblade palm, blade port or con-necting hardware when the hubis rotated (pages 12-24, 12-63).

Divers must verify that the sus-pended blade is clear of thedowel pins for a small rotationin order to ensure that no dam-age is done to the propellerblade palm, blade port, or con-necting hardware when the hubis rotated (pages 12-25, 12-64,12-103).

Be careful not to lower a bladeso rapidly onto the hub as towash out the cover plate O-ring. Never allow the forwardlever hoist to go completelyslack during the lowering pro-cess because this could lead toa sudden drop of the blade,causing O-ring washout (pages12-25, 12-64, 12-104).

Ultrasonic measurement proce-dures and equipment arerequired to achieve the accu-racy required in blade bolt mea-surement. Any ultrasonic bladebolt measurement proceduresand equipment utilized must beapproved by NAVSEA or itsauthorized representative inaccordance with NAVSEATechnical Publication 271(pages 12-28, 12-67, 12-105).

Before removing the blade,measures must be taken for oilcontainment and abatement inaccordance with local SeniorOfficer Present Afloat (SOPA)Manuals and reference c (page12-35).

If the jack pressure increasesrapidly without movement ofthe sleeve right at the start,

Fig. 12-3A, 12-14A, and 12-24A Tugit Lever Hoists (Harrington Pull-Chain Type have a two

part Reeve)

3 Ton1-½ Ton

4-½ Ton 6 Ton

TypicalRunning

BlockFlip

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stop jacking and inspect formisalignment. Retract the jackand remove the sleeve from thecenter post. If the sleeveremains serviceable, align thejacking assembly and restart(page 12-39, 12-77).

DO NOT attempt to measuredimension “B” between anexisting shim laying on thecrank pin ring and the bearingring. Dimension “B” must bemeasured between the actualcrank pin ring surface and thebearing ring. The elastic shimsurface makes the diver mea-surements with the outsidedepth micrometer unrepeatable(pages 12-40, 12-77).

The reduction of shim thick-ness or removal of shim asdetailed above is at best aninterim method to regain ablade port seal when bearingring wear has begun. Oncebegun, bearing ring wear willcontinue eventually causingblade port leaking to resume.Careful consideration of theship’s operational schedule anddrydock availabilities to performthe eventual replacement of theworn bearing ring is essential(pages 12-40, 12-78).

The blade seal base ring isheld in place only by a frictionfit at the 6 o'clock position. Dur-ing the jacking removal processthe ring will drop out under itsown weight (32 lbs.). Diversmust be prepared for the ring'sweight and to recover the 18springs which are retained bythe ring and may fall loose withthe ring (pages 12-41, 12-79).

Before removing the blade boltcaps, measures must be taken

for oil containment and abate-ment in accordance with localSenior Officer Present Afloat(SOPA) Manuals and referenced. of section 12-5.1, Require-ments (page 12-50).

Before removing the blade,measures must be taken for oilcontainment and abatement inaccordance with local SeniorOfficer Present Afloat (SOPA)Manuals and reference d (page12-73).

Torque vs. applied pressurecharts for the specific operatinghead and pump utilized mustbe available during operation(pages 12-85).

Torque vs. applied pressurecharts for the Sweeney RSL8operating head must be avail-able during operation (page 12-89).

Careful attention must be paidto connection of the hydraulichoses between topside pumpand underwater hydraulictorque link. The hoses must beconnected in accordance withmanufacturer's instructions(pages 12-85, 12-89).

Before removing the bladebolts, measures must be takenfor oil containment and abate-ment in accordance with localSenior Officer Present Afloat(SOPA) Manuals and referenced of Section 12-7.1, Require-ments (page 12-88).

Review the manufacturer’sinstruction manual for properuse of the topside hydraulicpump (page 12-89).

Do NOT use emery cloth orsandpaper for polishing theblade bolts (page 12-91).

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With the hoist under load,inspect the rigging beam instal-lation. Confirm that the beamis snug against the hull at thelifting tunnels. If any gap isobserved, slack the hoist andretighten the U-bolts (page 12-95).

Before installation, the boltthreads and the shoulder mustbe coated with nickel basedantiseize compound (page 12-105, 12-106).

The counter bore of the hexstock must face down duringassembly to avoid damagingthe transducer assembly (page12-106).

If the hydraulic tool is not prop-erly aligned, the UT inspectorwill see an initial rise in boltstretch on pressurization, fol-lowed by a drop in stretch dur-ing the return cycle. If thisoccurs, the alignment of thetool must be fixed to preventdamage to the ultrasonic sen-sor (page 12-108).

The pace of the operation mustbe slow enough to ensure theUT operator has sufficient timeto monitor bolt elongation,record ALL data and make cal-culations. The diver must leavethe transducer in place untildata is logged and the UT oper-ator calls for the transducer tobe moved (page 12-108).

In order to protect the precisionlead screw threads from corro-sion, a waterproof cap is sup-plied with the calibrationstandard. Before lowering thestandard into the local seawa-ter, this cap must be installed,and before removing the cap,topside, excess seawater must

be wiped off the standard. Inplacing the standard in its rotat-able base, an O-ring seal isformed to protect the leadscrew from seawater spill-over(page B-20).

xiv Change 1

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CHAPTER 12CONTROLLABLE PITCH PROPELLERS

SECTION 1 INTRODUCTION

12-1.1 GENERAL INFORMATION.As in all underwater ship husbandry, there areadvantages to removing and replacing control-lable pitch propeller (CPP) blades while theship is afloat. The most obvious advantage isthe elimination of costly dry-docking and theexpeditious return of the ship to operationalstatus. Another advantage is that the CPPblade can be removed and replaced virtuallyanywhere the ship is berthed.

12-1.2 PURPOSE.This chapter provides commands with techni-cal information and NAVSEA-approved proce-dures for the underwater replacement of CPPblades. Strict adherence to the procedures inthis chapter will provide the best assurancethat all tasks, both underwater and topside,are safely and efficiently completed and thatstringent quality control requirements are met.

All CPP blade bolt installationoperations require a NAVSEA00C technical representativeon-site.

12-1.3 SCOPE.This chapter provides step-by-step proce-dures for the planning and execution of water-borne CPP repair. This chapter does notsupersede information contained in the U.S.Navy Diving Manual or the Naval Ships’ Tech-nical Manual (NSTM). NAVSEA 00C5 is avail-able for consultation or technical assistanceduring CPP blade replacement planning andexecution.

12-1.3.1 Section 1 of this chapter describesCPP systems, discusses the components ofthe CPP blade and hub, explains the purposeof the CPP propulsion system, and introducesterminology commonly used in performingCPP blade change-out.

12-1.3.2 The remaining sections of this chap-ter provide step-by-step procedures for spe-cific CPP system repairs to specific classes ofships.

12-1.4 APPLICABILITY.

Blade replacement and blade port hub sealrepair procedures are provided for FFG 7, CG47, DDG 993, and DD 963 Class ships. A hubprairie air check valve repair procedure is pro-vided for FFG 7 Class ships. The prairie aircheck valve procedure can easily be appliedto CG 47, DDG 993, DD 963, and DDG 51Class ships. Blade replacement proceduresfor DDG 51 Class ships with "Fleet" typeblades are also provided. The DDG 51 Classblade bolt removal and installation proceduresare also applicable to CG 47 Class ships withhull numbers CG 66 and higher.

12-1.5 CONTROLLABLE PITCH PROPEL-LERS.

12-1.5.1 Description. CPP systems (Figures12-1 and 12-2) have blades that can pivot onthe hub to allow the pitch of the blades to bechanged. Blades are lettered “A” through “E”and are installed in balanced sets of five.Blade identification information is stamped onthe propeller blade palm. Each blade isinstalled in the blade port of the same letter.On several ship classes, a blade port coverplate and cover plate O-ring are installedwhere the blade mates to the hub, which pre-vents seawater from leaking in or oil from leak-ing out. Some older ship classes do not haveblade port cover plate seals, which forcesblade changes at the 6 o’clock position. Eachblade has two dowel pin holes and a prairie airnipple orifice. Likewise, each of the five bladeports on the hub has corresponding dowel pinholes and a prairie air nipple orifice. Twodowel pins and a prairie air nipple are installedwhere the blade mates to the hub. Each bladeis secured to the hub with blade bolts. Thebolts are stretched or torqued for installation.

WARNING

Change 1 12-1

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12-1.5.2 Purpose. The CPP propulsion sys-tem uses actuating mechanisms controlledfrom the bridge or engine room to provide afull range of ahead and astern thrust to thevessel while the main propulsion machineryoperates at a constant speed. Maximumahead thrust is provided with blades in the fullahead pitch position. By reversing the pitchinto the full astern pitch position, maximumastern thrust is provided without reversing theturning direction of the main propulsionmachinery, including the propeller shaft.

12-1.5.3 Terminology. Figures 12-1 and12-2 are labeled illustrations of a typical CPP

hub/blade assembly. The terms shown in Fig-ures 12-1 and 12-2 are defined below:

Hub. The center section of the propellerbolted onto the propeller shaft.

Pressure Face. The aft face of the propellerblade when the blade pitch is in the aheadposition.

Suction Face. The forward face of the propel-ler blade when the blade pitch is in the aheadposition.

Figure 12-1. CPP Terminology.

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NOTE

The pressure face and suctionface are reversed when theblade pitch is in the astern posi-tion.

Leading Edge. The blade edge adjacent tothe forward end of the propeller hub when theblade pitch is in the ahead position.

Trailing Edge. The blade edge adjacent tothe aft end of the propeller hub when the bladepitch is in the ahead position.

Blade Tip. The blade edge on the outermostradius of the propeller.

Blade Palm. As shown in Figure 12-3.

Blade Port. Recessed area of hub where thepropeller blade mates to the hub.

Emitter Holes. Holes drilled into a channelnear the leading edge of the blade that distrib-ute the prairie air.

Dowel Pins. Pins between the blade port andthe blade palm that transmit rotational torqueof the hub to the propeller blades and locatethe propeller blade in the blade port.

Hydrolube. A heavier than water hydraulicfluid used to dewater the blade bolt holes.

Prairie Air Nipple. Nipple that connects theprairie air tube located in the hub to the prairieair system located in the blade palm.

Figure 12-2. Top View of Clockwise Rotating Blade.

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Morgrip Bolts. Bolts used to secure blades tothe hub on FFG 7, DD 963, DD 993 and CG47 Class ships. These bolts are hydraulicallyelongated during installation and removal.After they are installed, the bolts retain a resid-ual stretch that provides a clamping force tohold the blades on the hub.

Hex Socket Bolts. Bolts used to secureblades to the hub on DDG 51 "Fleet" typeblades, and CG 47 Class ships with hull num-bers CG 66 and higher. These bolts arehydraulically torqued in place during installa-tion. The torquing process provides the clamp-ing force to hold the blades on the hub.

Figure 12-3. Blade Palm.

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SECTION 2 FFG 7 BLADE REMOVAL, RETRIEVAL, ANDREPLACEMENT PROCEDURE

12-2.1 REQUIREMENTS.

Commands that perform propeller bladereplacements must consider all requirements.If shop facilities are not available at the Com-mand with the overall tasking, the Commandmust arrange for them. A successful blade setchange requires one week. Provision must bemade for breasting the ship out by the stern sothe blades can be lifted between the ship andthe pier. Crane service, floating or pierside,must be available for propeller blade liftingand must have the required reach and angleto handle the propeller blades. An oil boom isrequired for oil abatement and containment inaccordance with local instructions. Also, thefollowing references provide specific informa-tion relevant to removing and replacing CPPblades:

a. NAVSEA 0941-LP-053-7010, FFG 7CP Propeller and Propulsion ShaftingSystem.

b. S9086-00-STM-000, Naval Ships'Technical Manual (NSTM), Chapter245, “Propellers.”

c. NAVSEA Best Management Practices(BMP) to Prevent/Mitigate Oil SpillsRelated to Waterborne Removal(s) ofBlades on Variable Pitch Propellers forNaval Vessels.

d. MIL-STD-2035(SH) 04 July 1991, Non-destructive Testing Criteria.

e. NAVSEA T9074-AS-GIB-010/271, 30April 1997, NAVSEA Technical Publi-cation, Requirements for Nondestruc-tive Testing Methods (referred to asNAVSEA Technical Publication 271).

12-2.2 PROCEDURE SYNOPSIS.

12-2.2.1 Rig the ship’s hull with two bellybands near the projection line and installhoists onto the belly bands at the keel.

12-2.2.2 Prepare each blade for removal byrotating the blade into the 12 o’clock positionand removing the Morgrip bolts connecting theblade palm to the hub.

12-2.2.3 Remove each blade from the 12o’clock position by rigging the blade with athree-point lifting assembly; relieving dowelpin binding until the blade clears the hub; andretrieving the blade to the surface.

12-2.2.4 Install each replacement blade byrigging the blade with the three-point liftingassembly; lowering the blade into position;seating the blade onto the hub; connecting theblade palm to the hub with four temporarybolts; and removing the three-point liftingassembly for return to the surface.

12-2.2.5 Secure each blade to the hub by:dewatering the open blade bolt holes; install-ing Morgrip bolts into the four open blade boltholes; removing the temporary bolts; dewater-ing the remaining bolt holes; installing theremaining four Morgrip bolts; measuringinstalled bolt lengths to determine properresidual stretch; dewatering installed Morgripbolts; and capping the bolts.

NOTE

While the following procedurerequires that the topside per-sonnel and the divers workclosely together, certain stepsmust be carried out by particu-lar personnel. To clarify thesesteps, abbreviations are placed

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at the beginning of each stepwhere the specific party needsto be identified: (DV) repre-sents diver, (TOP) representstopside personnel, and (SF)represents Ship’s Force per-sonnel and (UT) representsLevel II Ultrasonic Inspector.

12-2.3 PREPARATION.

12-2.3.1 Ship’s List and Trim. Ensure thatthe ship has no more than one degree of listand minimum possible trim during the actualblade removal. Excessive list or trim willadversely impact insertion of replacementblades into the propeller hub port.

It is essential that all tools andmaterials brought to the under-water job site are accounted forand removed at the completionof the job. Tools and materialsinadvertently left at the job sitecan generate unacceptablenoise and possibly causesevere damage to shipboardcomponents. Locally generatedwork packages shall ensurethat a general tool and materiallog sheet is prepared and main-tained during all UWSH opera-tions.

12-2.3.2 Inventory Tools, Materials andEquipment. NAVSEA 00C5 maintains a CPPblade change kit that contains most of thetools and equipment necessary to replaceCPP blades. This blade change kit should beobtained and positioned on site before begin-ning the task. An inventory of the items in thiskit is available from NAVSEA 00C5. Table 12-1identifies additional items that must be pro-vided by the repair activity. Ensure the avail-ability of all technical information, manuals,and drawings.

12-2.3.3 Prepare Quality Assurance (QA)Package. Prepare QA forms in accordancewith Table 12-2.

12-2.3.4 Review Bolt Elongation Measure-ment Procedure and Equipment. It is veryimportant that both the divers and the NDTinspection personnel study and understand allaspects of bolt elongation measurement asdetailed in Appendix A. Review of the tutorialdiscussion provided in Appendix A first willprovide a good general understanding of theresponsibilities for the divers and NDT inspec-tors. See Appendix J for NAVSEA NDT equip-ment details.

12-2.4 SPECIAL TOOLS AND EQUIPMENT.

Removal and replacement of the CPP bladerequires some special tools and equipment.The find numbers (FN) in the following para-graphs correspond to the find numbers in theNAVSEA CPP Blade Change Kit, the inventoryfor this kit is available from NAVSEA 00C5.The quantities of items contained in the CPPKit are the minimum recommended to be onhand prior to CPP blade removal and replace-ment. Their functions are described in the fol-lowing paragraphs.

12-2.4.1 Intensifier. The intensifier assembly(FN 37) pressurizes hydraulic fluid that is usedto install and remove Morgrip bolts andhydraulic temporary bolts. Low pressure (LP)air is the power source for the intensifier. Theintensifier is connected with a high pressure(HP) flexible tube to the Morgrip bolt powerhead tool and with a quick-connect hydraulichose to the hydraulic temporary bolts (seeAppendix C)

12-2.4.2 Morgrip Bolt Power Head Tool withBullets. The Morgrip bolt power head toolassembly (FN 38) is used to remove andinstall Morgrip bolts. This is accomplished byinserting the bullet rod into the Morgrip bolt;attaching the power head onto the bolt with aspanner wrench; connecting the power headto the intensifier with the HP tube; and pres-surizing the hydraulic fluid in the power head

CAUTION

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Change 1 12-6A

Chain twist in the working chainloops of manual chain hoistsand chain falls will cause chainfailure. Chain twist in the work-ing chain loop occurs when thechain has an improper reevethrough the chain sprocketsOR (more often) the runningblock has flipped up andthrough any of the chain loops(see figure 12-3A).

All chain hoists and chain fallsissued with NAVSEA SUP-SALV Underwater Ship Hus-bandry equipment kits havebeen checked for chain twistand the chain hoist/fall hasbeen loosely two-blocked sothat the running block can notflip over into the working chainloops during shipment.

OPERATORS must ensurethat the running block is notflipped over into the chain loopscreating chain twist whiledeploying and rigging the chainhoists/falls.


Hang the hoist from the tophook in a safe, accessible loca-tion. Tighten the hoist until lessthen one foot of separationexists between the hoist bodyand the running block. Theshort throw allows for mucheasier visual detection of twistin the individual chain reeves.Confirm that none of the chainlengths running from the work-ing chain sprocket to the run-

ning chain sprocket (chainreeves) have any twist causedby the running block beingflipped over and through theloop of the chain. If ANY chaintwist is detected, flip the run-ning block back through thechain loop until the twist isremoved. If ANY twist can notbe removed by flipping the run-ning block, the hoist chainMUST be removed from thehoist body and re-reeve exer-cising care not to twist thechain during installation.

CAUTION

Fig. 12-3A Tugit Lever Hoists (Harrington Pull-Chain Type have a two part Reeve)

3 Ton1-½ Ton

4-½ Ton 6 Ton

TypicalRunning

BlockFlip

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12-6B Change 1


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.

which forces the bullet rod into the bolt, thusstretching the bolt.

12-2.4.3 Bullet Rod Removal Tool. Thebullet rod is removed from the Morgrip boltwith the bullet rod removal tool (FN 38.4).

12-2.4.4 Morgrip Bolt. Morgrip bolts (FN 2)are used to secure the propeller blade to thehub. The Morgrip bolt contains a bored cavitythat enables the bolt to be stretched duringinstallation. After they are installed, the boltsretain a residual stretch that provides a clamp-ing force to hold the blades on the hub.

12-2.4.5 Blade Bolt Cap Wrench. Theblade bolt cap is threaded onto the head of theMorgrip bolt using the blade bolt cap wrench(FN 5). (See Appendix D).

12-2.4.6 Hydraulic Temporary Bolts.Hydraulic temporary bolts (FN 9) have twoquick-connect nipples so that pressurizedhydraulic fluid is directly connected from thebolts to the intensifier via a quick-connecthose assembly. Hydraulic temporary boltscontain a hydraulic chamber. Pressurized

hydraulic fluid in the chamber pushes the jack-ing body of the bolt down onto the blade palm.Simultaneously, the threaded portion of thebolt in the Morgrip bolt hole is pulled towardthe blade palm. This tension provides a tightfit. Hydraulic temporary bolts can be con-nected in series with short quick-connecthoses so that several bolts can be pressurizedat the same time (see Appendix E).

12-2.4.7 Lifting Assembly. The liftingassembly (FN 152) is attached to a propellerblade so the blade can be lifted and loweredwith the hook of a lever hoist (see AppendixF).

12-2.4.8 Righting Fixture. The righting fix-ture (FN 151) is installed onto the propellerblade and connected to the pier crane hook.The righting fixture is used to lift the propellerblade out of its shipping container and to standthe blade on its palm on wood timbers,enabling the blade to be outfitted with the lift-ing assembly (see Appendix G).

12-2.4.9 Modified Channel Lock Pliers. Therounded head of the channel lock pliers (FN

Table 12-1. Material To Be Provided by the Repair Activity.

Item No. Quantity Component Description Technical Specification

1 1 Transfer Line, 5/8″ x 100 ′ Commercial

2 3 Diver Tool Bag Commercial

3 1 Gallon of Hydraulic Fluid Tellus #15, Code 65203 (Shell Oil Company) or equal

4 3 Bag of Assorted Shop Rags Commercial

5 as required Timbers, 4″ x 4″ x 4 ′ (to set blades upright) Commercial

6 1 Combination Wrench, 1/2″ Commercial

7 1 Screwdriver, Flat Blade Commercial

8 as required Scotch-Brite Abrasive Pads Commercial

9 as required Grease Pencils Commercial

10 1 Tape Measure 8’ Minimum Commercial

11 as required Chafing Material Commercial

12 1 Degreaser/Carburetor Cleaner Commercial

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Table 12-2. FFG 7 Quality Assurance Points.

Blade Removal Initials

1. Ensure pitch is set at 110% full ahead [12-2.6.2].

2. Inspect removed blade bolt caps and plugs for damage [12-2.7.5].

3. Check Mapeco power head rupture disc torque at 100 ft.-lbs. [note prior to 12-2.8.2].

4. Remove blade bolts in the order: 2, 6, 3, 7, 1, 5, 4, 8 [Note prior to 12-2.8.3].

5. Clean blade bolts IAW Appendix A, [A-5.3.1], and conduct liquid penetrant inspection of removed blade bolts [12-2.8.27].

6. Ensure lifting fixture is installed with head clamp 64 inches from blade tip [12-2.9.11].

7. Check forward lever hoist centered with respect to keel and the forward shackle in the head clamp [12-2.9.16].

8. Measure blade palm spacing to relieve binding (if required) [12-2.9.24].

9. Benchmark the shaft [12-2.9.29].

Blade Installation Initials

1. Inspect blade port and blade [12-2.10].

2. Ensure edge guard material is used for lifting fixture clamps [12-2.11.5].

3. Check prairie air nipple fully inserted [12-2.11.8].

4. Check dowel pins fully inserted [12-2.11.9].

5. Ensure O-ring installed in blade port cover [12-2.11.13].


7. Check for cover plate O-ring washout [Caution prior to 12-2.11.32].

8. Check blade seating with 0.002-inch feeler gauge [12-2.11.51].

9. Record serial numbers and initial lengths of blade bolts to be installed. Use Inspection Report and Work Sheet, Figure A-3, Appendix A [12-2.12.1 and 12-2.12.3].

10. Apply thread lubricant to blade bolt shoulder and threads [12-2.12.15].

11. Dewater the blade bolt holes with Hydrolube [12-2.12.17].

12. Record final length and residual stretch when all eight bolts are installed. Residual stretch must be between 0.006 and 0.0084 inches. Use Inspection Report and Work Sheet Figure A-3 [12-2.13.1 and 12-2.13.2].

13. Ensure blade bolt cap seal is installed on blade bolt [12-2.14.5].

14. Torque blade bolt caps to 170 ft.-lbs. [12-2.14.7]

15. Dewater Morgrip bolt with Hydrolube [12-2.14.8].

16. Ensure blade bolt cap plugs are installed [12-2.14.9].

17. Test the CPP system performance [12-2.15].

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12) is ground off to a flat surface approxi-mately ¼-inch thick to allow for better accessto the Morgrip bolt Nylok pellet hole asdescribed in the note following step 12-2.14.2.

12-2.4.10 Spanner Wrench. The spannerwrench (FN 23) is used to tighten or loosenthe Morgrip blade bolts, attached to the powerhead assembly, into or out of the blade palm.

12-2.4.11 Dowel Pin Removal Tool. Thedowel pin removal tool (FN 13) is used toremove stuck dowel pins that cannot beremoved by hand.

12-2.4.12 Blade Guide Pins. The bladeguide pins (FN 14) are used to align the dowelpins with the blade palm at installation.

12-2.4.13 Bolt Elongation MeasurementTool. The bolt elongation measurement tool(FN 43) is a transducer assembly and ultra-sonic instrument specially designed to mea-sure the elongation of the Morgrip bolts. Thetutorial in Appendix A allows any IntermediateMaintenance Activity (IMA) Level II UltrasonicTesting (UT) inspector to perform measure-ments with this equipment.

12-2.4.14 Hydrolube. A heavier than waterhydraulic fluid used to dewater the blade boltholes.

12-2.5 RIG SHIP’S HULL.

Rig the ship’s hull with forward and aft bellybands and two 3-ton hoists in accordance withFigure 12-4 and the following procedure.

12-2.5.1 Rig Forward Belly Band. (TOP)Attach a line to one end of the belly band (FN157). Lower the line from the ship’s outboardaft deck to the diver.

12-2.5.2 (DV, TOP) Swim the line under theship’s hull to the inboard side and pass the bit-ter end of the line to topside personnel.

12-2.5.3 (TOP) With the belly band passingaround the hull of the ship, bring both ends ofthe belly band together on the aft deck.

12-2.5.4 (TOP) Join both ends of the bellyband with a 6-ton lever hoist (FN 156).

12-2.5.5 (TOP, DV) Working together, initiallyposition the forward belly band as indicated inFigure 12-4. Final adjustment will be madelater.

12-2.5.6 (TOP) Place a 12-inch half section of6-inch diameter pipe (FN 159) under the bellyband at the starboard and port locationswhere the belly band leaves the ship’s deck.Place each half section of pipe perpendicularto the belly band with circular side up. This willprevent chafing of the belly band cable causedby the edges of the deck when the weight ofthe blade is applied.

12-2.5.7 (TOP) Run both 3-ton lever hoists(10 and 30 foot throw) (FN 153 and FN 154) tothe "two blocked" position in order to confirmthe chain is not twisted.

12-2.5.8 (TOP, DV) Install a 1-inch safetyshackle (FN 161) on the belly band at themain deck. Attach a 3-ton lever hoist (10 ft.throw forward, 30 ft. throw aft) and an easingout line to the shackle. Lower the lever hoist tothe keel along the belly band.

12-2.5.9 (TOP) Tighten the 6-ton lever hoistjoining both ends of the belly band.

12-2.5.10 Rig Aft Belly Band. (TOP, DV) Rigthe aft belly band 30 inches aft of the forwardbelly band by repeating steps 12-2.5.1 through12-2.5.9. To prevent hazardous inboardmovement of the aft keel shackle during yardand stay of the blade to the surface, install apreventer wire rope pendant (FN 158) fromthe keel shackle along the 7/8″ belly band inthe direction away from the pier to the main

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Figure 12-4. Ship’s Hull Rigging.

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deck. Ensure the wire rope preventer iscinched tight at the main deck connection.

Rotating the propeller whiledivers are in the vicinity mayresult in serious injury to ordeath of divers. Divers must beclear of the propeller bladesand verify that dive hoses andrigging lines are clear of thepropeller blades. Divers mustbe warned when the propellerwill be rotating.

12-2.6 ROTATE BLADE TO BE REMOVEDINTO THE 12 O'CLOCK POSITION.

12-2.6.1 (SF) Rotate the shaft as directed bythe diver to bring the blade to the 12 o’clockposition.

12-2.6.2 (DV, SF) Ensure blade pitch is in the110% full ahead position. Benchmarks forpitch alignment are located adjacent to blade#1. Danger-tag the pitch controls in the lockedposition.

12-2.6.3 (SF) Danger tag the shaft in thelocked position.

Before removing the blade boltcaps, measures must be takenfor oil containment and abate-ment in accordance with localSenior Officer Present Afloat(SOPA) Manuals and referencec. of section 12-2.1, Require-ments.

12-2.7 REMOVE MORGRIP BLADE BOLTCAPS.

12-2.7.1 (DV) Remove the caps from all eightMorgrip blade bolts in any order in accordancewith steps 12-2.7.2 through 12-2.7.4.

NOTE

Morgrip blade bolt caps shouldbe installed at 170 ft.-lbs. (theinsta lla t ion torque require-ment) but they may be over-torqued and require a hydraulicwrench to remove.

12-2.7.2 (DV) Remove the 1/8-27 NPTF pipeplugs in the blade bolt caps using a 3/16-inchAllen wrench (FN 7.1). Retain caps and plugsfor reinstallation.

12-2.7.3 (DV) Place the blade bolt capwrench (FN 5) in the blade bolt cap spannerholes and tighten into the pipe plug hole.

NOTE

In some cases, the blade boltcap p lugs are imp rope r l yi ns ta l led and cannot beremoved. If this occurs, theblade bolt cap wrench may bemodified (by removing items 1,2, 3, and 4 from drawing inAppendix D) so that the wrenchwill set on top of the blade boltcap and engage the locking pinholes in the cap. Exercise carewhen using the tool in this man-ner, because the blade bolt capwrench i s no t pos i t i ve l ysecured on the blade bolt cap.

12-2.7.4 (DV) Using a breaker bar (FN 6.1)and 1 1/8-inch socket (FN 6.2) attached to theblade bolt cap wrench, remove the cap fromthe blade bolt.

WARNING

CAUTION

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12-2.7.5 (DV, TOP) Pass the blade bolt caps,the blade bolt cap plugs, the blade bolt capwrench, the breaker bar, the 1 1/8-inch socket,and the 3/16-inch Allen wrench topside.Inspect caps and plugs for damage (nicks,deformity, thread damage, improper fit of capplugs). The blade bolt caps and the blade boltcap plugs should be reused if not damaged.

12-2.8 REMOVE MORGRIP BLADE BOLTS.

12-2.8.1 (TOP) Set up the intensifier forMapeco power head pressurization in accor-dance with the instructions provided in Appen-dix C.

NOTE

The Mapeco power head isequipped with a pressure rup-ture disc to ensure that thepower head is not pressurizedabove 40,000 psi. It is impor-tant that the rupture disc hold-down nut (see drawing thataccompanies the power head)be torqued to 100 ft.-lbs. beforeusing the power head. Thetorque has been checked onthe power heads delivered withthe NAVSEA kit.

12-2.8.2 (TOP) Pass the Mapeco power headtool (FN 38.1), bullet rod (FN 38.5), spannerwrench (FN 23), and 5/8-inch open endwrench (FN 24) to the divers.

NOTE

Remove Morgrip blade bolts inthe following order: 2, 6, 3, 7, 1,5, 4, 8. Figure 12-5 shows theblade bolt numbering on theblade palm. Bolt hole numbersare stamped on the top of theblade palm next to the respec-tive hole.

12-2.8.3 (DV) Insert the bullet rod, cone endfirst, into the blade bolt.

12-2.8.4 (DV) Open the power head stopvalve one half turn to prevent hydraulic lock.

The power head must have fullthread engagement with theblade bolt to avoid catastrophicfailure and possible personnelinjury when the bolt is pressur-ized. Ensure seven full turns.Record each power head pres-surization in the log book pro-vided.

12-2.8.5 (DV) Thread the power head ontothe bolt head and seat firmly using the span-ner wrench. Count the number of turns as thepower head screws on. Seven to eight turnsshould seat the power head. Figure 12-6shows the power head/Morgrip bolt assembly.

12-2.8.6 (DV) Back the power head off fromthe bolt head ½ to 1 turn and retighten byhand to ensure that false bottoming has notoccurred since the bolt head flange and thepower head interface are not visible on theinstalled bolt. Seat the power head firmlyusing the spanner wrench.

12-2.8.7 (DV) Close the power head stopvalve, then open it no more than ¼ to ½ turn.

NOTE

The HP tube end fitting is aspecial design for extremelyhigh pressures. As illustrated inF igure 12-6 , an in te rna l l ythreaded ferrule must be posi-tioned on the threaded end ofthe fitting so that 2 to 3 threadsare exposed at the end of thef i t t ing be fo re the hose i sinserted into the power headconnection port. The ferruleposition must be checked priorto each connection of the hose.

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12-2.8.8 (DV) Remove the sealing plug fromthe most accessible power head connectionport and connect the HP tube from the sur-face, as shown in Figure 12-6. Inform topsidewhen ready to purge the HP tube.

12-2.8.9 (TOP, DV) Start and operate theintensifier pump by opening the air supplyvalve until a steady stream of hydraulic fluid(no air) bleeds from the loosened connectionopposite the HP tube in the power head. Fillthe intensifier reservoir with hydraulic fluid asthe tank level drops. Tighten the bleeding con-

nection with the 5/8-inch wrench to seat firmly(DO NOT OVERTIGHTEN).

High pressure oil jets can pene-trate the skin. Ensure thatdivers are aware that the powerhead is about to be pressur-ized. Divers should be clear ofthe power head.

Figure 12-5 Blade Bolt Numbering

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Figure 12-6. Power Head/Morgrip Bolt Assembly.

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12-2.8.10 (DV) Swim clear of the power headand inform topside that the HP tube is purgedand connected securely.

Hydraulic fluid pressure mustnot exceed 37,500 psi. Exceed-ing 37,500 psi may damagepower head or intensifier.

12-2.8.11 (TOP) Increase the intensifier pres-sure to 35,000 psi by slowly opening the airsupply valve. Secure the air supply valvewhen pressure is reached.

12-2.8.12 (TOP) Notify the divers when35,000 psi is reached.

12-2.8.13 (DV) Apply the spanner wrench tothe power head and attempt to loosen thepressurized blade bolt. If the bolt loosens, pro-ceed to step 12-2.8.18.

12-2.8.14 (DV, TOP) If the bolt does notcome loose, increase the pressure in 500-psiincrements and try again. Do not exceed37,500 psi.

12-2.8.15 (DV, TOP) If the attempt to removethe first bolt is unsuccessful, bleed pressure atthe intensifier, check connections, and repres-surize for another attempt. Cycling the powerhead through several pressurization cyclesmay loosen the bolt.

12-2.8.16 (DV, TOP) If the removal of anyremaining bolt becomes difficult, install ahydraulic temporary bolt in accordance withsteps 12-2.9.1 through 12-2.9.8 next to theproblem bolt and repeat the removal attempt.

12-2.8.17 (TOP) If no bolts can be loosenedat 37,500 psi, on-deck personnel must disas-semble, inspect, and clean all componentparts of the power head in accordance withthe drawing provided with the power head toensure their proper function. If the internalpressure “tire” seal to the valve stem has

failed the tire must be replaced. Reassemblethe power head, test in accordance with thedrawing, and return to step 12-2.8.1.

12-2.8.18 (DV) When a blade bolt has beenloosened, close the power head stop valve toisolate the pressure in the power head fromthe pressure in the HP tube.

12-2.8.19 (TOP) Depressurize the intensifierand the HP tube by slowly opening thehydraulic bypass valve on the intensifier.Inform the divers that the intensifier and HPtube have been depressurized.

High pressure oil jets can pene-trate the skin. Divers mustensure that topside personnelhave depressurized the intensi-fier before disconnecting theHP tube.

12-2.8.20 (DV) Disconnect the HP tube fromthe power head. Reinstall the sealing plug intothe exposed tubing connection fitting.

12-2.8.21 (DV) Remove the blade bolt andattached power head assembly from theblade. Lift the entire assembly to the surface ina diver tool bag. Do not loosen the powerhead stop valve underwater.

High pressure oil jets can pene-trate the skin. Ensure that top-side personnel are clear of thevalve opening when depressur-izing the power head.

12-2.8.22 (TOP) Remove one of the sealingplugs from a pressure connection port. Directthe orifice of the power head stop valve awayfrom personnel into a proper waste oil con-

CAUTION

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tainer. Open the power head stop valve todepressurize the power head.

12-2.8.23 (TOP) Remove the bolt from thedepressurized power head using the spannerwrench and strap wrench (FN 25). Sheet rub-ber wrapped around the shank of the bolt facil-itates a better grip with the strap wrench.

12-2.8.24 (TOP) Remove the bullet rod fromthe bolt. A special removal tool (part of FN38.4) is provided if suction makes bullet rodremoval difficult.

12-2.8.25 Repeat steps 12-2.8.2 through12-2.8.24 for the remaining blade bolts.

12-2.8.26 (TOP) Remove the used Nylok pel-let (see Figure 12-11) from each bolt. Use a1/16-inch drill bit to center drill the pellet andthen stick a scribe into the hole to pry out thepellet.

12-2.8.27 (TOP) Prior to use, all unthreaded,polished, external bolt surfaces must be liquid-penetrant inspected in accordance withNAVSEA Technical Publication 271. Group VII(solvent-removable) and Group IV (water-washable) fluorescent penetrant systems arepermitted for this application. Acceptance cri-teria shall be in accordance with MIL-STD-2035A, paragraph 7.6. Surface blemishes orscratches on the bolts’ polished surfaces maybe removed by rotating the bolt in a lathe whilepolishing with a Scotch-Brite pad. Do NOT useemery cloth or sand paper for polishing. Allpolished bolts must be reinspected as detailedabove. The Morgrip blade bolts that pass in-spection are to be reused with the replace-ment blades.

12-2.9 BLADE REMOVAL.

12-2.9.1 (TOP) Construct the lifting assembly(FN 152) in accordance with Appendix F.Ensure that the trailing edge clamp has the“FFG 7” delrin pads installed.

12-2.9.2 (TOP) Disconnect the trailing edgeclamp from the lifting assembly by removing

the two shackles joining the leg assemblies(both sides) to the trailing edge clamp. Lowerthe trailing edge clamp to the divers.

12-2.9.3 (TOP) Connect one 3/4-inch shackle(FN 162) to the forward hole of the headclamp.

12-2.9.4 (TOP) Connect one 3/4-inch shackleto the aft hole of the head clamp.

12-2.9.5 (TOP) Connect the aft shackle onthe head clamp to the transfer line. Lower thelifting assembly down the transfer line.

NOTE

Divers should mark each bladefor installation of the li ft ingassembly in accordance withstep 12-2.9.8.

12-2.9.6 (DV) Connect the single hook of theforward manual lever hoist to the 3/4-inchshackle attached to the forward hole of thehead clamp.

12-2.9.7 (DV) Using the forward manual leverhoist, rig the lifting assembly onto the blade.One diver should be guiding the leading edgeclamp onto the blade while another operatesthe lever hoist.

12-2.9.8 (DV) Ensure that the closest edge ofthe head clamp to the tip of the blade is 64inches from the tip of the blade. Position thetrailing edge clamp 18 inches up from the bot-tom of the blade edge. Measure along thepressure face (see Appendix F)

NOTE

The 18 inch dimension for posi-tioning the trailing edge clampprovides a good starting pointto set the length of the turnbuckles. During tightening, theclamps may move approxi-mately 1/2 to 1 inch.

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12-2.9.9 (DV) Attach the trailing edge clampto the shackles joining the legs of the liftingassembly (both sides) as shown in AppendixF.

12-2.9.10 Ensuring slack is in the forwardlever hoist, diver #1 maintains the head clampat the 64 inches mark on the blade. Diver #2tightens the head clamp to trailing edge clampturnbuckles on the aft and forward faces untilsnug at the 18 inch mark. This will assist inkeeping the head clamp from sliding along theedge towards the leading edge. Diver #2 thentightens the head clamp to leading edgeclamp turnbuckles until snug. Once this iscomplete, diver #2 tightens the trailing edgeclamp to leading edge clamp turnbuckles onthe aft and forward faces until snug.

12-2.9.11 (DV) Recheck the location of thehead clamp relative to the tip of the blade.

12-2.9.12 (DV) Take a strain on the headclamp with the forward lever hoist to seat theleading and trailing edge clamps on the blade.

12-2.9.13 (DV) Slacken the forward leverhoist and retighten the turnbuckles in thesame order as step 12-2.9.10.

12-2.9.14 (DV) Because the blade must belifted straight up to avoid binding, the verticalhang of the forward lever hoist must bechecked against the actual blade position.

12-2.9.15 (DV) Check the center keel positionof the forward manual lever hoist. Adjust thebelly band shackle to the center of the 14-inch-wide flat keel plate.

Rotating the propeller whiledivers are in the vicinity mayresult in serious injury to ordeath of divers. Divers must beclear of the propeller bladesand verify that dive hoses and

rigging lines are clear of thepropeller blades. Divers mustbe warned when the propellerwill be rotating.

12-2.9.16 (DV, TOP) Remove the forwardlever hoist hook from the head clamp of thelifting assembly and allow the hook to hangplumb. Check to ensure that the hook isdirectly above the forward shackle of the headclamp. If the hook is not directly above and inline with the forward shackle of the headclamp, then rotate the shaft the required dis-tance and direction to correct for port and star-board misalignment. Move the belly band tocorrect for fore and aft misalignment. The bellyband will need to be slackened to move for-ward or aft as required. Time spent to correctlyposition the belly band is usually paid backand then some in time to remove the blade.

12-2.9.17 (DV) Reconnect the forward leverhoist hook to the forward shackle of the headclamp.

12-2.9.18 Lifting Blade. (DV) Diver #1moves into position at the forward lever hoist.Diver #2 moves to the blade palm/hub inter-face.

12-2.9.19 (DV) Diver #1 takes the slack out ofthe forward lever hoist. Diver #2 places bothhands on the blade palm/hub in the vicinity ofbolt holes #1 and #4.

12-2.9.20 (DV) Diver #1 takes up on the for-ward lever hoist. At the same time, diver #2reports movement of the blade palm (indicat-ing that the blade palm made true upwardprogress from the hub or that the trailing orleading edge of the blade palm moved first).

12-2.9.21 (DV) Diver #1 continues taking upon the forward lever hoist until diver #2 reportsno blade palm movement. Do not exceed a

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heavy strain (belly band 12-18 inches awayfrom the hull) with the lever hoist.

Propel ler b lade edges aresharp. Avoid injury while han-dling blades.

Blade edges are easily dam-aged. Do not strike bladeedges with air cylinders, tools,or other equipment.

Careless use of tools or equip-ment may nick or gouge theshaft and propeller and causenoise or cavitation problems.Extreme care must be taken toensure that the propeller bladeand shaft are not damaged.

12-2.9.22 (DV) If diver #2 reports that theblade palm initially moved but that the bladepalm is no longer moving, then diver #1 needsto shake the blade tip VIGOROUSLY whilediver #2 reports any upward travel of the bladepalm. As long as steady upward progress ismade, continue with the “shake and pull”approach.

12-2.9.23 (DV/TOP) If diver #2 reports thatthe blade palm did not initially move or the“shake and pull” approach is not moving theblade palm, the dowel pins are binding and theshaft must be rotated in an attempt to locatethe position where binding is relieved. This is atrial and error process that may need to berepeated several times to find the appropriateposition. If diver #2 reported that the bladepalm did not initially move, the direction ofshaft rotation must be selected arbitrarily.

12-2.9.24 (DV) If a good degree of upwardmovement was encountered and ceasedbefore the blade became free, then divers arerequired to measure the spacing between theblade palm and propeller hub to assist indetermining the best direction to rotate theshaft. Using a 1/16-inch increment steel ruler(FN 15), record the distance between the hubface and the shoulder recess of the blade bolthole as shown in Figure 12-7. These mea-surements need to be taken through bolt posi-tions #1, #4, #5, and #8.

12-2.9.25 (DV, TOP) If the starboard sidemeasurements are greater than the port side,then the starboard side of the hub may bedown so the shaft should be rotated to port. Ifthe port side measurements are greater, thenthe shaft should be rotated to starboard. Ifthere is no clear difference between port andstarboard measurements, then arbitrarilyselect the direction of rotation. Record andkeep all measurements for the duration of theremoval process in order to monitor progress.

Rotating the propeller whiledivers are in the vicinity mayresult in serious injury to ordeath of divers. Divers must beclear of the propeller bladesand verify that dive hoses andrigging lines are clear of thepropeller blades. Divers mustbe warned when propeller willbe rotating.

12-2.9.26 (DV) Slack the forward lever hoisthook from the head clamp and prepare withShip’s Force to rotate the shaft.

Rotating the hub with the rig-ging attached poses a serious

WARNING

CAUTION

CAUTION

WARNING

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hazard. Rigging loads will eas-ily be exceeded if the jackinggear pulls against the rigging.Direct communication betweenthe Diving Supervisor and theShip’s Force personnel operat-ing the jacking gear is required.

12-2.9.27 (SF) Rotate the shaft for a count ofone second (bump) in the desired direction.

12-2.9.28 (DV, TOP) Try again to lift theblade. Again, the shaft rotation method ofrelieving dowel pin binding is often trial anderror to find the right position, so adjustmentsmay need to be repeated.

12-2.9.29 Benchmark the Shaft. (SF) Oncethe first successful blade removal shaft rota-

tion position is found inside the ship, withincommunication range of the jacking operator,benchmark the position on the shaft and a lo-cation that does not rotate with the shaft. Thenmeasure the shaft circumference and markfive equally spaced marks on the shaft to iden-tify the other blade removal locations. Labeleach mark with corresponding blade number.

12-2.9.30 Retrieve Blade to Surface. (DV)Note the location of the dowel pins and theprairie air nipple (in the hub or blade palm).Report the locations topside.

12-2.9.31 (DV) Connect the hook of the aftlever hoist to the aft 3/4-inch shackle of thehead clamp.

Figure 12-7. Morgrip Bolt Hole Measurements.

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12-2.9.32 (DV) Yard and stay the blade aftuntil the blade palm has cleared the propellerhub.

12-2.9.33 (DV) Remove the dowel pins andthe prairie air nipple from either the hub or theblade palm and send them topside. A specialdowel pin removal tool (FN 13) is available foruse on dowel pins that are hard to remove.

12-2.9.34 (DV) Continue the yard and stayprocess until the full weight of the blade istaken by the aft hoist.

12-2.9.35 (DV) Disconnect the forward leverhoist hook from the forward 3/4-inch shackleon the head clamp. Lower the blade to justbelow the hub with the aft lever hoist.

12-2.9.36 (TOP, DV) Install a pendant ontothe pier crane. Connect the crane pendant tothe same shackle of the head clamp that theaft lever hoist is attached. Use an additionalshackle to attach if required. This will help pre-vent rotation of the blade during the yard andstay to the crane.

12-2.9.37 (DV, TOP) Take the slack out of thecrane. Check all shackle arrangements forbinding. Yard and stay the blade until the fullweight of the blade is taken by the pier crane.When the pier crane has the full weight of theblade, disconnect the aft lever hoist. Raise theblade to the pier.

12-2.9.38 (TOP) Set the blade upright ontotwo 4″ by 4″ timbers on the pier.

12-2.9.39 (TOP) Disconnect the trailing edgeclamp from the assembly by removing the twoshackles joining the leg assemblies (bothsides) to the trailing edge clamp.

12-2.9.40 (TOP) Remove the lifting assemblyfrom the blade.

NOTE

If all five removed blades areset within reach of the craneupright on timbers (step 12-

2.9.38) as they are removed,topside personnel will haveplenty of time to shift removedblades to the special shippingpal lets as new b lades areremoved from the shipping pal-lets for installation.

12-2.9.41 (TOP) Later, after the new bladehas been prepared and removed from its spe-cial container, install the righting fixture (FN151) onto the old blade. Install the shacklesand wire rope pendants onto the righting fix-ture as shown in Figure 12-8.

12-2.9.42 (TOP) Flip the blade into a horizon-tal position using a two-part lift.

12-2.9.43 (TOP) Position it onto the specialshipping pallet the new blades were sent on.

12-2.10 BLADE PORT AND BLADEINSPECTION AND PREPARATION.

12-2.10.1 (DV/SF) For each empty hub bladeport, clean and inspect the cover plate, dowelpin holes, prairie air nipple orifice, center postsleeve, and O-ring groove. Figure 12-9 detailsthe hub blade port inspections. Scotch-Brite“greenie” pads work well for cleaning.

12-2.10.2 (TOP) Inspect the bottom of thereplacement blade, clean it if necessary, andremove the plug from the prairie air nipple ori-fice. Leave the protective shrink wrap on theblades until installation is complete.

12-2.10.3 (TOP) Inspect and clean the previ-ously removed dowel pins and prairie air nip-ple with an emery cloth (FN 29). Dowel pinsmust not be mushroomed or peened at eitherend.

Ensure that new O-rings areused for all installations.

12-2.10.4 (TOP) Lubricate the four new prai-rie air nipple O-rings (FN 16.2) with silicone

CAUTION

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Figure 12-8. Righting Fixture.

12-21

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Figure 12-9. Blade Port Inspection Details.

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grease (FN 17). Install the four O-rings ontothe prairie air nipple.

12-2.10.5 (TOP) Lightly coat the two dowelpins with oil. Confirm that both ends of eachdowel pin will fit in both blade palm holes.

12-2.10.6 (TOP) Inspect the two threadedplug holes in the blade palm. As required,install a blade palm plug (FN 18) into eachvacant plug hole using a 3/4-inch Allen wrench(FN 18.1).

12-2.11 BLADE INSTALLATION.


12-2.11.1 (DV, SF) Rotate the propeller hubblade port targeted for installation into the 12o’clock position. Align the bench mark madeduring the removal process to ease installa-tion.

12-2.11.2 (TOP) Send the dowel pins (FN19), prairie air nipple (FN 16.1), two taperedblade guide pins (FN 14.2) and blade guidepin turning bar (FN 14.1) down to the divers.

12-2.11.3 (TOP) Using the righting fixture,stand the replacement blade to be installedupright on the blade palm resting on two 4" x4" wood timbers.

12-2.11.4 (TOP) Remove the righting fixturefrom the blade.

12-2.11.5 (TOP) Install the three-point liftingassembly onto the blade as shown in Appen-dix F. Ensure that the head clamp is 64 inchesfrom the tip of the blade. Position the trailingedge clamp 18 inches up from the bottom ofthe blade edge. Measure along the pressureface. If edge guards are removed from newblades, cut a piece of metal edge guard andrubber material to insert between the clampsand the blade for protection. Cover anyexposed sharp edge of the edge guard piecewith tape to protect the diver.

12-2.11.6 (TOP) Take a strain on the headclamp with the crane chain fall to seat theleading and trailing edge clamps on the blade.

12-2.11.7 (TOP) Slack the crane and re-tighten the turnbuckles.

12-2.11.8 (DV) Install the prairie air nippleinto the prairie air nipple orifice in the hub untilit is fully seated. A mallet may be required tofully seat the double O-ring seal. When fullyseated, the nipple should extend 4 1/2 inchesout from the center post.

12-2.11.9 (DV) Press the dowel pins into thedowel pin holes by hand until fully seated.Measure to ensure that the dowel pins stickout of the hub no more than 3 3/8 inches.

NOTE

Dowel pins are extremely tightfitting and often present diffi-culty seating in water becauseof the small hydraulic relief.Care and continuous steadypressure should be applied.

12-2.11.10 (DV) Install the blade guide pinsinto bolt holes #2 and #6 of the blade port.


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12-2.11.11 (TOP) Send the blade port coverplate O-ring (FN 20) and the heavy grease(FN 21) to the divers.

12-2.11.12 (DV) Partially fill the O-ring groovein the cover plate with heavy grease. The O-ring groove is indicated in Figure 12-9.

NOTE

Do not over f i l l t he O- r inggroove. Excess grease canlead to seating problems.

12-2.11.13 (DV) Install the O-ring firmly intothe cover plate groove. Remove excessgrease.

12-2.11.14 (TOP) Connect the pier crane tothe forward 3/4-inch shackle of the headclamp.

12-2.11.15 (TOP) Using the crane, lower therigged blade to 10-15 feet below the water sur-face adjacent to the aft belly band.

12-2.11.16 (DV) Attach the aft lever hoist tothe aft shackle on the head clamp.

12-2.11.17 (DV) Yard and stay the blade untilthe full weight of the blade is taken by the aftlever hoist.

12-2.11.18 (DV, TOP) Slack the crane andunhook it from the forward shackle of the headclamp.

12-2.11.19 (DV) Attach the forward leverhoist hook to the forward shackle of the headclamp and take the slack out of the forwardlever hoist.

12-2.11.20 (DV) Check the shackle/hookarrangement on the forward end of the headclamp to ensure that it does not bind on theforward corner of the head clamp.

12-2.11.21 (DV) With diver #1 operating theforward lever hoist and diver #2 operating theaft lever hoist, yard and stay the blade forward

until the blade palm is approximately 2 inchesaft of the propeller hub.

12-2.11.22 (DV) Inspect the dowel pins, prai-rie air nipple, guide pins, and the cover plateO-ring for proper installation. Using diverpneumo, dewater the dowel pin holes in theblade palm to make penetration of the dowelpins easier.

12-2.11.23 (DV) Position the blade fully overthe propeller blade port. Ensure that the guidepins in bolt holes #2 and #6 align with the cor-responding bolt holes in the blade palm.

12-2.11.24 (DV) Detach the aft lever hoist.


Divers must verify that the sus-pended blade is clear of thehub in order to ensure that nodamage is done to the propellerblade palm, blade port or con-necting hardware when the hubis rotated.

12-2.11.25 (DV, TOP) Check to ensure thatthe blade is fully over the propeller blade portand that the guide pins in bolt holes #2 and #6align with the corresponding bolt holes in theblade palm. If the diver reports that the bladeport is not aligned with the suspended blade,then coordinate with Ship’s Force and rotate

WARNING

CAUTION

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the shaft the required distance and directionuntil the proper position is achieved.

12-2.11.26 (DV) Diver #1 moves into positionfor operating the forward lever hoist, and diver#2 moves into position at the blade port toreport the progress of the installation.

12-2.11.27 (DV) Slowly lower the blade withthe forward lever hoist onto the guide pins untilthe blade palm is approximately 1 inch abovethe top of the dowel pins.


Divers must verify that the sus-pended blade is clear of thedowel pins for a small rotationin order to ensure that no dam-age is done to the propellerblade palm, blade port, or con-necting hardware when the hubis rotated.

12-2.11.28 (DV) Visually check the O-ringplacement. Ensure that the top of each dowelpin is the same distance from the blade palm.If not, then rotate the shaft to balance the dis-tance.

12-2.11.29 (DV) If poor visibility makes thevisual dowel pin check (detailed in the previ-ous step) impossible, ensure that the bladepalm and hub are aligned by measuring thespacing between the blade palm and the hub.

Using a 1/16-inch increment steel ruler, recordthe distance between the hub face and theshoulder recess of the blade bolt hole asshown in Figure 12-7. These measurementsneed to be taken through bolt positions #1, #4,#5, and #8.

12-2.11.30 (DV, TOP) If the blade palm andhub are not aligned, then from the measure-ments determine the direction for rotating theshaft. If the starboard side measurements aregreater than the port side, the starboard sideof the hub is down and the shaft should berotated to port. If the port side measurementsare greater, the shaft should be rotated to star-board. Record and keep all measurements forthe duration of the installation process in orderto monitor progress.

Divers must not place hands orfingers between the blade palmand hub.

12-2.11.31 (DV) Diver #1 lowers the blade byletting out on the forward lever hoist until diver#2 reports no downward movement.

Be careful not to lower a bladeso rapidly onto the hub as towash out the cover plate O-ring. Never allow the forwardlever hoist to go completelyslack during the lowering pro-cess because this could lead toa sudden drop of the blade,causing O-ring washout.


WARNING

CAUTION

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CAUTION

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12-2.11.32 (DV) When downward progresshas ceased, slack the forward lever hoist to alight strain and have both divers commenceshaking the blade VIGOROUSLY at the tip.

12-2.11.33 (DV) If downward movement isencountered, diver #2 continues shaking theblade, while diver #1 slowly lets down on theforward lever hoist.

12-2.11.34 (DV) To establish if progress isbeing made, divers must measure the spacingbetween the blade palm and the hub. Usingthe 1/16-inch increment steel ruler, record thedistance between the hub face and the shoul-der recess of the blade bolt hole as shown inFigure 12-7. These measurements need to betaken through bolt positions #1, #4, #5, and#8.

12-2.11.35 (DV, TOP) If no downward move-ment can be achieved by shaking the blade,then from the measurements determine thebest direction for rotating the shaft. If the star-board side measurements are greater than theport side, the starboard side of the hub may bedown so the shaft should be rotated to port. Ifthe port side measurements are greater, theshaft should be rotated to starboard. If there isno clear difference between port and star-board measurements, arbitrarily select thedirection of rotation. Record and keep all mea-surements for the duration of the installationprocess in order to monitor progress.

12-2.11.36 (DV) Lift the blade until both dowelpins are disengaged from the blade.

Divers must not place hands orfingers between the blade palmand hub. Follow all safety pre-cautions concerning rotation ofblades.

12-2.11.37 (SF) Rotate the shaft in the direc-tion determined in step 12-2.11.35 until the

measurements are equal on the port and star-board sides.

12-2.11.38 (DV, TOP) Repeat steps 12-2.11.31 through 12-2.11.37 until the blade isfully seated.

12-2.11.39 Examine Morgrip Bolt Holes.(DV) Examine the blade bolt holes to see if thecover plate O-ring is visible, that is, washedout of the O-ring groove.

12-2.11.40 (DV) If the O-ring is visible, thenthe blade must be removed clear of the huband reinstalled after the O-ring is replaced.

12-2.11.41 Install Hydraulic TemporaryBolts. Temporary bolts are used to securethe blades onto the hub until the Morgrip boltsare installed. This is necessary to ensure theblade is properly seated.

12-2.11.42 (TOP) Pass four hydraulic tempo-rary bolt assemblies and the temporary boltturning bar to the divers. See Appendix E for adrawing of the temporary bolts.

12-2.11.43 (DV) Install the temporary boltassemblies into holes #1, #4, #5, and #8. Fig-ure 12-5 shows the blade bolt numbering onthe blade palm. Bolt hole numbers are sten-ciled on top of the blade palm next to therespective hole.

12-2.11.44 (TOP) Pass the two 2-foot hoses(FN 9.2) and one 6-foot hose (FN 9.3) down tothe divers.

12-2.11.45 (DV) Connect the hydraulic hosesinto the temporary bolts as follows: 2-foothose from position 1 to 4, 6-foot hose fromposition 4 to 5, 2-foot hose from position 5 to8, and 100-foot hose to position 8. This allowsfor simultaneous pressurization of all four tem-porary bolts. Figure 12-10 shows the arrange-ment for the hydraulic hoses. Inform topsidethat the hydraulic hoses are connectedsecurely. The hose quick-disconnects have

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locking collars that are screwed down by handto ensure that the connection is secure.

Maximum pressure for hydrau-lic temporary bolts is 3,000 psiand must not be exceeded.Serious injury to a diver couldoccur if hydraulic temporarybolts were to fail.

12-2.11.46 (TOP) Operate the intensifier to apressure of 1500 psi.

12-2.11.47 (DV) Hand tighten the temporarybolt collars onto the bolt shoulders using thetemporary bolt turning bar.

12-2.11.48 (TOP) Depressurize the intensifierby slowly opening the hydraulic bypass valveon the intensifier. Inform the divers that theintensifier has been depressurized.

12-2.11.49 (DV) Disconnect the hydraulichoses from the temporary bolts.

12-2.11.50 Remove Blade Guide Pins. (DV)Remove the blade guide pins from bolt holes#2 and #6.

12-2.11.51 Check Blade Seating. (DV) Us-ing a 0.002-inch feeler gauge (FN 22), checkthe gap between the blade palm and the hubat bolt holes #2, #3, #6, and #7. If the feelergauge penetrates at all, it should have a snug(touching both sides) fit. Check the gap in twoplaces along the line of the bolt circle. Thepurpose of this check is to determine the finalseating of the blade and that the O-ring in-stalled between the blade palm and the bladeport cover has not been washed out of itsgroove during the final seating of the blade.

12-2.11.52 Remove Three-Point LiftingAssembly. (DV) Loosen all of the turnbuck-les on the lifting assembly.

12-2.11.53 (DV) Remove the trailing edgeclamp and send to the surface.

12-2.11.54 (DV) Remove the lifting assemblyfrom the blade with the forward manual leverhoist. One diver must operate the lever hoistwhile the other diver guides the lifting assem-

Figure 12-10. Hydraulic Hose Schematic.

WARNING

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bly off the blade so as not to damage theblade.

12-2.11.55 (DV) Yard and stay the liftingassembly to the aft lever hoist and then out tothe crane and to the surface.

12-2.12 MORGRIP BOLT INSTALLATION.

It is very important that both the divers and theNDT inspection personnel study and under-stand all aspects of bolt elongation measure-ment as detailed in Appendix A. Review of thetutorial discussion provided in Appendix A willprovide a good general understanding of theresponsibilities for the divers and NDT inspec-tors. See Appendix J for NAVSEA NDT equip-ment details.

12-2.12.1 (UT) Record the serial number ofeach of the eight Morgrip blade bolts (FN 2) onthe Inspection Report and Work Sheet inAppendix A.

12-2.12.2 (UT) Set up the bolts in the installa-tion order (#2, #6, #3, #7, #1, #5, #4, and #8).

Ultrasonic measurement proce-du res and equ ipmen t a rerequired to achieve the accu-racy required in blade bolt mea-surement. Any ultrasonic bladebolt measurement proceduresand equipment utilized must beapproved by NAVSEA or itsauthorized representative inaccordance w i th NAVSEATechnical Publication 271.

12-2.12.3 (UT) Using NAVSEA-approvedultrasonic measurement procedure and equip-ment, record baseline dimension measure-ments for all eight bolts. A sample procedureusing NAVSEA-developed equipment is pro-vided in Appendix A.

12-2.12.4 (TOP) Set up intensifier for Mapecopower head pressurization in accordance withthe instructions provided in Appendix C.

12-2.12.5 (TOP) Insert the bullet rod into the#2 blade bolt, cone end first.

NOTE

The Mapeco power head isequipped with a pressure rup-ture disc to ensure that thepower head is not pressurizedabove 40,000 psi. It is impor-tant that the rupture disc hold-down nut (see drawing thataccompanies the power head)be torqued to 100 ft.-lbs. beforeusing the power head. Thetorque has been checked onthe power heads delivered withthe NAVSEA kit.

12-2.12.6 (TOP) Open the power head stopvalve one half turn to prevent hydraulic lock.


12-2.12.7 (TOP) Thread the power head ontothe bolt head and seat firmly using the span-ner wrench. Count the number of turns as thepower head screws on. Seven to eight turnsshould seat the power head. Figure 12-6shows the power head/Morgrip bolt assembly.

12-2.12.8 (TOP) Close the power head stopvalve, then open it no more than 1/4 to 1/2turn.

CAUTION

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NOTE

The HP tube end fitting is aspecial design for extremelyhigh pressures. As illustrated inF igure 12-6 , an in te rna l l ythreaded ferrule must be posi-tioned on the threaded end ofthe fitting so that 2 to 3 threadsare exposed at the end of thef i t t ing be fo re the hose i sinserted into the power headconnection port. The ferruleposition must be checked priorto each connection of the hose.

12-2.12.9 (TOP) Remove the pressure portsealing plug and connect the HP tube from theintensifier to the power head as shown in Fig-ure 12-6.

12-2.12.10 (TOP) Pump the intensifier until asteady stream of hydraulic fluid (no air) bleedsfrom the loosened connection opposite the HPtube in the power head. Fill the intensifier res-ervoir with hydraulic fluid as the tank leveldrops. Tighten the bleeding connection withthe 5/8-inch wrench to seat firmly (DO NOTOVERTIGHTEN).

High pressure oil jets can pene-trate the skin.


12-2.12.11 (TOP) Increase the intensifierpressure to 35,000 psi by slowly opening theair supply valve. Secure the air supply valvewhen pressure is reached.

12-2.12.12 (TOP) Confirm stable 35,000 psireading on the hydraulic pressure gauge, then

close the power head stop valve to isolate thepressure in the power head from the pressurein the HP tube.

12-2.12.13 (TOP) Depressurize the intensifiertank and the HP tube by slowly opening thehydraulic bypass valve on the intensifier.

12-2.12.14 (TOP) Disconnect the HP tubefrom the power head using the 5/8-inchwrench. Reinstall the sealing plug into theexposed tubing connection fitting.

12-2.12.15 (TOP) Apply thread lubricant (FN26) to the threads and shoulder of the Morgripblade bolt.

12-2.12.16 (TOP) Fill and clamp Hydrolubedispensers, one for each bolt hole, (FN 163.1)with 200 cc of Hydrolube (FN 163) each andpass to the divers.

12-2.12.17 (DV) Dewater blade bolt holes #2,#3, #6, and #7 by displacing the water in theholes with Hydrolube. Insert the dispensernozzle into the bolt hole so the Hydrolube(heavier than water) fills from the bottom of thebolt hole. This will displace the water with min-imum mixing action.

12-2.12.18 (TOP) Send bolt #2 (with powerhead attached) and a spanner wrench to thedivers.

12-2.12.19 (DV) Insert the bolt into bolt hole#2.

12-2.12.20 (DV) Seat the bolt using the span-ner wrench.

NOTE

Length of cheater pipe must beconsistent for all bolts.

12-2.12.21 (DV) Attach a 4-foot cheater pipe(FN 44) to the spanner wrench and tighten thebolt.

WARNING

CAUTION

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NOTE

A one-minute delay is requiredto allow hydraulic lock to relieveitself. It is critical to repeat untileach bolt will no longer tighten.

12-2.12.22 (DV) Wait one minute, thentighten the bolt again. Continue tightening thebolt, with a one minute pause between efforts,until the bolt stops advancing.

High pressure oil jets can pene-trate the skin. Ensure diversare clear of the valve openingwhen bleeding the power head.

12-2.12.23 (DV) Loosen one of the pressureport sealing plugs. Open the power head stopvalve to depressurize the power head and theMorgrip bolt.

12-2.12.24 (DV) Remove the depressurizedpower head from the bolt using the spannerwrench.

12-2.12.25 (DV) Remove the bullet rod fromthe bolt. The special removal tool is provided ifsuction makes the bullet rod removal difficult.Send the power head and the bullet rod to thesurface.

12-2.12.26 (DV, TOP) Repeat the bolt instal-lation procedure in the following boltsequence: #6, #3, and #7.

12-2.12.27 Remove Hydraulic TemporaryBolts (DV) Remove the temporary bolts frombolt holes #1, #5, #4, and #8 by reversingsteps 12-2.11.41 through 12-2.11.49.

12-2.12.28 Complete Morgrip Bolt Installa-tion. (DV, TOP) Repeat bolt installation pro-cedure (steps 12-2.12.1 through 12-2.12.25)for the following bolt sequence: #1, #5, #4,and #8.

12-2.13 MEASURE INSTALLED BOLTLENGTH.

12-2.13.1 (UT/DV) Using NAVSEA-approvedultrasonic measurement procedures and equip-ment, record the final measurements for alleight bolts.

12-2.13.2 Using the Inspection Report andWork Sheet, Figure A-3, compare the initialand final bolt lengths to determine residualstretch of bolts #1 through #8. Residualstretch must be between 0.006 and 0.0084inches.

12-2.13.3 (TOP) If any bolts are outside theresidual stretch required, corrections must bemade as follows. If residual stretch is too low,reinstall the power head and pressurize to35,500 psi, then reseat the bolt. If residualstretch is too high, reinstall the power headand pressurize to 35,000 psi. Loosen the boltand then reseat without the 4-foot cheater baron the power head spanner wrench.

12-2.13.4 (UT) Re-measure all eight bolts.Compare initial and final lengths to determineresidual stretch of all eight bolts. All final resid-ual stretch must be within the specified range(0.006-0.0084 inches).

12-2.14 BOLT CAP INSTALLATION.

12-2.14.1 (TOP) Prepare two Nylok pellets(1/4-inch diameter, 9/32 inch long) (FN 10) foreach bolt and pass them to the divers (one tobe installed and one as a spare).

12-2.14.2 (DV) Install one Nylok pellet intothe hole in the side of the threaded portion ofMorgrip bolt where the bolt cap is to beinstalled. Figure 12-11 shows the location ofthe Nylok pellet in the Morgrip bolt.

NOTE

Because access to the Nylokpellet hole is often partiallyobscured by the bolt recess inthe blade palm, one installation

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method is to grab the pelletwith needle nose pliers (FN 11)in order to hold the pellet in linewith the hole and then squeezethe pellet into the hole withmodified channel lock pliers(FN 12).

12-2.14.3 (TOP) Apply silicone grease to theblade bolt cap seals (FN 8).

12-2.14.4 (TOP) Pass the blade bolt capseals and a flat-blade screwdriver to the diver.

12-2.14.5 (DV) Install the blade bolt cap sealaround the blade bolt flange as shown in Fig-ure 12-11. Using the screwdriver, ensure thatthe seal is seated at the bottom of the bladeflange hole as shown in Figure 12-11.

NOTE

Check the fit and threads of allcap plugs in the blade bolt capsprior to sending the caps to thedivers.

12-2.14.6 (TOP) Pass the blade bolt caps (FN4), blade bolt cap plugs (FN 7), blade bolt capwrench (FN 5), and a 3/16-inch Allen wrench(FN 7.1) to the divers.

12-2.14.7 (DV) Install the blade bolt caps onall eight bolts using the blade bolt cap wrench.Torque to 170 ft.-lbs. using the torque wrench(FN 6.5) with the 1/2-inch drive to 3/4-inchdrive socket adapter (FN 6.6) and the impactsocket (FN 6.2). See Appendix D for details ofthe blade bolt cap wrench.

12-2.14.8 (DV) Dewater the Morgrip boltthrough the pipe plug hole in the cap by dis-placing the water with 200 cc of Hydrolube.

12-2.14.9 (DV) Install the blade bolt capplugs. Tighten the plugs flush with the caps.

12-2.15 TEST THE CPP AND PRAIRIE AIRSYSTEMS.

12-2.15.1 (DV, SF) Divers must watch forhydraulic leaks and smooth operation duringthe full range of pitch variation. Divers mustwatch for air leaks at the hub/blade palm dur-ing operation of the prairie air system.

12-2.16 FINAL PROCEDURES.

12-2.16.1 (DV) Remove all tools and equipment.

12-2.16.2 Take Inventory. (TOP) Collect, in-ventory, and pack equipment and tools. Mark

Figure 12-11. Location of Nylok Pellets in the Morgrip Bolt.

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or “red tag” damaged or malfunctioning toolsor equipment.

12-2.16.3 Debrief Ship's Force. (TOP) Thelead dive supervisor should debrief the perti-nent ship’s officers on the final status of theblade replacement. Ship systems that wereclosed and tagged out may be returned tooperation.

12-2.16.4 Prepare Final Report. (TOP) Pre-pare a final report documenting the accom-plished repair. Documentation which NAVSEA00C54 needs to help improve the procedureis: blade bolt liquid penetrate inspectionresults, blade bolt ultrasonic measurementinspection results, a description of any lost,damaged or malfunctioning tools or equipmentin the NAVSEA CPP Kit, a list of all consum-ables taken from the kit for the job, details

regarding any problems encountered, and rec-ommendations for new or special toolsneeded. The final report should be faxed or e-mailed to NAVSEA 00C54.

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SECTION 3 FFG 7, DD 963, DDG 993, CG 47, AND DDG 51 CLASS PRO-PELLER HUB PRAIRIE AIR CHECK VALVE REPAIR

12-3.1 FFG 7 CLASS REPAIR PROCEDURE.

12-3.1.1 NAVSEA 0941-LP-053-7010, FFG 7Class CP Propeller and Propulsion ShaftingSystem, should be used by repair personnelwhen accomplishing repairs to the FFG 7Class propeller hub prairie air system. The fol-lowing steps refer to sections of that manual.

12-3.1.2 Foldout 9 (Prairie Air Assembly) pro-vides a diagram of the prairie air assembly.Detail 14-A and View 17-B detail the configu-ration of the hub check valve.

12-3.1.3 Most often, the check valve spring(item 16) fails before the check valve (item10). When the spring fails, the check valve willnot reseat when air is secured and the prairieair tubing is flooded. Replacement of thespring is normally all that is required. If thecheck valve is damaged and must bereplaced, the check valve may need to be fit-ted to the prairie air tube (item 8) becauseeach check valve and tube are matched pairs.

12-3.1.4 To access the check valve, the prai-rie air adapter plug (item 17) must be removedfrom the aft end of the propeller hub. Removethe retaining set screw (item 30) so theadapter plug can be removed using a spannerwrench.

12-3.1.5 Once the adapter plug is removed,the check valve and spring can be pulled fromthe cavity. Slide the spring off the check valvestem and replace with a new spring.

12-3.1.6 Reinstall the check valve and theadapter plug. Ensure that the O-ring (item 22)on the adapter plug is checked. Replace ifnecessary.

12-3.1.7 Check the condition of the nylon setscrew (item 30), replace if necessary and rein-stall.

12-3.1.8 Table 7-1, page 7-6 contains a partslist for the applicable replacement parts.

12-3.2 DD 963, DDG 993, AND CG 47CLASS REPAIR PROCEDURE.

DD 963, DDG 993, and CG 47 Class shipshave the exact same configuration prairie airhub check valve, so the FFG 7 procedure inSection 12-3.1 may be applied directly.

12-3.3 DDG 51, CG 47 (CG 66 AND ABOVE),AND MODIFIED EARLIER CLASS SHIPSREPAIR PROCEDURE.

DDG 51 and CG 47 (CG 66 and above) Classships, and some modified earlier ship classes,have adapter plugs retained by a Nylok insertin the threads instead of a retaining set screw.Once the adapter plug is removed the springand check valve can be removed andreplaced. This procedure is similar to the FFG7 procedure outlined above and is specified inthe applicable ship class technical manualsand repair standards. The after prairie aircheck valve assemblies on these ships alsohave replaceable valve seats. These valveseats can be removed and taken topside for amore accurate fit-up before reinstallation. SeeFigure 12-12 for an illustrative comparison ofthe old and the new check valve configura-tions.

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Figure 12-12. Prairie Air Check Valve Configuration.

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SECTION 4 FFG 7 CLASS WATERBORNE BLADE PORT HUB SEAL REPAIR

12-4.1 REFERENCES.

a. NAVSEA 0941-LP-053-7010, Techni-cal Manual, FFG 7 Class CP Propellerand Propulsion Shafting System.

b. NAVSEA S9245-AF-TRS-010/FFG-7CL, Technical Repair Standard, Pro-peller Hub Assembly and Blades FFG7 Class.

c. NAVSEA Best Management Practices(BMP) to Prevent/Mitigate Oil SpillsRelated to Waterborne Removal(s) ofBlades on Variable Pitch Propellers forNaval Vessels.



Waterborne repair of the blade port hub sealrequires special tools and materials. The findnumbers (FN) in the following paragraphs cor-respond to the find numbers in the NAVSEACPP Blade Change Kit, the inventory is avail-able from NAVSEA 00C5. The qualities ofitems contained in the CPP kit are the mini-mum recommended to be on hand prior to a

blade port hub seal repair. Replacement partsfor five complete blade seal replacements areincluded in the NAVSEA CPP kit. Table 12-3lists quality assurance points when repairs areto be made.

12-4.3 REPAIR PROCEDURE.

NOTE

All item numbers in parenthesis( ) refer to Figure 12-13 unlessotherwise noted. Find Numbers(FN) refer to Parts List of theNAVSEA Blade Change Kit.

Before removing the blade,measures must be taken for oilcontainment and abatement inaccordance with local SeniorOfficer Present Afloat (SOPA)Manuals and reference c.

12-4.3.1 (DV) Remove affected propellerblade in accordance with Section 12-2 of thismanual.

12-4.3.2 (DV) Install a quick disconnect hubpressure test fitting (FN 51.2) (see Appendix I)into the lower of the two 1/2-inch pipe plug fit-tings on the forward end of the hub. The two1/2-inch fittings are approximately 180degrees apart from each other. DO NOT usethe two 1 1/4-inch pipe plug fittings which arealso located on the forward end of the hub.

12-4.3.3 (DV) Rotate the blade port to the 6o'clock position. Confirm that the hub centerpost sleeve (1) is not loose or cracked. SeeFigure 12-13 for identification of the centerpost sleeve. If the center post sleeve iscracked, locate and record the center post (2)outer diameter measurement which isstamped on the top of the center post and

CAUTION

CAUTION

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Item Name Reference

1 Center Post Sleeve FN 52.13 2 Center Post3 O-ring (dynamic) FN 544 O-ring (static) FN 555 Blade Port Cover Item 24 of fold-out 2 in reference a6 Capscrew FN 607 O-ring (static) FN 208 O-ring (dynamic) FN 569 Blade Seal Base Ring Item 7 of fold-out 2 in reference a10 O-ring (static) FN 5711 Spring FN 5312 Bearing Ring Item 6 of fold-out 2 in reference a13 Crank Pin Ring Item 2 of fold-out 2 in reference a14 Mylar Shim FN 66 (FFG 7 set)

Figure 12-13. Blade Port Assembly.

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machine a replacement sleeve in accordancewith NAVSEA Drawing 6699591, Center PostSleeve (see Appendix H). Should the outerdiameter measurement not be stamped on thetop of the center post sleeve, divers mustmake a repeatable measurement of the centerpost outer diameter using a 12-inch outsidevernier caliper (FN 63). Experience indicatesthat special eight-jaw chuck vice four-jawchuck lathe equipment is required to holdmachining tolerances on the thin walled centerpost sleeve blanks (FN 52.13). The centerpost sleeve can be machined out of solidround stock material on a standard four-jawchuck lathe if an eight-jaw chuck lathe is notavailable.

12-4.3.4 (DV) Install the second quick discon-nect hub pressure test fitting (FN 51.2) into the

other (opposite the one used in step 12-4.3.2)1/2-inch pipe plug fitting on the forward end ofthe hub.

12-4.3.5 (SF, DV) Secure the discharge valveat the ship's internal CPP head tank. This willprevent the head tank from emptying to thesea when the blade port cover is removed atthe 6 o'clock position. When the blade portcover is first removed, the oil entrapped in theCPP system will establish internal oil headpressure equal to outside seawater pressureat the 6 o'clock hub position.

12-4.3.6 (SF) Secure and tag out the CPPsystem.

12-4.3.7 (TOP, DV) Rig staging to the propel-ler under the 6 o'clock blade port or an alterna-

Table12-3. FFG 7 Class Waterborne Blade Port Hub Seal Repair Quality Assurance Points.

Quality Assurance Point Initial

1. Check for cracked center post sleeve. If cracked, record OD measurement stamped on the top of center post [12-4.3.3].

2. Confirm final machined dimensions of the replacement center post sleeve [12-4.3.14d].

3. Check alignment of the center post sleeve jacking assembly [12-4.3.14m].

4. Verify replacement center post sleeve is flush with the center post and did not crack during installation [12-4.3.14p].

5. Measure blade port cover to bearing ring clearance and determine shim requirements [12-4.3.15].

6. Ensure blade seal base ring positioning dowel is in position [12-4.3.19].

7. Inspect the blade seal base ring [12-4.3.20].

8. Reseat the blade seal base ring [12-4.3.23].

9. Remove excess O-ring seating grease and ensure Mylar shim is flat [12-4.3.24].

10. Ensure stable oil/water interface is level with hub port opening [12-4.3.25].

11. Observe O-rings in proper position during final seating of blade port cover [12-4.3.26].

12. Check distance between blade port cover and crank pin ring with 0.002-inch feeler gauge [12-4.3.29].

13. Check dowel pin fit and torque blade port cover cap screws to 33 ft.-lbs. [12-4.3.31].

14. Vent any air trapped in the hub [12-4.3.34].

15. Pressurize the system to check for leaks [12-4.3.36 and 12-4.3.40].

16. Final system test [12-4.3.39].

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tive method so the diver(s) can work from astable position for hub component removal.Wherever the stage is secured to the hub orblade bases, ensure that adequate chafinggear is used to prevent damage to any propel-ler surface. The diver must be stable to makethe required detailed measurements.

12-4.3.8 (DV) Remove every other cap screw(6) holding the blade port cover (5) (unitweight of cover is 183 lbs.) onto the crank pinring (13).

12-4.3.9 (DV) Install a handle nut approxi-mately four inches from the top of each of thefour 5/8-11 UNC 30-inch long all-thread rods.Make sure the handle on the handle nut isangled downward. The top of the all-threadrod is opposite the end with the flats machinedfor a 1/2-inch wrench. Installing the handlenuts onto the top of the all-thread rods prior toinstalling the all-thread rods avoids the needto run the handle nut all the way up the 30-inch length of the rods. Install a 5/8-inch flatwasher onto the rod so the handle nut willbear against the washer and not the blade portcover. Install the rod assemblies into the holesemptied in the previous step. Using the flats,tighten the rod assemblies in place with a 1/2-inch wrench.

12-4.3.10 (DV) Run the handle nuts back upthe all-thread rods until they are approximately1/4 inch from the surface of the blade portcover.

12-4.3.11 (DV) Remove the remaining fourcap screws holding the blade port cover to thecrank pin ring. The blade port cover shouldsettle onto the handle nuts installed on the5/8-inch all-thread rod assemblies.

NOTE

As the blade port cover is low-ered, watch for any of the fourO-rings (items 3, 4, 7, and 8)held in place under the bladeport cover. Also, watch for aMylar shim (14), if installed.

12-4.3.12 (DV) Lower the blade port coverevenly using the four handle nuts until theblade port cover is approximately 18 inchesfrom the blade port.

12-4.3.13 (DV) Remove the four O-ringsaccessible at this point (see Figure 12-13). If aMylar shim is found and is undamaged, leaveit in place. Measurements taken in step 12-4.3.15 will determine if the Mylar shim shouldremain in place, be removed, or be replacedwith a Mylar shim of different thickness.

12-4.3.14 (DV) If the center post sleeve iscracked or loose, replace it as detailed in thisstep. If the center post sleeve is not damaged,proceed with the next step.

a. Lower the blade port cover and removeit from the all-thread rods.

b. Remove the damaged center postsleeve from the center post. Thecracked sleeve should slide easily offthe center post.

c. Clean the center post using 360-gritwet/dry sand paper or Scotch-Britepads.

d. In accordance with step 12-4.3.3, thenew s leeve shou ld a l ready bemachined to obtain a 0.002 ± 0.0005-inch press fit onto the center post (seeNAVSEA drawing 6699591, CenterPost Sleeve, Appendix H).

e. Install the base plate (FN 52.3) on thefour all-thread rods using the handlenuts. Ensure that the handle nuts havefull thread engagement.

f. Place the Enerpac jack set (FN 9 ofNAVSEA Drawing 6699590, AppendixH) inside the tabs on the base plate.

g. Place the jacking plate (FN 52.2) on topof the Enerpac jack set so that thejack’s flat base rests in the indentation

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in the jacking plate and the tabs on thejacking plate are facing up.

h. Spray the inside diameter of the newcenter post sleeve with a lubricant thatwill not be displaced by the water (LPS-3 or equivalent) before the sleeve issent to the divers.

i. Place the new center post sleeve onthe jacking plate inside the tabs.Ensure that the end of the sleeve withthe taper on the inside diameter is fac-ing up towards the center post.

j. Place the pipe stand-offs (FN 52.4)over each of the base plate’s emptyholes and sl ide an a l l - thread rod(wrench flat end on the bottom) throughthe base plate and the pipe stand-offs,threading the end of the rod into thealigning hole in the crank pin ring. Fourall-thread rods with pipe stand-offsmust be installed. A total of eight all-thread rods are required, four with pipestand-offs and four without pipe stand-offs.

k. Ensure that the all-thread rods justinstalled are bottomed out in the crankpin ring bolt holes. Use a wrench on thewrench flats cut into the end of the rod.Install a handle nut on each rod.

l. Using all eight handle nuts, raise thebase plate until it is restrained by allfour pipe stand-offs. The pipe stand-offs will ensure that the base plate isparallel with the crank pin ring and thejacking plate is set at the proper height.

m. Check the entire setup prior to jackingthe new sleeve. Ensure that the taperon the inside diameter of the sleeve isfacing up toward the center post.Ensure that the whole jacking assem-bly is centered under the center post.

n. Extend the jack until the sleevetouches the center post. Verify align-ment of the sleeve with the center post.

If the jack pressure increasesrapidly without movement ofthe sleeve right at the start,stop jacking and inspect formisalignment. Retract the jackand remove the sleeve from thecenter post. If the sleeveremains serviceable, align thejacking assembly and restart.

o. Jack the sleeve into place. Do not stopjacking until the sleeve is flush with thecenter post.

p. Retract the jack and verify that thesleeve is flush with the center post.Verify that the new sleeve did not crackduring the press fit.

q. Remove the center post sleevereplacement assembly from the hubport. Leave four of the all-thread rods inthe crank pin ring.

r. Install the blade port cover onto the all-thread rods.

s. Continue with the next step in the pro-cedure.

12-4.3.15 (DV) Prior to reseating the bladeport cover, the measurements shown in Figure12-14 must be taken to determine if therequired 0.002-0.007-inch clearance will existbetween the bearing ring and the blade portcover after the blade port cover is bolted to thecrank pin ring. These same measurementsare made when the new hub is first assembledon the ship and often a Mylar shim must beadded between the blade port cover and thecrank pin ring to ensure that the requiredclearance is achieved between the blade portcover and the bearing ring after assembly.

CAUTION

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Over time, the rotation of the crank pin ring willcause wear on the bearing ring. As the bear-ing ring wears, dimension “B” in Figure 12-14will decrease. Since the blade port cover hasno wearing surface, dimension “A” on Figure12-14 stays the same. Therefore, over time,the thickness of Mylar shim required to main-tain the required clearance will decrease untilno shim is required and eventually the clear-ance will exceed the maximum, even with noshim.

DO NOT attempt to measuredimension “B” between anexisting shim laying on thecrank pin ring and the bearingring. Dimension “B” must bemeasured between the actualcrank pin ring surface and thebearing ring. The elastic shimsurface makes the diver mea-surements with the outsidedepth micrometer unrepeat-

able.

The reduction of shim thick-ness or removal of shim asdetailed above is at best aninterim method to regain ablade port seal when bearingring wear has begun. Oncebegun, bearing ring wear willcontinue eventually causingblade port leaking to resume.Careful consideration of theship’s operational schedule anddrydock availabilities to performthe eventual replacement of theworn bearing ring is essential.

NOTE

Mylar shims are very delicate.They are shipped with the CPPequipment kit in a PVC tube forprotection (FN 66). Shims of0.002, 0.003, 0.004, and 0.005-inch thickness are included

Figure 12-14. Shim Requirement Measurements.

CAUTION

CAUTION

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with the kit. The shims are alsoavai lable from the or ig inalequ ipment manufac tu re r(OEM), Bird-Johnson.

Referring to Figure 12-14, proceed with themeasurements as follows:

a. Perform all measurements to the near-est 0.001 inch and with the blade portat the 6 o’clock position.

b. It is essential that the same diver expe-rienced in the use of a depth microme-ter perform all dimension “A” and “B”measurements. This will ensure thatvariation based on measurement tech-nique will not effect the differencebetween “A” and “B”.

c. Perform eight measurements aroundboth the blade port and blade portcover, one adjacent to each Morgripbolt hole. Record the results. Becauseof access limitations, dimension “B” ismore difficult to measure. It is mostimportant to be consistent with thealignment and placement of the depthmicrometer at each location measured.

d. After the most repeatable measure-ments achievable have been recorded,average the eight measurements takenfor “B”.

e. Average the eight measurementstaken for “A”.

f. If “B” is greater then “A” a shim isrequired. The minimum shim thicknessis (“B” - “A”) + 0.002 inch. The maxi-mum shim thickness is (“B” - “A”) +0.007 inch.

g. If “B” is equal to “A”, or less than “A” byup to 0.002 inch, a shim is required.The shim thickness must be 0.002-0.005 inch.

h. If “B” is less then “A” by more then0.002 inch, no shim is required. How-ever, if “B” is less then “A” by more then0.007 inch, the maximum requiredclearance will be exceeded even with-out a shim.

i. If a shim is required, measure the thick-ness of any existing shim to determineif it meets the criteria above. Use athickness micrometer to measure theshim thickness. If an existing shimdoes not meet the above cri teria,replace it with a new shim. Selection ofshim stock thickness should be basedon an ideal blade port cover to bearingring clearance of 0.005 inch.

j. If no shim is required, any existing shimmust be removed.

12-4.3.16 (DV) Install four 5/16-18 UNC, 4-inch long jacking bolts 90 degrees apart intothe threaded through-holes provided in theblade seal base ring (9). Note the depth ofinsertion of the ring relative to the lip of thehub blade port opening. This will allow the ringto be reinstalled into the same position.

The blade seal base ring isheld in place only by a frictionfit at the 6 o'clock position. Dur-ing the jacking removal processthe ring will drop out under itsown weight (32 lbs.). Diversmust be prepared for the ring'sweight and to recover the 18springs which are retained bythe ring and may fall loose withthe ring.

12-4.3.17 (DV) Jack the blade seal base ringout evenly, taking care to avoid warping thering. Be prepared to recover the 18 springs(11) held in place by the blade seal base ring.

CAUTION

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12-4.3.18 (TOP, DV) Send the blade sealbase ring and the 18 springs to the surface.Work the blade seal base ring free of the allthread rods by removing each rod one at atime and reinstalling them outside the bladeseal base ring.

12-4.3.19 (TOP) Ensure that the blade sealbase ring positioning dowel pin (3/8-inch diam-eter, 1 1/4 inch long) remains press fit into thebearing ring (12).

12-4.3.20 (TOP, DV) Clean and inspect theblade seal base ring. Inspection tolerancesare specified in reference b. Install a new O-ring (10) onto the OD of the blade seal basering and send it to the divers with 18 newsprings.

12-4.3.21 (DV) Work the blade seal base ringback over the all-thread rods by removing andreinstalling the rods one at a time. Ensure thatthe blade seal base ring rests on the coverplate with the dynamic O-ring groove facingdown against the cover plate.

12-4.3.22 (DV) Install the 18 springs into thebearing ring. Use grease (FN 61), injected intothe bearing ring spring holes with the greasegun, to hold the springs in position overheadwhile the blade seal base ring is positioned inplace. An alternative method to retain thesprings is to dip the first three coils of eachspring in melted beeswax so the OD isincreased just enough to make for a tightinsertion (bearing ring hole is 3/4-inch diame-ter). If this method is used, ensure that all waxis removed from the end of the spring so thatthe spring will make metal-to-metal contactwith the bottom of the hole.

12-4.3.23 (DV) Push the blade seal base ringinto the groove in the bearing ring by hand,making sure to align the blade seal base ringwith the positioning dowel pin. Push the ringevenly into the groove to avoid warping thering or damaging the O-ring. Two divers arerequired to align and push in the blade sealbase ring far enough to ensure that it stays inplace.

NOTE

Ensure that items (3) and (8)(dynamically loaded O-rings)are replaced with fully moldedinstead of spliced O-rings. O-rings supplied by the stock sys-tem for items (3) and (8) areoften spliced instead of fullymolded.

12-4.3.24 (DV) Fill the empty O-ring grooveson the blade port cover ID, the inner and outerMorgrip bolt hole diameters on the crank pinring, and the blade seal base ring (four O-ringgrooves total) with grease and remove anyexcess. Seat four new O-rings (3, 4, 7 and 8)into their appropriate grooves and allow thegrease to hold them in place. Again, removeany excess grease. If a Mylar shim is installed,ensure that the shim lays flat against the crankpin ring or blade port cover.

12-4.3.25 (SF, DV) Allow the oil/seawaterinterface at the blade port to settle out andhave Ship’s Force release oil from the headtank until all sea water is displaced from thehub.

12-4.3.26 (DV) Raise the blade port coverevenly with the handle nuts until it is carefullyseated into place. Be careful to ensure that allthe O-rings remain seated in their proper loca-tions during the final seating of the blade portcover.

12-4.3.27 (DV) Install four 5/8-inch capscrews into the available holes to secure theblade port cover in place.

12-4.3.28 (DV) Remove the four 5/8-inch all-thread rods and install the remaining four 5/8-inch cap screws. Tighten all cap screwssnugly.

12-4.3.29 (DV) Check the clearance betweenthe blade port cover and the crank pin ring inall eight Morgrip holes with the 0.002-inchfeeler gauge. Confirm no fit or very tight fit offeeler gauge between the blade port coverand the crank pin ring. If the feeler gauge istight proceed with the next step. If the feeler

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gauge is not tight, one or more of the O-ringshas jumped its groove. Lower the blade portcover and check the four overhead O-rings.Repeat O-ring and blade port cover installa-tion until 0.002-inch feeler gauge is tight.

12-4.3.30 (SF, DV) Rotate the blade port tothe 12 o’clock position.

12-4.3.31 (DV) Ensure that the blade dowelpins will be able to slide through the blade portcover into the crank pin ring by placing theminto the blade dowel pin holes. If either isunable to fit, loosen the blade port cover capscrews to allow for minor rotational alignmentof the blade port cover with the crank pin ringuntil the dowel pins are able to slide insmoothly. Initial alignment of the two dowel pinholes will be evidenced by over an inch ofdowel pin insertion. Then, torque all the capscrews evenly to 33 ft.-lbs. using the torquewrench (FN 58) and the 1/2-inch Allen socket(FN 58.4). Recheck the dowel pin fit after thecap screws are tight. The dowel pins shoulddrop the rest of the way into the hole.

12-4.3.32 (DV) Connect the hub pressure testsystem hoses detailed in Appendix I into thequick disconnect fittings that were installed inthe hub earlier.

12-4.3.33 (SF) Open head tank valve.

12-4.3.34 (TOP) Vent any air trapped in thehub from the hose installed at the 12 o’clockposition.

12-4.3.35 (SF) Shut the head tank valve. Dur-ing the hub pressure test, the return oil side ofthe system will be pressurized as the hubcrosshead chamber is pressurized by thedivers.

12-4.3.36 (TOP, DV) Using the barrel pump ina barrel of clean CPP system oil, pressurizethe hub crosshead chamber to 20 psig. Main-tain pressure at 20 psig for 10 minutes whiledivers check for leaks at the blade port coverand the other blades.

NOTE

A value of 20 psig should below enough to not lift the crosshead chamber relief valve. Incases where the pressure con-sistently drops to some lowervalue (10 to 11 psig), use thisnew value for the pressure test.Hold pressure for 10 minutesand have the divers confirm noleaks. This will confirm that thehub seal has been reestab-lished.

12-4.3.37 (TOP) If leakage is NOT observed,proceed to the next step. If leakage isobserved, changes to the Mylar shim thick-ness based on measurements may not havebeen enough to regain sufficient blade portcover O-ring compression to get a seal. Theprocedure may be repeated to confirm mea-surements and perhaps reduce shim thick-ness. However, if bearing ring wear isindicated and the hub already has a long ser-vice life, the only alternative may be drydockreplacement of the worn bearing ring.

12-4.3.38 Replace the blade in accordancewith Section 12-2 of this manual.

12-4.3.39 (SF, DV) Remove out-of-servicetags. Cycle the blade pitch through normalrange of operation several times. Test andpurge the system in accordance with section6-14 (Testing of the System) of reference a,MRC 77 6WBM N (R-2W) and paragraph 12-4.3.40). Have divers check for leaks aroundthe blade palm and hub interface of all bladesduring the testing.

12-4.3.40 In performing system test andpurge, supplement the procedure outlined inMRC 77 6WBM N (R-2W) with the following.Purge for approximately 15 to 30 minutes. Toopen purge valve, (located in hub) take man-ual control (joystick) and slew pitch astern untilthe main system relief valve lifts (1000 psi).Slew pitch ahead just enough to reset the

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main relief valve. Purge valve is now openallowing oil from the hub crosshead cavity tobe flushed out and returned to the sump forpurification. It should be noted that, if the mainshaft is rotated (turning gear) in conjunctionwith the hub purge, this will improve the cross-head cavity flushing operation. Rotating theshaft during a hub purge is not mandatory andis left to the Chief Engineer/Main PropulsionAssistant discretion. Recommend hub purgebe conducted upon each return to port prior tosecuring the CPP system.

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SECTION 5 DD 963, AND CG 47 BLADE REMOVAL, RETRIEVAL, AND REPLACEMENT PROCEDURE


Commands that perform propeller bladereplacements must consider all requirements.If shop facilities are not available at the Com-mand with the overall tasking, the Commandmust arrange for them. A successful blade setchange requires one week. Provision must bemade for breasting the ship out by the stern sothe blades can be lifted between the ship andthe pier. Crane service, floating or pierside,must be available for propeller blade liftingand must have the required reach and angleto handle the propeller blades. An oil boom isrequired for oil abatement and containment inaccordance with local instructions. Also, thefollowing references provide specific informa-tion relevant to removing and replacing CPPblades:

a. NAVSEA S9245-BF-MMM-010, Main-tenance Manual for Controllable PitchPropeller in DD 963 Class.

b. NAVSEA S9245-AH-MMA-010, Instal-lation, Operation, Maintenance andRepair Instructions with Parts List,Controllable Pitch Propeller for CG 47Class Ships.

c. S9086-00-STM-000, Naval Ships'Technical Manual (NSTM), Chapter245, “Propellers.”

d. NAVSEA Best Management Practices(BMP) to Prevent/Mitigate Oil SpillsRelated to Waterborne Removal(s) ofBlades on Variable Pitch Propellers forNaval Vessels.

e. MIL-STD-2035(SH) 04 July 1991, Non-destructive Testing Criteria

f. NAVSEA T9074-AS-GIB-010/271, 30April 1997, NAVSEA Technical Publi-cation, Requirements for Nondestruc-

tive Testing Methods (referred to asNAVSEA Technical Publication 271).

12-5.1.1 Applicability. This procedureapplies to all DD 963, DDG 993 and CG 47Class ships. Within the CG 47 Class, CG 66and higher have torque-in-place blade boltsremoved and installed in accordance with theprocedure of Section 7 of this manual. Theblade rigging procedure for all CG 47 Classships is covered in this section.


12-5.2.1 Rig the ship’s hull with forward andaft 3-ton lever hoists.

12-5.2.2 Prepare each blade for removal byrotating the blade into the 12 o’clock positionand removing the Morgrip bolts connecting theblade palm to the hub.


12-5.2.4 Install each replacement blade byrigging the blade with the three-point liftingassembly; lowering the blade into position;seating the blade onto the hub; connecting theblade palm to the hub with four temporarybolts; and removing the three-point liftingassembly for return to the surface.

12-5.2.5 Secure each blade to the hub by:dewatering open blade bolt holes; installingMorgrip bolts into the four open blade boltholes, removing the temporary bolts; dewater-ing the remaining bolt holes; installing theremaining four Morgrip bolts; measuring theinstalled bolt lengths to determine the properresidual stretch; dewatering the installed Mor-grip bolts; and capping the bolts.

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NOTE

While the following procedurerequires that the topside per-sonnel and the divers workclosely together, certain stepsmust be carried out by particu-lar personnel. To clarify thesesteps, abbreviations are placedat the beginning of each stepwhere the specific party needsto be identified: (DV) repre-sents diver, (TOP) representstopside personnel, (SF) repre-sents Ship’s Force personne-land (UT) represents Level IIUltrasonic Inspector.

12-5.3 PREPARATION.


It is essential that all tools andmaterials brought to the under-water job site are accounted forand removed at the completionof the job. Tools and materialsinadvertently left at the job sitecan generate unacceptablenoise and possibly causesevere damage to shipboardcomponents. Locally generatedwork packages shall ensurethat a general tool and materiallog sheet is prepare and main-tained during all UWSH opera-tions.

12-5.3.2 Inventory Tools, Materials andEquipment. NAVSEA 00C5 maintains a CPPblade change kit that contains most of thetools and equipment necessary to replaceCPP blades. This blade change kit should be

obtained and positioned on site before begin-ning the task. An inventory of the items in thiskit is available from NAVSEA 00C5. Table 12-4 identifies additional items that must be pro-vided by the repair activity. Ensure the avail-ability of all technical information, manuals,and drawings.


12-5.3.4 Review Bolt Elongation Measure-ment Procedure and Equipment. It is veryimportant that both the divers and the NDTinspection personnel study and understand allaspects of bolt elongation measurement asdetailed in Appendix A. Review of the tutorialdiscussion provided in Appendix A first willprovide a good general understanding of theresponsibilities for the divers and NDT inspec-tors. See Appendix J for NAVSEA NDT equip-ment details.


Removal and replacement of the CPP bladerequires some special tools and equipment.The find numbers (FN) in the following para-graphs correspond to the find numbers in theNAVSEA CPP Blade Change Kit, the inven-tory for this kit is available from NAVSEA00C5. The quantities of items contained in theCPP Kit are the minimum recommended to beon hand prior to CPP blade removal andreplacement. Their functions are described inthe following paragraphs.

12-5.4.1 Intensifier. The intensifier assem-bly (FN 37) pressurizes hydraulic fluid that isused to install and remove Morgrip bolts andhydraulic temporary bolts. Low pressure (LP)air is the power source for the intensifier. Theintensifier is connected with a high pressure(HP) flexible tube to the Morgrip bolt powerhead tool and with a quick-connect hydraulichose to the hydraulic temporary bolts (seeAppendix C).

CAUTION

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Change 1 12-46A







CAUTION


3 Ton1-½ Ton

4-½ Ton 6 Ton

TypicalRunning

BlockFlip

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12-46B Change 1


S0600-AA-PRO-120

12-5.4.2 Morgrip Bolt Power Head Tool withBullets. The Morgrip bolt power head toolassembly (FN 38) is used to remove andinstall Morgrip bolts. This is accomplished byinserting the bullet rod into the Morgrip bolt;attaching the power head onto the bolt with aspanner wrench; connecting the power headto the intensifier with the HP tube; and pres-surizing the hydraulic fluid in the power headwhich forces the bullet rod into the bolt, thusstretching the bolt.

12-5.4.3 Bullet Rod Removal Tool. The bul-let rod is removed from the Morgrip bolt withthe bullet rod removal tool (FN 38.4).

12-5.4.4 Morgrip Bolt. Morgrip bolts (FN 2)are used to secure the propeller blade to thehub. The Morgrip bolt contains a bored cavitythat enables the bolt to be stretched duringinstallation. After they are installed, the boltsretain a residual stretch that provides a clamp-ing force to hold the blades on the hub.

12-5.4.5 Blade Bolt Cap Wrench. Theblade bolt cap is threaded onto the head of theMorgrip bolt using the blade bolt cap wrench(FN 5). (See Appendix D).

12-5.4.6 Hydraulic Temporary Bolts.Hydraulic temporary bolts (FN 9) have twoquick-connect nipples so that pressurizedhydraulic fluid is directly connected from thebolts to the intensifier via a quick-connecthose assembly. Hydraulic temporary boltscontain a hydraulic chamber. Pressurizedhydraulic fluid in the chamber pushes the jack-ing body of the bolt down onto the blade palm.Simultaneously, the threaded portion of thebolt in the Morgrip bolt hole is pulled towardthe blade palm. This tension provides a tightfit. Hydraulic temporary bolts can be con-nected in series with short quick-connecthoses so that several bolts can be pressurizedat the same time (see Appendix E).

12-5.4.7 Lifting Assembly. The lifting as-sembly (FN 152) is attached to a propellerblade so the blade can be lifted and loweredwith the hook of a lever hoist (see AppendixF).

12-5.4.8 Righting Fixture. The righting fix-ture (FN 151) is installed onto the propellerblade and connected to the pier crane hook.The righting fixture is used to lift the propellerblade out of its shipping container and to stand


Item No. Quantity Component Description Technical Specifications

1 1 Transfer Line, 5/8″ x 100′ Commercial


3 1 Gallon of Hydraulic Fluid Tellus #15, Code 65203 (Shell Oil Company) or equal


5 as required Timbers, 4″ x 4″ x 4′ (to set blades upright) Commercial

6 1 Combination Wrench, 1/2″ Commercial

7 1 Screwdriver, Flat Blade Commercial






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Table 12-5. DD 963, DDG 993, and CG 47 Quality Assurance Points.

Blade Removal: Initials

1. Ensure pitch is set at zero pitch position [12-5.6.1].

2. Inspect removed blade bolt caps and plugs for damage [12-5.7.5].

3. Check Mapeco power head rupture disc torque at 100 ft.-lbs. [Note prior to 12-5.8.2].

4. Remove blade bolts in the order: 2,6,3,7,1,5,4,8 [Note prior to 12-5.8.3].

5. Clean blade bolts IAW Appendix A [A-5.3.1] and conduct liquid penetrant inspection of removed blade bolts [12-5.8.27].

6. Ensure lifting fixture is installed with head clamp centered on the blade [12-5.9.8].

7. Measure blade palm spacing to relieve binding (if required). [12-5.9.23].

8. Benchmark the shaft [12-5.9.28].

Blade Installation: Initials

1. Inspect blade port and blade [12-5.10].

2. Ensure edge guard material is used for lifting fixture clamps [12-5.11.5].

3. Check prairie air nipple fully inserted [12-5.11.8].

4. Check dowel pins fully inserted [12-5.11.9].

5. Ensure O-ring installed in blade port cover [12-5.11.13].


7. Check for cover plate O-ring washout [Caution prior to 12-5.11.32].

8. Check blade seating with 0.002-inch feeler gauge [12-5.11.51].

9. Record serial numbers and initial lengths of blade bolts to be installed. Use Inspection Report and Work Sheet, Figure A-3, Appendix A [12-5.12.1 and 12-5.12.3].

10. Apply thread lubricant to blade bolt threads and shoulders [12-5.12.15].

11. Dewater the blade bolt holes with Hydrolube [12-5.12.17].

12. Record final length and residual stretch when all eight bolts are installed. Residual stretch must be between 0.006-0.0084 inches. Use Inspection Report and Work Sheet Figure A-3 [12-5.13.1 and 12-5.13.2].

13. Ensure blade bolt cap seal is installed on blade bolt [12-5.14.5].

14. Torque blade bolt caps to 170 ft.-lbs. [12-5.14.7]

15. Dewater Morgrip bolt with Hydrolube [12-5.14.8].

16. Ensure blade bolt cap plugs are installed [12-5.14.9].

17. Test the CPP system performance [12-5.15].

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the blade by its palm onto wood timbers,enabling the blade to be outfitted with the lift-ing assembly (see Appendix G).

12-5.4.9 Modified Channel Lock Pliers. Therounded head of the channel lock pliers (FN12) is ground off to a flat surface approxi-mately ¼-inch thick in order to allow for betteraccess to the Morgrip bolt Nylok pellet hole asdescribed in the note following step 12-5.15.2.

12-5.4.10 Spanner Wrench. The spannerwrench (FN 23) is used to tighten or loosenthe Morgrip blade bolts, attached to the powerhead assembly, into or out of the blade palm.

12-5.4.11 Dowel Pin Removal Tool. Thedowel pin removal tool (FN 13) is used toremove stuck dowel pins that cannot beremoved by hand.

12-5.4.12 Blade Guide Pins. The bladeguide pins (FN 14) are used to align the dowelpins with the blade palm at installation.

12-5.4.13 Bolt Elongation MeasurementTool. The bolt elongation measurement tool(FN 43) is a transducer assembly and ultra-sonic instrument specially designed to mea-sure the elongation of the Morgrip bolts. Thetutorial in Appendix A allows any IntermediateMaintenance Activity (IMA) Level II UltrasonicTesting (UT) inspector to perform measure-ments with this equipment.



Rig the ship’s hull with forward and aft 3-tonlever hoists (FN 153) in accordance with Fig-ure 12-15 and the following procedure.

12-5.5.1 Rig Forward Lever Hoist. Loop thenylon sling (FN 168) through the forward liftingtunnel (frame 496, over the propeller hub).Attach the eyes of the sling together with a 1-inch safety shackle (FN 161). Run both 3-ton

lever hoists (10 and 30 foot throw) to the “twoblocked” position in order to confirm the chainis not twisted. Hang the 10-foot throw 3-tonmanual lever hoist from the 1-inch safetyshackle. The manual lever hoist must be usedin the forward position to avoid over- stressingthe lifting assembly during blade removal.

12-5.5.2 Rig Aft Lever Hoist. Loop thenylon sling (FN 168) through the aft lifting tun-nel (frame 503, 7 feet aft of the forward tun-nel). Attach the eyes of the sling together witha 1-inch safety shackle (FN 161). Hang the30-foot throw manual lever hoist or hydraulicchain fall from the 1-inch safety shackle.Hydraulic hoist in the aft position eases theyard and stay of the blade to the surface.


12-5.6 ROTATE BLADE TO BE REMOVEDINTO THE 12 O'CLOCK POSITION.

12-5.6.1 (DV, SF) Ensure blade pitch is in thezero pitch position. Benchmarks for pitchalignment are located adjacent to blade #1.Danger tag the pitch controls in the lockedposition.

12-5.6.2 Attach head clamp (middle shackleposition) to the forward chainfall. Using thehead clamp as a plumb bob, verify centeringof the head clamp on the blade. Rotate theshaft if required to center the blade with thehanging head clamp. Benchmark the finalshaft position.

WARNING

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12-5.6.3 Return the head clamp to the sur-face.


Before removing the blade boltcaps, measures must be takenfor oil containment and abate-ment in accordance with localSenior Officer Present Afloat(SOPA) Manuals and referenced. of section 12-5.1, Require-ments.

12-5.7 REMOVE MORGRIP BLADE BOLTCAPS.

NOTE

For CG 66 use Paragraph 12-7.7 for bolt removal.

12-5.7.1 (DV) Remove the caps from all eightMorgrip blade bolts in any order in accordancewith steps 12-5.7.2 through 12-5.7.4.

NOTE

Morgrip blade bolt caps shouldbe installed at 170 ft.-lbs. (theinstal lat ion torque require-ment) but they may be over-torqued and require a hydraulicwrench to remove.

Figure 12-15. Ship’s Hull Rigging.

CAUTION

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12-5.7.2 (DV) Remove the 1/8-27 NPTF pipeplugs in the blade bolt caps using a 3/16-inchAllen wrench (FN 7.1). Retain plugs and capsfor reinstallation.

12-5.7.3 (DV) Place the blade bolt capwrench (FN 5) in the blade bolt cap spannerholes and tighten into the pipe plug hole.

NOTE

In some cases, the blade boltcap p lugs a re improper l yins ta l l ed and canno t beremoved. If this occurs, theblade bolt cap wrench may bemodified (by removing items 1,2, 3, and 4 from drawing inAppendix D) so that the wrenchwill set on top of the blade boltcap and engage the locking pinholes in the cap. Exercise carewhen using the tool in this man-ner because the blade bolt capwrench is no t pos i t i ve l ysecured on the blade bolt cap.

12-5.7.4 (DV) Using a breaker bar (FN 6.1)and 1 1/8-inch socket (FN 6.2) attached to theblade bolt cap wrench, remove the cap fromthe blade bolt.

12-5.7.5 (DV, TOP) Pass the blade bolt caps,the blade bolt cap plugs, the blade bolt capwrench, the breaker bar, the 1 1/8-inch socket,and the 3/16-inch Allen wrench topside.Inspect caps and plugs for damage (nicks,deformity, thread damage, improper fit of capplugs). The blade bolt caps and the blade boltcap plugs should be reused if not damaged.

12-5.8 REMOVE MORGRIP BLADE BOLTS.

12-5.8.1 (TOP) Set up the intensifier forMapeco power head pressurization in accor-dance with the instructions provided in Appen-dix C.

NOTE

The Mapeco power head isequipped with a pressure rup-ture disc to ensure that the

power head is not pressurizedabove 40,000 psi. It is impor-tant that the rupture disc hold-down nut (see drawing thataccompanies the power head)be torqued to 100 ft.-lbs. beforeusing the power head. Thetorque has been checked onthe power heads delivered withthe NAVSEA kit.

12-5.8.2 (TOP) Pass the Mapeco power headtool, bullet rod, spanner wrench, and 5/8-inchopen end wrench (FN 38.1, 38.5 and 23) tothe divers.

NOTE

Remove Morgrip blade bolts inthe following order: 2, 6, 3, 7, 1,5, 4, 8. Figure 12-16 shows theblade bolt numbering on theblade palm. Bolt hole numbersare s tamped on top of theblade palm next to the respec-tive hole.

12-5.8.3 (DV) Insert the bullet rod, cone endfirst, into the blade bolt.

12-5.8.4 (DV) Open the power head stopvalve one half turn to prevent hydraulic lock.

The power head must have full threadengagement with the blade bolt to avoid cata-strophic failure and possible personnel injurywhen the bolt is pressurized. Ensure seven fullturns. Record each power head pressurizationin the logbook provided..

12-5.8.5 (DV) Thread the power head ontothe bolt head and seat firmly using the span-ner wrench. Count the number of turns as thepower head screws on. Seven to eight turnsshould seat the power head. Figure 12-17shows the power head/Morgrip bolt assembly

WARNING

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12-5.8.6 (DV) Back the power head off fromthe bolt head ½ to 1 turn and retighten byhand to ensure that false bottoming has notoccurred since the bolt head flange and thepower head interface are not visible on theinstalled bolt. Seat the power head firmlyusing the spanner wrench.

12-5.8.7 (DV) Close the power head stopvalve, then open it no more than ¼ to ½ turn.

NOTE

The HP tube end fitt ing is aspecial design for extremelyhigh pressures. As illustrated inFigure 12-17, an internallythreaded ferrule must be posi-tioned on the threaded end of

the fitting so that 2 to 3 threadsare exposed at the end of thef i t t ing be fo re the hose i sinserted into the power headconnection port. The ferruleposition must be checked priorto each connection of the hose.

12-5.8.8 (DV) Remove the sealing plug fromthe most accessible power head connectionand connect the HP tube from the surface asshown in Figure 12-17. Inform topside whenready to purge the HP tube.

12-5.8.9 (TOP, DV) Start and operate theintensifier pump by opening the air supplyvalve until a steady stream of hydraulic fluid(no air) bleeds from the loosened connectionopposite the HP tube in the power head. Fill

Figure 12-16. Blade Bolt Numbering.

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Figure 12-17 Power Head/Morgrip Bolt Assembly.

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the intensifier reservoir with hydraulic fluid astank level drops. Tighten the bleed connectionwith the 5/8-inch wrench to seat firmly (DONOT OVERTIGHTEN).

High pressure oil jets can pene-trate the skin. Ensure thatdivers are aware that the powerhead is about to be pressur-ized. Divers should be clear ofthe power head.

12-5.8.10 (DV) Swim clear of the power headand inform topside that HP tube is purged andconnected securely.


12-5.8.11 (TOP) Increase the intensifier pres-sure to 35,000 psi by slowly opening the airsupply valve. Secure the air supply valvewhen pressure is reached.

12-5.8.12 (TOP) Notify the divers when35,000 psi is reached.

12-5.8.13 (DV) Apply the spanner wrench tothe power head and attempt to loosen thepressurized blade bolt. If bolt loosens, pro-ceed to step 12-5.8.18.

12-5.8.14 (DV, TOP) If the bolt does not comeloose, increase the pressure in 500-psi incre-ments, and try again. Do not exceed 37,500psi.

12-5.8.15 (DV, TOP) If the attempt to removethe first bolt is unsuccessful, bleed pressure atthe intensifier, check connections, and repres-

surize for another attempt. Cycling the powerhead through several pressurizations mayloosen the bolt.

12-5.8.16 (DV, TOP) If the removal of anyremaining bolt becomes difficult, install ahydraulic temporary bolt in accordance withsteps 12-5.9.1 through 12-5.9.8 next to theproblem bolt and repeat the removal attempt.

12-5.8.17 (TOP) If no bolts can be loosenedat 37,500 psi, on deck personnel must disas-semble, inspect, and clean all componentparts of the power head in accordance withthe drawing provided with the power head toensure their proper function. If the internalpressure “tire” seal to the valve stem hasfailed, the tire must be replaced. Reassemblethe power head, test in accordance with thedrawing, and return to step 12-5.8.1.

12-5.8.18 (DV) When a blade bolt has beenloosened, close the power head stop valve toisolate the pressure in the power head fromthe pressure in the HP tube.

12-5.8.19 (TOP) Depressurize the intensifierand the HP tube by slowly opening thehydraulic bypass valve on the intensifier.Inform the divers that the intensifier and HPtube have been depressurized.

High pressure oil jets can pene-trate the skin. Divers mustensure that topside personnelhave depressurized the intensi-fier before disconnecting theHP tube.

12-5.8.20 (DV) Disconnect the HP tube fromthe power head. Reinstall the sealing plug intothe exposed tubing connection fitting.

12-5.8.21 (DV) Remove the blade bolt andattached power head assembly from the

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CAUTION

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blade. Lift the entire assembly to the surface ina diver tool bag. Do not loosen the powerhead stop valve underwater.

High pressure oil jets can pene-trate the skin. Ensure topsidepersonnel are clear of the valveopening when depressurizingthe power head.

12-5.8.22 (TOP) Remove one of the sealingplugs from a pressure connection port. Directthe orifice of the power head stop valve awayfrom personnel into a proper waste oil con-tainer. Open the power head stop valve todepressurize the power head.

12-5.8.23 (TOP) Remove the bolt from thedepressurized power head using the spannerwrench (FN 23) and strap wrench (FN 25).Sheet rubber wrapped around the shank ofthe bolt may give a better grip with the strapwrench.

12-5.8.24 (TOP) Remove the bullet rod fromthe bolt. A special removal tool (FN 38.4) isprovided if suction makes bullet rod removaldifficult.

12-5.8.25 Repeat steps 12-5.8.2 through12-5.8.24 for remaining blade bolts.

12-5.8.26 (TOP) Remove the used Nylok pel-let (see Figure 12-22) from each bolt. Use a1/16-inch drill bit to center drill the pellet andthen stick a scribe into the hole to pry out thepellet.

12-5.8.27 (TOP) Prior to use, all unthreaded,polished, external bolt surfaces must be liquid-penetrant inspected in accordance withNAVSEA Technical Publication 271. Group VII(solvent-removable) and Group IV (water-washable) fluorescent penetrant systems arepermitted for this application. Acceptance cri-teria shall be in accordance with MIL-STD-

2035A, paragraph 7.6. Surface blemishes orscratches on the bolts’ polished surfaces maybe removed by rotating the bolt in a lathe whilepolishing with a Scotch-Brite pad. Do NOT useemery cloth or sand paper for polishing. Allpolished bolts must be reinspected as detailedabove. The Morgrip blade bolts that passinspection are to be reused with the replace-ment blades.


12-5.9.1 (TOP) Construct the lifting assembly(FN 152) in accordance with Appendix E.Ensure that the trailing edge clamp has “DD963/DDG 993/CG 47” pads installed.

12-5.9.2 (TOP) Disconnect the trailing edgeclamp from the lifting assembly by removingthe two shackles joining the leg assemblies(both sides) to the trailing edge clamp. Lowerthe trailing edge clamp to the divers.

12-5.9.3 (TOP) Connect one 3/4-inch shackle(FN 162) to the forward hole of the headclamp.

12-5.9.4 (TOP) Connect one 3/4-inch shackleto the aft hole of the head clamp.

12-5.9.5 (TOP) Connect the aft shackle onthe head clamp to the transfer line. Lower thelifting assembly down the transfer line.

12-5.9.6 (DV) Connect the single hook of theforward manual lever hoist to the 3/4-inchshackle attached to the forward hole of thehead clamp.

12-5.9.7 (DV) Using the forward manual leverhoist, rig the lifting assembly onto the blade.One diver should be guiding the leading edgeclamp onto the blade while another operatesthe lever hoist.

12-5.9.8 (DV) Ensure the head clamp is cen-tered on the blade.

12-5.9.9 (DV) Attach the trailing edge clampto the shackles joining the legs of the lifting

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Change 1 12-55

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assembly (both sides) as shown in AppendixF.

12-5.9.10 Ensuring slack is in the forwardlever hoist, diver #1 maintains the center ofthe head clamp at the center of the blade.Diver #2 tightens the head clamp to trailingedge clamp turnbuckles on the aft and forwardfaces until snug. This will assist in keeping thehead clamp from sliding along the edgetowards the leading edge. Diver #2 then tight-ens the head clamp to leading edge clampturnbuckles until snug. Once this is complete,diver #2 tightens the trailing edge clamp toleading edge clamp turnbuckles on the aft andforward faces until snug.

12-5.9.11 (DV) Recheck that the head clampis still centered on the blade.

12-5.9.12 (DV) Take a strain on the headclamp with the forward lever hoist to seat theleading and trailing edge clamps on the blade.

12-5.9.13 (DV) Slacken the forward leverhoist and retighten the turnbuckles in thesame order as step 12-5.9.10.

12-5.9.14 Check Forward Lever Hoist.Because the blade must be lifted directly up toavoid binding, the vertical hang of the leverhoist must be checked against the actualblade position.


12-5.9.15 (DV, TOP) Remove the forwardlever hoist hook from the head clamp of the

lifting assembly and allow the hook to hangplumb. Check to ensure that the hook isdirectly above one of the head clamp shacklepositions. If the hook is not directly above andin line with a head clamp shackle position,rotate the shaft the required distance anddirection to correct for port and starboard mis-alignment.

12-5.9.16 (DV) Reconnect the forward leverhoist hook to the shackle position on the headclamp with the best alignment.

12-5.9.17 Lifting Blade. (DV) Diver #1moves into position at the forward lever hoist.Diver #2 moves to the blade palm/hub inter-face.

12-5.9.18 (DV) Diver #1 takes the slack out ofthe forward lever hoist. Diver #2 places bothhands on the blade palm/hub in the vicinity ofbolt holes #1 and #4.

12-5.9.19 (DV) Diver #1 takes up on forwardlever hoist. At the same time Diver #2 reportsmovement of the blade palm (indicating thatthe blade palm made true upward progressfrom the hub or that the trailing or leadingedge of the blade palm moved first).

12-5.9.20 (DV) Diver #1 continues taking upon the forward lever hoist until diver #2 reportsno blade palm movement. Do not exceed aheavy strain (manual lever hoist too tight tomove) with the lever hoist.

Propel ler blade edges aresharp. Avoid injury while han-dling blades.

Blade edges are easily dam-aged. Do not strike bladeedges with air cylinders, tools,

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CAUTION

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or other equipment.


12-5.9.21 (DV) If diver #2 reports that theblade palm initially moved but that the bladepalm is no longer moving, then diver #1 needsto shake the blade tip VIGOROUSLY whilediver #2 reports any upward travel of the bladepalm. As long as steady upward progress ismade, continue with the “shake and pull”approach.

12-5.9.22 (DV/TOP) If diver #2 reports thatthe blade palm did not initially move or the“shake and pull” approach is not moving theblade palm, the dowel pins are binding and thebinding must be relieved. The dowel pin bind-ing may be caused by fore or aft misalignmentof the forward lifting tunnel with the center ofthe propeller hub. If observation indicates thatfore or aft misalignment may be a problem,lower the blade and try repositioning the headclamp shackle to a more forward or aft posi-tion. If the above fore or aft adjustment doesnot relieve the dowel pin binding, proceed withthe shaft rotation method. This is a trial-and-error process that may need to be repeatedseveral times to find the appropriate position.If diver #2 reports that the blade palm did notinitially move, the direction of shaft rotationmust be selected arbitrarily.

12-5.9.23 Relieve Dowel Pin Binding. (DV)If a good degree of upward movement wasencountered and ceased before the bladebecame free, then divers are required to mea-sure the spacing between the blade palm andpropeller hub to assist in determining the bestdirection to rotate the shaft. Using a 1/16-inchincrement steel ruler (FN 15), record the dis-

tance between the hub face and the shoulderrecess of the blade bolt hole as shown in Fig-ure 12-18. These measurements need to betaken through bolt positions #1, #4, #5, and#8.

12-5.9.24 (DV, TOP) If the starboard sidemeasurements are greater than the port side,then the starboard side of the hub may bedown so the shaft should be rotated to port. Ifthe port side measurements are greater, thenthe shaft should be rotated to starboard. Ifthere is no clear difference between port andstarboard measurements, then arbitrarilyselect the direction of rotation. Record andkeep all measurements for the duration of theremoval process in order to monitor progress.


12-5.9.25 (DV) Slack the forward lever hoisthook from the head clamp and prepare withShip’s Force to rotate the shaft.

Rotating the hub with the rig-ging attached poses a serioushazard. Rigging loads will eas-ily be exceeded if the jackinggear pulls against the rigging.Direct communication betweenthe Diving Supervisor and theShip’s Force personnel operat-ing the jacking gear is required.

CAUTION

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12-5.9.26 (SF) Rotate the shaft for a count ofone second (bump) in the desired direction.

12-5.9.27 (DV, TOP) Try again to lift theblade. Again, the shaft rotation method ofrelieving dowel pin binding is often trial anderror to find the right position, so adjustmentsmay need to be repeated.

12-5.9.28 Benchmark the Shaft. (SF) Oncethe first successful blade removal shaft rota-tion position is found inside the ship, withincommunication range of the jacking gear oper-ator, benchmark the position on the shaft anda location that does not rotate with the shaft.Then measure the shaft circumference andmark five equally spaced marks on the shaft toidentify the other blade removal locations. La-bel each mark with corresponding blade num-ber.

12-5.9.29 Retrieve Blade to Surface. (DV)Note the location of the dowel pins and theprairie air nipple (in the hub or blade palm).Report the locations topside.

12-5.9.30 (DV) Connect the hook of the aftlever hoist to the aft 3/4-inch shackle of thehead clamp.

12-5.9.31 (DV) Yard and stay the blade aftuntil the blade palm has cleared the propellerhub.

12-5.9.32 (DV) Remove the dowel pins andthe prairie air nipple from either the hub or theblade palm and send them topside. A specialdowel pin removal tool (FN 13) is available foruse on dowel pins that are hard to remove.

12-5.9.33 (DV) Continue the yard-and-stayprocess until the full weight of the blade istaken by the aft hoist.

Figure 12-18. Morgrip Bolt Hole Measurements.

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12-5.9.34 (DV) Disconnect the forward leverhoist hook from the forward 3/4-inch shackleon the head clamp. Lower the blade just belowthe hub with the aft lever hoist.

12-5.9.35 (TOP, DV) Install a pendant ontothe pier crane. Connect the crane pendant tothe same shackle of the head clamp that theaft lever hoist is attached. Use an additionalshackle to attach if required. This will help pre-vent rotation of the blade during the yard andstay to the crane.

12-5.9.36 (DV, TOP) Take the slack out of thecrane. Check all shackle arrangements forbinding. Yard and stay the blade until the fullweight of the blade is taken by the pier crane.When the pier crane has the full weight of theblade, disconnect the aft lever hoist. Raise theblade to the pier.

12-5.9.37 (TOP) Set the blade upright ontotwo 4″ x 4″ timbers on the pier.

12-5.9.38 (TOP) Disconnect the trailing edgeclamp from the assembly by removing the twoshackles joining the leg assemblies (bothsides) to the trailing edge clamp.

12-5.9.39 (TOP) Remove the lifting assemblyfrom the blade.

NOTE

If all removed blades are setw i th in reach o f the c raneupright on timbers (step 12-5.9.37) as they are removed,topside will have plenty of timeto shift removed blades to thespecial shipping pallets as newblades are removed from theshipping pallets for installation.

12-5.9.40 (TOP) Later, after the new bladehas been prepared and removed from its spe-cial container, install the righting fixture (FN151) onto the old blade. Install three shacklesonto the righting fixture as shown in Figure 12-19.

12-5.9.41 (TOP) Flip the blade to a horizontalposition using a two-part lift.

12-5.9.42 (TOP) Position it onto the specialshipping pallet that the new blades were senton.

12-5.10 BLADE PORT AND BLADEINSPECTION AND PREPARATION.

12-5.10.1 (DV) For each empty hub bladeport, clean and inspect the cover plate, dowelpin holes, prairie air nipple orifice, center postsleeve, and O-ring groove. Figure 12-20details the hub blade port inspections. Scotch-Brite “greenie” pads work well for cleaning.


12-5.10.3 (TOP) Inspect and clean the previ-ously removed dowel pins and prairie air nip-ple with an emery cloth (FN 124). Dowel pinsmust not be mushroomed or peened at eitherend.


12-5.10.4 (TOP) Lubricate the four new prai-rie air nipple O-rings (FN 16.2, FN 114 for CG66) with silicone grease (FN 17, FN 115 forCG 66). Install the four O-rings onto the prairieair nipple.


12-5.10.6 (TOP) Inspect the two threadedplug holes in the blade palm. As required,install a blade palm plug (FN 18, FN 84 for CG66) into each vacant plug hole using a 3/4-inchAllen wrench (FN 18.1, FN 116 for CG 66).

CAUTION

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12-60


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12-61

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12-5.11.1 (DV, SF) Rotate the propeller hubblade port targeted for installation into the 12o’clock position. Align the bench mark madeduring the removal process to ease installa-tion.

12-5.11.2 (TOP) Send the dowel pins (FN 19,FN 85 for CG 66), prairie air nipple (FN 16.1,FN 83 for CG 66), two tapered blade guidepins (FN 14.1, FN 81 for CG 66) and bladeguide pin turning bar (FN 14.2, FN 118 for CG66) down to the divers.

12-5.11.3 (TOP) Using the righting fixture,stand the replacement blade to be installedupright on the blade palm resting on two 4″ x4″ wood timbers.


12-5.11.5 (TOP) Install the three-point liftingassembly onto the blade as shown in Appen-dix F. Ensure the head clamp is centered onthe blade. If edge guards are removed fromnew blades, ensure a piece of metal edgeguard and rubber material is inserted betweenthe clamps and the blade for protection. Coverthe sharp edge of the edge guard piece withtape to protect the diver.

12-5.11.6 (TOP) Take a strain on the headclamp with the crane chain fall to seat theleading and trailing edge clamps on the blade.


12-5.11.8 (DV) Install the prairie air nippleinto the prairie air nipple orifice in the hub untilit is fully seated. A mallet may be required tofully seat the double O-ring seal. When fullyseated the nipple should extend 4 1/2 inchesout from the center post.

12-5.11.9 (DV) Press the dowel pins into thedowel pin holes by hand until fully seated.Measure to ensure the dowel pins stick out ofthe hub no more than 3 3/8 inches.

NOTE

Dowel pins are extremely tightfitting and often present diffi-culty seating in water becauseof the small hydraulic relief.Care and continuous steadypressure should be applied.

12-5.11.10 (DV) Install the blade guide pinsinto bolt holes #2 and #6 of the blade port.


12-5.11.11 (TOP) Send the blade port coverplate O-ring (FN 20, FN 120 for CG 66) andthe heavy grease (FN 21, FN 121 for CG 66)to the divers.

12-5.11.12 (DV) Partially fill the O-ring groovein the cover plate with heavy grease. The O-ring groove is indicated in Figure 12-20.

NOTE

Do not over f i l l the O- r inggroove. Excess grease canlead to seating problems.

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12-5.11.14 (TOP) Connect the pier crane tothe forward 3/4-inch shackle of the headclamp.

12-5.11.15 (TOP) Using the crane, lower therigged blade to 10-15 feet below the water sur-face adjacent to the aft lever hoist, frame 503.

12-5.11.16 (DV) Attach the aft lever hoist tothe aft shackle on the head clamp.


12-5.11.18 (DV, TOP) Slack the crane andunhook it from the forward shackle of the headclamp.

12-5.11.19 (DV) Attach the forward leverhoist hook to the forward shackle of the headclamp and take the slack out of the forwardlever hoist.

12-5.11.20 (DV) Check the shackle/hookarrangement on the forward end of the headclamp to ensure that it does not bind on theforward corner of the head clamp.

12-5.11.21 (DV) With diver #1 operating theforward lever hoist and diver #2 operating theaft lever hoist, yard and stay the blade forwarduntil the blade palm is approximately 2 inchesaft of the propeller hub.

12-5.11.22 (DV) Inspect the dowel pins, prai-rie air nipple, guide pins, and the cover plateO-ring for proper installation. Using diverspneumo, dewater the dowel pin holes in theblade palm to make penetration of the dowelpins easier.

12-5.11.23 (DV) Position the blade fully overthe propeller blade port. Ensure that the guidepins in bolt holes #2 and #6 align with the cor-responding bolt holes in the blade palm.



Divers must verify that the sus-pended blade is clear of thehub in order to ensure that nodamage is done to the propellerblade palm, blade port or con-necting hardware when the hubis rotated.

12-5.11.25 (DV, TOP) Check to ensure thatthe blade is fully over the propeller blade portand that the guide pins in bolt holes #2 and #6align with the corresponding bolt holes in theblade palm. If the diver reports the blade portis not aligned with the suspended blade, thencoordinate with Ship’s Force and rotate theshaft the required distance and direction untilthe proper position is achieved.

12-5.11.26 (DV) Diver #1 moves into positionfor operating the forward lever hoist, and diver#2 moves into position at the blade port toreport the progress of the installation.

12-5.11.27 (DV) Slowly lower the blade withthe forward lever hoist onto the guide pins until

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the blade palm is approximately 1 inch abovethe top of the dowel pins.


Divers must verify that the sus-pended blade is clear of thedowel pins for a small rotationin order to ensure that no dam-age is done to the propellerblade palm, blade port, or con-necting hardware when the hubis rotated.

12-5.11.28 (DV) Visually check the O-ringplacement. Ensure that the top of each dowelpin is the same distance from the blade palm.If not, then rotate the shaft to balance the dis-tance.

12-5.11.29 (DV) If poor visibility makes thevisual dowel pin check in the previous stepimpossible, ensure blade palm and hub arealigned by measuring the spacing between theblade palm and the hub. Using a 1/16-inchincrement steel ruler, record the distancebetween the hub face and the shoulder recessof the blade bolt hole as shown in Figure 12-18. These measurements need to be takenthrough bolt positions #1, #4, #5, and #8.

12-5.11.30 (DV, TOP) If the blade palm andhub are not aligned, then from the measure-ments determine the direction for rotating the

shaft. If the starboard side measurements aregreater than the port side, the starboard sideof the hub is down and the shaft should berotated to port. If the port side measurementsare greater, the shaft should be rotated to star-board. Record and keep all measurements forthe duration of the installation process in orderto monitor progress.


12-5.11.31 (DV) Diver #1 lowers the blade byletting out on the forward lever hoist until diver#2 reports no downward movement.

Be careful not to lower a bladeso rapidly onto the hub as towash out the cover plate O-ring. Never allow the forwardlever hoist to go completelyslack during the lowering pro-cess because this could lead toa sudden drop of the blade,causing O-ring washout.

Propel ler blade edges aresharp. Avoid injury while han-dling blades.

12-5.11.32 (DV) When downward progresshas ceased, slack the forward lever hoist to alight strain and have both divers commenceshaking the blade VIGOROUSLY at the tip.

12-5.11.33 (DV) If downward movement isencountered, diver #2 continues shaking theblade, while diver #1 slowly lets down on theforward lever hoist.

WARNING

CAUTION

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CAUTION

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12-5.11.34 (DV) To establish if progress isbeing made, divers must measure the spacingbetween the blade palm and the hub. Usingthe 1/16-inch increment steel ruler, record thedistance between the hub face and the shoul-der recess of the blade bolt hole as shown inFigure 12-18. These measurements need tobe taken through bolt positions #1, #4, #5, and#8.

12-5.11.35 (DV, TOP) If no downward move-ment can be achieved by shaking the blade,then from the measurements determine thebest direction for rotating the shaft. If the star-board side measurements are greater than theport side, the starboard side of the hub may bedown and the shaft should be rotated to port. Ifthe port side measurements are greater, theshaft should be rotated to starboard. If there isno clear difference between port and star-board measurements, arbitrarily select thedirection of rotation. Record and keep all mea-surements for the duration of the installationprocess in order to monitor progress.

12-5.11.36 (DV) Lift the blade until both dowelpins are disengaged from the blade.


12-5.11.37 (SF) Rotate the shaft in the direc-tion determined in step 12-5.11.35 until themeasurements are equal on the port and star-board sides.


12-5.11.39 Examine Morgrip Bolt Holes.

(DV) Examine the blade bolt holes to see if thecover plate O-ring is visible, that is, washedout of the O-ring groove.

12-5.11.40 (DV) If the O-ring is visible, theblade must be removed clear of the hub andreinstalled after the O-ring is replaced.

NOTE

For CG 66 use Paragraph 12-7.11 through 12-7.14 for boltinstallation.

12-5.11.41 Install Hydraulic TemporaryBolts. Temporary bolts are used to securethe blades onto the hub until the Morgrip boltsare installed. This is necessary to ensure theblade is properly seated.

12-5.11.42 (TOP) Pass four hydraulic tempo-rary bolt assemblies and the temporary boltturning bar to the divers. See Appendix E for adrawing of the temporary bolts.

12-5.11.43 (DV) Install the temporary boltassemblies into holes #1, #4, #5, and #8. Fig-ure 12-16 shows the blade bolt numbering onthe blade palm. Bolt hole numbers are sten-ciled on top of the blade palm next to therespective hole.

12-5.11.44 (TOP) Pass the two 2-foot hoses(FN 9.2) and one 6-foot hose (FN 9.3) down tothe divers.

12-5.11.45 (DV) Connect the hydraulic hosesinto the temporary bolts as follows: 2-foothose from position 1 to 4, 6-foot hose fromposition 4 to 5, 2-foot hose from position 5 to8, and 100-foot hose to position 8. This allowsfor simultaneous pressurization of all four tem-porary bolts. Figure 12-21 shows the arrange-ment for the hydraulic hoses. Inform topsidethat the hydraulic hoses are connectedsecurely. The hose quick-disconnects have

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locking collars that are screwed down by handto ensure the connection is secure.

Maximum pressure for hydrau-lic temporary bolts is 3,000 psiand must not be exceeded.Serious injury to a diver couldoccur if hydraulic temporarybolts were to fail.

12-5.11.46 (TOP) Operate the intensifier to apressure of 1500 psi.

12-5.11.47 (DV) Hand tighten the temporarybolt collars onto the bolt shoulders using thetemporary bolt turning bar.

12-5.11.48 (TOP) Depressurize the intensifierby slowly opening the hydraulic bypass valveon the intensifier. Inform the divers that theintensifier has been depressurized.

12-5.11.49 (DV) Disconnect the hydraulichoses from the temporary bolts.

12-5.11.50 Remove Blade Guide Pins. (DV)Remove the blade guide pins from bolt holes#2 and #6.

12-5.11.51 Check Blade Seating. (DV) Us-ing a 0.002-inch feeler gauge (FN 22), checkthe gap between the blade palm and the hubat bolt holes #2, #3, #6, and #7. If the feelergauge penetrates at all, it should have a snug(touching both sides) fit. Check the gap in twoplaces along the line of the bolt circle. Thepurpose of this check is to determine the finalseating of the blade and that the O-ring in-stalled between the blade palm and the bladeport cover has not been washed out of itsgroove during the final seating of the blade.

12-5.11.52 Remove Three-Point LiftingAssembly. (DV) Loosen all of the turnbuckleson the lifting assembly.


12-5.11.54 (DV) Remove the lifting assemblyfrom the blade with the forward manual leverhoist. One diver must operate the lever hoistwhile the other diver guides the lifting assem-

Figure 12-21. Hydraulic Hose Schematic.

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bly off the blade so as not to damage theblade.


12-5.12 MORGRIP BOLT INSTALLATION.

It is very important that both the divers and theNDT inspection personnel study and under-stand all aspects of bolt elongation measure-ment as detailed in Appendix A. Review of thetutorial discussion provided in Appendix A willprovide a good general understanding of theresponsibilities for the divers and NDT inspec-tors. See Appendix J for NAVSEA NDT equip-ment details.

12-5.12.1 (UT) Record the serial number ofeach of the eight Morgrip blade bolts (FN 2)onto the Inspection Report and Worksheet,Figure A-3 in Appendix A.

12-5.12.2 (UT) Set up the bolts in the installa-tion order (#2, #6, #3, #7, #1, #5, #4, and #8).

Ultrasonic measurement proce-dures and equ ipment a rerequired to achieve the accu-racy required in blade bolt mea-surement. Any ultrasonic bladebolt measurement proceduresand equipment utilized must beapproved by NAVSEA or itsauthorized representative inaccordance w i th NAVSEATechnical Publication 271.

12-5.12.3 (UT) Using NAVSEA-approvedultrasonic measurement procedures andequipment, record baseline dimension mea-surements for all eight bolts on the InspectionReport and Worksheet, Figure A-3. A sampleprocedure using NAVSEA-developed equip-ment is provided in Appendix A.

12-5.12.4 (TOP) Set up intensifier for MapecoPower head pressurization in accordance withthe instructions provided in Appendix C.

12-5.12.5 (TOP) Insert the bullet rod into the#2 blade bolt, cone end first.

NOTE

The Mapeco power head isequipped with a pressure rup-ture disc to ensure that thepower head is not pressurizedabove 40,000 psi. It is impor-tant that the rupture disc holddown nut (see drawing thataccompanies the power head)be torqued to 100 ft.-lbs. beforeusing the power head. Thetorque has been checked onthe power heads delivered withthe NAVSEA kit.

12-5.12.6 (TOP) Open the power head stopvalve one half turn to prevent hydraulic lock.


12-5.12.7 (TOP) Thread the power head ontothe bolt head and seat firmly using the span-ner wrench. Count the number of turns as thepower head screws on. Seven to eight turnsshould seat the power head. Figure 12-17shows the power head/Morgrip bolt assembly.

12-5.12.8 (TOP) Close the power head stopvalve, then open it no more than 1/4 to 1/2turn.

CAUTION

WARNING

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NOTE

The HP tube end fitt ing is aspecial design for extremelyhigh pressures. As illustrated inFigure 12-17, an internallythreaded ferrule must be posi-tioned on the threaded end ofthe fitting so that 2 to 3 threadsare exposed at the end of thef i t t i ng be fo re the hose i sinserted into the power headconnection port. The ferruleposition must be checked priorto each connection of the hose.

12-5.12.9 (TOP) Remove a pressure portsealing plug and connect the HP tube from theintensifier to the power head as shown in Fig-ure 12-17.

12-5.12.10 (TOP) Pump the intensifier until asteady stream of hydraulic fluid (no air) bleedsfrom the loosened connection opposite the HPtube in the power head. Fill the intensifier res-ervoir with hydraulic fluid as tank level drops.Tighten the bleeding connection with the 5/8-inch wrench to seat firmly (DO NOT OVER-TIGHTEN).

High pressure oil jets can pene-trate the skin.


12-5.12.11 (TOP) Increase the intensifierpressure to 35,000 psi by slowly opening theair supply valve. Secure the air supply valvewhen pressure is reached.

12-5.12.12 (TOP) Confirm stable 35,000 psireading on hydraulic pressure gauge, then

close the power head stop valve to isolate thepressure in the power head from the pressurein the HP tube.

12-5.12.13 (TOP) Depressurize the intensifiertank and the HP tube by slowly opening thehydraulic bypass valve on the intensifier.

12-5.12.14 (TOP) Disconnect the HP tubefrom the power head using the 5/8-inchwrench. Reinstall the sealing plug into theexposed tubing connection fitting.

12-5.12.15 (TOP) Apply thread lubricant (FN26) to the threads and shoulder of the Morgripblade bolt.

12-5.12.16 (TOP) Fill and clamp Hydrolubedispensers, one for each bolt (FN 163.1) with200 cc of Hydrolube (FN 163) each and passto the divers.

12-5.12.17 (DV) Dewater blade bolt holes #2,#3, #6, and #7 by displacing the water in theholes with Hydrolube. Insert the dispensernozzle into the bolt hole so the Hydrolube(heavier than water) fills from the bottom of thebolt hole. This will displace the water with min-imum mixing action.

12-5.12.18 (TOP) Send bolt #2 (with powerhead attached) and a spanner wrench to thedivers.

12-5.12.19 (DV) Insert the bolt into bolt hole#2.

12-5.12.20 (DV) Seat the bolt using the span-ner wrench.

NOTE

Length of cheater pipe must beconsistent for all bolts.

12-5.12.21 (DV) Attach a 4-foot cheater pipe(FN 44) to the spanner wrench and tighten thebolt.

WARNING

CAUTION

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NOTE

A one minute delay is requiredto allow hydraulic lock to relieveitself. It is critical to repeat untileach bolt will no longer tighten.

12-5.12.22 (DV) Wait one minute, thentighten the bolt again. Continue tightening thebolt, with a one-minute pause between efforts,until the bolt stops advancing.

High pressure oil jets can pene-trate the skin. Ensure diversare clear of the valve openingwhen bleeding the power head.

12-5.12.23 (DV) Loosen one of the pressureport sealing plugs. Open the power head stopvalve to depressurize the power head and theMorgrip bolt.

12-5.12.24 (DV) Remove the depressurizedpower head from the bolt using the spannerwrench.

12-5.12.25 (DV) Remove the bullet rod fromthe bolt. The special removal tool is provided ifsuction makes the bullet rod removal difficult.

Send the power head and the bullet rod to thesurface.

12-5.12.26 (DV, TOP) Repeat the bolt instal-lation procedure in the following boltsequence: #6, #3, and #7.

12-5.12.27 Remove Hydraulic TemporaryBolts. (DV) Remove the temporary bolts frombolt holes #1, #5, #4, and #8 by reversingsteps 12-5.11.41 through 12-5.11.49.

12-5.12.28 Complete Morgrip Bolt Installa-tion. (DV, TOP) Repeat bolt installation pro-cedure (steps 12-5.12.1 through 12-5.12.25)for the following bolt sequence: #1, #5, #4,and #8.


12-5.13.1 (UT/DV) Using NAVSEA-approvedultrasonic measurement procedures andequipment, record the final measurements forall eight bolts.

12-5.13.2 (UT) Using the Inspection Reportand Work Sheet, Figure A-3, compare the ini-tial and final bolt lengths to determine residualstretch of bolts #1 through #8. Residualstretch must be between 0.006 and 0.0084inches.

Figure 12-22. Location of Nylok Pellets in the Morgrip Bolt.

WARNING

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12-5.13.3 (TOP) If any bolts are outside theresidual stretch required, corrections must bemade as follows. If residual stretch is too low,reinstall the power head and pressurize to35,500 psi, then reseat the bolt. If residualstretch is too high, reinstall the power headand pressurize to 35,000 psi. Loosen the boltand then reseat without the 4-foot cheater baron the power head spanner wrench.

12-5.13.4 (UT) Re-measure all eight bolts.Compare initial and final lengths to determineresidual stretch of all eight bolts. All final resid-ual stretch must be within the specified range(0.006-0.0084 inches).

12-5.14 BOLT CAP INSTALLATION.

12-5.14.1 (TOP) Prepare two Nylok pellets(1/4-inch diameter, 9/32 inch long) (FN 10) foreach bolt and pass to divers (one to beinstalled and one as a spare).

12-5.14.2 (DV) Install one Nylok pellet intothe hole in the side of the threaded portion ofMorgrip bolt where the bolt cap is to beinstalled. Figure 12-22 shows the location ofthe Nylok pellet in the Morgrip bolt.

NOTE

Because access to the Nylokpellet hole is often partiallyobscured by the bolt recess inthe blade palm, one installationmethod is to grab the pelletwith needle nose pliers (FN 11)in order to hold the pellet in linewith the hole and then squeezethe pellet into the hole withmodified channel lock pliers(FN 12).

12-5.14.3 (TOP) Apply silicone grease to theblade bolt cap seals. (FN 8)

12-5.14.4 (TOP) Pass the blade bolt capseals and a flat-blade screw driver to the diver.

12-5.14.5 (DV) Install the blade bolt cap sealaround the blade bolt flange as shown in Fig-ure 12-22. Using the screwdriver, ensure theseal is seated at the bottom of the bladeflange hole as shown in Figure 12-22.

NOTE

Check the fit and threads of allcap plugs in the blade bolt capsprior to sending the caps to thedivers.

12-5.14.6 (TOP) Pass the blade bolt caps (FN4), blade bolt cap plugs (FN 7), blade bolt capwrench (FN 5), and a 3/16-inch Allen wrench(FN 7.1) to the divers.

12-5.14.7 (DV) Install the blade bolt caps onall eight bolts using the blade bolt cap wrench.Torque to 170 ft.-lbs. using the torque wrench(FN 6.5) with the 1/2-inch drive to 3/4-inchdrive socket adapter (FN 6.6) and the impactsocket (FN 6.2). See Appendix D for details ofthe blade bolt cap wrench.

12-5.14.8 (DV) Dewater the Morgrip boltthrough the pipe plug hole in the cap by dis-placing the water with 200 cc of Hydrolube.

12-5.14.9 (DV) Install the blade bolt capplugs. Tighten the plugs flush with the caps.




12-5.16.1 (DV/TOP) Remove all tools andequipment. Derig the transfer line for retrievaltopside.

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12-5.16.2 Take Inventory. (TOP) Collect,inventory, and pack equipment and tools.Mark or “red tag” damaged or malfunctioningtools or equipment.


12-5.16.4 Prepare Final Report. (TOP) Pre-pare a final report documenting the accom-plished repair. Documentation which NAVSEA00C54 needs to help improve the procedure

is: blade bolt liquid penetrate inspectionresults, blade bolt ultrasonic measurementinspection results, a description of any lost,damaged or malfunctioning tools or equipmentin the NAVSEA CPP Kit, a list of all consum-ables taken from the kit for the job, detailsregarding any problems encountered, new orspecial tools needed. The final report shouldbe faxed or e-mailed to NAVSEA 00C54.

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SECTION 6 DD 963, DDG 993, AND CG 47 CLASS WATERBORNE BLADE PORT HUB SEAL REPAIR

12-6.1 REFERENCES.

a. NAVSEA S9245-BF-MMM-010, Main-tenance Manual for Controllable PitchPropeller in DD 963 and DDG 993Classes.

b. NAVSEA S9245-AF-TRS-010, Techni-cal Repair Standard, Propeller HubAssembly and Blades DD 963 andDDG 993 Classes.

c. NAVSEA S9245-AH-MMA-010, Tech-nical Manual for Controllable Revers-ible Pitch Propeller for CG 47 ClassShips.




Removal and replacement of the blade hubseal requires some special tools and equip-

ment. The find numbers (FN) in the followingparagraphs correspond to the find numbers inthe NAVSEA CPP Blade Change Kit, theinventory for this kit is available from NAVSEA00C5. The quantities of items contained in theCPP Kit are the minimum recommended to beon hand prior to blade port hub seal repairs.Replacement parts for five complete bladeseal replacements are included in theNAVSEA CPP kit. Table 12-6 lists qualityassurance points when repairs are to bemade.

12-6.3 REPAIR PROCEDURE

Note

All item numbers in parenthesis( ) refer to Figure 12-23 unlessotherwise noted. Find Numbers(FN) refer to parts list of theNAVSEA Blade Change Kit.

Before removing the blade,measures must be taken for oilcontainment and abatement inaccordance with local SeniorOfficer Present Afloat (SOPA)Manuals and reference d.

12-6.3.1 (DV) Remove affected propellerblade in accordance with Section 12-5 of thismanual.

12-6.3.2 (DV) Install a quick disconnect hubpressure test fitting (FN 51.2) (see Appendix I)into the lower of the two 1/2-inch pipe plug fit-tings on the forward end of the hub. The two1/2-inch fittings are approximately 180degrees apart from each other. DO NOT usethe two 1-1/4 inch pipe plug fittings which arealso located on the forward end of the hub.

CAUTIONCAUTION

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12-6.3.3 (DV) Rotate blade port to the 6o'clock position. Confirm that the hub centerpost sleeve (1) is not loose or cracked. SeeFigure 12-23 for identification of the centerpost sleeve. If the center post sleeve iscracked, locate and record the center post (2)outer diameter measurement which isstamped on the top of the center post andhave a replacement sleeve machined inaccordance with NAVSEA drawing 6699591,Center Post Sleeve (see Appendix H). Shouldthe outer diameter measurement not bestamped on the top of the center post sleeve,divers must make a repeatable measurementof the center post outer diameter using a 12-inch outside vernier caliper (FN 63). Experi-ence indicates that special eight-jaw chuckvice four-jaw chuck lathe equipment isrequired to hold machining tolerances on thethin walled center post sleeve blanks (FN

52.13). The center post sleeve can bemachined out of solid round stock material ona standard four-jaw chuck lathe if an eight-jawchuck lathe is not available.

12-6.3.4 (DV) Install the second quick discon-nect hub pressure test fitting (FN 51.2) into theother (opposite the one used in step 12-6.3.2)1/2 inch pipe plug fitting on the forward end ofthe hub.

12-6.3.5 (SF, DV) Secure the discharge valve(1CRP-31 on the hydraulic schematic Figure2-12 of reference (a)) at the ship's internalCPP head tank. This will prevent the headtank from emptying to the sea when the bladeport cover is removed at the 6 o'clock position.When the blade port cover is first removed,the oil entrapped in the CPP system will estab-lish internal oil head pressure equal to outside

Table 12-6. DD 963, DDG 993, and CG 47 Class Waterborne Blade Port Hub Seal RepairQuality Assurance Points.

Quality Assurance Point Initial

1. Check for cracked center post sleeve. If cracked, record OD measurement stamped on the top of center post [12-6.3.3].

2. Confirm final machined dimensions of the replacement center post sleeve [12-6.3.14(d)].

3. Check alignment of the center post sleeve jacking assembly [12-6.3.14m].

4. Verify replacement center post sleeve is flush with the center post [12-6.3.14p].

5. Measure blade port cover to bearing ring clearance and determine shim requirements [12-6.3.15].

6. Ensure blade seal base ring positioning dowel is in position [12-6.3.19].

7. Inspect the blade seal base ring [12-6.3.20].

8. Reseat the blade seal base ring [12-6.3.23].

9. Remove excess O-ring seating grease and ensure Mylar shim is flat [12-6.3.24].

10. Ensure stable oil/water interface is level with hub port opening [12-6.3.25].

11. Observe O-rings in proper position during final seating of blade port cover [12-6.3.26].

12. Check distance between blade port cover and crank pin ring with 0.002-inch feeler gauge [12-6.3.29].

13. Check dowel pin fit and torque blade port cover cap screws to 33 ft.-lbs. [12-6.3.31].

14. Vent any air trapped in the hub [12-6.3.34].

15. Pressurize the system to check for leaks [12-6.3.36].

16. Final system test [12-6.3.39].

S0600-AA-PRO-120

seawater pressure at the 6 o'clock hub posi-tion.

12-6.3.6 (SF) Secure and tag out the CPPsystem.

12-6.3.7 (TOP, DV) Rig staging to the propel-ler under the 6 o'clock blade port or an alterna-tive method for the diver(s) to work from astable position for hub component removal.Wherever the stage is secured to the hub orblade bases ensure adequate chafing gear isused to prevent damage to any propeller sur-

face. The diver must be stable to make therequired detailed measurements.

12-6.3.8 (DV) Remove every other cap screw(6) holding the blade port cover (5) (unitweight of cover is 183 lbs.) onto the crank pinring (13).

12-6.3.9 (DV) Install a handle nut approxi-mately four inches from the top on each of thefour 5/8-11 UNC 30-inch long, all-thread rods.Make sure the handle on the handle nut isangled downward. The top of the all-thread

Item Name Reference1 Center Post Sleeve FN 52.132 Center Post3 O-ring (dynamic) FN 544 O-ring (static) FN 555 Blade Port Cover Item 24 of Figure 8-15a in reference a or FO2 in reference c6 Capscrew FN 607 O-ring (static) FN 20, FN 120 for CG 668 O-ring (dynamic) FN 569 Blade Seal Base Ring Item 7 of Figure 8-15a in reference a or FO2 in reference c10 O-ring (static) FN 5711 Spring FN 5312 Bearing Ring Item 6 of Figure 8-15a in reference a or FO2 in reference c13 Crank Pin Ring Item 2 of Figure 8-15a in reference a or FO2 in reference c14 Mylar Shim FN 67 (DD 963, DD 993, and CG 47 set)

Figure 12-23. Blade Port Assembly.

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rods are opposite the end with the flatsmachined for a 1/2-inch wrench. Installing thehandle nuts onto the top of the all-thread rodsprior to installing the all-thread rods avoids theneed to run the handle nut all the way up the30-inch length of the rods. Install a 5/8-inchflat washer onto the rod so the handle nut willbear against the washer and not the blade portcover. Install the rod assemblies into the holesemptied in the previous step. Using the flats,tighten the rod assemblies in place with a 1/2-inch wrench.

12-6.3.10 (DV) Run the handle nuts back upthe all-thread rods until they are approximately1/4 inch from the surface of the blade portcover.

12-6.3.11 (DV) Remove the remaining fourcap screws holding the blade port cover to thecrank pin ring. The blade port cover shouldsettle onto the handle nuts installed on the5/8-inch all-thread rod assemblies.

NOTE

As the blade port cover is low-ered, watch for any of the fourO-rings (items 3, 4, 7, and 8)held in place under the bladeport cover. Also, watch for aMylar shim (14), if installed.

12-6.3.12 (DV) Lower the blade port coverevenly using the four handle nuts until theblade port cover is approximately 18 inchesfrom the blade port.

12-6.3.13 (DV) Remove the four O-ringsaccessible at this point (see Figure 12-23). If aMylar shim is found and is undamaged, leaveit in place. Measurements taken in step 12-6.3.15 will determine if the Mylar shim shouldremain in place, be removed, or be replacedwith a Mylar shim of different thickness.

12-6.3.14 (DV) If the center post sleeve iscracked or loose, replace as detailed in thisstep. If the center post sleeve is not damaged,proceed with the next step.

a. Lower the blade port cover and removefrom the all-thread rods.

b. Remove the damaged center postsleeve from the center post. Thecracked sleeve should slide easily offthe center post.

c. Clean the center post using 360-gritwet/dry sand paper or Scotch-Britepads.

d. In accordance with step 12-6.3.3, thenew s leeve shou ld a l ready bemachined to obtain a 0.002+/-0.0005-inch press fit onto the center post (seeNAVSEA drawing 6699591, CenterPost Sleeve, Appendix H).

e. Install the base plate (FN 52.3) on thefour all-thread rods using the handlenuts. Ensure the handle nuts have fullthread engagement.

f. Place the Enerpac jack set (FN 9 ofNAVSEA Drawing 6699590, AppendixH) inside the tabs on the base plate.

g. Place the jacking plate (FN 52.2) on topof the Enerpac jack set so that thejack’s flat base rests in the indentationin the jacking plate and the tabs on thejacking plate are facing up.

h. Spray the inside diameter of the newcenter post sleeve with a lubricant thatwill not be displaced by the water (LPS-3 or equivalent) before the sleeve issent to the divers.

i. Place the new center post sleeve onthe jacking plate inside the tabs.Ensure that the end of the sleeve withthe taper on the inside diameter is fac-ing up towards the center post.

j. Place the pipe stand-offs (FN 52.4)over each of the base plate’s emptyholes and sl ide an a l l thread rod(wrench flat end on the bottom) through

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the base plate and the pipe stand-offsthreading the end of the rod into thealigning hole in the crank pin ring. Fourall-thread rods with pipe stand-offsmust be installed. A total of eight all-thread rods are required, four with pipestand-offs and four without pipe stand-offs.

k. Ensure the all-thread rods just installedare bottomed out in the crank pin ringbolt holes. Use a wrench on the wrenchflats cut into the end of the rod. Install ahandle nut on each rod.

l. Using all eight handle nuts, raise thebase plate until it is restrained by allfour pipe stand-offs. The pipe stand-offs will ensure the base plate is paral-lel with the crank pin ring and the jack-ing plate is set at the proper height.

m. Check the entire setup prior to jackingthe new sleeve. Ensure the taper onthe inside diameter of the sleeve is fac-ing up toward the center post. Ensurethe whole jacking assembly is centeredunder the center post.

n. Extend the jack until the sleevetouches the center post. Verify align-ment of the sleeve with the center post.

If the jack pressure increasesrapidly without movement ofthe sleeve right at the start,stop jacking and inspect formisalignment. Retract the jackand remove the sleeve from thecenter post. If the sleeveremains serviceable, align thejacking assembly and restart.

o. Jack the sleeve into place. Do not stopjacking until the sleeve is flush with thecenter post.

p. Retract the jack and verify that thesleeve is flush with the center post.Verify that the new sleeve did not crackduring the press fit.

q. Remove the center post sleevereplacement assembly from the hubport. Leave four of the all-thread rods inthe crank pin ring.

r. Install the blade port cover onto the all-thread rods.

s. Continue with the next step in the pro-cedure.

12-6.3.15 (DV) Prior to reseating the bladeport cover the measurements shown in Figure12-24 must be taken to determine if therequired 0.002-0.007-inch clearance will existbetween the bearing ring and the blade portcover after the blade port cover is bolted to thecrank pin ring. These same measurementsare made when the new hub is first assembledon the ship and often a Mylar shim must beadded between the blade port cover and thecrank pin ring to ensure that the requiredclearance is achieved between the blade portcover and the bearing ring after assembly.Over time, the rotation of the crank pin ring willcause wear on the bearing ring. As the bear-ing ring wears, dimension “B” in Figure 12-24will shorten. Since the blade port cover has nowearing surface, dimension “A” on Figure 12-24 stays the same. Therefore, over time, thethickness of Mylar shim required to maintainthe required clearance will decrease until noshim is required and eventually the clearancewill exceed the maximum, even with no shim.

DO NOT attempt to measuredimension "B" between anexisting shim laying on thecrank pin ring and the bearingring. Dimension "B" must bemeasured between the actual

CAUTION

CAUTION

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crankpin ring surface and thebearing ring. The elastic shimsurface makes the diver mea-surements with the outsidedepth micrometer unrepeat-able.

The reduction of shim thick-ness or removal of shim asdetailed above is at best aninterim method to regain ablade port seal when bearingring wear has begun. Oncebegun, bearing ring wear willcontinue, eventually causingblade port leaking to resume.Careful consideration of theship’s operational schedule anddrydock availabilities to performthe eventual replacement of theworn bearing ring is essential.

NOTE

Mylar shims are very delicate.They are shipped with the CPP

equipment kit in a PVC tube forprotection (FN 67). Shims of0.002, 0.003, 0.004 and 0.005-inch thickness are includedwith the kit. The shims are alsoavai lable from the or ig inalequ ipment manufac tu re r(OEM), Bird-Johnson.

Referring to Figure 12-24, proceed with themeasurements as follows:

a. Perform all measurements to the near-est 0.001 inch and with the blade portat the 6 o’clock position.

b. It is essential that the same diver,experienced in the use of a depthmicrometer, perform all dimension “A”and “B” measurements. This w il lensure that variation based on mea-surement technique will not effect thedifference between “A” and “B”.

c. Perform eight measurements aroundboth the blade port and blade portcover, one adjacent to each Morgripbolt hole. Record the results. Becauseof access limitations, dimension “B” ismore difficult to measure. It is most

Figure 12-24. Shim Requirement Measurements.

CAUTION

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important to be consistent with thealignment and placement of the depthmicrometer at each location measured.

d. After the most repeatable measure-ments achievable have been recorded,average the eight measurements takenfor “B”.

e. Average the eight measurementstaken for “A”.

f. If “B” is greater then “A”, a shim isrequired. The minimum shim thicknessis (“B” - “A”) + 0.002 inch. The maxi-mum shim thickness is (“B” - “A”) +0.007 inch.

g. If “B” is equal to “A” or less then “A” byup to 0.002 inch, a shim is required.The shim thickness must be 0.002-0.005 inch.

h. If “B” is less then “A” by more then0.002 inch, no shim is required. How-ever, if “B” is less then “A” by more then0.007 inch the maximum requiredclearance will be exceeded even with-out a shim.

i. If a shim is required, measure the thick-ness of any existing shim to determineif it meets the criteria above. Use athickness micrometer to measure theshim thickness. If an existing shimdoes not meet the above cri teria,replace with a new shim. Selection ofshim stock thickness should be basedon an ideal blade port cover to bearingring clearance of 0.005 inch.

j. If no shim is required, any existing shimmust be removed.

12-6.3.16 (DV) Install four 5/16-18 UNC, 4-inch long jacking bolts 90 degrees apart intothe threaded through-holes provided in theblade seal base ring (9). Note the depth ofinsertion of the ring relative to the lip of the

hub blade port opening. This will allow the ringto be reinstalled into the same position.

The blade seal base ring isheld in place only by a frictionfit at the 6 o'clock position. Dur-ing the jacking removal processthe ring will drop out under itsown weight (32 lbs.). Diversmust be prepared for the ring'sweight and to recover the 18springs which are retained bythe ring and may fall loose withthe ring.

12-6.3.17 (DV) Jack the blade seal base ringout evenly taking care to avoid warping thering. Be prepared to recover the 18 springs(11) held in place by the blade seal base ring.

12-6.3.18 (TOP, DV) Send the blade sealbase ring and the 18 springs to the surface.Work the blade seal base ring free of the allthread rods by removing each rod one at atime and reinstalling outside the blade sealbase ring.

12-6.3.19 (TOP) Ensure that the blade sealbase ring positioning dowel pin (3/8-inch diam-eter x 1 1/4 inch long) remains press fit intothe bearing ring (12).

12-6.3.20 (TOP, DV) Clean and inspect theblade seal base ring. Inspection tolerancesare specified in reference (b). Install a new O-ring (10) onto the OD of the blade seal basering and send it to the divers with 18 newsprings.

12-6.3.21 (DV) Work the blade seal base ringback over the all thread rods by removing andreinstalling the rods one at a time. Ensure thatthe blade seal base ring rests on the coverplate with the dynamic O-ring groove facingdown against the cover plate.

CAUTION

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12-6.3.22 (DV) Install the 18 springs into thebearing ring. Use grease (FN 61), injected intothe bearing ring spring holes with the greasegun, to hold the springs in position overheadwhile the blade seal base ring is positioned inplace. An alternative method to retain thesprings is to dip the first three coils of eachspring in melted beeswax so the OD isincreased just enough to make for a tightinsertion (bearing ring hole is 3/4-inch diame-ter). If this method is used, ensure that all waxis removed from the end of the spring so thatthe spring will make metal-to-metal contactwith the bottom of the hole.

12-6.3.23 (DV) Push the blade seal base ringinto the groove in the bearing ring by hand,making sure to align the blade seal base ringwith the positioning dowel pin. Evenly pushthe ring into the groove to avoid warping thering or damage to the O-ring. Two divers arerequired to align and push in the blade sealbase ring far enough to ensure that it stays inplace.

NOTE

Ensure that items (3) and (8)(dynamically loaded O-rings)are replaced with fully moldedinstead of spliced O-rings. O-rings supplied by the stock sys-tem for items (3) and (8) areoften spliced instead of fullymolded.

12-6.3.24 (DV) Fill the empty O-ring grooveson the blade port cover ID, the inner and outerMorgrip bolt hole diameters on the crank pinring, and the blade seal base ring (four O-ringgrooves total) with grease and remove anyexcess. Seat four new O-rings (3, 4, 7 and 8)into their appropriate grooves and allow thegrease to hold them in place. Again, removeany excess grease. If a Mylar shim is installed,ensure the shim lays flat against the crank pinring or blade port cover.

12-6.3.25 (SF, DV) Allow the oil/seawaterinterface at the blade port to settle out andhave Ship’s Force release oil from the head

tank until all seawater is displaced from thehub.

12-6.3.26 (DV) Raise the blade port coverevenly with the handle nuts until it is carefullyseated into place. Be careful to ensure that allthe O-rings remain seated in their proper loca-tions during the final seating of the blade portcover.

12-6.3.27 (DV) Install four 5/8-inch capscrews into the available holes to secure theblade port cover in place.

12-6.3.28 (DV) Remove the four 5/8-inch all-thread rods and install the remaining four 5/8-inch cap screws. Tighten all cap screwssnugly.

12-6.3.29 (DV) Check clearance betweenblade port cover and crank pin ring in all eightMorgrip holes with the 0.002-inch feelergauge. Confirm no fit or very tight fit of feelergauge between the blade port cover and thecrank pin ring. If the feeler gauge is tight, pro-ceed with the next step. If the feeler gauge isnot tight, one or more of the O-rings hasjumped its groove. Lower the blade port coverand check the four overhead O-rings. RepeatO-ring and blade port cover installation until0.002-inch feeler gauge is tight.

12-6.3.30 (SF, DV) Rotate the blade port tothe 12 o’clock position.

12-6.3.31 (DV) Ensure that the blade dowelpins will be able to slide through the blade portcover into the crank pin ring by placing theminto the blade dowel pin holes. If either isunable to fit, loosen the blade port cover capscrews to allow for minor rotational alignmentof the blade port cover with the crank pin ringuntil the dowel pins are able to slide insmoothly. Initial alignment of the two dowel pinholes will be evidenced by over an inch ofdowel pin insertion. Then, evenly torque all thecap screws to 33 ft.-lbs. using the torquewrench (FN 58) and the 1/2-inch Allen socket(FN 58.4). Recheck the dowel pin fit after the

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cap screws are tight. The dowel pins shoulddrop the rest of the way into the holes.

12-6.3.32. (DV) Connect hub pressure testsystem hoses detailed in Appendix I into thequick disconnect fittings that where installed inthe hub earlier.

12-6.3.33. (SF) Open head tank valve.

12-6.3.34. (TOP) Vent any air trapped in thehub from the hose installed at the 12 o’clockposition.

12-6.3.35. (SF) Secure the head tank valve.During the hub pressure test, the return oilside of the system will be pressurized as thehub crosshead chamber is pressurized by thedivers.

12-6.3.36. (TOP, DV) Using the barrel pump ina barrel of clean CPP system oil, pressurizethe hub crosshead chamber to 20 psig. Main-tain pressure at 20 psig for 10 minutes whiledivers check for leaks at the blade port coverand the other blades.

NOTE

A value of 20 psig should below enough to not lift the crosshead chamber relief valve. Incases where the pressure con-sistently drops to some lowervalue (10 to 11 psig), use thisnew value for the pressure test.Hold pressure for 10 minutesand have the divers confirm noleaks. This will confirm that thehub seal has been re-estab-lished.

12-6.3.37. (TOP) If leaking is NOT observed,proceed to the next step. If leaking isobserved, changes to the Mylar shim thick-ness based on measurements may not havebeen enough to regain sufficient blade portcover O-ring compression to get a seal. Theprocedure may be repeated to confirm mea-

surements and perhaps reduce shim thick-ness. However, if bearing ring wear isindicated and the hub already has a long ser-vice life, the only alternative may be drydockreplacement of the worn bearing ring.

12-6.3.38. Replace blade in accordance withSection 12-5 of this manual.

12-6.3.39. (SF, DV) Remove out-of-servicetags. Cycle the blade pitch through normalrange of operation several times. Test andpurge the system in accordance with section6-7 of reference a for the DD 963 and DDG993 Classes or Section 6-3d of reference c forthe CG 47 Class, MRC 77 6WBM N (R-2W)and paragraph 12-4.3.40. Have divers checkfor leaks around the blade palm and hub inter-face of all blades during the testing.

12-6.3.40. In performing system test andpurge, supplement the procedure outlined inMRC 77 6WBM N (R-2W) with the following.Purge for approximately 15 to 30 minutes. Toopen purge valve, (located in hub) take man-ual control (joystick) and slew pitch astern untilthe main system relief valve lifts (1000 psi).Slew pitch ahead just enough to reset themain relief valve. Purge valve is now openallowing oil from the hub crosshead cavity tobe flushed out and returned to the sump forpurification. It should be noted that, if the mainshaft is rotated (turning gear) in conjunctionwith the hub purge, this will improve the cross-head cavity flushing operation. Rotating theshaft during a hub purge is not mandatory andis left to the Chief Engineer/Main PropulsionAssistant discretion. Recommend hub purgebe conducted upon each return to port prior tosecuring the CPP system.

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SECTION 7 DDG 51 "FLEET" TYPE BLADE REMOVAL, RETRIEVAL, AND REPLACEMENT PROCEDURE


Commands that perform propeller bladereplacements must consider all require-ments. If shop facilities are not available atthe Command with the overall tasking, theCommand must arrange for them. A success-ful blade set change requires one week. Pro-vision must be made for breasting the ship outby the stern so the blades can be liftedbetween the ship and the pier. Crane service,floating or pierside, must be available for pro-peller blade lifting and must have the requiredreach and angle to handle the propellerblades. An oil boom is required for oil abate-ment and containment in accordance withlocal instructions. Personnel performing boltelongation measurements in accordance withthis procedure shall be certified in accordancewith NAVSEA Technical Publication T9074-AS-GIB-010/271 as Ultrasonic Inspector(Level II , or Level II Limited) or Examiner(Level III). The following references providespecific information relevant to removing andreplacing CPP blades:

a. NAVSEA S9245-AM-MMA-010, Sys-tem Manual for Controllable Pitch Pro-peller System, DDG 51 Class, Model156, S1/5.

b. NAVSEA S9245-AT-TRS-010/07309,Technical Repair Standard for Over-haul Procedures, Propeller Hub andBlade Assembly.

c. S9086-00-STM-000, Naval Ships'Technical Manual (NSTM), Chapter245, “Propellers.”


e. MIL-STD-2035(SH) 04 July 1991, Nonde-structive Testing Criteria

f. NAVSEA T9074-AS-GIB-010/271, 30 April1997, NAVSEA Technical Publication,Requirements for Nondestructive TestingMethods (referred to as NAVSEA Techni-cal Publication 271),

12-7.1.1 Applicability. This procedureapplies to DDG 51 class ships with “Fleet”type blades. Within the CG 47 class, CG 66and higher have torque in place blade boltsremoved and installed in accordance with thisprocedure. The blade rigging procedure for allCG 47 class ships is covered in Section 5 ofthis manual.


12-7.2.1 Rig the ship’s hull with the riggingbeam and the 4.5 ton lever hoist, forward, the6.0 ton lever hoist, aft, and blade holdback rig-ging.

12-7.2.2 Prepare each blade for removal byrotating the blade into the 12 o’clock position,removing all eight blade bolts connecting theblade palm to the hub.


12-7.2.4 Install each replacement blade byrigging the blade with the three-point liftingassembly; lowering the blade into position andseating the blade onto the hub. Dewater fourblade bolt holes. Install and tighten the fourbolts to 800 ft-lbs. Check the blade for properseating.

12-7.2.5 Secure each blade to the hub bydewatering the four open blade bolt holes,

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12-84

installing remaining blade bolts into the lubri-cated holes, and fully tightening all bolts.Measure the installed bolt lengths to deter-mine the proper residual stretch, and installfairing/sealing plug in blade bolt measurementcavities.

NOTE

While the following procedurerequires that the topside per-sonnel and the divers workclosely together, there are cer-tain steps that must be carriedout by particular personnel. Toclarify these steps, abbrevia-tions are placed at the begin-ning of each step where thespecific party needs to be iden-tified: (DV) represents diver,(TOP) represents topside per-sonnel, (SF) represents Ship’sForce personnel and (UT) rep-resents Level I I Ul trasonicInspector.

12-7.3 PREPARATION.


NOTE

It is essential that all tools andmaterials brought to the under-water job site are accounted forand removed at the completionof the job. Tools and materialsinadvertently left at the job sitecan generate unacceptablenoi se and poss ib ly causesevere damage to shipboardcomponents. Locally gener-ated work packages sha l lensure that a general tool andmaterial log sheet is prepared

and main ta ined dur ing a l lUWSH operations.

12-7.3.2 Inventory Tools, Materials andEquipment. NAVSEA 00C5 maintains aCPP blade change kit that contains most ofthe tools and equipment necessary to replaceCPP blades. This blade change kit should beobtained and positioned on site before begin-ning the task. An inventory of the items in thiskit is included in the kit and available fromNAVSEA 00C5. Table 12-7 identifies addi-tional items that must be provided by therepair activity. Ensure the availability of alltechnical information, manuals, and drawings.

12-7.3.3 Review Bolt Elongation Measure-ment Procedure and Equipment. It is veryimportant that both the divers and the NDTinspection personnel study and understand allaspects of bolt elongation measurement asdetailed in Appendix B. Review of the tutorialdiscussion provided in Appendix B first willprovide a good general understanding of theresponsibilities for the divers and NDT inspec-tors. See Appendix J for NAVSEA NDT equip-ment details.



Removal and replacement of the CPP bladerequires some special tools and equipment.The find numbers (FN) in the following para-graphs correspond to the find numbers in theNAVSEA CPP Blade Change Kit, the inven-tory for this kit is included in the kit and avail-able from NAVSEA 00C5. The quantities ofitems contained in the CPP Kit are the mini-mum recommended to be on hand prior toCPP blade removal and replacement. Theirfunctions are described in the following para-graphs.

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Change 1 12-84A







CAUTION


3 Ton1-½ Ton

4-½ Ton 6 Ton

TypicalRunning

BlockFlip

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12-84B Change 1


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12-7.4.1 Hydraulic Bolt Torquing Equip-ment. The hydraulic bolt torquing equipmentis used to tighten the blade bolts. The equip-ment must be operated in accordance withmanufacturer's instructions.

Torque vs. applied pressurecharts for the specific operatinghead and pump utilized mustbe available during operation.

Careful attention must be paidto connection of the hydraulichoses between topside pumpand underwater hydraulictorque link. The hoses must beconnected in accordance withmanufacturer's instructions.

12-7.4.2 Lifting Assembly. The liftingassembly (See Appendix F) is attached to apropeller blade so the blade can be lifted andlowered with the hook of a lever hoist.

12-7.4.3 Righting Fixture. The righting fix-ture (See Appendix G) is installed onto the

propeller blade and connected to the piercrane hook. The righting fixture is used to liftthe propeller blade out of its shipping con-tainer and to stand the blade by its palm ontowood timbers, enabling the blade to be outfit-ted with the lifting assembly.

12-7.4.4 Dowel Pin Removal Tool. Thedowel pin removal tool is used to removestuck dowel pins that cannot be removed byhand.

12-7.4.5 Blade Guide Pins. The bladeguide pins are used to align the blade palmwith the dowel pins at installation.

12-7.4.6 Bolt Elongation MeasurementTool. The bolt elongation measurement toolis a transducer assembly and ultrasonic instru-ment specially designed to measure the elon-gation of the blade bolts. The bolt elongationmeasurement procedure outlined in AppendixB allows any Intermediate Maintenance Activ-ity (IMA) Level II Ultrasonic Testing (UT)inspector to perform measurements with thisequipment.

12-7.4.7 Overhead Rigging Beam. Theoverhead rigging beam is installed with the U-bolts on to the lifting tunnels at Frame 442.This beam provides a single lifting point toremove and install the blades from the hub.


Item No. Quantity Component Description Technical Specifications

1 1 Transfer Line, 5/8” x 100’ Commercial



4 as required Timbers, 4” x 4” x 4’ (to set blades upright) Commercial






CAUTION

CAUTION

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Table 12-8. DDG 51 Quality Assurance Points.

Blade Removal Initials

1. Inspect rigging [12-7.5]

2. Ensure pitch is set at full ahead pitch position [12-7.6.1].

3. Discard used Teflon blade bolt O-ring [12-7.7.6]

4. Clean blade bolts [Appendix B, B-2.6.2 and 12-7.7.7]

5. Conduct liquid penetrant inspection of removed blade bolts [12-7.7.8]

6. Ensure lifting fixture is installed with head clamp 67" from blade tip[12-7.8.9]

7. Confirm orientation of lifting rigging [12-7.8.16]

8. Measure blade palm spacing to relieve binding (if required) [12-7.8.18a]

9. Benchmark the shaft [12-7.8.19]

Blade Installation Initials

1. Inspect blade port and blade [12-7.9]

2. Ensure edge guard material is used for lifting fixture clamps [12-7.10.6]

3. Check prairie air nipple fully inserted [12-7.10.9]

4. Check dowel pins fully inserted [12-7.10.10]

5. Ensure O-ring installed in blade port cover [12-7.10.31]

6. Measure blade palm spacing to relieve binding (if required) [12-7.10.35]

7. Check for cover plate O-ring washout [Caution prior to 12-7.10.40]

8. Check blade seating with 0.002-inch feeler gauge [12-7.10.43]

9. Record serial numbers, hub position, and initial lengths of blade bolts to be installed. Use Hex Socket Bolt Baseline and Post-Elongation Measurement Worksheet, Figure B-4 [12-7.11.2]

10. Install new Teflon Blade Bolt O-Ring and apply lubricant to blade bolt threads and shoul-der [12-7.11.4 and 12-7.11.11]

11. Record actual measured bolt elongation as each bolt is torqued. Use Hex Socket Bolt Elongation Measurement During Installation Worksheet, Figure B-5 [12-7.11.15]

12. Record final length and residual stretch when all eight bolts are installed. Hex Socket Bolt Baseline and Post-Elongation Measurement Worksheet on Figure B-4 [12-7.12.1]

13. Compare final with baseline and confirm proper residual stretch [12-7.12.2]

14. Ensure blade bolt 2-1/4-inch hex plug, rubber washer, and retaining screw are installed [12-7.14.1]

15. Test the CPP system performance [12-7.15]

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Rig the ship’s hull in accordance with Figures12-25, 12-26, 12-27 with an overhead 4.5-tonand aft 6-ton lever hoist and the following pro-cedure.

12.7.5.1 Assemble Rigging Beam. Bolt thetwo sections of the rigging beam (FN 139)together in accordance with Appendix K.

12-7.5.2 Overhead Rigging Beam. Feed U-bolts (FN 139.7) through offset lifting tunnelsat frame 442, 9 ft and 17 ft 11-1/4 inches offcenterline. Attach a tagline to the riggingbeam and lower the beam into the water. Thebeam is positively buoyant underwater. Havethe divers swim the beam to the work areaand fit the beam onto the U-bolts. Place flatwashers, split washers and nuts on the U-bolts and tighten until the beam is snugagainst the hull. Verify that the beam mountingplates are flush against the lifting tunnels,reposition as necessary. Securely tighten thenuts. Place a 7/8-inch anchor shackle in theforward hole of the lifting padeye on the beam.

12-7.5.3 Overhead Lifting Hoist. Run a 4.5ton lever hoist (FN 155) to the “two blocked”position in order to confirm the chain is nottwisted. Install a tool bag onto the lever hoistto stow excess chain out of the way of divers.Pass the lever hoist to the divers and hangfrom the 7/8-inch anchor shackle (FN 165) onthe rigging beam.

12-7.5.4 Rig Aft Lever Hoist. Loop one 84”long synthetic sling (FN 143) (ensure the slingis protected from chaffing using old firehose orsuitable material) through the aft lifting tunnelat frame 448, 13 ft 8-1/8 inch off centerline.Attach the ends of the sling together with a 11/4-inch safety shackle (FN 166). Run a 6 tonlever hoist (FN 156) to the “two blocked” posi-tion in order to confirm the chain is not twisted.

Hang the hoist from the 1 1/4-inch safetyshackle. Install a tool bag onto the lever hoistto stow excess chain out of the way of theblades.

12-7.5.5 Rig Forward Holdback Hoist. Fab-ricate a bridle to attach to the master links onthe forward (suction) face side of the trailingand leading edge blade lifting fixture clamps.As close as possible try to have the bridle cen-ter the pull approximately 3.5 inches outboardof the port to starboard centerline of the blade(blade CG location). The bridle may have tobe adjusted to find the “sweet spot” when theblade is lifted. Choker rig a 10 ft syntheticsling (6000 LB capacity) (FN 144) around theinboard main bearing strut as the forwardattachment point for the holdback hoist. Posi-tion the choke point (hoist attachment point) ofthe synthetic sling at the middle of the out-board side of the inboard strut. This positionwill act to center the holdback hoist pull withthe port to starboard CG of the blade as muchas possible. Attach a 3 ton lever hoist (FN153) between the special bridle and the syn-thetic sling.


12-7.6 ROTATE BLADE TO BE REMOVEDINTO THE 12 O’CLOCK POSITION.

12-7.6.1 (DV, SF) Ensure blade pitch is in thefull ahead pitch position. Benchmarks forpitch alignment are located adjacent to blade

WARNING

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#1. Danger tag the pitch controls in the lockedposition.


Before removing the bladebolts, measures must be takenfor oil containment and abate-ment in accordance with localSenior Officer Present Afloat(SOPA) Manuals and referenced of Section 12-7.1, Require-ments.

12-7.7 REMOVE BLADE BOLTS.

12-7.7.1 (DV) Remove nylon plug, washer andretaining screw from 2-1/4 inch hex hole in topof each blade bolt. Discard the used washers.

12-7.7.2 (TOP) Rig the SWEENEY modelRSL8 female 2 1/4-inch hydraulic torque link.(FN 78.4). On the surface, test operate theSweeney link so that the topside operator andthe diver can become familiar with the operat-ing characteristics of the tool, i.e. short rota-tion, release switch, allow tool to recycle, andstart again. Note that without a load the toolhex socket may travel in both directions duringcycle and release, this will not happen underload and also, the cycle time will be longer

Figure 12-25. Blade Rigging Detail, Key Detail.

CAUTION

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under full load and pressure. Position theSweeney tool with the hose marked with bluetape down to tighten and up to loosen.

12-7.7.3 (TOP) In a divers tool bag place two6 1/2 inch pieces of 2 1/4-inch hex stock, (FN78.9) two shims (1 and 3 inch) (FN 78.10,78.11) and pass to the divers along with theSweeney Tool. See Figure 12-28.

Torque vs. applied pressurecharts for the Sweeney RSL8operating head must be avail-able during operation.

Careful attention must be paid

to connection of the hydraulichoses between topside pumpand underwater hydraulictorque link. The hoses must beconnected in accordance withmanufacturer’s instructions.

Review the manufacturer’sinstruction manual for properuse of the topside hydraulicpump.

NOTE

Proper shim size and tool reac-tion location are provided inTable 12-9 or 12-10 for properseating of the tool. Values aredifferent for right vs. left handblades and for tightening vs.loosening bolts.

Figure 12-26. Blade Rigging Details, Hold Back Detail.

CAUTION

CAUTION

CAUTION

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12-7.7.4 (DV) Bolt removal is performed inthe following sequence, #1, #4, #5, #8, #2, #3,#6, and #7 (see Figure 12-29). Insert the 6 1/2inch long x 2 1/4 inch hex stock into #1 bolthead. Locate the proper shim size (1 or 3inch) and place it over the hex stock. Positionthe hydraulic link over the hex stock in theloosening mode. Adjust the reaction arm ofthe hydraulic link to the proper location asdetermined in Table 12-9 or 12-10.

NOTE

The diver must ensure that thehydraulic link stays in placeduring tightening and looseningoperations. Diver communica-tion with the tool operator iscritical.

NOTE

Patience is required whenusing the Sweeney tool. Therecycle time is approximately12 seconds and 12 full cyclesare required for one revolutionof the bolt.

12-7.7.5 (TOP/DV) Apply hydraulic pressureto the link until #1 bolt is broken loose. Repeatprocess in accordance with Table 12-9 or 12-10 until all bolts are broke loose. In order toavoid damaging the bolts, individually removeeach bolt and send it to the surface.

12-7.7.6 (TOP) Discard the used blade boltTeflon O-ring.

12-7.7.7 (TOP) Prior to use, all unthreaded,polished, external bolt surfaces must be

Figure 12-27. Blade Rigging Details, View at FR 448.

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cleaned in accordance with Appendix B, para-graph B-2.6.2

12-7.7.8 (TOP) Liquid-penetrant inspect allbolts in accordance with NAVSEA TechnicalPublication 271. Group VII (solvent-remov-able) and Group IV (water-washable) fluores-cent penetrant systems are permitted for thisapplication. Acceptance criteria shall be inaccordance with Reference e, MIL-STD-2035A, paragraph 7.6. Surface blemishes orscratches on the bolts’ polished surfaces maybe removed by rotating the bolt in a lathe whilepolishing with a Scotch-Brite pad. All polishedbolts must be re-inspected as detailed above.The blade bolts that pass inspection are to bereused with the replacement blades.

Do NOT use emery cloth or

sandpaper for polishing theblade bolts.


12-7.8.1 (TOP) Construct the lifting assemblyin accordance with Appendix F (FN 152 and141 or 142). Ensure that the trailing edgeclamp has the appropriate size Delrin padsinstalled in accordance with Appendix F.

12-7.8.2 (TOP) Disconnect the trailing edgeclamp from the lifting assembly by removingthe two shackles joining the leg assemblies(both sides) to the trailing edge clamp. Lowerthe trailing edge clamp to the divers.

12-7.8.3 (TOP) Connect one 3/4-inchshackle (FN 162) capturing two 3/4-inch mas-ter links (FN 164) to the aft lifting hole in theDDG 51 head clamp. The aft hole will be thepressure face for blades set in the full aheadposition.

Figure 12-28. Hex Socket Bolt With Hydraulic Torque Link.

CAUTION

Change 1 12-91

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12-7.8.4 (TOP) Connect one 1 1/4-inchshackle to one of the master links installedabove.

12-7.8.5 (TOP) Connect the 1 1/4-inchshackle on the master link to the transfer line.Lower the lifting assembly down the transferline.

12-7.8.6 (DV) Connect the hook of the over-head manual lever hoist to the lazy 3/4-inchmaster link attached to the 3/4-inch shackle inthe head clamp.

12-7.8.7 (DV) Using the overhead manuallever hoist, rig the lifting assembly onto theblade. One diver should be guiding the lead-ing edge clamp onto the blade while anotheroperates the lever hoist.

12-7.8.8 (DV) Use a grease pencil to markthe position of the head clamp 67 inches fromthe blade tip to the nearest corner of the headclamp. Also mark the position of the leadingand trailing edge clamps 21 inches from thebottom edge of the blade to the nearest cornerof each edge clamps.

Note

The 21 inch dimension for posi-tioning the leading and trailingedge clamps provides a goodstarting point to set the lengthof the turnbuckles. Duringt ightening the clamps maymove approximately 1/2 to 1-inch.

12-7.8.9 (DV) Place the head clamp on theblade. Ensure the head clamp is 67 inchesfrom the blade tip to the nearest corner of thehead clamp.

12-7.8.10 (DV) Attach the trailing edge clampto the shackles joining the legs of the liftingassembly (both sides) as shown in AppendixF.

12-7.8.11 (DV) Ensuring slack is in the over-head lever hoist, diver #1 maintains the headclamp at 67 inches from the blade tip to thenearest corner of the head clamp. Diver #2tightens the head clamp to trailing edge clampturnbuckles on the aft and forward faces untilsnug. This will assist in keeping the headclamp from sliding along the edge towards theleading edge. Diver #2 then tightens the headclamp to leading edge clamp turnbuckles untilsnug. Once this is complete, Diver #2 tightensthe trailing edge clamp to leading edge clampturnbuckles on the aft and forward faces untilsnug while ensuring each clamp remains atthe marked position.

12-7.8.12 (DV) Recheck that the head clampis still at the marked position.

12-7.8.13 (DV) Take a strain on the headclamp with the overhead lever hoist to seat theleading and trailing edge clamps on the blade.

12-7.8.14 (DV) Slacken the overhead leverhoist and retighten the turnbuckles in thesame order as step 12-7.8.11.

12-7.8.15 (DV) Attach the holdback hoist bri-dle to the

12.7.8.16 (DV) With the lifting rigging securelyin place, confirm the alignment of the 4.5 tonhoist. The hoist should be positioned for a ver-tical and slightly aft lift, not tending port or star-board. An obvious port or starboard angle inthe rigging most likely means the shaft needsto be rotated to bring the blade into betterposition if the rigging beam position and headclamp position were checked carefully. leadingand trailing edge clamps .

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Table 12-9 Sweeney Tool Fit-Up DDG 51: Right Hand Blade

Bolt PositionLOOSEN TIGHTEN

Shim Size React Against Shim Size React Against

1 1 inch Hex in bolt 2 1 inch Blade*

2 1 inch Hex in bolt 3 1 inch Hex in bolt 1


4 3 inch Blade * 1 inch Hex in bolt 3




8 1 inch Blade* 1 inch Hex in bolt 7

*Reaction arm may be re-positioned on the hydraulic torque link to achieve a best fit against the blade palm.

Sweeney Tool Fit-Up DDG 51: Left Hand Blade.












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Table 12-10. Sweeney Tool Fit-Up CG 66 and Higher: Right Hand Blade.












Sweeney Tool Fit-Up CG 66 and Higher: Left Hand Blade.












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Rotating the hub with the rig-ging attached poses a serioushazard. Rigging loads will eas-ily be exceeded if the jackinggear pulls against the rigging.Direct communication betweenthe Diving Supervisor and theShip’s Force personnel operat-ing the jacking gear is required.


12-7.8.17 Lifting Blade.

a. (DV) Take a strain on the holdbackhoist.

b. (DV) Diver #1 moves into position at theoverhead lever hoist. Diver #2 movesto the blade palm/hub interface.

c. (DV) Diver #1 takes the slack out of theoverhead lever hoist. Diver #2 placesboth hands on the blade palm/hub inthe vicinity of bolt holes #1 and #4.

With the hoist under load,inspect the rigging beam instal-

lation. Confirm that the beamis snug against the hull at thelifting tunnels. If any gap isobserved, slack the hoist andretighten the U-bolts.

d. (DV) Diver #1 takes up on overheadlever hoist. At the same time Diver #2reports movement of the blade palm(indicating that the blade palm madetrue upward progress from the hub orthat the trailing or leading edge of theblade palm moved first).

e. (DV) Diver #1 continues taking up onthe overhead lever hoist until diver #2reports no blade palm movement. Donot exceed a heavy strain (manuallever hoist too tight to move) with thelever hoist.


Blade edges are easily dam-aged. Do not strike bladeedges with air cylinders, tools,or other equipment.


f. (DV) If diver #2 reports that the bladepalm initially moved but that the blade

WARNING

WARNING

CAUTION

WARNING

CAUTION

CAUTION

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palm is no longer moving, then diver #1needs to shake the blade tip VIGOR-OUSLY while the lever hoist has astrain to see if any additional move-ment can be gotten diver #2 reportsany upward travel of the blade palm.As long as steady upward progress ismade, continue with the “shake andpull” approach. If the blade shows nosign of movement discontinue the“shake and pull” approach.

g. (DV/TOP) If diver #2 reports that theblade palm did not initially move or the“shake and pull” approach is not mov-ing the blade palm, the dowel pins arebinding and the b inding must berelieved. The dowel pin binding maybe caused by the holdback hoist beingtoo loose or too tight. The divers maywant to try loosing or tightening the

holdback hoist to relieve dowel pinbinding. The holdback hoist rig mayneed to be shifted to improve the pullangle. If the above holdback hoistadjustment does not relieve the dowelpin binding, proceed with the shaft rota-tion method. This is a trial-and-errorprocess that may need to be repeatedseveral times to find the appropriateposition. If diver #2 reports that theblade palm did not initially move, thedirection of shaft rotation must beselected arbitrarily.

12-7.8.18 Relieve Dowel Pin Binding.

a. (DV) If a good degree of upward move-ment was encountered and ceasedbefore the blade became free, thendivers are required to measure thespacing between the blade palm and

Figure 12-29. Blade Bolt Numbering.

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propeller hub to assist in determiningthe best direction to rotate the shaft.Using a 1/16-inch increment steel ruler(FN 113), record the distance betweenthe hub face and the shoulder recess ofthe blade bolt hole as shown in Figure12-30. These measurements need tobe taken through bolt positions #1, #4,#5, and #8.

b. (DV, TOP) If the starboard side mea-surements are greater than the portside, then the starboard side of the hubmay be down so the shaft should berotated to port. If the port side mea-surements are greater, then the shaftshould be rotated to starboard. If thereis no clear difference between port andstarboard measurements, then arbi-trarily select the direction of rotation.Record and keep all measurements forthe duration of the removal process inorder to monitor progress.


c. (DV) Slack the overhead lever hoisthook from the head clamp and preparewith Ship’s Force to rotate the shaft.

Rotating the hub with the rig-ging attached poses a serioushazard. Rigging loads will eas-

ily be exceeded if the jackinggear pulls against the rigging.Direct communication betweenthe Diving Supervisor and theShip’s Force personnel operat-ing the jacking gear is required.

d. (SF) Rotate the shaft for a count of onesecond (bump) in the desired direction.

e. (DV, TOP) Try again to lift the blade.Again, the shaft rotation method ofrelieving dowel pin binding is often trialand error to find the right position, soadjustments may need to be repeated.

12-7.8.19 Benchmark the Shaft. (SF) Oncethe first successful blade removal shaft rota-tion position is found inside the ship withincommunication range of the jacking gear oper-ator, benchmark the position on the shaft anda location that does not rotate with the shaft.Then measure the shaft circumference andmark five equally spaced marks on the shaft toidentify the other blade removal locations.Label each mark with the corresponding bladenumber.

12-7.8.20 Retrieve Blade to Surface.

a. (DV) Note the location of the dowelpins and the prairie air nipple (in thehub or blade palm). Report the loca-tions topside. Slack the holdback hoistuntil the blade hangs from the over-head hoist. Detach the holdback hoist.

b. (DV) Connect the hook of the aft leverhoist to the aft 1 1/4-inch shackle of thehead clamp.

c. (DV) Yard and stay the blade aft, untilthe blade palm has cleared the propel-ler hub.

d. (DV) Remove the dowel pins and theprairie air nipple from either the hub orthe blade palm and send them topside.A special dowel pin removal tool (FN

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80) is available for use on dowel pinsthat are hard to remove.

e. (DV) Continue the yard-and-stay pro-cess until the full weight of the blade istaken by the aft hoist.

f. (DV) Disconnect the overhead leverhoist hook from the forward 3/4-inchmaster link on the head clamp. Lowerthe blade just below the hub with the aftlever hoist.

g. (TOP, DV) Install a pendant onto thepier crane. Connect the crane pendantto the same shackle of the head clampthat the aft lever hoist is attached. Usean additional shackle attached to the3/4-inch master link if required. Thiswill help prevent rotation of the bladeduring the yard and stay to the crane.

h. (DV, TOP) Take the slack out of thecrane. Check all shackle arrange-ments for binding. Yard and stay theblade until the full weight of the blade istaken by the pier crane. When the piercrane has the full weight of the blade,disconnect the aft lever hoist. Raisethe blade to the pier.

i. (TOP) Set the blade upright onto two4”x 4” timbers on the pier.

j. (TOP) Disconnect the trailing edgeclamp from the assembly by removingthe two shackles joining the leg assem-blies (both sides) to the trailing edgeclamp.

k. (TOP) Remove the lifting assemblyfrom the blade.

Figure 12-30. Blade Bolt Hole Measurements.

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NOTE

If all removed blades are setw i th in reach o f the c raneupright on timbers (step 12-7.8.20i) as they are removed,topside will have plenty of timeto shift removed blades to thespecial shipping pallets as newblades are removed from theshipping pallets for installation.

l. (TOP) Later, after the new blade hasbeen prepared and removed from itsspecial container, install the righting fix-ture onto the blade. Install two 3/4-inchand one 1-inch shackle (FN 151.19 &151.18) onto the righting fixture asshown in Figure 12-31.

m. (TOP) Flip the blade to a horizontalposition using a two-part lift.

n. (TOP) Flip the blade and position itonto the special shipping pallet that thenew blades were sent on.

12-7.9 BLADE PORT AND BLADE INSPEC-TION AND PREPARATION.

12-7.9.1 (DV) For each empty hub bladeport, clean and inspect the cover plate, dowelpin holes, prairie air nipple orifice, center postsleeve, and O-ring groove. Figure 12-32details the hub blade port inspections.Scotch-Brite “greenie” pads work well forcleaning.


12-7.9.3 (TOP) Inspect and clean the previ-ously removed dowel pins and prairie air nip-ple with an emery cloth. Dowel pins must notbe mushroomed or peened at either end.

Ensure new O-rings are used for all installa-tions.


12-7.9.4 (TOP) Lubricate the four new prairieair nipple O-rings (FN 114) with siliconegrease (FN 115). Install the four O-rings ontothe prairie air nipple.




12-7.10.1 (DV, SF) Rotate the propeller hubblade port targeted for installation into the 12o’clock position. Align the benchmark madeduring the removal process to ease installa-tion.

12-7.10.2 (TOP) Send the dowel pins (FN85), prairie air nipple (FN 82), two taperedblade guide pins (FN 81) and blade guide pinturning bar (FN 118) down to the divers.

12-7.10.3 (TOP) Using the righting fixture(FN 140), stand the replacement blade to beinstalled upright on the blade palm resting ontwo 4” x 4” wood timbers.

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12-7.10.5 (TOP) Use a grease pencil to markthe position of the head clamp 67 inches fromthe blade tip to the nearest corner of the headclamp. Also mark the position of the leadingand trailing edge clamps 21 inches from thebottom edge of the blade to the nearest cornerof each edge clamps.

12-7.10.6 (TOP) Install the three-point liftingassembly (FN 141 or 142 and 152) onto theblade as shown in Appendix E. Ensure thehead clamp is 67 inches from the tip of thetrailing edge and the leading and trailing edgeclamps are 21” up from the blade palm. Ifedge guards are removed from new blades,cut a piece of metal edge guard and rubbermaterial to insert between the clamps and the

blade for protection. Cover any exposedsharp edges of the edge guard piece with tapeto protect the diver.

NOTE

The blade must be lifted fromthe aft hole of the head clamp.This is the pressure face for leftand right hand blades.

12-7.10.7 (TOP) Take a strain on the headclamp with the crane to seat the leading andtrailing edge clamps on the blade.


12-7.10.9 (DV) Install the prairie air nippleinto the prairie air nipple orifice in the hub until


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it is fully seated. A mallet may be required tofully seat the double O-ring seal. When fullyseated the nipple should extend 6 1/2 inchesout from the center post.

12-7.10.10 (DV) Press the dowel pins intothe dowel pin holes by hand until fully seated.Measure to ensure the dowel pins stick out ofthe hub no more than 3 3/8 inches.

NOTE

Dowel pins are extremely tightfitting and often present diffi-culty seating in water becauseof the small hydraulic relief.Care and continuous steadypressure should be applied. Ahoning tool may be needed toclean out the dowel pin hole inthe hub.


12-7.10.11 (TOP) Send the blade port coverplate O-ring (FN 120) and the heavy grease(FN 121) to the divers.

12-7.10.12 (DV) Partially fill the O-ringgroove in the cover plate with heavy grease.The O-ring groove is indicated in Figure 12-32.

NOTE

Do not over f i l l t he O- r inggroove. Excess grease canlead to seating problems.


12-7.10.14 (TOP) Connect the pier crane tothe masterlink without the 1 1/4-inch shackleon the head clamp.

12-7.10.15 (TOP) Using the crane, lower therigged blade to 10-15 feet below the water sur-face adjacent to the aft lever hoist.

12-7.10.16 (DV) Attach the aft lever hoist tothe 1 ¼-inch shackle in the other masterlink onthe head clamp.


12-7.10.18 (DV, TOP) Slack the crane andunhook it from the masterlink on the headclamp.

12-7.10.19 (DV) Attach the overhead leverhoist hook to the masterlink on the head clampand take the slack out of the overhead leverhoist.

12-7.10.20 (DV) With diver #1 operating theoverhead lever hoist and diver #2 operatingthe aft lever hoist, yard and stay the blade for-ward until the blade is hanging from the over-head hoist aft of the propeller hub. Slack theaft lever hoist.

12-7.10.21 (DV) Attach the holdback hoistrigging to the blade.

12-7.10.22 (DV) Inspect the dowel pins, prai-rie air nipple, and the cover plate O-ring forproper installation. Using diver’s pneumo,dewater the dowel pin holes in the blade palmto make penetration of the dowel pins easier.

12-7.10.23 (DV) Position the blade fully overthe propeller blade port by taking a strain onthe holdback hoist.

12-7.10.24 (DV) Install the blade guide pins(FN 81) into bolt holes #2 and #6 of the bladeport after the blade is positioned over the hub.Ensure that the guide pins in bolt holes #2 and#6 align with the corresponding bolt holes inthe blade palm.

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NOTE

Guide pins need to be installedthrough the holes after theblade is positioned over thehub. The rigging will not allowthe blade to clear the hub if theguide pins are in place.



Divers must verify that the sus-pended blade is clear of thedowel pins for a small rotationin order to ensure that no dam-age is done to the propellerblade palm, blade port or con-necting hardware when the hubis rotated.

12-7.10.26 (DV, TOP) Check to ensure thatthe blade is fully over the propeller blade portand that the guide pins in bolt holes #2 and #6align with the corresponding bolt holes in theblade palm. Check that the blade port isaligned with the suspended blade by ensuringthe top of both dowel pins are the same dis-tance from the blade palm. If alignment isincorrect, first try repositioning or adjusting theholdback lever hoist to correct the alignment.If that does not work, coordinate with Ship’sForce and bump the shaft the required dis-

tance and direction until the proper position isachieved.

12-7.10.27 (DV) If poor visibility makes thevisual dowel pin check in the previous stepimpossible, ensure blade palm and hub arealigned by measuring the spacing between theblade palm and the hub. Using a 1/16-inchincrement steel ruler (FN 113), record the dis-tance between the hub face and the shoulderrecess of the blade bolt hole as shown in Fig-ure 12-30. These measurements need to betaken through bolt positions #1, #4, #5, and#8.

12-7.10.28 (DV, TOP) If the blade palm andhub are not aligned, then from the measure-ments determine the direction for rotating theshaft. If the starboard side measurements aregreater than the port side, the starboard sideof the hub is down and the shaft should berotated to port. If the port side measurementsare greater, the shaft should be rotated to star-board. Record and keep all measurements forthe duration of the installation process in orderto monitor progress.

12-7.10.29 (DV) Diver #1 moves into positionfor operating the overhead lever hoist, anddiver #2 moves into position at the blade portto report the progress of the installation.


12-7.10.30 (DV) Slowly lower the blade withthe overhead lever hoist onto the dowel pins.

12-7.10.31 (DV) Make a final visually checkto ensure the O-ring is still in place as theblade is lowered into position.

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12-7.10.32 (DV) Diver #1 lowers the blade byletting out on the overhead lever hoist untildiver #2 reports no downward movement.

Be careful not to lower a bladeso rapidly onto the hub as towash out the cover plate O-ring. Never allow the overheadlever hoist to go completelyslack during the lowering pro-cess because this could lead toa sudden drop of the blade,causing O-ring washout.


12-7.10.33 (DV) When downward progresshas ceased, slack the overhead lever hoist toa light strain and have both divers commenceshaking the blade VIGOROUSLY at the tip.The holdback hoist tension will need to beadjusted during the blade lowering to avoiddowel pin binding.

12-7.10.34 (DV) If downward movement isencountered, diver #2 continues shaking theblade, while diver #1 slowly lets down on theoverhead lever hoist.

12-7.10.35 (DV) To establish if progress isbeing made, divers must measure the spacingbetween the blade palm and the hub. Usingthe 1/16-inch increment steel ruler, record thedistance between the hub face and the shoul-der recess of the blade bolt hole as shown inFigure 12-30. These measurements need tobe taken through bolt positions #1, #4, #5, and#8.

12-7.10.36 (DV, TOP) If no downward move-ment can be achieved by shaking the blade, or

by adjusting/re-positioning the holdback hoist,then from the measurements determine thebest direction for rotating the shaft. If the star-board side measurements are greater than theport side, the starboard side of the hub may bedown and the shaft should be rotated to port.If the port side measurements are greater, theshaft should be rotated to starboard. If thereis no clear difference between port and star-board measurements, arbitrarily select thedirection of rotation. Record and keep allmeasurements for the duration of the installa-tion process in order to monitor progress.

12-7.10.37 (DV) Lift the blade until bothdowel pins are disengaged from the blade forrotation of the shaft.


12-7.10.38 (SF) Rotate the shaft in the direc-tion determined in step 12-7.10.36 until themeasurements are equal on the port and star-board sides.


12-7.10.40 Examine Blade Bolt Holes.

(DV) Examine the blade bolt holes to see if thecover plate O-ring is visible, that is, washedout of the O-ring groove.

12-7.10.41 (DV) If the O-ring is visible, theblade must be removed clear of the hub andreinstalled after the O-ring is replaced.

12-7.10.42 (DV) Remove the blade guidepins from bolt holes #2 and #6.

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12-7.10.43 Check Blade Seating. (DV)Using a 0.002-inch feeler gauge (FN 122),check the gap between the blade palm andthe hub at bolt holes #2, #3, #6, and #7. If thefeeler gauge penetrates at all, it should have asnug (touching both sides) fit. Check the gapin two places along the line of the bolt circle.The purpose of this check is to determine thefinal seating of the blade and that the O-ringinstalled between the blade palm and theblade port cover has not been washed out ofits groove during the final seating of the blade.

12-7.11 BLADE BOLT INSTALLATION.

NOTE

All blade bolts by now shouldhave been c leaned andinspected and returned by theNDT lab. If all bolts are deter-mined good, reuse all bolts forinstallation of the replacementblade. Replace any bolt that isproven defective.

Ultrasonic measurement proce-dures and equipment arerequired to achieve the accu-racy required in blade bolt mea-surement. Any ultrasonic bladebolt measurement proceduresand equipment utilized must beapproved by NAVSEA or itsauthorized representative inaccordance with NAVSEATechnical Publication 271.

NOTE

The ultrasonic inspector mustcontrol the flow of work. Thehydraulic pump operator mustwait for direction from the UTinspector. The diver mustleave the transducer in placeuntil the UT inspector calls tohave it moved.

12-7.11.1 Review Bolt Elongation Measure-ment Procedure and Equipment. It is veryimportant that both the divers and the NDTinspection personnel study and understand allaspects of bolt elongation measurement asdetailed in Appendix B. Review of the tutorialdiscussion provided in Appendix B will providea good general understanding of the responsi-bilities for the divers and NDT inspectors. SeeAppendix J for NAVSEA NDT equipmentdetails.

12-7.11.2 (TOP/UT) Using NAVSEA-approved ultrasonic measurement proceduresand equipment (FN 167 & 112), record base-line (un-stretched) dimension measurementsfor all eight bolts. Use Hex Socket Bolt Base-line and Post-Elongation Measurement Work-sheet, Figure B-4. A sample procedure usingNAVSEA-developed equipment is provided inAppendix B.

12-7.11.3 (TOP) Fill and cap four lubricantdispensers (FN 163.1), one for each of the firstfour bolt holes, with 200 cc of Hydrolube (FN163) each and pass to the divers.

12-7.11.4 (TOP) Install an O-ring (FN 107) inthe O-ring groove on blade bolts #1, #4, #5,and #8. The special teflon O-ring must becarefully stretched slightly to fit tightly in the O-ring groove on the outer diameter of the bolthead. Coat the blade bolt threads and theshoulder on these bolts with nickel based anti-seize compound (FN 123).

Before installation, the boltthreads and the shoulder mustbe coated with nickel basedantiseize compound.

12-7.11.5 (DV) Inject one full dispenser ofHydrolube into each of bolt holes #1, #4, #5,and #8. Insert the dispenser nozzle into thebolt hole so the Hydrolube (heavier thanwater) will fill from the bottom of the bolt hole.This will displace the water with minimum mix-

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ing action. Pass dispensers to surface afteruse.

12-7.11.6 (DV) Install blade bolts #1, #4, #5,and #8 in their respective bolt holes. Inserthex stock (FN 78.9) in bolt head of #1 and witha ratchet or speed wrench (FN 111), snug uptight to seal the bolt hole. Repeat this processfor bolts #4, #5, and #8.

NOTE

For the Sweeney RSL-8 Link,set the pump to 1100 psi toobtain 800 ft-lbs.

12-7.11.7 (DV/TOP) Use the Sweeney Tool(FN 78) to torque bolts #1, #4, #5, and #8 to800 ft-lbs. Note that since not all bolts are inplace the tool will have to react against theblade. The diver should position the tooland/or adjust the reaction arm on the tool for a"best fit".

12-7.11.8 (DV) Insert a .002 feeler gauge(FN 122) into bolt holes #2, #3, #6, and #7between the blade palm and port cover plate.This step will verify that blade is, or is notseated on the port cover. If the feeler gaugecan be inserted at all, it should be a snug(touching both sides) fit. Any looser fit indi-cates that the blade is not seated and themost probable cause is that the port cover O-ring is not properly inserted. This problem willhave to be corrected before continuing withthe installation.

12-7.11.9 (TOP) Fill and cap lubricant dis-pensers (FN 163.1), one for each of theremaining four blade bolt holes, with 200 cc ofHydrolube (FN 163) each and pass to thedivers.

12-7.11.10 (DV) Inject one full dispenser ofHydrolube into each of bolt holes #2, #3, #6,and #7. Insert the dispenser nozzle into thebolt hole so the Hydrolube (heavier thanwater) will fill from the bottom of the bolt hole.This will displace the water with minimum mix-

ing action. Pass dispensers to surface afteruse.

12-7.11.11 (TOP) Install an O-ring (FN 107)in the O-ring groove on blade bolts #2, #3, #6,and #7. The special teflon O-ring must becarefully stretched slightly to fit tightly in the O-ring groove on the outer diameter of the bolthead. Coat the blade bolt threads and theshoulder on these bolts with nickel based anti-seize compound (FN 123).

Before installation, the boltthreads and the shoulder mustbe coated with nickel basedantiseize compound.

12-7.11.12 (DV) Install these bolts in theirrespective bolt holes. Insert a hex stock (FN78.9) in bolt head of #2 and with a ratchet orspeed wrench (FN 111), snug up tight to sealthe bolt hole. Repeat this process for bladebolts #6, #3, and #7.

12-7.11.13 (UT) Assemble the bolt elonga-tion measurement assembly as shown in Fig-ure 12-33. Insert the transducer into thecenter hole of the hex stock. Secure the hous-ing hand wheel on the top of the transducer.Pass the assembly to the divers.

The counter bore of the hexstock must face down duringassembly to avoid damagingthe transducer assembly.

12-7.11.14 (DV/UT) As shown in Figure 12-33 and 12-34, place the bolt elongation mea-surement assembly into bolt head #2. Screwthe transducer into the bolt head finger tightuntil it comes to an abrupt halt. Using the cor-rect shim and reaction arm location (see

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Figure 12-33. Bolt Elongation Measurement Assembly.

Figure 12-34. Blade Bolt and Transducer Interface.

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Tables 12-9 and 12-10), position the hydraulictorque link over the hex stock in the tighteningmode (blue taped hose down). The weight ofthe hydraulic torque link should rest on theshim. The diver should only have to lightlyhold the link reaction arm against the appropri-ate reaction arm location. Anything else indi-cates misalignment of the installation.Lubricate the underwater matable connectoron the transducer lead with antiseize com-pound and plug it into the transducer.

If the hydraulic tool is not prop-erly aligned, the UT inspectorwill see an initial rise in boltstretch on pressurization, fol-lowed by a drop in stretch dur-ing the return cycle. If thisoccurs, the alignment of thetool must be fixed to preventdamage to the ultrasonic sen-sor.

NOTE

Clear communication must bemaintained between the UTinspector, hydraulic pump oper-ator and diver. The diver mustensure that the hydraulic link isp rope r l y sea ted and on l ymoves to rotate the bolt . TheUT inspector must te l l thehydraulic pump operator tostart and stop the hydraulicpump until he observes the cor-rect bolt elongation.

NOTE

Patience is required in the tight-ening mode. Several cycles ofthe hydrau l i c l ink may berequ i red be fo re s t re tch isobserved. Remember thehydraulic pump operator mustrelease the switch and allow

time (approximately 12 sec-onds) for the tool to reset tocomplete a cycle.

12-7.11.15 (DV/UT/TOP) In accordance withAppendix B, the ultrasonic inspector calls forhydraulic pressure while ultrasonically mea-suring bolt elongation for bolt #2. Repeat thisprocess for bolts #6, #3, #7, #1, #5, #4 and #8in that order. The required stretch for bolts is.005 to .007 inch. Record data on the HexSocket Bolt Elongation Measurement DuringInstallation Worksheet, Figure B-5 of Appen-dix B. This measurement of bolt elongation(residual stretch) is taken while the bolt isbeing installed, this allows the UT operator tostop the torque when the residual stretch isjust right for each bolt. Record the final torqueapplied in figure B-4, Appendix B.

The pace of the operation mustbe slow enough to ensure theUT operator has sufficient timeto monitor bolt elongation,record ALL data and make cal-culations. The diver must leavethe transducer in place untildata is logged and the UT oper-ator calls for the transducer tobe moved.


12-7.12.1 (UT/DV) Using NAVSEA-approvedultrasonic measurement procedures andequipment, record the final measurements forall eight bolts on the same data sheet used torecord “baseline” measurements, Figure B-4Appendix B. The final measurement com-pared with the baseline measurements willprovide a second measure of the final residualstretch. This measurement should be

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extremely close to the measurement takenwhile the bolt was being torqued.

12-7.12.2 (UT) Compare the baseline andfinal bolt lengths to determine residual stretchof bolts 1 through 8 using the worksheet, Fig-ure B-4 of Appendix B. Residual stretch mustbe between 0.005 and 0.007 inches for allbolts.

12-7.12.3 (UT/TOP/DV) Since all the boltswere installed with a correct measured resid-ual stretch, all the “final-baseline” measuresshould simply confirm the correct residualstretch. The purpose of the second measure-ment is to confirm that installation of anyadjoining or opposite bolt did not affect thefinal stretch of another bolt.

12-7.12.4 (UT/TOP/DV) If any final residualstretch is outside the specified range contactNAVSEA 00C5 for further guidance.

12-7.13 REMOVE THREE-POINT LIFTINGASSEMBLY

12-7.13.1 (DV) Detach the holdback hoist.Loosen all of the turnbuckles on the liftingassembly.


12-7.13.3 (DV) Remove the lifting assemblyfrom the blade with the overhead manual leverhoist. One diver must operate the lever hoistwhile the other diver guides the lifting assem-bly from the blade so as not to damage theblade.


12-7.14 BOLT NYLON PLUG AND SCREWINSTALLATION.

12-7.14.1 (DV) As shown in Figure 12-35,install new rubber washer in base of a polyeth-ylene plug. Install polyethylene plug with

retaining screw into the 2-1/4-inch hex hole intop of blade bolt. Tighten screw only untilpolyethylene plug is flush with top of blade boltwell.




12-7.16.1 (UT/TOP/DV) Remove all toolsand equipment. De-rig the transfer line forretrieval topside.

12-7.16.2 Take Inventory. (TOP) Collect,inventory, clean, and pack equipment andtools. Mark or "red tag" damaged or malfunc-tioning tools or equipment.


12-7.16.4 Prepare Final Report. (TOP) Pre-pare a final report documenting the accom-plished repair. Documentation which NAVSEA00C54 needs to help improve the procedureis: blade bolt liquid penetrate inspectionresults, blade bolt ultrasonic measurementinspection results, a description of any lost,damaged or malfunctioning tools or equipmentin the NAVSEA CPP Kit, a list of all consum-ables taken from the kit for the job, detailsregarding any problems encountered, and rec-ommendations for new or special toolsneeded. The final report should be faxed or e-mailed to NAVSEA 00C54.

Change 1 12-109

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Figure 12-35. Blade Bolt Plug and Screw Installation.

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A-1

A-1 TUTORIAL DISCUSSION

A-1.1 INTRODUCTION.

This procedure for measuring the elongationof Controllable Reversible Pitch PropellerBlade Bolts is a variation of standard ultra-sonic thickness gauging. We assume thatinspectors using this procedure are alreadyproficient in ultrasonic thickness gauging, andunderstand the underlying principles. This dis-cussion is a "self-help" document whichexplains some of the reasoning behind themeasurement procedure. It should takeapproximately four hours of reading and prac-tice to master the measurement procedure.

A-1.1.1 In this tutorial discussion we attemptto highlight the similarities and differencesbetween conventional thickness gauging andbolt elongation measurement. Discussion ofthe differences will serve to deepen theinspector's understanding of the measurementprocess, and help avoid problems areas thatcan arise from improper application of the pro-cedure.

A-1.2 PRINCIPLES OF OPERATION.

The Bolt Elongation Measurement (BEM) pro-cess measures the waterpath that existsbetween the face of the BEM transducer andthe bottom of a blade bolt cavity. By compar-ing this dimension before and after installation,elongation can be detected and measured.Velocity variations due to temperature andsalinity changes are compensated by use of areference bolt at each stage of the measure-ment process. When properly applied, themeasurement process is accurate to betterthan half a thousandth of an inch.

A-1.2.1 When the Bolt Elongation Measure-ment tool is inserted into a blade bolt, thesmall transducer at the tip of the tool is

brought within about a tenth of an inch of thebottom of the bolt's cavity. Each ultrasonicpulse therefore travels through approximately0.1 inch of water before it reflects back to thetransducer, and shows up as the first interfaceecho (IFE). The returning pulse is alsoreflected off the face of the transducer, and ittravels back to the bottom of the cavity,reflects again off the metal surface, andreturns to the transducer as the second IFE.This process continues, with each signalattenuated a bit more than the previous one.In conventional thickness gauging by the con-tact method, the ultrasonic instrument shows aseries of backwall echoes from the part beingmeasured, while in this test we display aseries of interface echoes. This test is verymuch like a contact thickness test, where thepart being measured is the "piece of water"that lies between the transducer and the bot-tom of the bolt. Cleanliness of the transducerface and the bottom of the blade bolt cavityare very important since debris which wewould normally ignore cannot be ignored for ameasurement with only half a thousandth ofan inch tolerance.

A-1.2.2 Calibration of the ultrasonic instru-ment results in an A-scan screen on whicheach major division of the screen represents0.005 inch of waterpath length, and eachminor tick mark along the baseline represents0.001 inch. Calibration is accomplished byusing a calibration standard that allows thetransducer height above the bottom of the boltcavity to be changed by exactly 0.015 inch,0.020 inch, or 0.025 inch. Changing height ofthe transducer adds to the waterpath length,and causes the ultrasonic echo to move 3, 4,or 5 major screen divisions, respectively.

A-1.2.3 When properly calibrated, full screenrepresents just 0.050 inch, or one twentieth ofan inch. This is very different from conven-tional thickness gauging setups, where full

APPENDIX A

MORGRIP BOLT ELONGATION MEASUREMENT PROCEDURE

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A-2

screen may more typically represent one orseveral inches of metal thickness. The veryexpanded screen looks different in that theshape of each pulse is quite visible, and is notvery much of a sharp spike. To increase thesharpness of the signal, without sacrificingsensitivity, we have chosen to monitor theposition of the second IFE rather than the firstIFE. The reasoning for this choice follows.When the waterpath being measuredincreases by 0.005 inch (one CRT screen divi-sion), the round trip pathlength for the firstinterface echo increases by 0.010 inch. Forthe second IFE two round trips are involved;the total pathlength increases by 0.020 inch,and the echo moves twice as far on the CRT.Using this echo allows us to get one fullscreen division for each 0.005 inch waterpathchange with a less expanded signal, whichmakes reading the signal's position easier.

A-1.2.4 To see the increased sensitivity of thesecond IFE in practice, follow the CalibrationProcedure through Section A-5.2.1.3, wherethe CRT is roughly set up with the main bangat the left edge of the screen and several inter-face echoes are visible. Carefully raise thetransducer carrier a few thousandths of aninch and note that the second IFE movestwice as fast as the first IFE. The third inter-face echo, which travels three round trips,moves three times as fast; it would be an evenmore sensitive echo to use, but its signalstrength is unreliable.

A-1.2.5 Each bolt is slightly different, so base-line measurements must be made beforeinstallation. The baseline measurementsestablish how much longer or shorter eachbolt is than the reference bolt. Measurementsmade after installation will also show each boltto be different from the reference bolt, and dif-ferent from the way it was before installation.Thus, a bolt which was manufactured 0.0015inch shorter than the reference bolt, andended up 0.0050 inch longer than the refer-ence bolt, would have stretched 0.0065 inchduring installation.

A-1.3 COMPENSATION FOR TEMPERA-TURE AND SALINITY CHANGES.

The process of calibrating the BEM systemcreates a correspondence between bolt lengthand screen position of the interface echo. Thiscorrespondence is based on the velocity ofsound in the water that fills the blade bolt cav-ity, but velocity can change if temperature orsalinity changes. To see this in practice, cali-brate the system in accordance with sectionA-5.2, and note that the second interface echois at 5.00 screen divisions. Now empty the boltand refill it with hot water. The echo will nolonger be at 5.00 screen divisions, but as thehot water cools down, the echo will drift backtoward 5.00 screen divisions.

A-1.3.1 We assume that the reference boltand all of the blade bolts can be kept at aboutthe same temperature as each other duringbaseline measurements. Temperature under-water may be quite a bit different than thebolt's temperature during baseline measure-ments, but for measurements on the installedbolts, we assume that the reference bolt andthe installed bolts are all at about the sametemperature. It is absolutely mandatory thatthe reference bolt be right at the underwaterwork site in order to achieve the requiredaccuracy.

A-1.3.2 Accuracy better than ±0.0005 inchcan be achieved when these conditions aremet, despite wide differences between base-line and underwater conditions. The key is tohave the reference bolt in exactly the samecondition as the other bolts whenever a mea-surement is taken.

A-1.4 POTENTIAL PROBLEM AREAS.

Because the required measurement accuracyis far smaller than an ultrasonic wavelength, itis crucial that exactly the same part of theultrasonic waveform be used for all measure-ments. The ultrasonic instrument's receiversection performs a number of functions: ampli-fication of the rf signal, rectification (to pro-duce the "video" signal), and filtering. Reject is

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also available to clip low amplitude portions ofthe signal. The point at which the signal"breaks the baseline" depends on which halfcycle of the waveform is used, and thatdepends on gain, reject, and filter choices. Asa general rule, all signals should be brought toabout full screen height using gain, and once afilter has been selected it should not bechanged. To see the impact of filter choice, setup on the reference bolt and compare theecho position when the positive half of thewaveform is used to the position when thenegative half is used - the difference should beabout 0.3 screen divisions (1.5 tick marks).Also try adjusting the reject level to completelysuppress one or more of the initial peaks;each time one peak is suppressed the point ofmeasurement moves over to the next peak -the difference should be about 0.6 screen divi-sions (3 tick marks) when either the positive ornegative half wave rectification is used, andhalf that much when full wave rectification isused. None of these errors are acceptable;exactly the same part of the waveform mustbe measured every time.

A-1.4.1 The bottom of each bolt's cavity ismachined with a cutting tool that may leave aslightly uneven surface or a tiny bump right inthe center of the flat-bottomed cavity. Certainbolts may not reflect the ultrasonic pulse aswell as others, leading to a weaker signal fromthose bolts. Gain adjustments are required toensure that the same part of the waveform isbeing measured for each bolt. All signalsshould be brought to about full screen heightbefore looking for the position of the echo. Tosee the effect of gain, set up properly on thereference bolt, with the IFE at 5.000 screendivisions, and the peak echo at full screen.Then reduce the peak echo height to about20% of full screen height and note the positionof the echo. If the part of the signal being usedfor measurement was the peak before thelargest peak in the waveform, it may be lostcompletely, shifting the reading about 3 tickmarks to the right. Even if this does not occur,there will be a small shift to the right since theecho does not rise straight up from the base-line. Note that bolts that are troublesome in

this respect during baseline measurementswill also be troublesome underwater. It is wiseto note those bolts which required extra gainduring baseline measurements, and prepareto add gain for the same bolts when they aremeasured underwater.

A-1.4.2 The BEM tool rests with three legs onthe bolt's upper reference surface, and thereshould, theoretically, be only one stable posi-tion. However, because some clearance isrequired between the tool and the bolt cavity itis possible to lean on the tool and rock itslightly, lifting one leg off the bolt's referencesurface. During baseline measurements this isnot likely, since the inspector will not generallybe holding the tool while reading the ultasonicinstrument. Underwater, however, the divermay keep hold of the knurled part of the toolwhile the inspector reads the ultrasonic instru-ment, and this may tilt the tool. The divershould be instructed to let go of the BEM toolafter inserting it.

A-1.4.3 The bottom of each bolt's cavity maynot be perfectly flat, and certain rotationalpositions may be a bit different from others. Tosee this potential problem, set up on any bolt,and note what happens when you rotate thetransducer carrier through 360q. This is han-dled in the procedure by requiring alignment ofa scribe line on the transducer carrier with thethread-lock on the bolt. It is important toprompt the driver to properly align the tool oneach bolt, including the reference bolt.

A-1.4.4 Debris in the bottom of the bolt cavitycan cause serious errors in the waterpathmeasurement, since even the smallest bit offlotsam is likely to be more than 0.001 inchthick. Presuming that the bolt cavity is properlycleaned before baseline measurements areattempted, it is still possible that a bit of trashis introduced in the water used to fill the cavity.The signal will normally be degraded in ampli-tude, and may change if the BEM tool ismoved. This kind of problem is easily elimi-nated during baseline measurements, but atthe underwater site it may be necessary tohave the diver "pump" the BEM tool in and out

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of the bolt cavity or purge the cavity with ablast of air from the pneumofathometer.

A-1.4.5 It is absolutely essential that theinspector have full confidence in baseline val-ues; there will be no opportunity to later recon-firm them. Repeated measurements arerecommended, and if any variations over0.001 inch (i.e. ±0.0005 inch) are noted for agiven bolt, the cause of this variation shouldbe determined and eliminated. Should it beimpossible to get consistent readings, seektechnical support form NAVSEA or the CoastalSystems Station, Panama City, FL.

A-1.4.6 Elongation measurements are madeby comparing each bolt to the reference bolt,before and after installation. If the referencebolt is lost between baseline measurementsand the underwater measurements, the com-parison cannot be made. Warn the divers thatthe reference bolt is priceless. If at all possi-ble, take the precautionary step of measuringa spare bolt during baseline measurements.Should the reference bolt disappear, it may bepossible to obtain a waiver form NAVSEA touse the spare bolt as a basis for comparisons.Should this be necessary, seek technical sup-port from NAVSEA or the Coastal SystemsStation.

A-1.5 OUT-OF-RANGE READINGS.

Specifications require 0.006 inch to 0.0084inch residual elongation, measured with a sys-tem accurate to within about 0.0005 inch. It isgenerally felt that the specification on residualelongation accounts for any measurementuncertainty. There is no reason to restrict therange of acceptable readings more tightlywithin this band of 0.006 inch to 0.0084 inch.

A-1.5.1 When out-of-range readings areencountered the offending bolts must beretightened in an attempt to produce accept-able readings. All of the factors that contributeto bolt elongation are not well understood, butit is clear that the following variables areimportant:

• Seating the blade with temporary bolts

• Hydraulic pressure used to stretch thebolt

• Diver-applied torque to seat the bolt

• Thread lubrication

• Seating surface flatness

A-1.5.2 It is not the inspector's job to produceacceptable readings. If, at any time, the accu-racy of the inspection process comes intoquestion, the inspector should verify that allprocedural steps have been performed prop-erly (bolt cleanliness, rotational alignment, nottilting the BEM tool, etc.) and that signal qual-ity is essentially unchanged from baselinemeasurements to in-water measurements.Proof of proper operation can always be sup-plied by taking the calibration standard under-water and demonstrating that the systemproperly measures waterpaths different fromthe reference bolt waterpath. Once thesesteps have been taken to ensure and demon-strate the measurement process, the actualvalue for bolt elongation is up to the divers andthe project engineer.

A-1.6 DIVER TRAINING

The diver is responsible for:

• Ensuring that all bolts are clean (free ofoil, air bubbles and debris).

• Placing the BEM tool in the bolt speci-fied by the inspector.

• Ensuring proper rotational alignment.

• Ensuring that the BEM tool is restingfirmly on its three legs.

A-1.6.1 It is useful to familiarize the diverswith the tool and the ultrasonic instrument,and to show them how sensitive it is. To thisend the system should be set up on site, andcalibrated in accordance with section A-5.2.

A-1.6.2 Show the divers the bolt elongationmeasurement tool, or transducer carrier, and

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explain that the transducer sends out ultra-sonic pulses much like the fathometer ordepth finder on a boat.

A-1.6.3 Show the divers the reference boltand point out that the very bottom of the cavityis milled flat, and serves as a reflector for theultrasound. Point out that the flat surface ontop of the bolt is a reference surface and thatthe bolt's elongation is measured from thatsurface to the bottom of the cavity.

A-1.6.4 Place the transducer in the referencebolt, and as you do, explain that the trans-ducer carrier puts the tip of the transducerabout a tenth of an inch away from the flat bot-tom of the cavity.

A-1.6.5 Pull the transducer out of the cavityand show the divers that the tip of the trans-ducer is fragile ... warn against bumping it onthe bolt. Put the transducer back into the bolt,and show that as you insert the tool into thebolt, it centers the transducer, protecting itfrom damage.

A-1.6.6 Show the scribe mark on the trans-ducer carrier and the thread insert hole in theupper threads on the bolt. Demonstrate properrotational alignment.

A-1.6.7 Rock the transducer and show thedivers how the signal moves on the CRT.Explain that the amount of motion they see isfar more than the allowable ±0.0005 inch.

A-1.6.8 Rotate the transducer 360° in the ref-erence bolt to show that the signal may movedue to improper rotational alignment. Empha-size that the required tolerance, ±0.0005 inch,is very tight, and that there is no room for inat-tention to details.

A-1.6.9 Lift the transducer carrier a bit andslide a piece of paper under one leg to showhow much the signal is affected. Reiterate thatthe system is very sensitive.

A-1.6.10 Explain that when the diver gets inthe water to take elongation readings, he will

have the reference bolt with him. Each readingon an installed bolt will be preceded by a read-ing on the reference bolt. After the diver estab-lishes the correct rotational alignment, you willadjust the signal to 5.00 screen divisions. Youwill then ask the diver to put the tool in a spe-cific bolt identified by its position on the hub.Again the diver will align rotation, and let youknow when it's ready. You will take a readingand then ask for the transducer to be put backin the reference bolt and aligned. When alleight bolts are finished you may call forrepeated measurements on one or more ofthem. When all measurements are complete,the diver will return to the surface with theBEM tool and the reference bolt.

A-2 SCOPE

This appendix contains a sample procedurefor performing bolt elongation measurementsin accordance with NAVSEA Technical Publi-cation 271, Requirements for NondestructiveTesting Methods using equipment developedfor this task by the Naval Sea Systems Com-mand (NAVSEA 00C5). The hardwarerequired by this procedure is completely spec-ified by the referenced engineering drawings.The following list of components and subas-semblies is depicted in NAVSEA Drawing6698352 as an aid to field operations:

Ultrasonic Test Instrument

Transducer Assembly (pre-assembled)Bolt Elongation Cable AssemblyTransducerTransducer CarrierTransducer Carrier CapCalibration StandardReference Bolt

This procedure establishes requirements forultrasonic measurement of Morgrip bolts usedto attach Controllable Pitch Propeller (CPP)blades to the hub. These bolts are stretchedprior to installation, and must retain a specificelongation when properly installed. This pro-cedure establishes the change in length bymeasuring both the bolt being installed and a

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reference bolt which undergoes the same tem-perature changes as the bolt being installed,but is not stretched. This procedure alsoestablishes personnel qualification require-ments, inspection material requirements, testprocedures, acceptance standards, andreporting requirements. Hardware is definedby NAVSEA Drawing 6698352. NAVSEA 00Cmaintains a limited number of systems for useby field activities.

Note

It is essential that all UltrasonicTechnicians, especially thosewi th no bo l t measuremen texperience carefully review allof Appendix A and the applica-ble bolt installation portion ofthe blade replacement proce-dure prior to commencing mea-surements. A good place tostart your review is Section A-1of this appendix (Tutorial Dis-cussion).

A-3 REFERENCED DOCUMENTS

a. NAVSEA T9074-AS-GIB-010/271, 30April 1997, NAVSEA Technical Publi-cation, Requirements for Nondestruc-tive Testing Methods

b. ASTM E 1316-95a, Standard Terminol-ogy for Nondestructive Examination

c. NAVSEA Drawing #6698352, BoltElongation Measurement System,Assembly

A-4 GENERAL

A-4.1 DEFINITIONS.

Standard terminology (ASTM E 1316-95a)related to ultrasonic examination is usedthroughout this document.

A-4.2 PRECAUTIONS.

Safety precautions contained in the Installa-tion and Removal procedure must beobserved at all times. Additionally, groundfault interruption must be used with all under-water equipment requiring AC power.

A-4.3 EQUIPMENT AND MATERIALS.

A-4.3.1 Ultrasoni c Instrument. A standardA-scan type instrument conforming to therequirements of NAVSEA Technical Publica-tion 271 shall be used. Within six months priorto use for bolt elongation measurements, theinstrument must be qualified in accordancewith NAVSEA Technical Publication 271 para-graph 6.5.1.1. Records of this instrument qual-ification must be retained with records of thebolt installation.

A-4.3.2 Transducer Carrier (Bol t Elon gationMeasurement Too l). Figure A-1 shows thebolt elongation measurement tool which hasbeen designed for this application. NAVSEAapproval of transducers and associated fix-tures is required.

A-4.3.3 Reference Bol t. A standard bladebolt, modified in accordance with NAVSEAdrawing 6698352, (Appendix J) is supplied byNAVSEA as part of the Bolt Elongation Mea-surement system. This bolt must be reservedfor use only as a calibration standard.

A-4.3.4 Calibr ation Standard. A referencestandard enabling the inspector to position thetransducer carrier in direct contact with the ref-erence bolt (slot #1), 0.015 inch above the bolt(slot #2). 0.020 inch above the bolt (slot #3), or0.025 inch above the bolt (slot #4). See FigureA-2.

A-4.3.5 Coupl ant. Water is used as the cou-plant material. The reference bolt and the boltbeing measured must have the same kind ofwater in them for valid readings to be taken.

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Figure A-1. Bolt Elongation Measurement Tool.

Figure A-2. Bolt Elongation Measurement Calibration Standard.

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Figure A-3. Bolt Elongation Measurement Inspection Report and Worksheet

NDT File #: J.O.N.: Work Center: Date:

Ship: System: CRP Controller Component: Blade

Job Description: Inspect Morgrip Bolt Elongation

Type of Inspection: Ultrasonic Inspection DWG NO. NAVSEA 6698352

Inspection STD: S0600-AA-PRO-120 Acceptance STD: S0600-AA-PRO-120

Port:

Project (Ship):

Blade Serial Number:

Ultrasonic Instrument:

Calibration Standard:

Reference Bolt:

Transducer:

Bolt Serial #and

Position in Hub

Installed ScreenPosition

Initial ScreenPosition

Difference(Screen div.)

Length Change(Difference x0.005"/div.)

NDT Inspector: Date: Level III Examiner: Date:

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Temperature and salinity are salient character-istics of the water.

A-4.3.6 Transducer Cables. Transducercables shall be of coaxial construction with a50 ohm characteristic impedance, approxi-mately 100 feet in length.

A-4.3.7 Ancil lary Equip ment. Measuringand marking tools required for the inspectionshall be chosen by the inspector. Ground faultinterruption is required for all equipment oper-ating off AC power and used by the diver (forexample, lights or the ultrasonic instrument).

A-4.4 POLICY.

A-4.4.1 The Project Engineer shall specify UTrequirements by requesting inspection inaccordance with this procedure.

A-4.4.2 Personnel performing bolt elongationmeasurements according to this procedureshall be certified UT inspectors (Level II).Additionally, prior to performing bolt elongationmeasurements according to this procedure,inspectors shall demonstrate capabilities asspecified in paragraph A-8.

A-5 PROCEDURE

A-5.1 GENERAL.

This procedure is based upon measurementof the small gap that is formed between theface of an ultrasonic transducer and the bot-tom of a Morgrip bolt's internal cavity, assketched in Figure A-1. This gap is filled withwater, and the measurement is essentially acontact test, where the material to be gaugedis the water. An ultrasonic pulse is launchedinto the water gap, and after reflecting fromthe bottom of the bolt cavity, the pulse isreceived by the same transducer. The timerequired from transmission of the pulse until itsreception, multiplied by the speed of sound inwater, gives the round trip distance traveled.By calibrating the screen of a conventionalultrasonic instrument the gap, or waterpath,can be determined.

A-5.1.1 Calibr ation Standard. As with allultrasonic thickness measurements, theinstrument's CRT must be calibrated by posi-tioning echoes from samples of known dimen-sions. A special calibration fixture (Figure A-2)provides the necessary water path dimensions(0.015 inch, 0.020 inch, and 0.025 inch).

A-5.1.2 Temperature and Salini ty. This pro-cedure recognizes that the apparent value ofan ultrasonically tested dimension dependsupon temperature and composition, whichinfluence sound velocity. To minimize theeffect of temperature and salinity differencesin measurements taken before and afterinstallation, an extra (reference) bolt is mea-sured every time the actual bolts are mea-sured. This reference bolt stays at the sametemperature and is filled with water of thesame salinity as the bolts being installed, butis not stretched or stressed in any way.

A-5.1.3 Rotation al A lign ment. Each Mor-grip bolt is fabricated with a flat-bottomed holethat is used for dimensional gauging. How-ever, the flatness of the bottom of the holemay not have been held to 0.0005 inch. This isaddressed procedurally by requiring that thetransducer carrier be rotationally aligned witheach bolt, for all calibration and in-situ mea-surements. The transducer carrier has ascribe line on it. Each Morgrip bolt has a 1/4-inch diameter flat-bottomed hole (for a threadlocking insert) in the upper threaded section.These are to be aligned.

A-5.2 CALIBRATI ON.

Note

This procedure was developedfor the Stavely 132D UltrasonicInstrument. For other instru-ments, minor differences in thedescription of the controls mayexist.

A-5.2.1 Coarse Alig nment. This procedurewill ensure that the ultrasonic instrument andtransducer fixture settings are close enough to

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the final settings that FINE RANGE and FINEDELAY controls can be used to complete thecalibration.

A-5.2.1.1 Set the ultrasonic instrument'sCOARSE RANGE to 1 inch and the COARSEDELAY to the minimum value. Set thereceiver's frequency selection to match thetransducer, or to wideband (WB).

A-5.2.1.2 Using a conventional 5 or 10 Mhzcontact transducer and steel calibration block,set the CRT display to show 0.25 inch per divi-sion (2.5 inch full screen). A 1/2-inch calibra-tion step should produce echoes at 2, 4, 6, 8,and 10 screen divisions.

A-5.2.1.3 Change to the Bolt Elongation Mea-surement (BEM) transducer. Fill the bottom ofthe reference bolt with water, and place thecalibration standard on the reference bolt.Place the BEM transducer fixture in the refer-ence bolt, ensuring proper rotational align-ment. Rotate the calibration standard to placethe fixture's legs in the through slots (#1 slots).

A-5.2.1.4 Turn the COARSE RANGE controlto the minimum value (typically 0.25 inch).

A-5.2.1.5 Using the FINE RANGE ("materialcalibration" or "material velocity") and FINEDELAY controls, set the first Interface Echo(IFE) at 0 and the second IFE at 10 divisionson the CRT.

A-5.2.2 Fine Calibration . This procedureresults in a calibrated system where a changeof 0.005 inch in the waterpath between thetransducer and the bottom of the Morgripbolt's internal cavity which results in the sec-ond interface echo shifting one major division(five minor tick marks) on the CRT. Each minortick will therefore represent 0.001 inch.

A-5.2.2.1 Move the second IFE to 5.00 divi-sions on the CRT using only the FINE DELAYcontrol.

A-5.2.2.2 Using gain, filter, and reject con-trols, obtain an interface echo which presents

a clearly defined breakpoint. A broadband(wideband or WB) setting on the receiver andhalfwave rectification produces the most reli-able results.

A-5.2.2.3 Lift the transducer carrier slightly,and rotate the calibration standard so that thetransducer carrier's legs rest in the shallowestslot (#4 slot). This raises the transducer 0.025inch above the reference surface of the refer-ence bolt.

A-5.2.2.4 Using only the FINE RANGE (MATLCAL) control, position the second IFE to 10.00divisions on the CRT.

A-5.2.2.5 Return the calibration standard tothe position where the transducer carrier'slegs are in the through slots of the calibrationstandard.

A-5.2.2.6 Using only the FINE DELAY control,position the second IFE at 5.00 divisions onthe CRT.

A-5.2.2.7 Repeat steps A-5.2.2.3 through A-5.2.2.6 until no further adjustments are neces-sary. Note that slightly overshooting thedesired positions will speed up this process.

A-5.2.2.8 The linearity of the calibration canbe verified by rotating the calibration standardto place the transducer carrier's legs in each ofthe four sets of slots on the calibration stan-dard. These slots place the transducer directlyon the bolt, and 0.015 inch, 0.020 inch, or0.025 inch above the reference bolt's refer-ence surface, and should produce echoeslocated at 5.0, 8.0, 9.0 and 10.0 screen divi-sions, plus or minus 0.05 screen divisions (±1/4 tick-marks), respectively. If this is not thecase, and calibration has been performedproperly, then the instrument's linearity isunacceptable and it must not be used for boltelongation measurements.

A-5.2.2.9 Once the system has been cali-brated, the FINE RANGE control must not bemoved, and all other instrument settingsexcept reject, gain, and fine delay must not be

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changed. Record the FINE RANGE controlposition, and if possible, lock the FINERANGE control in this position to prevent acci-dental disturbance. From this point on, theFINE DELAY control, alone, will be used toadjust the position of the reference bolt signalto 5.00 screen divisions before each measure-ment is made.

A-5.3 BASELINE DIMENSION MEASURE-MENTS.

A-5.3.1 Carefully clean the internal cavities ofall Morgrip bolts to be used, including the ref-erence bolt. This measurement procedure isextremely sensitive, and can give erroneousresults if oil or debris is left in the bottom of thebolts' cavities. Cotton swabs (FN 27) in theCPP Kit are useful for cleaning the bolt inter-nal cavities.

A-5.3.2 Pour a small amount of water into thebottom of each bolt. Water from the harbor isdesirable since salinity affects the speed ofsound, and thus the accuracy of results. Allbolts, including the reference bolt, should beat roughly the same temperature, to minimizethe effect of temperature-induced changes inthe speed of sound. Care should be taken tokeep bolts out of direct sunlight, where radiantheating may raise temperatures significantly.

A-5.3.3 Place the transducer in the referencebolt, ensuring proper rotational alignment.Check the position of the IFE. It should bepositioned at 5 divisions on the CRT, and canbe repositioned using the FINE DELAY controlonly. Gain should be set to produce an inter-face echo height between 80% and 100% offull screen height.

A-5.3.4 Move the transducer to the bolt to bemeasured, ensuring proper rotational align-ment. Adjust gain as required to produce aninterface echo height between 80% and 100%of full screen height. If significant adjustmentis required, the bottom of the cavity may notbe properly cleaned, there may be loosedebris in the cavity, or the reflecting surface atthe bottom of the bolt cavity may not be as flat

or smooth as the reference bolt. After correct-ing conditions of cleanliness and debris, makenote of bolts which remain "troublesome"since they will also be "troublesome" wheninstalled. Note the position of the IFE andrecord this screen position as the baselinemeasurement for this bolt.

A-5.3.5 Repeat steps A-5.3.3 and A-5.3.4 foreach bolt. Note that each time the transduceris placed in the reference bolt the IFE shouldappear at 5 screen divisions. If adjustmentsare required it is likely that the transducer hasnot been properly aligned relative to the bolt(see section A-5.1.3), or that the referencebolt has not been properly cleaned (see sec-tion A-5.3.1).

A-5.4 UNDERWATER MEASUREMENTSAFTER INSTALLATI ON.

A-5.4.1 Measurements will be taken with theblade in the 12 o'clock position to ensure thatthe bolt cavities are completely filled withwater. In this position, the transducer carriercan be allowed to rest in the bolt without beingheld by the diver. This helps ensure that it isnot tilted.

A-5.4.2 The diver ensures that each installedbolt's cavity is clean, and free from oil. Imme-diately prior to placing the transducer carrier ineach bolt, the diver purges the bolt cavity withair from the pneoumofathometer.

A-5.4.3 The diver places the transducer car-rier in the reference bolt, and ensures properrotational alignment. The topside inspectorplaces the second IFE at 5 divisions on theCRT using the FINE DELAY control only.

A-5.4.4 The diver moves the transducer car-rier to the installed bolt specified by the top-side inspector, and rotates it to the properposition. The topside inspector records thescreen position of the second IFE.

A-5.4.5 Steps A-5.4.2 and A-5.4.3 arerepeated for each of the installed bolts.

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A-5.5 ELONGATION.

A-5.5.1 Bolt elongation is determined by cal-culating the difference between the secondIFE's screen position prior to, and after instal-lation of each bolt. Use Figure A-3 (Bolt Elon-gation Measurement Inspection Report andWorksheet) to record data. Each major screendivision has been calibrated to represent0.005 inch. See the example in paragraph A-5.2.

A-6. EVALUATION

Bolts which show an elongation of 0.006 inchto 0.0084 inch are acceptable. Bolts whoseelongation falls outside this range must bereinstalled in accordance with NAVSEA proce-dures.

A-6.1 EXAMPLE.

Baselin e Measurements

Place transducer carrier in reference bolt,rotate to the proper position, and set IFE at 5divisions on the CRT

..... inspector confirms IFE at 5 divisions.

Place transducer carrier in bolt number XXX,rotate to the proper position, and read theposition of the IFE

..... inspector records screen position of IFE(say, 5.8 screen divisions).

Repeat previous two steps for each bolt.

For each bolt, record the position on the bladepalm where the bolt will be installed. Wheninstructing the diver for underwater measure-ments, refer to the bolt's position rather thanthe bolt's serial number. In this example, boltXXX will be placed in position X.

Underwater Measurements

Diver installs all bolts, rotate the blade to the12 o'clock position, and carry the referencebolt to the underwater work site.

Inspector directs the diver:

Place the transducer in the reference bolt andalign it.

Diver places the transducer carrier in the refer-ence bolt and rotates it until the scribe mark isaligned with the thread-lock hole.

...... inspector adjusts fine delay to positionIFE at 5 screen divisions.

Inspector directs the diver to place the trans-ducer in the bolt at position X on the bladepalm:

Place the transducer in bolt X and align it.

Diver places the transducer carrier in the boltat X position and rotates it to achieve align-ment.

...... inspector reads the CRT and records theIFE position (say, 6.5 screen divisions).

Inspector calculates elongation:

Difference:6.5 div. - 5.8 div.) = 0.7 screen divi-sions

Length Change:0.7 div. x 0.005"/div = 0.0035"elongation

A-7 RECORDING AND REPORTING

All records associated with an underwaterCRP blade change will be maintained byNAVSEA 00C54.

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A-8 PERSONNEL QUALIFICATION ANDCERTIFICATION REQUIREMENTS

Personnel performing bolt elongation mea-surements in accordance with this procedureshall be certified in accordance with NAVSEATechnical Publication 271 (latest revision) asan Ultrasonic Inspector (Level II, or Level IILimited) or Examiner (Level III).

Competence and familiarity with the procedureand system hardware may be acquired byrepeated measurements on a set ofunstressed bolts. The normal variation ofreadings about the mean for any one bolt isapproximately ±0.0005 inch. Readings morethan 0.001 inch from the mean indicateimproper application of the procedure, or hard-ware deficiencies.

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APPENDIX B

HEX SOCKET BOLT ELONGATION MEASUREMENT PROCEDURE

B-1. TUTORIAL DISCUSSION

B-1.1 SCOPE

B-1.1.1 This tutorial covers ControllablePitch Propeller (CPP) blade bolt measurementfor hex socket bolts used on the DDG 51"Fleet" blade and CG 47 (CG 66 and higher)class ships.

B-1.2 INTRODUCTION

B-1.2.1 This procedure for measuring theelongation of Controllable Pitch PropellerBlade Bolts is a variation of standard ultra-sonic thickness gauging. We assume thatinspectors using this procedure are alreadyproficient in ultrasonic thickness gauging, andunderstand the underlying principles. Thisdiscussion is a "self-help" document whichexplains some of the reasoning behind themeasurement procedure. It should takeapproximately four hours of reading and prac-tice to master the measurement procedure.

B-1.2.2 In this tutorial discussion we attemptto highlight the similarities and differencesbetween conventional thickness gauging andbolt elongation measurement. Discussion ofthe differences will serve to deepen theinspector's understanding of the measurementprocess, and help avoid problem areas thatcan arise from improper application of the pro-cedure.

B-1.3 PRINCIPLE OF OPERATION

B-1.3.1 The Bolt Elongation Measurement(BEM) process measures the waterpath thatexists between the face of the BEM trans-ducer and the bottom of a blade bolt cavity.By comparing this dimension before and afterinstallation, elongation can be detected andmeasured. Elongation can be measureddirectly, during the installation process. Veloc-

ity variations due to temperature and salinitychanges, as well as offsets due to transducerand cable length variations, are compensatedby use of a reference bolt at each stage of themeasurement process. When properlyapplied, the measurement process is accurateto better than half a thousandth of an inch.

B-1.3.2 For in place measurements, the boltelongation measurement assembly is puttogether as shown in Figure B-1. Insert thetransducer into the center hole of the hexstock. Secure the transducer cap on the topof the transducer. During in water operations,the assembly is passed to the divers for useas outlined in section 7.

B-1.3.3 As shown in figure B-1, place the boltelongation measurement assembly into thebolt head. Screw the transducer into the bolthead until it comes to an abrupt halt. Section 7provides detailed guidance on operations anduse of in water torquing equipment.

B-1.3.4 As shown in Figure B-2, when theBolt Elongation Measurement tool is insertedinto a blade bolt, the small transducer at thetip of the tool is brought within about a quarterof an inch of the bottom of the bolt's cavity.Each ultrasonic pulse therefore travelsthrough approximately 0.25" of water before itreflects back to the transducer, and shows upas the first interface echo (IFE). The returningpulse is also reflected off the face of the trans-ducer, and it travels back to the bottom of thecavity, reflects again off the metal surface, andreturns to the transducer as the second IFE.This process continues, with each signalattenuated a bit more than the previous one.In conventional thickness gauging by the con-tact method, the ultrasonic instrument shows aseries of backwall echoes from the part beingmeasured, while in this test we display aseries of interface echoes. This test is verymuch like a contact thickness test, where the

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Figure B-1 Bolt Elongation Measurement Assembly

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part being measured is the "piece of water"that lies between the transducer and the bot-tom of the bolt. Cleanliness of the transducerface and the bottom of the blade bolt cavityare very important since debris which wewould normally ignore cannot be ignored for ameasurement with only half a thousandth ofan inch tolerance.

B-1.3.5 Calibration of the ultrasonic instru-ment results in an A-scan screen on whicheach major division of the screen represents0.0025" of waterpath length, and each minortick mark along the baseline represents0.0005". As shown in Figure B-3, the calibra-tion standard for this procedure duplicates thebolt's geometry, with a moveable piston whoseface simulates the flat bottom of the bolt hole.The piston is driven by a precision lead screw,allowing the distance between the transducerand the piston face to be accurately controlledin increments of exactly 0.005".

B-1.3.6 When properly calibrated, full screenrepresents just 0.025". This is very differentfrom conventional thickness gauging set-ups,

where full screen may more typically representone or several inches of metal thickness. Thevery expanded screen looks different in thatthe shape of each pulse is quite visible, and isnot very much of a sharp spike. To increasethe sharpness of the signal, without sacrificingsensitivity, we have chosen to monitor theposition of the second IFE rather than the firstIFE. The reasoning for this choice follows.The width of the instrument's display is cali-brated for distance, but screen width is actu-ally a specific amount of time. For a given fullscale setting, the first and second IFE wave-forms will be similar in sharpness because thatdepends only on the amount of time corre-sponding to one wavelength at the trans-ducer's operating frequency, and how much ofthe screen width that occupies. However, itwill be easier to read changes in the positionof the second IFE because the correspondingwaterpath change is twice as great as for thefirst IFE: for every 0.001" of bolt elongation,the roundtrip waterpath change for the firstIFE is 0.002", and for the second IFE (whichinvolves two round trips), it is 0.004" Since ittakes twice as long for the sound to make the

Figure B-2 Hex Socket Bolt Elongation Measurement Tool

TRANSDUCER

TRANSDUCER

ULTRASONIC INSTRUMENT

WATER GAP

FLAT BOTTOMHOLE

REFERENCESURFACE

COAXIAL CABLE

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Figure B-3. Hex Socket Bolt Calibration Standard

PRECISIONLEAD SCREW

LEAD SCREWCAP

CALIBRATIONBASE

BENCHMARKTRANSDUCER

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two round trips, the signal moves twice as far(as the first IFE echo) across the display.

B-1.3.7 To see the increased sensitivity ofthe second IFE in practice, follow the Calibra-tion Procedure to the point where the CRT isroughly set up with the main bang at the leftedge of the screen and several interface ech-oes are visible. Carefully unscrew the trans-ducer carrier part of one revolution and notethat the second IFE moves twice as fast as thefirst IFE. The third interface echo, which trav-els three round trips, moves three times asfast; it would be an even more sensitive echoto use, but its signal strength is unreliable.

B-1.3.8 Each bolt is slightly different, sobaseline measurements must be made beforeinstallation. The baseline measurementsestablish how much longer or shorter eachbolt is than the reference bolt. Measurementsmade after installation will also show each boltto be different from the reference bolt, and dif-ferent from the way it was before installation.Thus, a bolt which was manufactured 0.0015"shorter than the reference bolt, and ended up0.0050" longer than the reference bolt, wouldhave stretched 0.0065" during installation.

B-1.4 COMPENSATION FOR TEMPERA-TURE AND SALINITY CHANGES

B-1.4.1 The process of calibrating the BEMsystem creates a correspondence betweenbolt length and screen position of the interfaceecho. This correspondence is based on thevelocity of sound in the water that fills theblade bolt cavity, but velocity can change iftemperature or salinity changes. To see thisin practice, calibrate the system in accordancewith the written procedure, then adjust the cal-ibration standard to place the second interfaceecho at 5.00 screen divisions. Now empty thebolt and refill it with hot water. The echo willno longer be at 5.00 screen divisions, but asthe hot water cools down, the echo will driftback toward 5.00 screen divisions.

B-1.4.2 We assume that the reference boltand all of the blade bolts can be kept at about

the same temperature as each other duringbaseline measurements. Temperature under-water may be quite a bit different than thebolts' temperature during baseline measure-ments, but for measurements on the installedbolts, we assume that the reference bolt andthe installed bolts are all at about the sametemperature. It is absolutely mandatory thatthe reference bolt be right at the underwaterwork site in order to achieve the requiredaccuracy.

B-1.4.3 Accuracy better than ±0.0005" canbe achieved when these conditions are met,despite wide differences between baselineand underwater conditions. The key is to havethe reference bolt in exactly the same condi-tion as the other bolts whenever a measure-ment is taken.

B-1.5 OFFSETS DUE TO DIMENSIONALVARIATIONS

B-1.5.1 The total time between the mainbang and the arrival of the second interfaceecho determines the position of that echo onthe instruments display. That total travel timeincludes electrical propagation through thecoaxial cable, and acoustic propagationthrough water between the transducer and thereflecting surface at the bottom of the bolt orcalibration standard's cavity. It is clear that thelength of the transducer housing determineshow close the transducer is to the reflectingsurface, and will affect the absolute position ofthe interface echoes. It is less obvious thatcable length also affects the echoes' positions.In conventional inspections the effect of cablelength is entirely negligible, but with longcables it is quite easily measured. The speedof electrical propagation in the coaxial cable isabout 200,000,000 meters per second (ascompared to the speed of sound in water,which is about 1500 meters per second). In acable 125' long (38 meters) the pulse takes0.38 microseconds to go down and back;that's about the same amount of time it takessound to travel .023" in water. That soundpathlength corresponds to physical water path-length one quarter as long (about 0.006")

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when the position of the second IFE is moni-tored, since the sound must travel from thetransducer to the reflecting surface, and back,twice. Variations in cable length will visiblyaffect the absolute position of the second IFE,but this variable is removed by the measure-ment procedure.

B-1.5.2 For baseline measurements, thesame transducer and the same cable are usedto measure all of the blade bolts and the refer-ence bolt, and the length of each blade bolt isrecorded after subtracting out the length of thereference bolt. Absolute echo position isimmaterial, since any constant offset (due tothe transducer or cable's length) is subtractedout. Similarly, when measurements are takenafter all the bolts are installed, the procedurecalls for the reference bolt to be measured in-situ, with the same transducer and cable as isused for the blade bolt measurements. Again,subtracting the length of the reference boltfrom the length of each blade bolt eliminatesconstant offsets. In the case of in-processmeasurements, the transducer and cableremain connected to the transducer during theentire tightening process, and changes in thesecond IFE's position are monitored, not theabsolute position of this echo.

B-1.6 POTENTIAL PROBLEM AREAS

B-1.6.1 Because the required measurementaccuracy is far smaller than an ultrasonicwavelength, it is crucial that exactly the samepart of the ultrasonic waveform be used for allmeasurements. The ultrasonic instrument'sreceiver section performs a number of func-tions: amplification of the rf signal, rectification(to produce the "video" signal), and filtering.Reject is also available to clip low amplitudeportions of the signal. The point at which thesignal "breaks the baseline" depends on whichhalf cycle of the waveform is used, and thatdepends on gain, reject, and filter choices. Asa general rule, all signals should be brought toabout full screen height using gain, and once afilter has been selected it should not bechanged. To see the impact of filter choice,set up on the reference bolt and compare the

echo position when the positive half of thewaveform is used to the position when thenegative half is used - the difference should beabout 0.6 screen divisions (3 tick marks). Alsotry adjusting the reject level to completely sup-press one or more of the initial peaks; eachtime one peak is suppressed the point of mea-surement moves over to the next peak - thedifference should be about 1.2 screen divi-sions (6 tick marks) when either the positive ornegative half wave rectification is used, andhalf that much when full wave rectification isused. None of these errors are acceptable;exactly the same part of the waveform mustbe measured every time.

B-1.6.2 The bottom of each bolt's cavity ismachined with a cutting tool that may leave aslightly uneven surface or a tiny bump right inthe center of the flat bottomed cavity. Certainbolts may not reflect the ultrasonic pulse aswell as others, leading to a weaker signal fromthose bolts. Gain adjustments are required toensure that the same part of the waveform isbeing measured for each bolt. All signalsshould be brought to about full screen heightbefore looking for the position of the echo. Tosee the effect of gain, set up properly on thereference bolt, with the IFE at 5.000 screendivisions, and the peak echo at full screen.Then reduce the peak echo height to about20% of full screen height and note the positionof the echo. If the part of the signal beingused for measurement was the peak beforethe largest peak in the waveform, it may belost completely, shifting the reading about 6tick marks to the right. Even if this does notoccur, there will be a small shift to the rightsince the echo does not rise straight up fromthe baseline. Note that bolts which are trou-blesome in this respect during baseline mea-surements will also be troublesomeunderwater. It is wise to note those boltswhich required extra gain during baselinemeasurements, and prepare to add gain forthe same bolts when they are measuredunderwater.

B-1.6.3 The distance of the transducerabove the bottom of the bolt's flat-bottomed

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hole depends on how far it is screwed into thebolt. The three feet on which the transducerassembly rests should come into hard contactwith the bolt's reference surface quite abruptly,and there should be no more tightening possi-ble after this contact has been made. If thetransducer assembly gets tight, but can still beturned, it is likely that the bolt's threads are notproperly cleaned; this situation must be cor-rected before baseline measurements aretaken.

B-1.6.4 Debris in the bottom of the bolt cavitycan cause serious errors in the waterpathmeasurement, since even the smallest bit offlotsam is likely to be more than 0.001" thick.Presuming that the bolt cavity is properlycleaned before baseline measurements areattempted, it is still possible that a bit of trashis introduced in the water used to fill the cavity.The signal will normally be degraded in ampli-tude, and may change if the transducerassembly is moved. This kind of problem iseasily eliminated during baseline measure-ments, but at the underwater site it may benecessary to have the diver "pump" the trans-ducer assembly in and out of the bolt cavity orpurge the cavity with a blast of air from thepneumofathometer.

B-1.6.5 It is absolutely essential that theinspector have full confidence in baseline val-ues; there will be no opportunity to later recon-firm them. Repeated measurements arerecommended, and if any variations over0.001" (i.e. ±0.0005") are noted for a givenbolt, the cause of this variation should bedetermined and eliminated. Should it beimpossible to get consistent readings, seektechnical support from NAVSEA 00C5.

B-1.6.6 For elongation measurements thatare made by comparing each bolt to the refer-ence bolt (as opposed to in-process measure-ments), the same reference bolt must be usedbefore and after installation. If the referencebolt is lost between baseline measurementsand the underwater measurements, the com-parison cannot be made. Warn the divers thatthe reference bolt is priceless. If at all possi-

ble, take the precautionary step of measuringa spare bolt during baseline measurements.Should the reference bolt disappear, it may bepossible to obtain a waiver from NAVSEA touse the spare bolt as a basis for comparisons.Should this be necessary, seek technical sup-port from NAVSEA or the Coastal SystemsStation.

B-1.7 OUT-OF-RANGE READINGS

B-1.7.1 Specifications require 0.005" to0.007" residual elongation, measured with asystem accurate to within about 0.0005". It isgenerally felt that the specification on residualelongation accounts for measurement uncer-tainty; there is no reason to further restrict therange of acceptable readings with logic like inorder to be real sure the stretch is between0.005" and 0.007" we better get a readingbetween 0.0055" and 0.0065". In-processmeasurements typically aim for 0.0065"stretch, but tightening may result in anyacceptable stretch.

B-1.7.2 When stretch is also calculated frombaseline and final underwater measurements,the calculated values must also be in theacceptable range. If the blade is not properlyseated on the hub before bolts are installed, itis possible that in-process stretch will bealtered by the installation of subsequent bolts.This can be caused by an improperly seatedo-ring, or other material between the hub andthe blade. If a significant difference betweenin-process and before/after measurements isfound, seek technical guidance fromNAVSEA.

B-1.7.3 When out-of-range readings areencountered the offending bolts must beretightened in an attempt to produce accept-able readings. All of the factors that contributeto bolt elongation are not well understood, butit is clear that the following variables areimportant:

· seating the blade with temporary bolts

· hydraulic pressure used to stretch the

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bolt

· diver-applied torque to seat the bolt

· thread lubrication

· seating surface flatness

B-1.7.4 It is not the inspector's job to produceacceptable readings. If, at any time, the accu-racy of the inspection process comes intoquestion, the inspector should verify that allprocedural steps have been performed prop-erly (bolt cleanliness, rotational alignment, nottilting the transducer assembly, etc.) and thatsignal quality is essentially unchanged frombaseline measurements to in-water measure-ments. Proof of proper operation can alwaysbe supplied by taking the reference bolt andan unstressed blade bolt underwater, and rep-licating the baseline measurement for thatblade bolt. Once these steps have been takento ensure and demonstrate the measurementprocess, the actual value for bolt elongation isup to the divers and the project engineer.

B-1.8 DIVER TRAINING

The diver is responsible for:

· Ensuring that all bolts are clean (free ofoil, air bubbles and debris).

· Placing the transducer assembly in thebolt specified by the inspector.

· Tightening the transducer assembly inthe bolt.

· Placing the hydraulic drive over thetransducer assembly.

· Connecting the coaxial cable to thetransducer.

B-1.8.1 It is useful to familiarize the diverswith the tool and the ultrasonic instrument,and to show them how sensitive it is. To thisend the system should be set up on site, andcalibrated using the calibration standard.

B-1.8.2 Show the divers the bolt elongationmeasurement tool, or transducer carrier, andexplain that the transducer sends out ultra-

sonic pulses much like the fathometer ordepth finder on a boat.

B-1.8.3 Show the divers the reference boltand point out that the very bottom of the cavityis milled flat, and serves as a reflector for theultrasound. Point out that the flat surface atthe bottom of the hexagonal recess is a refer-ence surface and that the bolt's elongation ismeasured from that surface to the bottom ofthe cavity. Show the calibration standard andthe precision lead screw. Explain that itadvances a piston inside the standard, allow-ing the measured distance to be accuratelyvaried in increments of 0.005" per half rotationof the base.

B-1.8.4 Place the transducer in the calibra-tion standard, and as you do, explain that thetransducer carrier puts the tip of the trans-ducer about a quarter of an inch away fromthe flat bottom of the cavity.

B-1.8.5 Pull the transducer out of the cavityand show the divers that the tip of the trans-ducer is fragile and warn against bumping it onthe bolt. Put the transducer back into thestandard, and show that as you screw it in, itcomes abruptly to a stop, placing the ultra-sonic signal repeatable at a particular screenlocation.

B-1.8.6 Loosen the transducer slightly, toshow the motion of the ultrasonic signal. Rockthe transducer and show the divers how thesignal moves on the CRT. Explain that theamount of motion they see is far more than theallowable ±0.0005".

B-1.8.7 Explain that when the diver gets inthe water to take in-process measurements,the transducer will be in the bolt the wholetime. Inserting the transducer into a bladebolt, show that after the transducer is installed,you will need a moment to position the echo at2 screen divisions.

B-1.8.8 For final length measurements, afterall bolts have been installed, explain that read-ings must be taken on the reference bolt, as

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well as each blade bolt. Show the process ofpositioning the signal, and recording zero off-set on the reference bolt, then a blade bolt, sothe diver will know about how long that pro-cess takes.

B-1.8.9 Explain that if discrepancies existbetween in-process measurements and finalmeasurements, it may indicate a problem withseating the blade. In this case one or morebolts may have to be remeasured, and possi-bly retightened.

B-2. MEASUREMENT PROCEDURE

B-2.1 SCOPE

B-2.1.1 This section describes ultrasonicmeasurement of bolt elongation during water-borne installation of controllable pitch propel-ler (CPP) blades, as required by reference (a)for CG 47 (CG 66 and higher) class ships(0.005-0.007 inch elongation) and reference(b) for DDG 51 class ships with "Fleet" typeblades (0.005-0.007 inch elongation). Boltelongation must be measured within 0.0005inches.

B-2.1.2 Program management for water-borne blade changes is under NAVSEA 00C5cognizance (703-607-2761).

B-2.2 BACKGROUND

B-2.2.1 Waterborne replacement of CPPblades involves the removal and reinstallationof eight bolts on each of five blades. Thesebolts are approximately 9 inches long with 2¾-8-UNR-2A threads, and a 2¼ inch hex socket.A hydraulic drive is used to install the boltswith approximately 2700 ft-lbs. of torque. Asthe bolts are tightened, they stretch severalthousandths of an inch, developing in excessof 100,000 lb. clamping force. Ultrasonicinstrumentation is used to measure boltlengths before and after installation, and tomonitor bolt elongation during installation.

B-2.2.2 The typical order of events relevantto this procedure is as follows:

1. Blades are removed in the 12 o'clockposit ion. Bol ts are sent topside,cleaned, and penetrant tested. Theinternal cavity is then cleaned thor-oughly, and baseline length measure-ments relative to a reference bolt arerecorded. These bol ts are thenreturned to the test site, lubricated andset aside for reinstallation.

2. The new blade is set in place in the 12o'clock position, Bolt holes # 1, # 4, # 5,and # 8 are dewatered using hydrol-ube prior to installing and torquing thebolts to 800 ft-lbs.

3. The four interior holes (# 2, # 3, # 6, and# 7) are dewatered with hydrolube.

4. Bolts # 2, # 3, # 6, and # 7 are installedand tightened with a ratchet or speedwrench, tight enough to seal the hole,but not stretch the bolt measurably

5. The interior bolts are torqued to achievethe required stretch.

6. The initial bolts (# 1, # 4, # 5, and # 8)are torqued to achieve the requiredstretch.

7. The blade lifting assembly is removedand final measurements taken on allbolts.

B-2.3 REFERENCES

a) S9245-AV-MMA-010/07309, Techni-cal Manual, Installation, Operation,Maintenance and Repair Instructionswith Parts List, Controllable ReversiblePitch Propeller for CG 66 and FollowShips, 30 APR 1991

b) S9245-AM-MMA-010/07309, SystemManual for Controllable Pitch PropellerSystem, DDG 51 Class, Model 156,Type S1/5, 15 AUG 1990

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c) T9074-AS-GIB-010/271, NAVSEATechnical Publication, Requirementsfor Nondestructive Method, 30 April1997

B-2.4 PERSONNEL QUALIFICATION ANDCERTIFICATION REQUIREMENTS

B-2.4.1 Personnel performing bolt elongationmeasurements in accordance with this proce-dure shall be certified in accordance withNAVSEA Technical Publication 271 (latestrevision) as an Ultrasonic Inspector (Level II,or Level II Limited) or Examiner (Level III).

B-2.4.2 Competence and familiarity with theprocedure and system hardware may beacquired by repeated measurements on a setof unstressed bolts. The normal variations ofreadings about the mean for any one bolt isapproximately + 0.0005 inch. Readings morethan 0.001 inch from the mean indicatedimproper application of the procedure, or hard-ware deficiencies.

B-2.5 DESCRIPTION OF MEASUREMENTSYSTEM COMPONENTS

B-2.5.1 Ultrasonic instrument - a conven-tional flaw detector capable of displaying therequired signals, with full screen representing0.025" of seawater. Owing to the relativelylong cable lengths used, the instrument shouldhave a variable damping control that matchesinstrument and cable/transducer impedance's.

B-2.5.2 Transducer- a specially fabricated 10MHz transducer that fits into the blade boltsand positions the active element approxi-mately 0.25" from the flat bottom of the mea-surement cavity. The transducer is fitted withan underwater matable connector. The cur-rent configuration is controlled by NAVSEAdrawings.

B-2.5.3 Cable- coaxial cable with a charac-teristic impedance of 50 ohms, and a ruggedexterior jacket typically neoprene or polyure-thane. Cables are typically over 100 feet longto permit operation of the ultrasonic instrument

in a location convenient for communicationswith the torque tool operator.

B-2.5.4 Connectors - cables are terminatedat the topside end with a BNC connector, andat the underwater end with an underwatermatable connector that matches the trans-ducer's connector.

NOTE:

The underwater matable elec-trical connector must be lubri-cated. The choice of lubricantis important because the lubri-cant must not interfere with sig-nal transmission. Most O-ringgrease is insulating, which isdetrimental to signal transmis-sion; however copper andnickel based antiseize com-pounds (used on the bladebolts) have been used suc-cessfully. In addition to lubri-cating the rubber and metalconnector parts, these com-pounds are conductive. Thesmall metal particles (nickel, forinstance) may be slightly abra-sive; this may keep the electri-cal contacts clean.

B-2.5.5 Calibration Standard - the calibra-tion standard for this procedure duplicates thegeometry of the bolts' flat-bottomed hole; how-ever, the flat bottom is formed by the face of apiston. This piston's position is accuratelycontrolled by a 100 threads-per-inch precisionlead screw. Scribe marks on the side of thestandard and the rotatable base of the stan-dard, which turns the lead screw, allow theface of the piston to be advanced exactly0.005" per one-half rotation of the lead screw.A protective cover is also provided to keep theprecision lead screw dry when the calibrationstandard is lowered into the local water for on-site calibration checks.

B-2.5.6 Reference Bolts - standard bladebolts removed from inventory, measured and

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used as a reference during the blade boltinstallation process.

B-2.5.7 Cleaning tools - for cleaning the flatbottom of the bolt cavity: 3/8" diameter cylin-drical felt bobs, mounted on a 3/8" round stockshaft and rotated with an electric drill motor.For cleaning the internal walls, a 1/2" diametercylindrical wire brush with soft wire bristles.For cleaning external surfaces, soft wirebrushes (typical wire diameter 0.007"). Sol-vent cleaner/degreaser, or carburetor/chokecleaner.

B-2.6 PROCEDURE

B-2.6.1 A summary of the major proceduralelements is provided in this section. Details ofinstrument set-up for calibration and measure-ment are included in an instrument-specificaddendum, Section B-3.

B-2.6.2 Exterior cleaning. Bolts removedfrom an in-service propeller require cleaning toremove all biofouling and corrosion prior topenetrant testing. This cleaning may be per-formed with a soft wire brush (typically having0.007" diameter wires) to avoid damage to thebolt surface, threads or copper cladding. Anordinary green ScotchBrite scouring pad mayalso be used for exterior cleaning; however,no form of sandpaper or abrasive cloth is per-mitted.

B-2.6.3 Penetrant testing. Bolts areinspected using a visible dye, solvent remov-able system. The inspection area is from thetop of the threads up to the head of the bolt,including the underside of the head. Fluores-cent systems (solvent removable, post emulsi-fiable, or water washable) can be used . Nolinear indications in excess of 1/16" areallowed.

B-2.6.4 INTERIOR CLEANING

B-2.6.4.1 Bolt elongation measurements aremade by reflecting ultrasound off the bottom ofa flat-bottomed hole approximately 5½ inchesdeep on the axis of the bolt. This surface must

be completely free of contaminants, as therequired measurement accuracy is ±0.0005inches. The side wall of the hole is initiallycleaned with a rotary wire brush, using solventcleaner as required to remove oil. The flatbottom surface is then cleaned to bright metal.This is accomplished with a felt polishing padmounted at the end of a long shaft, and pow-ered by a rotary drill. A solvent cleaner isused as an initial cleaning medium, followedby a water jet rinse, and dry swabbing. Theultimate quality of the ultrasonic signal, andtherefore the quality of the inspection process,is dependent on this step.

B-2.6.4.2 To verify that cleaning has beenadequate, pour a small amount of water in thebottom of each bolt, insert a transducer, andensure that a good clean ultrasonic signal isproduced. Note that if the signal deteriorateswhen the transducer is installed underwater, itis possible that foreign material or gas bubbleshave gotten into the cavity. These can gener-ally be removed by having the diver vigorouslypump the cavity with a length of 3/8 inch diam-eter round stock.

B-2.6.5 CALIBRATION

B-2.6.5.1 The objective of this calibration isto adjust the material velocity control (finerange) to produce a signal motion of 2 screendivisions (20% of screen width) for each0.005" of relative motion between the trans-ducer and the bottom of the flat bottomedhole. The calibration standard for this proce-dure duplicates the bolt's geometry, with amoveable piston whose face simulates the flatbottom of the bolt hole. The piston is driven bya precision lead screw, allowing the distancebetween the transducer and the piston face tobe accurately controlled in increments of0.005". The second interface echo from thisreflecting surface is used (in preference to thefirst interface echo) to double the sensitivity ofthe measurement.

B-2.6.5.2 With the screen set up with twoscreen divisions representing 0.005", eachmajor division will represent 0.0025", and each

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minor tick (of which there are five per majordivision) will represent 0.0005". On analoginstrument CRT's the signal position may beread to half this amount quite easily, while ondigital instruments the reading accuracy maybe limited to 0.0005" by pixel size. Parallaxerrors that can exist when the marked graticleis not in the same plane as the signal can beeliminated by lining the ultrasonic signal upwith the reflection of the inspector's pupil in thescreen. To maintain highest accuracy, thewater in the calibration standard should be asclose as possible to the same salinity and tem-perature as the operating environment.

B-2.6.5.3 Details of the calibration proce-dure, and subsequent measurement proce-dures, are tailored to the ultrasonic instrumentbeing used; an example is included as anaddendum, Section B-3, to this procedure.The calibration procedure is a variation on thestandard calibration procedure for thicknessgauging with a dual transducer, which usestwo thickness' (in this case, two differentwaterpath lengths between the transducer andthe reflecting surface), to establish the properRANGE and ZERO OFFSET (delay) settings.Repetitive adjustments of ZERO OFFSETwhen measuring the shorter waterpath, andRANGE when measuring the longer water-path, converge on settings for which no furtheradjustments are necessary. At this point, theRANGE setting is the correct value to producea full screen width representing 0.025", andmust not be altered for the rest of the inspec-tion. ZERO OFFSET (delay) can be adjustedfor the operator's convenience, as describedin the instrument-specific procedure.

B-2.6.6 BASELINE MEASUREMENTS

B-2.6.6.1 Baseline length measurements arerequired to verify the stretch on bolts after theentire blade change is completed. Althoughthe primary measurement mode for this sys-tem (i.e. measurement during torquing) doesnot require baseline measurements, any after-the-fact measurement of elongation willrequire them. Baseline measurements aremeasurements which determine the difference

between each blade bolt and a reference bolt,before the blade bolt is stretched. These willbe compared to the difference between eachblade bolt and the reference bolt, after theblade bolts are installed.

B-2.6.6.2 With the reference bolt and theblade bolt stabilized at the same temperature,and filled with the same water, the differencein their lengths is determined by noting thescreen position of the second interface echowhen the transducer is installed in the refer-ence bolt, then the blade bolt. These data arerecorded in the chart provided as Figure B-4.This baseline difference in lengths is recorded,and later subtracted out of the difference inlengths when the blade bolt is stretched. Toensure that the "before" and "after" readingsare directly comparable, the position of thesame characteristic waveform feature must beobserved in each case. The first major posi-tive-going peak of the rf waveform, which willgenerally be the first major peak of the full-wave rectified signal, is generally a goodchoice.

B-2.6.6.3 It should be noted that the flat bot-tomed hole depth in K-monel and Inconel boltsmay be different enough that it is impossible toset the ZERO OFFSET (delay) to a positionfor which both second interface echoes can beviewed, since full screen represents just 0.025inches. If the instrument-specific procedurecalls for direct on-screen comparisonsbetween the reference bolt and each bladebolt, it may be necessary to use two differentreference bolts ( K-monel and Inconel).

B-2.6.7 MEASUREMENTS DURING INSTAL-LATION

B-2.6.7.1 After bolt holes are dewatered andbolts have been installed and hand tightenedto seal the bolt holes, the transducer carrier,with the hex key already in place, is installedby screwing it into the bolt to be tightened.The transducer carrier is designed to screwinto the bolt easily, coming to an abrupt stopwhen the transducer carrier's feet contact thebolt. Verify with the diver that this is the case;

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if not, threads in the bolt or on the transducercarrier should be cleaned. The torque tool isthen placed over the transducer, and the elec-trical cable is connected. At this point the sec-ond interface echo is positioned exactly at aconvenient graticle mark on the screen. If thesignal is not as crisp as it was immediatelyafter cleaning the flat bottomed hole, thetransducer should be removed and the holecleaned out before proceeding.

B-2.6.7.2 Bolt elongation will be measuredby a shift in the signal position caused by rela-tive motion between the transducer (which isscrewed into, and fixed relative to the top ofthe flat bottomed hole) and the bottom of theflat bottomed hole as the bolt is stretched.The exact amount of signal motion is relatedto the amount of stretch through the calibra-tion procedure, which ensures that each0.005" of elongation will move the signal twomajor screen divisions to the right. Once thesignal is positioned at a convenient screenposition prior to torquing the bolt, no furtherinstrument adjustments are permitted. Anychange in the fine range control would destroythe calibration, any change in fine delay wouldinvalidate the signal's reference position, andany change in gain indicates that some unac-ceptable change in the installation hasoccurred. Just prior to applying torque, checkthe tightness of the transducer installationsince loosening will cause a change in thetransducer's position relative to the flat bot-tomed hole's reflecting surface.

B-2.6.7.3 As torque is applied, the ultrasonicsignal will move smoothly to the right, indicat-ing an elongation of the waterpath betweenthe transducer and the flat bottomed hole'sreflecting surface. When the desired stretchhas been achieved, tightening should behalted. All in process measurements shall berecorded on the chart provided as Figure B-5.

B-2.6.8 POST-INSTALLATION MEASURE-MENTS

B-2.6.8.1 Once the bolts have all beeninstalled, a post-installation check on elonga-

tion is required. To accomplish this, the differ-ence in the lengths of each blade bolt and thereference bolt are again measured, this timewith the blade bolt stretched but the referencebolt in its original (unstretched) condition.Accuracy is attained by measuring both boltsside by side, underwater; this ensures thatthey are under identical conditions of tempera-ture and salinity.

B-2.6.8.2 Post-installation measurementsare made by carrying the reference bolt under-water to the blade palm, where it will quicklycome to thermal equilibrium. The transduceris first screwed into the reference bolt, thenthe blade bolt, and the ZERO OFFSET is setat a position for which both echoes are viewedwith no adjustments of any instrument set-tings.

The same echo feature chosen for baselinemeasurements must be used for this mea-surement as well. As with the baseline mea-surements, the length of the blade bolt,relative to the reference bolt, is determined bythe difference in their signal positions. Then,subtracting the baseline difference from thepost-installation difference gives the blade boltelongation. These data are recorded in theworksheet provided as Figure B-4.

B-2.7 MAINTENANCE

B-2.7.1 Maintenance is generally limited to afreshwater rinse for all saltwater wetted andsprayed components, other than the ultrasonicinstrument. Exterior surfaces and connectorsshould be sprayed with a moisture displacinganticorrosive spray prior to storage. The cali-bration standard should be thoroughly cleanedand lubricated to prevent corrosion of the pre-cision lead screw. Under normal use it is notnecessary to disassemble the transducerassembly. Should the transducer fail orbecome damaged it is replaceable. Note thatin order to preserve high dimensional stability,parts have been assembled with a threadlocking compound.

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Figure B-4. Hex Socket Bolt Baseline and Post-Elongation Measurement Worksheet

Blade BoltPosition

Boltserial #

BaselineMeasurement

(NOTE)

Post InstallationMeasurement

(NOTE)

BoltElongation

Final HydraulicTorquingPressure

FinalInstallation

Torque

Reference Bolt

Blade 1/Bolt #1Blade 1/Bolt #2

Blade 1/Bolt #3

Blade 1/Bolt #4

Blade 1/Bolt #5

Blade 1/Bolt #6

Blade 1/Bolt #7

Blade 1/Bolt #8

Reference Bolt


Blade 2/Bolt #3

Blade 2/Bolt #4

Blade 2/Bolt #5

Blade 2/Bolt #6

Blade 2/Bolt #7

Blade 2/Bolt #8

Reference Bolt


Blade 3/Bolt #3

Blade 3/Bolt #4

Blade 3/Bolt #5

Blade 3/Bolt #6

Blade 3/Bolt #7

Blade 3/Bolt #8

Reference Bolt


Blade 4/Bolt #3

Blade 4/Bolt #4

Blade 4/Bolt #5

Blade 4/Bolt #6

Blade 4/Bolt #7

Blade 4/Bolt #8

Reference Bolt

Blade 5/Bolt #1 ‘Blade 5/Bolt #2

Blade 5/Bolt #3

Blade 5/Bolt #4

Blade 5/Bolt #5

Blade 5/Bolt #6

Blade 5/Bolt #7

Blade 5/Bolt #8Note: Enter ZERO Offset (in microseconds, msec.) required to place the second interface echo at 2 screen divisions

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NOTE:

Figure B-4, Hex Socket Boltbaseline and Post-ElongationMeasurement Worksheet, isalso provided as a WindowsOffice 97 EXCEL worksheet(Elongation.xls) containing theformulas required to calculatebolt elongation. This work-sheet may be launched directlyfrom this CD-ROM or the filemay be copied to another com-puter directory for ease of use.

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B-2.7.2 Replacement of the cleaning padsused to clean the flat bottom of the bolt cavity(3/8 inch flat bobs mounted on 3/8 inch roundstock) can be done using a hot melt glue gun.

B-3. EPOCH II ADDENDUM

B-3.1 SCOPE

B-3.1.1 This section presents a detaileddescription of DDG 51 and CG 47 (CG 66 andhigher) class ships bolt elongation measure-

ment procedures using an EPOCH II ultra-sonic instrument and a 10 MHz transducerprovided by NAVSEA 00C. The ultrasonicinspection requirement for blade bolts consistsof three measurements:

a) Baseline measurements which relatethe length of each bolt to the length of areference bolt. These measurementsare taken in the laboratory after boltshave been cleaned and penetrantinspected.

Figure B-5. Hex Socket Bolt Elongation Measurement During Installation Worksheet

NDT File #: J.O.N.: Work Center: Date:

Ship: System: CRP Controller Component: Blade

Job Description: Inspect Morgrip Bolt Elongation

Type of Inspection: Ultrasonic Inspection DWG NO. NAVSEA 6698352

Inspection STD: S0600-AA-PRO-120 Acceptance STD: S0600-AA-PRO-120

Port:

Project (Ship):

Blade Serial Number:

Ultrasonic Instrument:

Calibration Standard:

Reference Bolt:

Transducer:

Bolt Serial #and

Position in Hub

Installed ScreenPosition

Initial ScreenPosition

Difference(Screen div.)

Length Change (Difference x 0.0025”/div.)

NDT Inspector: Date: Level II Examiner Date:

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b) In-process measurements of elongationtaken during blade installation. Thesemeasurements are used to control theapplication of torque to the bolts.

c) Final stretch measurements taken afterall bolts are tightened, to confirm thefinal stretch on each bolt. Under cer-tain circumstances the initial stretchachieved on any one bol t may beaffected by tightening subsequentbolts.

B-3.1.2 The principle of operation for each ofthese measurements is the same as for con-ventional thickness gauging. For these mea-surements, the material being gauged is asmall amount of water that separates the tip ofan ultrasonic transducer from the bottom of aflat-bottomed hole into which the ultrasonicprobe is inserted. The flat-bottomed hole ispart of the blade bolt design, and is intendedfor conventional depth gauging with a depthmicrometer. The ultrasonic probe is aNAVSEA design that screws into the top of theflat-bottomed hole, and places a 10 MHztransducer element about 0.25 inches awayfrom the bottom of the hole (see Figure B-2).As the bolt stretches, the length of the flat-bot-tomed hole increases, moving the flat bottomaway from the tip of the transducer (which isstationary with respect to the top of the hole).The ultrasonic instrument accurately mea-sures the ultrasonic pulse's round-trip traveltime, and allows this time to be calibrated interms of distance, which is related to traveltime through the speed of sound. To ensureaccuracy throughout these measurements,every effort is made to keep conditions of tem-perature and salinity (which affect the speedof sound) the same for calibration and boltmeasurements. Also, to improve resolution,the ultrasonic pulse is allowed to bounce backand forth between the flat-bottomed hole andthe transducer element twice, effectively dou-bling any change in the waterpath lengthbetween the transducer element and the bot-tom of the flat-bottomed hole.

B-3.2 INSTRUMENT CALIBRATION

B-3.2.1 The EPOCH II is calibrated to show0.0025 inches per division. This makes eachsmall tickmark represent 0.0005 inches, andfull screen represents 0.025 inches. The cali-bration standard (see Figure B-3) used forthese measurements simulates the bolt hole'sflat bottom with the face of a piston that can beraised or lowered precise amounts. The pis-ton is driven by a 100 threads-per-inch (tpi)precision lead screw (0.010" advance per rev-olution). During calibration the distance fromthe transducer tip to the piston face is varied inincrements of 0.005" by turning the precisionlead screw one-half revolution at a time. Forcalibration and baseline measurements, thecalibration standard must be at the same tem-perature and filled with the same water as thereference bolt and all the blade bolts to elimi-nate sound velocity variations, between bolts,due to temperature or salinity. To minimizesubsequent variations between these calibra-tion settings and on-site instrument settings,the water should be drawn from the harbor,rather than using tap water.

B-3.2.2 Initial settings for the EPOCH IIshould be as shown in Table B-1, using a 10MHz transducer provided by NAVSEA 00C.

B-3.2.3 The calibration standard and therotatable base are assembled by placing thestandard in the base, ensuring the O-ring onthe calibration standard is lightly lubricated,and that the slot in the base accepts the align-ment dowel on head of the lead screw. Asmall amount of seawater is then poured intothe calibration standard, and the transducer isscrewed into the calibration standard, ensur-ing that the face of the transducer is free ofbubbles. The precision lead screw should beadjusted mid range, leaving about one quarterinch of water between the transducer and theface of the piston. Connect the cable to theultrasonic instrument and the transducer,using a small amount of antiseize compoundto lubricate the underwater matable connec-tor. The first objective is to identify the second

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interface echo (IFE) and adjust gain to bringthis echo to about 80% screen height. Withdelay and zero offset set to zero, and rangeset to 0.050"/div. the screen should show theinitial pulse and at least three IFE's. Adjustgain to bring the second IFE to 80% screenheight.

B-3.2.4 In the remainder of the procedure itis important that signal position be estimatedas accurately as possible; using the position ofthe leading edge of the signal is not recom-mended. Many waveform features can beused to track position, but the preferred fea-ture is the peak of the first positive-going half-cycle of the waveform. The rf waveform typi-cally shows a small negative-going peak fol-lowed by a large positive-going peak, a largenegative-going peak, and several muchsmaller peaks (Figure B-6). With full waverectification all peaks appear positive, so thepeak that is generally used is the second peakin the video display, even if the third peak (cor-responding to the second negative-going

peak) is slightly larger (Figure B-7). In theremainder of this discussion, the position ofthe second IFE means the position of thispeak.

B-3.2.5 The next objective is to reduce therange to 0.0025"/div. and position the secondIFE at 5 screen divisions. Note that becausethe RANGE SELECT... display is limited tothree decimals, it will not be possible to actu-ally display "0.0025 in / DIV" (it will read 0.002or 0.003 in / DIV instead). Press the RANGEbutton, then the UP ARROW until the secondIFE reaches the right edge of the screen. TheRANGE SELECT... display will read about0.025 in / DIV at this point. Then press theZERO OFFSET button and the LEFT ARROWuntil the second IFE is at the left edge of thescreen. Then press the RANGE button, andthe UP ARROW until the RANGE SELECT...reads 0.002 in / DIV. Finally, press the ZEROOFFSET button and use the LEFT or RIGHTarrows to position the second IFE at 5 screendivisions.

Table B-1. EPOCH II Initial Settings

Reject: 0% Range 0.050 in / DIV

Velocity: 0.0300 in/µs.* XCR- 15.0 MHz ON

Thickness: 0.000 Pulser HIGH, 50W

Zero: 0.000 µs. FULL WAVE

Delay: 0.000 in. PULSE-ECHO MODE

Angle: 0.0°

* The published speed of sound in seawater is about 0.06 inches/microsecond, or about twice the recommended set-up value. This discrepancy arises because the procedure calls for using the second interface echo, which means that travel time for the ultrasonic pulse is twice as long as it would be for the first interface echo.

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B-3.2.6 The next objective is to calibrate thescreen to give two screen divisions per 0.005".The calibration standard allows the waterpathbelow the transducer to be accuratelychanged in increments of 0.005", since index-ing marks allow the 100 tpi precision leadscrew to be rotated one-half revolution withina fraction of a degree. Once the second inter-face echo has been set to 5 screen divisions,the lead screw will be adjusted to add andsubtract 0.010" to the waterpath, and the

instrument will be adjusted to produce achange of 4 screen divisions up (to the ninthdivision), and 4 screen divisions down (to thefirst division), making one division correspondto 0.0025" change in waterpath length. Start-ing with the second IFE at 5 screen divisions,rotate the base of the calibration standardclockwise one full revolution, adding 0.010" tothe waterpath. The second IFE will move tothe right as this is done. Press the RANGEbutton and use the LEFT or RIGHT arrows to

Figure B-6. rf Ultrasonic Signal

Figure B-7. Full Wave Rectified Signal

0

20

40

60

80

100

120

140

160

180

200

Time

Sig

nal

Am

plit

ud

e

0

10

20

30

40

50

60

70

80

90

100

Time

Sig

nal

Am

plit

ud

e

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position the echo at 9 screen divisions. Then,turn the base of the calibration standard twofull revolutions counterclockwise to reduce thewaterpath by 0.020" (this is 0.010" less thanthe initial waterpath length). Press the ZEROOFFSET button and use the arrows to positionthe signal at 1 screen division. Repeatedlylengthen the waterpath by 0.020" (two rota-tions clockwise) and use RANGE to positionthe signal at 9 screen divisions, then shortenthe waterpath by 0.020" (two rotations coun-terclockwise) and use ZERO OFFSET to posi-tion the signal at 1 screen division. Repeatthese adjustments until the signal is properlypositioned for both waterpaths without furtheradjustments to the instrument. Make the finaladjustments being extremely careful that thetransducer is firmly seated.

B-3.2.7 Accuracy can be checked at thispoint by using the gate. Set GATE START to0.0000 inches. Press GATE WIDTH and thenthe RIGHT ARROW until the gate reachesexactly 10 screen divisions. The GATEWIDTH display should read 0.0250 within0.0001 inches. The full screen width repre-sents exactly 0.025" by virtue of the calibrationprocedure, but the gate width calculated bythe instrument depends on sound velocity,which can vary slightly with temperature andsalinity. Presuming that the screen calibrationhas been performed extremely accurately, theVELOCITY may be adjusted slightly to makethe full screen GATE WIDTH display 0.0250inches. No further changes should be madeto the RANGE or VELOCITY values for theremainder of the baseline measurement pro-cess.

B-3.3 BASELINE MEASUREMENTS

B-3.3.1 REFERENCE BOLT MEASURE-MENTS

B-3.3.1.1 The purpose of baseline measure-ments is to document the initial (unstretched)length of each bolt relative to a well identifiedreference bolt. Later, when all of the bladebolts have been installed, their new(stretched) lengths will again be compared to

the reference bolt. The difference betweenthese two relative lengths is the amount theblade bolt has stretched. The first step in thisprocess is to establish the position of the refer-ence bolt's second IFE signal. In the followingdiscussion, it is assumed that the same cableand transducer is used for the reference boltand the blade bolts, both before and afterinstallation, since the physical lengths of thetransducer and cable both contribute to theabsolute echo arrival time.

B-3.3.1.2 For this, and all subsequent bladebolt measurements, cleanliness is a criticalissue. Any small piece of material in the mea-surement hole will affect the measurement byits thickness; the goal of ±0.0005" accuracywill not tolerate any such loose material at all.

B-3.3.1.3 Pour a small amount of seawaterinto the reference bolt, and screw the trans-ducer in securely. Ensure that the shape ofthe waveform is reasonable (small negativepeak, followed by a large positive and a largenegative peak, then several smaller peaks). Ifthe waveform is not as "clean" as expected,there may be loose material in the hole, orsmall bubbles adhered to the face of the trans-ducer: eliminate these conditions.

B-3.3.1.4 Position the second IFE at 2screen divisions using ZERO OFFSET, withDELAY=0.000. Record the zero offsetrequired to achieve this screen position.

B-3.3.2 BLADE BOLT BASELINE MEA-SUREMENTS

B-3.3.2.1 After ensuring that each blade boltis well cleaned, pour a small amount of sea-water into the flat-bottomed hole. Insert thetransducer and screw it in securely. Positionthe second IFE at 2 screen divisions, checkthat DELAY is 0.000, and record the ZEROOFFSET required. If the blade bolt is shorterthan the reference bolt, less ZERO OFFSETwill be required, and the relative length will berecorded as a negative number. These dataare recorded on the chart provided as FigureB-4. The calculation of length is:

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Relative blade bolt length =

((Reference bolt offset - Blade bolt offset) *Velocity) / 2

EXAMPLE:

Reference bolt offset = 17.875 microseconds

Blade bolt offset = 16.975 microseconds

Velocity = 0.0300 inches/microsecond

Relative blade bolt length = -((17.875 -16.975) * 0.0300) / 2 = -0.0135 inches

(The blade bolt is 13.5 thousandths of an inchshorter than the reference bolt).

B-3.3.2.2 Save each bolt signal in memory.Note bolts with unusual waveforms. Assum-ing that the flat-bottomed hole has been prop-erly cleaned, an unusual waveform is theresult of the geometry of the hole bottom, andcan be expected to recur during all measure-ments on that bolt.

B-3.3.2.3 Print out each bolt waveform forcomparison with the signal obtained during in-process and final measurements.

B-3.4 IN-PROCESS MEASUREMENTS

B-3.4.1 INITIAL CALIBRATION

B-3.4.1.1 The instrument calibration shouldbe checked on-site to account for minor varia-tions in the speed of sound. To accomplishthis, immerse the calibration standard in localseawater until thermally stabilized, thenrecover it full of seawater. Install the calibra-tion standard in its base and make minoradjustments to RANGE and ZERO OFFSETas required to achieve a calibrated screen.Finally, set the gate to full screen width andadjust VELOCITY to produce a GATE WIDTHof 0.0250 inches. These adjustments should

be very minor (less than 1% variation in veloc-ity is expected).

In order to protect the precisionlead screw threads from corro-sion, a waterproof cap is sup-plied with the calibrationstandard. Before lowering thestandard into the local seawa-ter, this cap must be installed,and before removing the cap,topside, excess seawater mustbe wiped off the standard. Inplacing the standard in its rotat-able base, an O-ring seal isformed to protect the leadscrew from seawater spill-over.

B-3.4.2 SITE CONSIDERATIONS

B-3.4.2.1 The ultrasonic instrument shouldbe set up in a location which allows directcommunication with the hydraulic tool opera-tor. As each bolt is tightened the ultrasonicinspector will monitor the stretch, and call fortorquing to stop when the appropriate stretchhas been attained.

B-3.4.2.2 Cables should be routed from theultrasonic instrument to the dive site in such away as to prevent damage to the cables. Careshould be taken to prevent the cables frombeing pinched or cut, and to prevent personnelfrom tripping on the cables. Chafing protec-tion must be provided where the cable mightabrade as it passes over the side, or throughwindows or doorways. Cables should becoiled using either a figure-of-eight pattern orthe "over/under" technique to prevent kinksfrom forming. A small amount of metal-basedantiseize compound should be applied to theunderwater end of the cable before passing itover the side.

B-3.4.2.3 Active radar and large dieselengines near the ultrasonic instrument may

CAUTION

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affect the ultrasonic signal. At the presenttime there is no effective remedy, and no pro-cedural changes are permitted withoutNAVSEA approval. If the source of intensenoise on the ultrasonic display cannot belocated and shut down, measurements mustbe delayed until the ultrasonic signal appearsnormal.

B-3.4.3 MEASUREMENTS DURING TIGHT-ENING

B-3.4.3.1 Before hydraulic tightening, boltshave been hand tightened to capture hydrol-ube in the bolt hole, but the bolts have notbeen measurably stretched. For DDG-51class, tightening should result in 0.006 to0.008 inches stretch for bolt holes 1,2,3,4,6,7,and 0.007 to 0.008 inches for bolt holes 5 and8. The ultrasonic inspector should keep thehydraulic pump operator advised of stretch,and tightening should be halted when stretchis about 0.0075 inches. For CG66 and higherall bolts should be stretched 0.005 to 0.007inches and during tightening aim for 0.0065inches.

B-3.4.3.2 The ultrasonic inspector must con-trol the flow of work. Once the transducer isinstalled in each bolt, the hydraulic pumpoperator must wait until the signal has beenpositioned (DELAY and GAIN) and datalogged. The ultrasonic operator then calls forhydraulic power to be applied ("Start torqu-ing"). When the target stretch (typically0.0075") is reached, the ultrasonic operatorhalts the torquing ("Whoa!"). The divers mustleave the transducer in place until data islogged, the waveform is stored, and the ultra-sonic operator calls for the transducer to bemoved.

B-3.4.3.3 The diver will install the transducer,with the hex key already in place, but thecable disconnected. The hydraulic tool willthen be slipped over the transducer carrierand onto the hex key. At this point the cable isconnected. Divers should be advised thatthey should never strain the cable itself, onlythe connector bodies.

B-3.4.3.4 Before hydraulic power is applied,the second IFE is placed at 2 screen divisions,and the quality of the signal is checked. If it isnot "clean" the diver should be instructed todisconnect, unscrew the transducer, andpump it in the hole to get rid of foreign mate-rial. Without disconnecting the cable, thediver should slightly loosen, then retighten thetransducer, and the inspector should verifythat the signal returns to exactly the sameposition on the display; this verifies that thetransducer is properly seated with its feet rest-ing on the bolt's reference surface. Proceedwith measurements only when a clean andstable signal is obtained.

B-3.4.3.5 With the signal at 2 screen divi-sions, call for hydraulic power, and observethe signal move to the right as the bolt isstretched.

B-3.4.3.6 During tightening the signal shouldmove smoothly as the bolt is stretched. Anyabrupt jumps in signal position may indicateimproper lubrication or improper placement ofthe torque tool's reaction foot. These condi-tions should be corrected to ensure that theproper stretch is achieved. Any significantchange in the signal's shape during tighteningindicates improper installation, typically aloose transducer. These conditions must becorrected before reliable measurements canbe taken. If necessary, back the bolt out to alow level of stretch (to ensure captured hydrol-ube is not lost) and retighten once the trans-ducer installation has been corrected. Recordthe in-process measurements in the chart pro-vided as Figure B-5.

B-3.5 FINAL LENGTH MEASUREMENTS

B-3.5.1 After all bolts have been installed,verify the final stretch by repeating measure-ments relative to the reference bolt. To ensurethat all bolts are at the same temperature andsalinity, the reference bolt is lowered to thehub, and the ZERO OFFSET required to placethe signal at 0, 2, and 10 screen divisions isrecorded. The calibration check during in-pro-cess measurements is sufficient for this

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phase, unless there have been significantchanges in the water (this could happen inareas with a strong tidal flow). Should therebe any question, repeat the in-process calibra-tion procedure before measuring final lengths.

B-3.5.2 Each bolt is checked by inserting thetransducer, positioning the signal at 2 screendivisions, checking the quality of the signal,and recording the ZERO OFFSET. The rela-tive bolt length is calculated as describedabove. The change in relative bolt lengthbetween this measurement and the baselinemeasurement indicates stretch, and shouldcorrespond with the in-process stretch mea-surement. Slight variations can be expecteddue to inherent measurement error (approxi-mately ±0.0005"), and bolt interactions. Anysignificant differences must be resolved aslarge changes in stretch may indicate anunsatisfactory installation. Record these datain the chart provided as Figure B-4.

B-3.5.3 Recording and Reporting. All recordsassociated with an underwater CPP bladechange will be maintained by NAVSEA00C54.

B-3.6 PERSONNEL QUALIFICATION ANDCERTIFICATION REQUIREMENTS

B-3.6.1 Personnel performing bolt elongationmeasurements inaccordance with this proce-dure shall be certified in accordance withNAVSEA Technical Publication 271 (latestrevision) as an Ultrasonic Inspector (Level II,or Level II Limited) or Examiner (Level III).

B-3.6.2 Competence and familiarity with theprocedure and system hardware may beacquired by repeated measurements on a setof unstressed bolts. The normal variations ofreadings about the mean for any one bolt isapproximately + 0.0005 inch. Readings morethan 0.001 inch from the mean indicatedimproper application of the procedure, or hard-ware deficiencies.

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