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Motor Pleasure Yachts

February 2000



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ABSOUNDED 1

Guide for Building and Classing

Motor Pleasure Yachts

February 2000

American Bureau of Shipping

Incorporated by Act of the Legislature of

the State of New York 1862

Copyright © 2000



Foreword

This Guide is applicable to motor pleasure craft 24 m (79 ft) or

greater in length overall up to Elm (200 ft) in length, that are

not required to be assigned a load line. Application to vessels

outside these limits will be specially considered.

The format in Sections 8 to 11 is a change from other ABS Rules

in that design loads are defined together with stress/deflection

criteria for three materials, i.e. steel, aluminum and FRP. The

equations are based on the current design practice and

satisfactory service experiences.

The machinery Sections are developed from the Rules for Building

and Classing Steel Vessels Under 90 meters (295 feet) in Length

incorporating refinements since 1983.

This Guide is being released at this time, with the intent that

modifications will be made as may be found necessary and

appropriate so that formal Rules may be published after a

reasonable period of its trial use.

The subject February 2000 edition is a consolidation of the

November 1990 edition into which the Corrigenda No. 1, dated

August 1992 and the Rule Change Notice No. 2 dated January 1997

have been incorporated, together with some minor additional

editorial changes for clarification purposes.



Contents

Guide for Building and Classing Motor Pleasure Yachts

Section

1 cope and Conditions of Classification

2 efinitions

3 eneral

4 aterials

5 abrication and Quality Control

6 tructural Arrangement7 etails and Fastenings

8 esign Pressures

9 ull Scantlings, High Speed Craft

10 ull Scantlings, Displacement Craft

11 ongitudinal Strength

12 eels, Stems, Stern Frames and Shaft Struts

3 udders

14 losing Appliances and Bulwarks, Rails, Vents, Ventilators and Freeing Ports, Portlights and

Windows

15 elding16 quipment

17 orrosion Prevention and Protective Coatings

18 ropulsion, Steering Gear and Auxiliary Machinery

19 hafting and Propellers

20 umps and Piping Systems

21 lectrical Installations

22 ire Extinguishing Systems

24 urveys after Construction



SECTION

Scope and Conditions of Classification

1.1 Classification

1.1.1 rocess

The Classification process consists of a) the development of

rules, guides, standards and other criteria for the design and

construction of marine vessels and structures, for materials,

equipment and machinery, b) the review of design and surveyduring and after construction to verify compliance with such

rules, guides, standards or other criteria, c) the assignment and

registration of class when such compliance has been verified, and

d) the issuance of a renewable Classification certificate, with

annual endorsements, valid for five years.

The Rules and standards are developed by Bureau staff and

passed upon by committees made up of naval architects, marine

engineers, shipbuilders, engine builders, steel makers and by

other technical, operating and scientific personnel associatedwith the worldwide maritime industry. Theoretical research and

development, established engineering disciplines, as well as

satisfactory service experience are utilized in their development

and promulgation. The Bureau and its committees can act only upon

such theoretical and practical considerations in developing Rules

and standards.

For classification, vessels are to comply with both the hull

and the machinery requirements of the Rules.

1.1.2 Certificates and Reports

a. Plan review and surveys during and after construction are



classification, the owners will be given the opportunity to

verify the accuracy of the information prior to release.

1.1.3 Representations as to Classification

Classification is a representation by the Bureau as to the

structural and mechanical fitness for a particular use or service

in accordance with its Rules and standards. The Rules of American

Bureau of Shipping are not meant as a substitute for the

independent judgement of professional designers, naval

architects, marine engineers, owners, operators, masters and crew

nor as a substitute for the quality control procedures of

shipbuilders, engine builders, steel makers, suppliers,

manufacturers and sellers of marine vessels, materials, machinery

or equipment. The Bureau, being a technical society, can only act

through Surveyors or others who are believed by it to be skilled

and competent.

The Bureau represents solely to the vessel Owner or client of

the Bureau that when assigning class it will use due diligence in

the development of Rules, Guides and standards, and in using

normally applied testing standards, procedures and techniques as

called for by the Rules, Guides, standards or other criteria of

the Bureau for the purpose of assigning and maintaining class.

The Bureau further represents to the vessel Owner or other client

of the Bureau that its certificates and reports evidence

compliance only with one or more of the Rules, Guides, standards

or other criteria of the Bureau in accordance with the terms of

such certificate or report. Under no circumstances whatsoever are

these representations to be deemed to relate to any third party.

The user of this document is responsible for ensuring

compliance with all applicable laws, regulations and othergovernmental directives and orders related to a vessel, its

machinery and equipment, or their operation. Nothing contained

in any Rule, Guide, standard, certificate or report issued by the



not responsible for the consequences arising from the use by

other parties of the Rules, Guides, standards or other criteria

of the American Bureau of Shipping, without review, plan approval

and survey by the Bureau.

The term approved shall be interpreted to mean that the

plans, reports or documents have been reviewed for compliance

with one or more of the Rules, Guides, standards, or other

criteria of the Bureau.

The Rules are published on the understanding that

responsibility for stability and trim, for reasonable handling

and loading, as well as for avoidance of distributions of weight

which are likely to set up abnormally severe stresses in vessels

does not rest upon the Committee.

1.3 Suspension and Cancellation of Classification

1.3.1 ermination of Classification

The continuance cf the Classification of any vessel is

conditional upon the Rule requirements for periodical, damage and

other surveys being duly carried out. The Committee reserves the

right to reconsider, withhold, suspend, or cancel the class of

any vessel or any part of the machinery for noncompliance with

the Rules, for defects reported by the Surveyors which have not

been rectified in accordance with their recommendations, or for

nonpayment of fees which are due on account of Classification,

Statutory or Cargo Gear Surveys. Suspension or cancellation of

class may take effect immediately or after a specified period of

time.

1.3.2 otice of Surveys



classification or the structural integrity, quality or fitness

for a particular use or service.

b lass will be suspended and the Certificate of Classification

will become invalid in any of the following circumstances:

1 if recommendations issued by the Surveyor are not carried out

by their due dates and no extension has been granted,

2 if Continuous Survey items which are due or overdue at the

time of Annual Survey are not completed and no extension has

been granted,

3 if the periodical surveys required for maintenance of class,

other than Annual, Intermediate or Special Surveys, are not

carried out by the due date and no Rule allowed extension has

been granted, or4 if any damage, failure, deterioration, or repair has not been

completed as recommended.

c lass may be suspended, in which case the Certificate of

Classification will become invalid, if proposed repairs as

referred to in 1.25.1 have not been submitted to the Bureau and

agreed upon prior to commencement.

d Class is automatically suspended and the Certificate of

Classification is invalid in any of the following circumstances:

1 if the Annual Survey is not completed by the date which isthree (3) months after the due date,

2 if the Intermediate Survey is not completed by the date which

is three (3) months after the due date of the third Annual

Survey of the five (5) year periodic survey cycle, or

3 if the Special Survey is not completed by the due date, unless

the vessel is under attendance for completion prior to

resuming rading. nder xceptional ircumstances,

consideration may be given for an extension of the Special

Survey,a provided the vessel is attended and the attending Surveyor

so recommends; such an extension shall not exceed three (3)

months, or



1.3.6 ancellation of Class

a If the circumstances leading to suspension of class are not

corrected within the time specified, the vessel's class will

be canceled.b A vessel's class is canceled immediately when a vessel

proceeds to sea without having completed recommendations which

were reauired to be dealt with before leaving port.

c When class has been suspended for a period of three (3) months

due to overdue Annual, Intermediate, Special, or other

periodical surveys required for maintenance of class; overdue

Continuous urvey tems; r verdue utstanding

recommendations, class will be canceled. A longer suspension

period may be granted for vessels which are either laid up,

awaiting disposition of a casualty, or under attendance for

reinstatement.

1.3.7 lternative Procedures for Certain Types of Vessels

Alternatives to I/1.3.4d procedures for automatic suspension of

class and 1/1.3.6c procedures for cancellation of class, may be

applied to military vessels; commercial vessels owned orchartered by governments which are utilized in support of

military operations or service; or laid- up vessels:

1.4 pplication

This Guide is applicable to motor pleasure craft 24 m (79 ft.) or

greater in length overall to 61 m (200 ft) in length as defined

in 2.1, that are not required to be assigned a load line.Application to vessels outside these limits will be specially

considered.



entered in the Record indicating that classification has

incorporated the provisions of this paragraph. Submission of

plans is to be in accordance with 1.15 and 1.17.

1.7 Novel Features

Craft that contain novel features of design in respect of hull,

equipment or machinery to which the provisions of the Rules are

not directly applicable may be classed, when approved by the

Committee, on the basis that the Rules insofar as applicable have

been complied with and that special consideration has been given

to the novel features based on the best information available at

the time.

1.9 Effective Date of Changes

1,9.1 ix Month Rule

Changes to the Guide are to become effective on the date

specified by the Bureau. In general, the effective date is not

less than six months from the date of their publication.However, the Bureau may bring into force individual changes

before that date if necessary or appropriate.

1.9.2 mplementation of Changes

In general, until the effective date, plan approval for designs

will follow prior practice unless review under the latest Guide

is specifically requested by the party signatory to the

application for classification. If one or more vessels are to beconstructed from plans previously approved, no retroactive

application of the later changes will be required except as may

be necessary or appropriate for all contemplated construction.



1.11.2 quipment Symbol

The symbol I D placed after the symbols of classification, e.g.

C4A1 I D Yachting Service, signifies that a yacht's equipment ofanchors and anchor cables complies with the requirements in

Section 16 for that symbol.

1.11.3 achinery

a VUVIS Symbols Machinery constructed and installed to

the satisfaction of the Surveyors to the Bureau to the full

requirements of this Guide, or their equivalent, when found

satisfactory after trial and approved by the Committee, will be

classed and distinguished in the Record by the symbols godms.

b MS Symbols Machinery not constructed and installed

under survey to this Bureau, but submitted for classification,

will be subjected to special classification surveys. When found

satisfactory and thereafter approved by the Committee, the

machinery will be classed and distinguished in the Record by the

symbols AMS. he mark C4 signifying the survey during

construction will be omitted.

1.11.4 entralized or Automatic Control Systems

Where, in addition to individual unit controls, remote,

centralized, or automatic control systems are proposed to be

provided for propulsion units, or essential auxiliaries, relevant

data is to be submitted to permit the assessment of the effect of

such systems on the safety of the yacht. All controls necessary

for the safe operation of the yacht are to be proved to the

Surveyor's satisfaction.

1.11.5 perational Limits



are governed by the Rules, Guides, standards, or other criteria

of the American Bureau of Shipping who shall remain the sole

judge thereof-

1.15 Olmission of Hull Plans

Plans showing the scantlings, arrangements, and details of the

principal parts of the hull structure of each vessel to be built

under survey and of each vessel to have Bureau plan approval, are

to be submitted and approved. Plans are to be submitted before

the work of construction is commenced. hese plans are to

indicate clearly the scantlings and fastenings, the minimum

physical properties of the construction materials, and details of

construction. n general, plans should include the following;

some of the structural items, where practicable, may be shown on

the same plan.

General arrangement

Midship and framing sections

Scantling profile and scantling deck plans

Bottom construction, floors, girders, etc.

Inner bottomShell expansion

Pillars and girders

Watertight and tank bulkheads

Non-tight structural bulkheads

Machinery casinos

Engine and main auxiliary foundations

Welding schedule and details, bonding details (FRP)

Rudders and steering gear

Shaft strutsSuperstructures and deckhouses and their closing appliances

Hatches, portlights, windows and closing arrangement

Ventilation system exposed to weather



Arrangement and details of propulsion system:

Engine

Reduction gear

Propellers

Propulsion Shafting

Engine foundation arrangement, rating,

design pproval etails rommanufacturer, if not of previous approved

design.

Foundation arrangement, rating, design

approval details from manufacturer, if

not of previous approved design.

Material specifications, design approval

details and strength calculations, if not

in accordance with Rules.

See 19.3.

Torsional Vibration Analysis

Steering Gear

Boilers and Pressure Vessels

Piping Systems

Electrical Equipment & Systems

See 18.5

See 18.11.2 and 21.3

See 18.3

See 20.3

See 21.3

Arrangement & Details of Engine Exhaust Systems

Arrangement and Details of Fire Extinguishing Systems

Waterjet Units ee 19.27

Plans to be reviewed by an ABS Technical office should generally

be submitted in triplicate, one copy to be returned to those

making the submission, one copy for the use of the Surveyor where

the vessel is being built, and one copy to be retained in the ABS

Technical office for record. Additional copies may be required

where the required attendance of the Surveyor is anticipated at



1.23 rials

A final under-way trial is to be made of machinery and

engineering systems covered by classification, including thesteering gear. All automatic controls, including trips which may

affect the vessels propulsion systems, are to be tested underway

or alongside the dock, to the satisfaction of the Surveyor. See

18.9, 18.11.11 and 21.31.

1.25 Conditions for Surveys after Construction

1.25.1 Damage, Failure and Repair

Damage, failure, deterioration or repair to hull, machinery orequipment which affects or may affect classification, is to be

submitted by the owners or their representatives for examination

by the Surveyor at first opportunity. ll repairs found

necessary by the Surveyor are to be carried out to his

satisfaction. Nothing contained in this section or in a rule or

regulation of any government or other administration, or the

issuance of any report or certificate pursuant to this section or

such a rule or regulation, is to be deemed to enlarge upon their

representations expressed in subsections 1.1.1 through 1.1.4hereof and the issuance and use of any such reports or

certificates are in all respects to be governed by subsections

1.1.1 through 1.1.4 hereof.

1.25.2 Notification and Availability for Survey

The Surveyors are to have access to classed vessels at all

reasonable times. For the purpose of Surveyor Monitoring,

monitoring Surveyors shall also have access to classed vessels at

all reasonable times. Such access may include attendance at thesame time as the assigned Surveyor or during a subsequent visit

without theassigned Surveyor. The Owners or their

representatives are to notify the Surveyors on all occasions when



affect classification, ABS Surveyors will also cooperate with

Port States by providing inspectors with background information,

if requested. Such information includes text of conditions of

class, survey due dates, and certificate expiration dates.

Where appropriate, the vessel's flag state will be notified

such attendance and survey.

1.27 ees

Fees in accordance with normal ABS practice will be charged

all services rendered by the Bureau. xpenses incurred by the

Bureau in connection with these services will be charged inaddition to the fees. ees and expenses will be billed to

party requesting that particular service.

1.29 overnment and Other Regulations

While this Guide covers the requirements for the classification

of new vessels, the attention of Owners, designers, and builders

is directed to the regulations of international, governmental,

canal and other authorities dealing with those requirements inaddition to or over and above the classification requirements.

1.31 IACS Audit

The International Association of Classification Societies (IACS)

conducts audits of processes followed by all its member societies

to assess the degree of compliance with the IACS Quality System

Certification Scheme requirements. For this purpose, auditors

from IACS may accompany ABS personnel at any stage of theclassification or statutory work which may necessitate the

auditors having access to the vessel or access to the premises of



1.35 isagreement

1.35.1 Rules and Guides

Any disagreement regarding either the proper interpretation of

ABS Rules and Guides, or translation of the Rules and Guides from

the English language edition, is to be referred to the Bureau for

resolution.

1.35.2 Surveyors

In case of disagreement between the Owners or builders and the

Surveyors regarding the material, workmanship, extent of repairs,

or application of the Rules relating to any vessel classed or

proposed to be classed by this Bureau, an appeal may be made in

writing to the Committee, who will order a special survey to be

held. Should the opinion of the Surveyor be confirmed, the

expense of this special survey is to be paid by the party

appealing.

1.37 ype Approval

Equipment, fittings, and materials not required to be

certificated may be type approved by ABS and included in the ABS

List of Type Approved Equipment. Type approval comprises a

technical review to a designated standard, a plant inspection and

a quality assurance verification. ABS type approval eliminates

the need for verification of the manufacturer's data and survey

for each individual application.



SECTION 2

DEFINITIONS

The following definitions of symbols and terms are to be understood (in the

•bsence of other specifications) where they appear in the Guide.

2.1 ength

L is the distance in meters or feet on the estimated summer loadline or design waterline, from the foreside of the stem to the

after side of the rudder post or sternpost; where there is not a

rudder post or sternpost, L is to be measured to the centerline of

the rudder stock. or use with the Guide, L is not to be less

than 96% and need not be greater than 97% of the length on the

summer load line or design waterline.

2.3 readth

B is the greatest molded breadth in meters or feet.

2.5 epth

D is the molded depth in meters or feet, measured at the middle of

L, from the base line or rabbet line to the underside of the main

weather deck at side.

2.7 raft

d is the draft in meters or feet measured at the middle of L from

the base line or rabbet line at its lowest point to the summer



2.31 Motor Pleasure Craft

Motor pleasure craft are those engaged exclusively in

recreational, non-revenue earning services. Vessels chartered asmotor yachts and considered by the administration as yachts, and

not passenger vessels, are considered motor pleasure craft.

2.32 Administration

For use with this Guide, the Administration is defined as the

government of the State whose flag the yacht is entitled to fly.

2.33 Fiber-Reinforced Plastic (FRP)

FRP consists of two basic components: a glass-filament or other

material fiber reinforcement filament and a plastic, or resin, in

which the reinforcing material is imbedded.

2.33.1 Reinforcement

Reinforcement is a strong, inert material bonded into the plastic

to improve its strength, stiffness and impact resistance.

Reinforcements are usually fibers of glass (a lime-alumina-silicate composition having a low alkali content) or other

approved material such as aramid or carbon fiber, in a woven or

non-woven form, with a strong adhesive bond with the resin.

a Strand A bundle of continuous filaments combined in a

single, compact unit.b Chopped-strand Mat blanket of randomly oriented

chopped-glass strands held together with binder.

c Roving A band or ribbon or parallel strands groupedtogether.

d Woven Roving A coarse fabric woven from rovings.

A twisted strand or strands suitable for weaving



I Warp he roving or yarn running lengthwise in woven

fabric.

m Fill, Weft or Woof The roving or yarn running at right

angles to the warp in a woven fabric.n Binder A substance applied in small quantities to fibers

to hold them lightly together in mat form.

o Size A substance applied to fibers at the time of their

formation to allow resin to flow freely around and adhere to them,

and to protect them from abrasion.

p Finish A substance applied to fabrics to promote wetting

of the fibers by the resin, to improve adhesion, and to reduce

interfilament abrasion.

2.33.2 esin

Resin is a highly reactive synthetic that in its initial stage is

a liquid, but upon activation is transformed into a solid.

a Accelerator A material that, when mixed with resin, speeds

the cure time.

b Catalyst or Initiator A material that is used to activate

resin, causing it to harden.

c Crazing Hairline cracks, either within or on the surface

of resin, caused by mechanical or thermal stresses.d Cure To change resin from a liquid to a solid.

e Cure time The time required for resin to change from a

liquid to a solid after a catalyst has been added.

f Exothermic Heat The heat given off as the result of the

action of a catalyst on resin.

g Filler A material added to resin to modify its working

properties or other qualities, or to lower costs.

h Gel A partially cured resin in a semi-solid state similar

to gelatin in consistency. ot to be confused with gel coat(2.33.3e).

i Gel Time The time required to change a flowable, liquid



a Bi-directional Laminate A laminate with fibers oriented

primarily in the warp and fill directions in the plane of the

laminate and where the mechanical properties in the warp and fill

of the laminate are similar. i-directional laminates may beconstructed of bi-axial, double bias, tri-axial, mat or uni-

directional reinforcing layers, or a combination of any of these.

b Uni-directional Laminate A laminate with substantially

more of the fibers in the plane of the laminate oriented in one of

the two principal axis of the laminate plane so that the physical

properties along that axis, are appreciably higher than along the

other natural axis.

c Barcol Hardness measurement of the hardness of a

laminate and thereby the degree of completion of the cure.d Delamination The separation of the layers of material in a

laminate.

e Gel Coat he first resin applied to a mold when

fabricating a laminate. It provides a smooth protective surface

for the laminate. or decorative purposes, it usually has a

coloring matter added. Not to be confused with gel (see 2.35.2h).

f Layup The process of applying to a mold the layers of

resin and reinforcing materials that make up a laminate. These

materials are then compressed or densified with a roller orsqueegee to eliminate entrapped air and to spread resin evenly.

Also a description of the component materials and geometry of a

laminate and laminate that has been assembled.

g Peel Ply A partially impregnated, lightly bonded layer of

glass, cloth or woven roving used to protect a laminate in

anticipation of secondary bonding, providing a clean, fresh

bonding surface.

h Secondary Bonding The practice of bonding fresh material

to a cured or partially cured laminate.i Verified Minimum Physical Property The physical properties

verified by the appropriate test given in Table 5.1.

j Laminate Principal Ares The two principal axes of a square



2.37 echanical Properties

2.37.1 teel and Aluminum

a Yield Stress Throughout this Guide, yield stress refers to

either yield point or yield strength as applicable to the

material.

i Yield Point The yield point is the first stress in a

test at which an increase in strain occurs without an increase in

stress. Ordinary strength steels and some higher strength steels

have a yield point.

ii) Yield Strength The yield strength is the stress at

which a material exhibits an offset strain of 0.2% for aluminum

and steel or for steel an extension under load of 0.5%.

b Tensile Strength The stress obtained by dividing the maximum

load a specimen sustains during a test by the original cross-

sectional area of the specimen.

2.37.2 iber-Reinforced Plastic

a Flexural Strength The measure of the capability of a plate

to withstand a bending load without failing.

b Flexural Modulus The number used to calculate the distance

a plate will deflect under a given bending load.

c Tensile Strength The measure of the capability of a plate

or stiffening member to withstand a stretching load without

failing.

d Tensile Modulus The number used to calculate the amount a

plate or stiffening member will increase in length when a

stretching load is applied to it.

e Compressive Strength The measure of the capability of a

plate or stiffening member to withstand a compressing load without

crushing.

f Compressive Modulus The number used to calculate the



b Modulus of Elasticity The number used to calculate the

distance a plate or stiffening member will deflect under a given

bending load. Values given are generally for bending parallel to

the grain.c Tensile Strength Parallel to Grain The maximum stretching

load divided by the initial sectional area of the specimen,

parallel to the grain, that a plate or stiffening member can

withstand without rupture. As relatively few data are available

for this property it may be conservatively estimated, for clear,

straight-grained wood, by the modulus of rupture in bending.

d Tensile Strength Perpendicular to Grain he maximum

stretching load divided by the initial sectional area of the

specimen, perpendicular to the grain, that a plate or stiffeningmember can withstand without rupture.

e Compressive Strength A measure of the maximum compressive

load a plate or stiffening member can withstand without crushing.

It is obtained by the maximum load that can be carried without

crushing, divided by the cross-sectional area of the plate

stiffening member. alues given are generally for the

compressive stress parallel to the grain.

2.39 Systems of Measurement

This Guide is written in three systems of units, i.e., SI units,

MKS units and US customary units. ach system is to be used

independently of any other system.

The format of presentation in the Guide of the three systems of

units is as follows:

SI units (MKS units, US customary units)

unless indicated otherwise.



SECTION 3

GENERAL

3.1 aterialsThe materials of which the hull is constructed will be indicated

in the Record as, steel, higher strength steel, (HTS), or fiber

reinforced plastic (FRP). here advanced composits are

substantially used, the material will be identified as FRP,

Advanced Composites.

3.3 Structural Arrangement and Details

The structural arrangements and details are to be in accordance

with Sections 6 and 7. Major openings such as hatches and large

vents are to be avoided in the hull in close proximity to the

gunwale. Corners of openings in strength structures are to have

generous radii. Compensation may be required for openings.

3.5 tructural. Members

The scantling requirements of this Guide are applicable to eitheraluminum or steel standard rolled or extruded structural shapes

and bars, including flat bars, or fabricated sections, or fiber

reinforced plastic members, with or without effective cores. The

section modulus of a stiffening member is obtained in association

with the plating to which the member is attached. The effective

width of plating is given in 3.7. The section modulus of a shape,

bar, or fabricated section, or layed-up member not attached to

plating is that of the member only.

3.7 ffective Width of Plating

3.7.1 eneral



FIGURE 3.1

Effective Width of F1RP Platirig

9t r

tc = LSt b.



FIGURE 3.2

Bracket

y

TABLE 3.1

Steel Brackets

Metric

Length of Face hickness, mm idth of

f, mm lain Flanged lange, mm

Not exceeding 305 .0 --

Over 305 to 455 .5 .0 8

Over 455 to 660 .0 .5 0

Over 660 to 915 .5 .0 3Over 915 to 1370 1.0 .5 5



SECTION 4

MATERIALS

4.1 Aluminum Alloys

The weld filler metals and aluminum alloys used in vessels built

to comply with this Guide are to be in accordance with the

requirements in Sections 30 and 35 of the Rules for Building and

Classing Aluminum Vessels . onsideration will be given to

aluminum alloys of different properties provided they are

suitable for marine applications and welding. are is to be

taken that aluminum alloys are insulated where necessary from

other metals. imber and paints containing copper, lead or

mercury are not to be used with aluminum alloys.

For guidance, Table 4.1 gives the physical properties of some of

the aluminum alloys in Sections 30 and 35 of the Rules for

Building and Classing Aluminum Vessels . The physical properties

of other aluminum alloys suitable for marine applications,

specified in recognized national or industrial standards, will

also be considered. equirements for welding are given in

Section 15.

4.3 Steel

The steel used in vessels built to comply with this Guide are to

be in accordance with the requirements for Grade A ordinary-

strength hull structural steel or Grade AH higher-strength

structural steel in Part 2, Chapter 2 of the latest edition of

the Rules for Building and Classing Steel Vessels , or steel in

accordance with other approved standards. Flat-rolled steel andflat bars less than 5 mm (0.20 in.) in thickness and shapes of

cross-section less than 645 mm2 (1 in`) need not be subjected to



the cured laminate properties. ee also Section 17, Corrosion

Prevention and Protective Coatings.

4.5.2 ResinsResins for the basic laminate of this Guide, other than those

utilized for gel coats, are to be unsaturated, general-purpose or

fire-retardant polyesters suitable for marine use, and are to be

catalyzed n trict ccordance ith anufacturers'

recommendations. Other resins, such as epoxy or vinylester, may

be used. The properties of a resin are to be for the final form

of the resin actually used in production with all additives and

fillers included. The amount of silicon dioxide or other material

added to provide thixotrophy is to be the minimum necessary to

resist flowing or draining. If mineral fillers are added,they are

to be of a type recommended by the resin manufacturer. ll

additives are to be in accordance with the resin manufacturers

recommendations. he strain at failure of the cured gel coat

resin is generally to exceed that of the cured laminating resin.

Relevant details of the resins in liquid and cured form are to be

submitted.

4.5.3 Reinforcing Materials

Fiber reinforcing materials are to be as described in 2.33.1.

Binders, where used, are to be soluble polyester, epoxy, or

vinylester resin, as appropriate for the laminating and gel coat

resins. Sizes and finishes are to be of the silane type, and are

to be compatible with the laminating resins. Binders, sizes and

finishes are to be non-water-soluble.

4.5.4 L aminates

a Basic Laminate The basic laminate consists of general-

purpose polyester resin and alternate plies of fiberglass mat and

fiberglass woven roving. he minimum glass content of this

laminate is 35% by weight.



the laminate. he cured resin-and-woven roving plies may be

taken to have having average thickness equal to 0.12 millimeters

per 100 grams of woven roving in each square meter (0.0016 inches

per ounce of woven roving in each square yard) of the basiclaminate.

For mat and woven roving laminate differing from the basic FRP

laminate in glass content, the average cured laminate thickness,

t, varying with the glass content, can be obtained from the

following equations:

Wk(05t = — .690 mm (in.)

c \ fg

Where: k = 0.35 mm (0.0138 in.)

fg= the glass percentage content by weight, of one ply of

the mat and one ply of the woven-roving of the

laminate to be used

c = glass content per pair of composite fiberglass

reinforcement of basic laminate,

= 1272 g/m2 or 4.17 oz/ft2

W = total weight of fiberglass reinforcement in g/m2 or

az/ft2, of the laminate to be used

Thicknesses obtained form the above equations are average

effective thicknesses not including exemptions, see 4.5.4c.

e omposites Differing from Basic Laminate here bi-

directional reinforced-plastic laminates other than the basic

laminate are to be used, the appropriate verified minimum

physical properties are to be used in the scantling equations.

See 5.3.6h3 and 4. These properties of the laminate, and lay-up

detail showing the thickness and weight of the plies are to be



4.7 ood

Member ill Strength/Warp Strength

Panel, aspect ratio - 1.0 .80

Panel, aspect ratio > 2.0 .61

Stiffening member .25

For panels with aspect ratios between 1.0 and 2.0, the factors are

to be obtained by interpolation.

The required scantlings are to be determined by using the

appropriate verified minimum physical properties in the scantling

equations. he values of EF/F, ET/T and Ec/C in the fill

direction are not to exceed the same ratios in the warp direction.Where the properties of the finished laminates forming the

crown, webs or shell or deck flanges of an internal member differ

in the direction of bending stresses, the internal is to meet the

requirements of Section 9 or 10, as appropriate, for each

different strength laminate.

Where the arrangements of the layers and the physical

properties of the laminate are such that the laminate meets the

definition of a bi-directional laminate it may be considered as

such.

4.7.1 General

All wood used is to be of good marine quality, properly seasoned,

clear, free of defects adversely effecting its strength and with

the grain suitable for the purpose intended. Wood members, except

cold-molded wood laminates coated with resin, are to be treated

with a preservative.The strength properties for some such woods are given in

Table 4.4. here other woods are to be used, the strength



Table 4.1

Properties of Aluminum Alloys

Sheet and Plate

Alloy Thickness

Minimum UltimateTensile Strength

N/mm2 g f / n m i 2 si

Minimum Yield Strength

Unwelded Condition

N/mm2 gf/mm2 siHO Up to 38mm (1.5 in) 275 28.1 40000 125 12.6 18000H116 Up to 38mm (1.5 in) 275 28.1 40000 215 21.8 31000

5083 H321 Up to 38mm (1.5 in) 275 28.1 40000 215 21.8 31000

H112 Up to 12.5 mm (0.499in) 240 24.6 35000 125 12.6 18000H112 Up to 25.5 mm (1.0 in) 240 24.6 35000 110 11.2 16000

5086 H116 Up to 51.0 mm (2.0 in) 240 24.6 35000 195 19.7 28000

H32 Up to 51.0 mm (2.0 in) 240 24.6 35000 195 19.7 28000

H34 Up to 25.5 mm (1.0 in) 240 24.6 35000 235 24.0 34000H32 Up to 51.0 mm (2.0 in) 215 21.8 31000 180 18.3 26000

5454 H34 Up to 25.5 mm (1.0 in) 215 21.8 31000 200 20.4 29000

H116 Up to 38 mm(1.5 in) 290 29.5 42000 215 21.8 310005456 H321 Up to 38.0 mm (1.5 in) 290 29.5 42000 215 21.8 31000

Table 4.1

Properties of Aluminum Alloys

Extrusion

Minimum Ultimate inimum Yield Strength

Tensile Strength nwelded Condition

Alloy elded Condition

Ninm 2 kgf/nme psi N/nm2 kgf/mme psi



TABLE 4.2

Properties of Steels

Minimum intimateStrength

MinimumYield Strengthensile

Grade Ninme Kgf/m/a2 pal witme K g f t i o n t2 psi

A 400 4 1 58,000 235 24 34,000

AH32 470 48 68,000 315 32 45,000AH36 490 50 71,000 355 36 51,000

Table 4.3

Properties of Fiber Reinforced

Plastic Basic Laminate

N/mm2 K g f i r a r a2 psi

Flexural strength, F 172 17.5 25,000Flexural modulus, Ey 7580 773 1.1 x 106

Tensile strength, T 124 12.6 18,000

Tensile modulus, ET 6890 703 1.0 x 106

Compressive strength, C 117 11.9 17,000

6890 703 1.0 x 106ompressive modulus, Ec

Shear strength perpendicular to warp 76 7.7 11,000

Shear strength parallel to warp, 62 6.3 9,000

Shear modulus parallel to warp,Es 3100 316 0.45 x 106

Interlaminar shear strength 17.3 1.76 2500



TAB LE 4.4

Properties of Various Woods

Bending

Modulus

Tensile Strength

Moduluzl erpendicular ompressing Strength

Specific of Rupture of Elasticity o Grain Parallel to Grainommon Name

of Species Gravity N/mm2 N/=m 2 /mm2 8imm2

(kgf/mm2

si) (kgf/mm2, psi kgf/mm2, psi Ckglimm2, psi

Ash, White 106 12.00=103

5.5 51

0.60 (10.87, 5400) (1228, .74=106

) (.56, 40) (5.22, 400)

2adas,Alaaka 76 9.79=103

2.5 44

0.44 (7.84, 1100) (1002, ,42=106) (.25, 60) (4.45, 310)

Cedar, Western 52 7.65x103 1.5 31

Red 0.32 (5.30, 500) (783, .11=106 ) (.16,220) (3.22, 560)

Elm, American 81 9.242:103 4.6 38

0.50 (6.33, 1800) (964, .34=105

) (.47,660) (3.90, 520)

Elm, British 41 7.52=103

34

0.56 (4.24, 000) (783, .11=106

) (-, ) (3.53, 000)

Elm, Rock 102 10.52=103

49

0.53 (10.45, 4800) (1087, .54x106 ) (-, ) (4.98, 050)

Fir, Douglas 86 13.45x103 2.3 50

0.48 (8.75, 2400) (1376, .95x106 ) (.24,340) (5.11, 240)

Mahogany, Central 80 10.41x103 - 46

& South America (8.19, 1600) (1065. .51=106

) (-, ) (4.63, 630)

Oak, English 66 10.00=103

30

0.70 (6.78, 500) (1023, .45=106

) (-, ) (5.08, 200)

Oak, White 105 12.27=103

5.5 51

0.68 (10.73, 5200) (1255, .78x105) (.55,800) (5.25, 440)

Pine,Longleaf 100 13.65x103 3.2 56

Yellow 0.59 (10.24, 4500) (1398, .98=106) (.33,470) (5.98, 470)

Pine, Oregon 85 13.43=103

2.3 50

0.48 (8.75, 2400) (1375, _95=105

) (.24,340) (5.11, 240)



Table 4.5

Core Material Properties

MinimumDensity hear Strength

Material g/m3 lb/f t3 N/mm2 gf/nme si

Balsa, end-grain 28 .9 .19* 70*Balsa, end-grain 44 .1 .21* 00*Polyvinyl chloride, 0 .0 to 1.2 0.10 to 0.12 145 to 170

crosslinked 00 .25 .4 to 1.5 0.14 to 0.15 200 to 215

Polyvinylchloride, 0-96 5-6 .2 .12 70linear

Note: * These values are for Ecuadorian balsa.



SECTION 5

FABRICATION AND QUALITY CONTROL

5.1 Steel and Aluminum

The requirements of this Guide apply to all-welded vessels;

workmanship is to be of good quality. In general, the welding for

steel or aluminum vessels is to comply with Section 15.

5.3 iber Reinforced Plastic

5.3.1 General

The use of fabricating procedures differing from those in thisGuide will be specially considered.

5.3.2 Fabrication Proceduresa General The laminate is to be fabricated by the contact

or hand-layup process for either single-skin or sandwich

construction. ther methods of fabrication will be subject to

consideration. The resin gel time used in production is to be

within the limits recommended by the resin manufacturer.

b Laminate Layup A layer or ply of reinforcing material may

consist of a number of pieces. The pieces are to be lapped along

their edges and ends. The width of each lap is to be not less

than 50 mm (2 in.). Unless otherwise specifically approved, no

laps in the various plies of a laminate are to be closer than 100mm (4 in.) to each other.

Transitions in laminate thickness are to be tapered over a

length not less than three times the thickness of the thicker

laminate. A gradual transition in fiber reinforcement is to be

provided between bi-directional and uni- directional laminates.



consideration being given to the adhesive used to bond the ply to

the core.

d Secondary Bonds he surfaces of cured laminates are to

be fresh and free from wax, grease, dirt and dust. The first ply

of the secondary layup is to be chopped-strand mat.The final ply

of laminate along the bond line of the cured laminate is to be

preferably chopped-strand mat.

5.3.3 Building Process Description

The building process description is to be submitted for review by

the builder before construction starts.

Information on the following items is to be included.

Description of construction facilities, including environmental

control and material storage and handling. Specifications

for resins, reinforcing products, and core materials.

Layup procedures, including type, orientation of

reinforcements, sequence, resin mixing methods, and resin

pot-life limits

Secondary bounding procedures

Inspection and quality-control systems

Laminate properties derived from destructive qualificationtesting

5.3.4 Building Facilities

a. aterial Storage Premises

The premises are to be equipped and arranged so that the material

manufacturer's recommendations for storage and handling can be

followed:

i) Premises are to be cool, clean, dry and sufficiently free ofdust so that materials are not contaminated or degraded,

materials are to be remain sealed in storage as recommended



b. aminating Premises

Premises are to be arranged and equipped so that the material

manufacturer's recommendations and builder's standards for

handling, laminating and curing can be followed:

i) Premises are to be fully enclosed, dry, clean, shaded from

the sun, and adequately ventilated and lighted.

ii) Temperature is to be maintained adequately constant at atemperature between 16C and 32C (60F and 90F). The humidity

is to be kept adequately constant to prevent condensation

and is not to exceed 80%. Where spray molding is taking

place the humidity is not to be less than 40%. Temperatureand humidity are to be within limits recommended by the

materials manufacturer's.

Departures from the foregoing will be considered provided

temperatures and humidity are within the limits recommended

by manufacturer and are reviewed by the Bureau prior to

laminating.

iii) Scaffolding is to be provided where necessary so that alllaminating work can be carried out without standing on cores

or on laminated surfaces.

5.3.5 Inspection

Inspection is to be carried out by the builders and Surveyors as

indicated and approved in the building process description andbuilding quality control manual. A constant visual inspection of

the laminating process is to be maintained by the builder. If

improper curing or blistering of the laminate is observed,immediate remedial action is to be taken. nspections of thefollowing are to be carried out.



vi) Check that curing is occurring as specified. mmediate

redemial action is to be taken when improper curing or

blistering is noted.

vii) Visual overall inspection of completed lay-up for defectsthat can be corrected before release from the mold.

viii) Check and record hardness of cured hull prior to release

from mold.

5.3.6 Quality Control

a eneral A quality-control system is to be set up in

association with the building process description. The objective

of the system is to measure and record compliance with approved

plans and the process description. Quality-control records are to

be carefully kept, and are to be available at all times for review

and routine verification by the Surveyor to the Bureau. Prior to

conducting the tests described in h, the dates of the tests are to

be given to the Surveyors by the builder.

b eceiving s all materials are received by the

builder, they are to be inspected by the builder to assure

conformance with the builder's purchase orders, which in turn are

to reflect the material specifications on the approved plans and

in the process description. ests are to be carried out as

necessary on the resins and results recorded.

c el Time The builder is to establish and implement a

resin gel-time control system for the gel-time desired in

production. This gel time is to be within the gel-time upper and

lower limits recommended by the resin manufacturer. Resin mixes

are to be monitored and recorded to assure proper gel times.

During layup the temperature and humidity in the laminating area

is to be recorded at regular intervals, and the catalyst and geltime are to be adjusted to suit changing conditions.

d Lamination The plies and cores as applicable are to



Barcol hardness number of the cured laminate measured on the

surface without the gel coat, is to be not less than 4 0.

2 urnout and Thickness The builder is to conduct and

record the results of a predetermined, sufficient number of tests

for glass/fiber content and thickness checks on cutouts or plugsthat have been removed from laminates to make way for through-hull

and through-deck fittings. he plugs are to be identified by

their location in hull. Each burnout test for glass reinforced

laminates is to be made on a sample that is at least 25 mm (1 in.)

in diameter. record is to be made of the cured laminate

thickness and the glass content by weight. iber content

measurement for carbon and aramid (kevlar) fiber reinforced

laminates are to be carried out by acid tests.

Additionally, a visual inspection of the residue may berequired to determine the types and the number of layers of

reinforcement used in the laminate.

3 aminate Properties Determination of laminate

properties (specific gravity, glass content, tensile strength and

modulus, flexural strength and modulus, shear strength, and, where

glass content is 40% or more, interlaminar shear strength) is to

be made on the basis of destructive qualification tests of panels

assembled by the fabricator under environmental conditions and

using resin formulations and process techniques simulating theconditions, formulations, and techniques to be used in actual

production.

The fabricator is to lay up the test panels at an angle of

about 45°. All panels are to be tested in the as-cured condition.

Test procedures are to be in accordance with American Society for

Testing and Materials (ASTM) specifications or equivalent. All

test results are to be reported. Bureau review of laminate design

will be predicated on the quality of laminate produced by the

fabricator. aminate properties derived from qualificationtesting of sample panels, which are to be witnessed as necessary

by the Surveyor are to be included in the process description.



Length (L)

Under 9./

ft

Under 30

9.1 o 2.2 30 to 40

12.2 o 15.2 40 to 50

15.2 to 18.3 50 to 60

18.3 to 21.3 60 to 70

21.3 to 24.4 70 to 80

24.4 and over 80 and over

Frequency

of testing

Every 12th vessel

Every 10th vessel

Every 8th vessel

Every 6th vessel

Every 4th vessel

Every other vessel

Every vessel

The tests associated with the laminate properties are shown in

Table 5.1. Tests alternative to those listed will be specially

considered.

4. Test Results ne copy of the test results is to be

forwarded promptly to the technical office doing hull plan

approval. Where test results are less than laminate design

properties indicated on approved plans, this is to be drawn to

the attention of the technical office. ne copy of all test

results is to be filed. in the classification survey report.

In the case of advanced composites, one copy of all test

results is to be forwarded to the technical hull plan approval

staff.

5. Tests Hull hydrostatic, hose tests and machinery and

electrical tests are to comply with applicable Rule or Guide

requirements.



TABLE 5.1

Tests for Physical Properties of F.R.P. Laminates

Flexural Strength

Flexural Modulus

Tensile Strength

Tensile Modulus

Compressive Strength

Compressive Modulus

Shear Strength, Perpendicular to Warp

Shear Strength, Parallel to arp

Interlaminar Shear Strength

Test

ANSIIASTM D 790 or 0790M

ANSI/ASTM D 790 or D 790M

ANSI/ASTM D 638 or D638M or ASTM D 3039

ANSI/ASTM D 636 or D638M or ASTM D 3039

ANSI/ASTM D 695 or D 695M or ASTM D 3410

ANSI/ASTM D 695 or D 695M or ASTM D 3410

FTMS 406 1041

FTMS 406 1041

ASTM D 3846

ASTM C 273

ASTM C 273

I L I M rty

Single

Core hear Strength

Shear Modulus

Tensile Strength, Facings STM C 393

Sandwich ompressive Strength. Facings STM C 393

Composite lexural Strength, Composite STM C 393

(Structural hear Stiffness, Composite STM C 393

Test) hear Strength, Composite STM C 393

Bond Strength, Core to Facings STM C 393



not less than 0.051. abaft the stem at the design load waterline.

This bulkhead is to extend to the main weather deck, and may be

stepped, provided the forward end of any step is not less than

0.05L, measured horizontally, from the stem. In vessels having

long superstructures at the forward end, the bulkhead is to beextended weathertight to the superstructure deck. Provided the

extensions are not less than 0.051. abaft the stem at the design

load waterline, they need not be fitted directly over the

collision bulkhead; in such cases, the part of the deck that

forming the step is to be weathertight.

One door or opening with a watertight closing appliance may

be fitted in the collision bulkhead below the freeboard or main

weather deck of vessels less than 30.5 m (10 0 ft) in length. This

door or closure is to be kept closed and secured at sea.

b. Engine Room

The engine room is to be enclosed by watertight bulkheads

extending to the main weather deck except that for smaller vessels

consideration may be given to the extent and arrangement of

enclosing the engine space.

c. Chain Locker

Chain lockers located abaft collision bulkheads or extending intoforepeak tanks are to be watertight.

6.1.3 Tanks

The arrangement of all integral tanks, their intended service, and

the heights of the overflow pipes are to be indicated clearly on

the drawings submitted for approval.

Where potable water tanks are fitted, water closets are not

to be installed on top of the tanks nor are soil lines to run over

the top of the tanks. Pipes containing nonpotable liquids are notto be run through the tanks. ttention is directed to the

regulations of national authorities that might govern the



stiffeners within integral tanks are to penetrate the tank

boundaries. No gasoline tanks are to be fitted integrally.

All internal surfaces of FRP tanks are to be covered with

fiberglass chopped strand mat weighing at least 600 grams per

square meter (2 ounces per square foot). This covering is to be

in addition to the scantlings required by this Guide. A heavy

coat of the laminating resin, or other suitable coating, is to be

applied to this covering, alternatively a suitable thickness gel-

coat is to be applied.

6.3.2 Encapsulation

a. Wood Softwoods encapsulated in FRP are considered effective

structural materials where used in the shell above the waterline

and clear of tanks. They are not recommended for use in the shellbelow the waterline or in or as boundaries of tanks. If used in

these locations they are to be considered nonstructural core

materials.

Hardwoods are not to be used as core materials in the shell

or tank boundaries except that balsa may be used in these

locations. onsideration will be given to the hardwood

encapsulation in decks.

b. Plywood lywood encapsulated in FRP is considered an

effective structural core. The required inertia of the laminate

is to meet the requirements for FRP. The structure is to be

considered as a composite section with the areas adjusted for

modulii, and stresses in the plywood and FRP determined by

distance from neutral axis and strain. Resulting stresses are not

to exceed allowable design limits.

c onding ffective wood or plywood cores are to be bonded

to the encapsultory member and to the shell, deck or bulkhead

plate, at joints in the core and at end connections.



7A.3 Fabrication

7A.3.1 eneral

The requirements in this Guide apply to vessels of weldedconstruction. Aluminum rivets, where desired, are to be in

accordance with 7A.3.2. Expanding rivets may be used within

the limitation in 7A.3.3.

See also Section 15 for welding and Section 17 for corrosion

prevention.

7A.3.2 luminum Rivets

Non-heat-treatable and heat-treatable aluminum alloy coldheading rod and wire for use in manufacturing rivets is to

be in agreement with a specification equivalent to ASTM

Designation B316. aterial differing from ASTM B316 in

chemical composition, mechanical properties or heat-

treatment may be specially considered.

7A.3.3 xpanding Rivets

Rivets of the expanding type (blind or pop rivets) may be

used for lightly loaded connections where lack ofaccessibility prohibits the use of through fastenings. Such

rivets are not to be used for permanently joining components

having a total thickness exceeding 12.5 mm (0.50 in.) nor

for joining decks to hulls.



PART B IBER REINFORCED PLASTIC HULLS

7B.1 Structural Details

7B.1.1 eneral

Structural continuity is to be maintained and where changes

in thickness or structural section occur, they are to be

gradual to prevent notches, hard spots and other structural

discontinuities. The requirements below are for the basic

laminate given in 4.5.1 ; special consideration will be given

where other laminates or resins are used. The ends of all

internal structural members are to provide end-fixity and

load transmission to the supporting member, departures fromthis may be considered where the alternative structure has

equivalent strength.

7B.1.2 penings, Holes and Raw Edges

Access and lighting holes with suitably radiused corners are

to be arranged as necessary and clear of areas of load

concentration or high stresses. Their depths and lengths

are generally not to exceed 0.5 and 0.75 times respectively

the depths of the members. Air and limber holes are to be

arranged to eliminate air pockets and avoid any accumulation

of water or other liquids. In general they are to be not

less than 40 mm (1 1/2 in.) or 1/3 the depth of the member

whichever is less. All exposed edges of FRP single-skin

laminates are to be sealed with resin. Edges of sandwich

panels and edges of holes in sandwich panels are to be

sealed with resin-impregnated mat. errules installed in

sandwich panels or stiffeners for drains or wire

penetrations are to be set in bedding compound.

7B.1.3 tiffeners



Where the stiffeners are of laminates with properties

differing from the basic laminate, the thickness is to be

modified by the factor

Eb ompressive modulus of basic laminate given in 4.5.4b.

E = compressive modulus of proposed laminate.

sub— ultimate compressive strength of basic laminate given

in 4.5.4b.

s u — ultimate compressive strength of proposed laminate.

Lesser thicknesses may be considered where shear strength

and a panel stability are satisfactory.

Hat-section stiffeners constructed by laying FRP over

premolded FRP forms (Figure 7.2a) are to conform with Figure

7.1 and the above equations; the premolded forms may be

considered structurally effective if their physical

properties are at least equal to those of the overlay

laminates.Premolded stiffeners bonded to the laminates with FRP

angles, flanges or tapes (Figure 7.2b) are also to conform

to Figure 7.1 and the above equations. The thickness of

each bonding angle, flanges or tapes, is to be not less than

the thickness of the webs of the stiffeners, and the legs of

the bonding angle, flange or tape, are to be of equal length

in accordance with 78.3.4. Joints in premolded stiffeners

are to be scarphed and spliced or otherwise reinforced to

maintain the full strength of the stiffeners.

c tiffeners with Structural Cores Where approved



An acceptable type of continuous girder and longitudinal-

frame FRP connection is shown in Figure 7.3. The laps of

the connections onto the supporting structure are to be not

less than the over-all widths of the structural members

including flanges, and the thicknesses of the connections

are to be not less than the thicknesses of the structural-

member flanges or tapes.

7B.1.5 hell Details

a Keels Plate keels are to meet the requirements in

Figures 7.4a and 7.4b and vertical keels or skegs are to

comply with Figures 7.5a and 7.5b.

b Chines and Transoms Chines and transoms are to meet therequirements in Figure 7.6.

7B.1.6 ngine FoundationsThe engine beds are to be of thicknesses and widths

appropriate to the holding- down bolts, are to be set in mat

putty or resin putty to assure uniform bearing against the

girders, and are to be bolted through the webs of the

girders. igure 7.7 shows several typical, acceptable

engine foundations.

7B.1.7 eck Fittings

Deck fittings such as cleats and chocks are to be bedded in

sealing compound or gaskets, through-bolted, and supported

by either oversize washers or metal, plywood, or wood

backing plates. Where washers are used, the laminate in way

of the fittings is to be increased at least 25% in

thickness.

7B.1.8 iping and Wiring in Foam

Piping and wiring passing through foam-filled spaces is to



required, suitable sealants or bedding compounds are to be

used in addition to the fastenings. or materials of

fastenings, see 4.13.

7B.3.2 olts and Machine ScrewsBolts or machine screws are to be used where accessibility

permits. The diameter of each fastener is to be at least

equal to the thickness of the thinner component being

fastened. Bolts and machine screws less than 6.5 mm (0.25

in.) in diameter are not to be used. Fasteners are to be

spaced at a minimum of 3d center to center and are to be

located at a distance from the edges of laminates not less

than 3d where d is the fastener diameter.

In way of bolts and machine screws, low-density corematerials are to be replaced with structurally effective

inserts. iameters of fastening holes are not to exceed

fastening diameters by more than 0.4 mm (0.016 in.).

Washers or backing plates are to be installed under all

fastening heads and nuts that otherwise would bear on

laminates. Washers are to measure not less than 2.25d in

outside diameter and 0.1d in thickness. uts are to be

either of the self-locking type,, or other effective means

are to be provided to prevent backing off.Care is to be taken to ensure that the bolt, nut or other

components into which the bolt is screwed are of materials

having the same mechanical properties. Where materials of

different strength are used, this is to be considered in

determining the length of thread engagement between members.

7B.3.3 elf-tapping Screws

Self-tapping screws having straight shanks may be used for

lightly loaded connections where lack of accessibilityprohibits the use of through fastenings. elf-tapping

screws are not to be used for joining laminates either of



of the single-skin laminate or the mean thickness of the

skins of the sandwich panel being attached, whichever is

less.

The thickness of each FRP-to-FRP boundary angle also is tobe not less than obtained from the following equation,

0.11L .0 mm t .00132L + 0.04 in.

but need not exceed 6 mm (0.24 in).

where

length, in m or ft, as defined in Section 2

The width of each flange is to be at least 10 times the

thickness given above or 50 mm (2 in.) if that be greater

and the width including the end taper, 13 times the

thickness given above.

b Plywood or Wood to FRP Plywood or wood girders, plywood

floors, and bulkheads are to be bedded in foam, a slow-

curing polyester putty, a microballoon-and-resin mixture, or

other approved material. Boundary angles of FRP are to beapplied over fillets made of the bedding material. he

nominal size w of each fillet is to be 9.5 mm to 1 2.5 mm(0.375 in. to 0.50 in.). The boundary angles are to be at

least equal in thickness to one-half the thickness of thelaminate, and the width of each flange is to be as shown in

Figure 7.9a. Secondary bonding of these angles to FRP is to

be in accordance with 5.3.3.

Where plywood floors and structural bulkheads are to be

secured with boundary angles and bolts or machine screws, itis to be as shown in Figure 7.9b. Each boundary angle is to

be at least equal in thickness to one-half the thickness of



minimum bolt diameters, and maximum bolt spacing are to be

in accordance with Tables 7.1 and 7.2. Intermediate values

may be obtained by interpolation.

FRY bonding angles, where used, are to have flanges that are

at least one-half as thick as the hull or deck laminate,whichever is thicker. The widths of the flanges are to be

in accordance with the widths of overlaps in Table 7.2.

Each joint is to be protected as shown in Figure 7.10 by a

guard, molding, fender, or rail cap of metal, wood, rubber,

plastic, or other approved material. he size and

ruggedness of this protective strip are to be consistent

with the severity of the service for which the vessel is

intended. The strip is to be installed in such a manner

that it may be removed for repair or replacement withoutendangering the integrity of the deck-to- hull joint.

b Interior Joints Interior decks are to be joined to the

hulls by shelves, stringers, or other structural devices

that resist vertical and horizontal loads. Alternatively,

glassed-in interior decks will be considered.

7B.3.6 Joints in Wood or Plywood Longitudinals

Glued joints in wood or plywood girders, shelves, clamps,and other longitudinals are to be scarphed. Bolted joints

in wood members are to be scarphed and nibbed, and may be

hooked, key-locked, or hooked and key- locked. The slopes of

the scarphs are to be not greater than 1 in 12. The depth

of each nib and hook and the width of each key are to

approximate 25% of the depth of the member (see Figure

7.11). In a member having two or more scarphs, the scarphs

are to be not less than 1.5 m (5 ft) apart.

In a bolted joint the bolt diameter is to approximate 17% ofthe width of the member. Each scarph is to be fastened with

at least four bolts. ashers, essentially of the same



FIGURE 7.1

Propordans of Stiffeners

re

t

Mini=tuni Ina = 0.2h or 50 =avrizic.z . ev er is gezr.L.7however lap 1 im e= of50 inza (2. hi..) need not 3e

m.r.er .113. lot

h



FIGURE 7.3

Conner:ion of Loncitudinals to Transverses

eb. or aaar



FIGURE - 4a

Plate Keel in One-Piece Hull

13/10

FIGURE -. 7 . 4b

Plat= Keel in Hull McIdec; in Halves



FIGURE --- .6

Chine or Transom

=3:



Nitestil =sic

bracket

FiCURE 7.7

Entine Foundaticns



SandwioXius~ie sic

FiGURE 7.8

Boundary Andes for FRP Ccrnpcnents

FiGUSE 7. 9

Boundary Andes Connectinc Plywood cr

Wood tc FRP

alvisemdeammoite-..aro

cer462.4.v.

ladMt or 50 c ool fa in.)vim/Cr-ever

is csr=t=

Boit aia = t or 6-5

= (WM to.) Nvi:ith.ev=ix geo.ter

0.5t



FIGURE 7.11

Bolted S=r;h Joints

Nibbed and : zoc iker i

N i b b e d s a d k e y - lo c k e d

Nibber i . nd key-:Locked

r e y s are doable wedrz



TABLE 7 . 1

Maximum Boit Spacing

Metric Units

Length of Vessel

L m

Bolt Spacing. mm

Umestried

Service

Limited

Service

9 152.5 228.5

12 185.0 241.5

15 177.5 254.0

18 190.5 268.5

21 203.0 279.5

24 216.0 292.0

27 228.5 305.0

30 241.5 317.5

33 254.0 330.0

38 266.5 343.0

Inch Units

Length of Vessel

L. ft

Bolt Spacing, in.

Unrestricted

Service

Limited

Service

30 8.0 9.0

40 6.5 9.5

50 7.0 10.0

607.5 10.5

70 8.0 11.0



TABLE 7.2

Deck-to- Hull Joints

Metric Units

Length

of Vessel

L, m

Minimum Width

of Overlap,

mm

Minimum Bolt

Diameter,

mm

9 63.5 6.5012 75.0 7.75

15 87.5 9.00

18 100.0 10.25

21 112.5 11.50

24 125.0 12.75

27 137.5 14.00

30 150.0 15.25

33 162.5 16.5036 175.0 17.75

Inch Units

Length

of Vessel

L, ft

Minimum Width

of Overlap

in.

Minimum Bolt

Diameter,

in.

30 2.5 0.2540 3.0 0.30

50 3.5 0.35



SECTION 8

DESIGN PRESSURES

8.1 emi-Planing and Planing Craft

8.1.1 Bottom Structure Design Pressure

The minimum bottom design pressure is to be the greatest of a, b

or c as given in the following equations, for the location under

consideration. Lesser pressures may be used for operation limited

to protected or partially protected waters.

a b — NI, (1 + n) FD Fv1 kN/m2 (tf/m2,psi)

LwB

b. Pi .5k1 NdFDFV2 N/m2 (tf/m2, psi)

c. PD a 9.5 (D+1.22) N/m2,PD 0+1.22) tf/m2,PD .44(D+4)psi

Where:

(L + 1.009 r (50 -0 ) V2 B2

B

Ni 0.1 SI units (0.01 MKS units, 0.069 US units)

N2 .0046 SI units (0.0046 MKS units, 0.00094 US units)

A isplacement, stationary, in kg or lbs, at design

waterline

Fv2 = Vertical acceleration distribution factor given in Figure



8.3

AD = esign area, cm2 (in2); for plating it is the actual area of

the shell plate panel but not to be taken as more than 2 s2.For longitudinals, stiffeners, transverses and girders it is

the shell area supported by the longitudinal stiffener,

transverse or girder; for transverses and girders the area

need not be taken less than 0.33 e.

= reference area, cm2 (in2 ),

= 6.95 A/d cm2

= 1.61 A/d in2

= spacing of longitudinals or stiffeners, in cm or in.

d = stationary draft in m or ft, vertical distance from outer

surface of shell at centerline to design waterline at middle

of design waterline length, but generally not to be taken as

less than 0.04L.

N = service dynamic factor, depending on displacement, speed and

sea conditions, in general to be taken not less than 1.00except that where the sea and speed induced vertical

acceleration at LOG may exceed 9.806 m/sec2 (32.2 ft/sec2),

an appropriately higher value is to be used. here the

vertical acceleration at LOG will be less than 9.806 m/see

(32.2ft/sec2) appropriately lesser values of 1.00 may be

specially considered. In both cases designers are to submit

details of speed, displacement, running trim, sea conditions

and predicted vertical acceleration at LOG. perational

guidance may also be required on board.



V in knots from 21 o 6I L in feet,

8.1.2 Side Structure, Design Pressure

The side design pressure, ps is to be not less than given by the

equation

Ps — klh+0.20 Pb kN/m2 (tf/m2,psi)

Where:

ki s defined in 8.1.1

h distance in m or ft, from lower edge of plate panel or

from center of area supported by the longitudinal ortransverse, to the freeboard or main weather deck at

side, but not less than 0.5D.

Pb - design pressure given in 8.1.la,except that Fvi may be

taken as 1.0 for forward 0.45L.

D molded depth in m or ft as defined in 2.5.

8.1.3. Deck and Deck House Structure Design Pressure

The design pressures, pd, are to be as given in Table 8.1.

8.1.4. Bulkhead Structure, Design Pressure

a Tank Boundaries The design pressure for tank boundaries is to

be not less than given by the following equation

Pt N/m2 (tf/m2, psi)

Where:

The heights of overflows are to be clearly indicated on the plans



submitted for approval.

Pressurized tanks will be subject to special consideration.

b atertight Boundaries he design pressure for watertight

boundaries is to be not less than given by the following equation:

Pw = kih kN/m2 (tf/m2, psi)

Where:

kl — as defined in 8.1.1

h distance in m or ft from the lower edge of the platepanel or the center of area supported by the stiffener

to the bulkhead deck at centerline

8,3 isplacement C raft

Where the maximum speed in knots is less than 2.36/7 L in meters

or 1.30iL, L in ft, the design heads are to be as given in Table

8.2.

8.5 ydrofoils, Air Cushion Vehicles, Surface Effect Craft, and Multi-

hull Vessels

Design pressures for shell, bulkheads and decks are to be not less

than given in 8.1.1, 8.1.2 and 8.1.3. hose from 8.1.1 may be

obtained using N values appropriate to vessel service and type.

Design calculations for the external design pressures due to sea

loading for the various operational modes and for structures

peculiar to the vessel type such as hydrofoil struts and foils

etc, are to be submitted for review.



:u li

kG,

W

O N -4

II



Design Area Factor - F

0 4 4 1 P i I

0.6 018, i

RP1 ) P i0'002 0 00I 4013 o Nt

b . D I

( 1 1_. .) . :1iI1)J

1514. n X 7'i L

6 1516

e t 4.49q109 t r N i c r e -J 4 11 .zogiv 4atyLsia



S i

M y

•

3u3a raoDy reonzaA

1 -1.11t.t L114111 II kil 1.1114.1 KU IL, LL11111.4.1.1.1.141.141.1_11{ (I 11.1.1111(1 k1.1.1.1 U U I iiiLinn111.1111111.1.11ili MIMIMtn

7,'0 J

46 1516

vta V G O I -A mqd



Section 9



Hull Scantlings, High Speed Craft

9.1 pplication

This section applies to crafts having maximum speed (in knots)

not less than 2.36 j(1.30 NE) where L is the length in m (ft)

as defined in 2.1.

Part A lating

9A.1 liminum or Steel

General

The bottom shell is to extend to the chine or upper turn of

bilge. he thickness of sea chests, where installed, is to be

not less than required for the bottom shell. In general the side

shell is to be of the same thickness from its lower limit to the

gunwale. ll openings are to have well rounded corners and

generous radii are to be provided at hull breaks. Thick plating

of sufficient breadth to prevent damage is to be fitted around

hawse pipes. The plating is to be effectively protected against

corrosion.

9A.1.2 Thickness

The thickness of the plating is to be not less than given by the

greater of the following equations,

a All Plating

t =pk k

mm = s n1000 a, ,

where:



s he spacing, in mm or in, of the shell, deck, superstructures,

deckhouse or bulkhead longitudinals or stiffeners, and always the

lesser dimension of the plate panelp esign pressure, in kN/m2, (tf/m2, psi) given in Section 8

k — plate panel aspect ratio factor, given in Table 9A.1

aa— design stress, in N/mm2 (kgf/mm2, psi) given in Table 9A.2

L = vessel length in m or ft as defined in 2.1

c1 — actor for service and location, given in Table 9A.3

q 35/ r y SI units (24/ay MKS units, 34000/ay US units)

a ield stress of material in N/mm2 kgf/mm2 psi).required hull- girder section modulus given in Section 11

S i roposed hull-girder section modulus of midship sectionE — odulus of elasticity in N/mm2 ( k g f / n i n a2, psi)

kb— with longitudinal framing, 2.5

with transverse framing, 1.5 for . 2 / s — 2.0 or above

with transverse framing, 2 for l/s — 1.0

Shell thickness in way of skegs and shaft struts is to be not less than

50% greater than the required thickness for the bottom shell from

equation a, using the pressure Pb in 8.1.1 and actual frame spacing.

Suitable framing reinforcement is to be provided in way of shaft struts.

9A.3 Fiber Reinforced Plastic

9A.3.1 eneral

The shell, decks and bulkheads may be either single skin or sandwich

construction. here both are used, a suitable transition is to be

obtained between them.

The bottom shell is to extend to the chine or upper bilge turn. A

suitable transition is to be obtained between the bottom and side shell

plating. The thickness in way of the keel is to be at least 50% greater

and in way of shaft struts and skegs it is to be at least 100% greater



A = istance in mm or in. measured perpendicular from the

chord of length, s, to the highest point of the curved



plate arc between the panel edges

design pressure, given in Section 8

k or k1 = co-efficient varying with plate panel aspect ratio as

given in Table 9A.1

kb s defined in 9A.1.2

da = esign stress, given in Table 9A.5.

k2 = or shell, deck and bulkhead=0.015; for superstructures

and deckhouse fronts=0.020

E, lexural modulus of laminate, in N/mm2 (kgf/mm2,psi).

L = essel length in m or ft as defined in 2.1

cl & k, = factor for service and location, given in Table 9A.4

qi = 70/F SI units (17.5/F MKS unit, 25000/F US units)

minimum flexural strength of laminate, in N/mm2

(kgf/mm2, psi)

auc inimum compressive strength of laminate in N/mm2

(kgf/mm2,psi).

E, = ompressive modulus of elasticity in N/mm 2 (kgf/mm2, psi)

k b = s defined in 9A.1.1.

SMR = equired hull-girder section modulus given in Section 11

SNa = roposed hull-girder section modulus of midship section

b With Different Properties in 00 and 900 Axes

For laminates with different strength and elastic properties in

the 00 and 900 (principal panel) axes where the strength is less,



C Y ai= esign stress, for inner skin, given in Table 9A.5, based on strength

of inner skin in direction parallel to s



Crri3sc)2 pke

6x105 c i ae ,In

2 n direction parallel to

SM0 SI% = (sc)2pke e

6 c 7 a e , E 5

ET C = 0-5(Ec + ET)

Ec = mean of compressive modulii of inner and outer skins, in N/mm2

(kgf/mm2, psi)

ET = mean of tensile modulii of inner and outer skins, in N/mm2 (kgf/mm2,

psi)

Laminates with Different sending Strength and Stiffness in 0° and 90°Axes

For laminates with different properties in the 0° and 90° (principal panel)

axes the section modulus and moment of inertia about the neutral axis of a

strip of sandwich panel, 1 cm (1 in.) unit width, are to be also not less

than given by the following equations.

1 n direction parallel to s

S M M(sc)2 pks

M = in(SC)

2pk,

7 -

6x105aaso 6aso

3 n direction parallel to s

SM = m3

M =(sc)2pks sc)2pks

i

6x105 c r a s iaa s,

SM1 = equired section modulus, in cm- or in 3, to inner skin

co-efficient for plate panel aspect ratio, given in Table 9A.1A.



C13.130 = esign stress, for outer skin, given in Table 9A.5 based on

strength properties in direction parallel to s

C 3a0 = esign stress, for outer skin, given in Table 9A.5 based on

strength properties in direction perpendicular to s

oast' = esign stress, for inner skin, given in Table 9A.5 based on

strength properties in direction parallel to s

owi = esign stress, for inner skin, given in Table 9A.5 based on

strength properties in direction perpendicular to s

0.5 (ET, + Er,)

E .5 (E rm Erm)

ETs, Erg = ean of tensile modulii of inner and outer skins, and mean of

compressive modulii of inner and outer skins, in N/mm2(kgf/mm2,

psi) in direction parallel to s, respectively

ELF Ecf ean of tensile modulii of inner and outer skins, and mean of

compressive modulii of inner and outer skins, in N/mm2 (kgf/mm2,

psi) in direction parallel to P, respectively

c. Shear Strength

The average thickness of core and sandwich laminate is to be not less than

given by the following equation. Special consideration will be given where

cores differing from those in 4.11 are proposed. ee also 9A.3.4e for

minimum thickness of skin.

vps o d vpsmm n.

p - design pressure in kN/m2 (tic/m.2, psi), as given in Section 8,

except that AD is to be taken not less than s2 and FD isto be



taken not less than 0.75.

r - design stress, in N/mm2(kgf/mm2, psi) is 0.40 times minimum

ultimate shear strength of core material. See 4.11.

Skin Stability

The skin buckling stress, cc, given by the following equation, is in

general to be not less than 2.0 aai and 2.0 aac

ac = 0.6 3,/ ES . Ec . Cc /mm2 (kg.f/mm2, psi)

Where:

Es ompressive modulus of skins, in N/mm2 (kgf/mm2, psi) in 0° and

90° in- plane axis of panel

compressive modulus of core, in N/mm2

(kgf/mm2, psi),

perpendicular to skins

core shear modulus, in N/mm2 (kgf/mm2 psi), in the direction

parallel to load

e. inimum Skin Thickness

After all other requirements are met, the thickness of the outer skin,

tcs and inner skin, tis, is in general to be not less than given by the

following equations.

TABLE RA.1



Aspect Ratio Co-efficient For Isotropic Plates

Panel Aspect Ratio

> .0 0.50 0.028

2.0 0.497 0.028

1 .9 0.493 0.027

1.8 0.487 0.027

1.7 0.479 0.026

1.6 0.468 0.025

1.5 0.454 0.024

1.4 0.436 0.0241.3 0.412 0.021

1.2 0.383 0.019

1.1 0.348 0.017

1.0 0.308 0.014

s = shorter edge of plate panel in mm or in

= longer edge of plate panel in mm or in

TABLE 9A.1A

Aspect Ratio Co-efficient for Orthotropic Plates

k P(//s) k,

TABLE 9A.2



DESIGN STRESSES, aa , ALUMINUM AND STEEL PLATING

ALUMINVIe TEEL

SHELL .70 ay /0.58 a u y

DECKS .50 ay 10.42 ou .6 ay

SUPERSTRUCTURE & DECKHOUSES

FRONTS, SIDES & ENDS .78 o,/0.65 o uY

TOPS .50 ay /0.42 ou .6 u,

TANK EHDS .50 ay /0.42 a, .6 cy

W.T. EHDS .75 a /0.62 a, .0 a,

ay - yield stress of steel or unwelded aluminum, in N/mm2 (kgf/mm2, psi)

uu = ultimate tensile strength of welded aluminum, in N/ mm2 (kgf/mm2, psi)

Note: he lower of the indicated values is to be used.



TABLE 9A.3

Bottom Shell

Side Shell

Strength Deck

ALUMINUM AND STEEL

FACTOR cl

Steel luminum

mm (in) m (in)

2.5 (0.10) .5 (0.14)

2.00 (0.08) .0 (0.12)

1.80 (0.07) .7 (0.11)

Consideration will be given to lesser values for vessels limited to

service in relatively sheltered waters.



TABLE 9A.4

FIBER REINFORCED PLASTIC

FACTOR c1 and k3

ci k3

mm (in)

3.2 (0.125)

Bottom Shell ide Shell & Deck

Consideration will be given to lesser value of c l for vessels limited toservice in relatively sheltered waters.



TABLE 9A.5

DESIGN STRESSES FRP, ca

Bottom Shell .33au

Side Shell .33au

Decks .33au

Superstructures and Deckhouses

Front

Sides,

Ends

Tops

Tanks Bhds

W.T. Bhds

Core Shear

0.33au

0.33au

0.50au

O.5ru

au or single skin laminate, minimum flexural strength,in N/mm2 (kgf/mm2, psi)

— for sandwich laminates;

- for shell or deck outer skin, minimum tensile strength,in N /mm2 (kgf/mm2, psi)

for shell or deck inner skin, minimum compressive strength,in N/mm2 kgf/mm2 psi)



Part B Internals



913.1 Aluminum and Steel

93.1.1 eneral

Structural arrangements and details are to be in accordance with

Sections 6 an 7.

913.1.2 ection Modulus

The section modulus of each longitudinal, beam, transverse frame,

stiffener, transverse web, stringer or girder is to be not less than

given by the following equation.

SM — 83.3 ps/2 cm3 SM 44ps/2 n3

as a

where

p — design pressure in kN /m2 (tf/m2 , psi) given in Section 8

s pacing in m or ft, of longitudinal, beam, transverse frame,

stiffener, transverse web or girder

/ — length, in m or ft, of the longitudinal stiffener, transverse web

or girder, between supports; where bracketed end connections are

supported by bulkheads, shell or decks, I may be measured onto

the bracket, the distance, 0.5 x bracket length from the toe of

bracket, provided both bracket arms are about the same length

design stress, in N /mm2 kgf/mm2 psi) as given in Table 93.1

93.1.3 roportionsa. Aluminum

For built-up sections, the web depth to thickness ratio is not to exceed

55 and the flange width to thickness ratio is to be not more than 12.

9B.3 Fiber Reinforced Plastic

9B.2.1 eneral



Structural arrangments and details are to be in accordance with Sections

6 and 7.

Laminates may be bi-directional, having comparable strength and elastic

properties in the two, in-plane, principal axes of the panel or they may

be uni- directional, having different strengths and elastic properties in

the two, in-plane, principal axes of the panel. Bonding angles, flanges

or tapes are to have strength and elastic properties same as the

laminates of the plating and internal being bonded.

9B.3.2 iber Reinforcement

The basic laminate given in 4.5.4a, or other approved laminate, of

glass, aramid, or carbon fiber, in mat, woven roving, cloth knitted

fabric, or woven or non-woven uni- directional reinforcing plies may be

used. The plies are in general to be layed-up parallel to the direction

of the internal. he strength of the laminate in a direction

perpendicular to the direction of the internal is in general not to be

less than 25% of the warp strength except for the uni-directional caps

of the flange or crown of the internal members. In way of continuous

longitudinal members, the section modulus and moment of inertia of

transverse members is to be attained by the shell or deck plating andthat part of the transverse member that is continuous over the

longitudinal member.

Where higher strength or higher modulus plies are used in the flange or

crown of the internal, it may be advisable to provide similar higher

strength, higher modulus local plies in the shell or deck plating, in

the direction parallel to the internal to balance the strength and

stiffness of the high strength and high modulus plies in the flange or

crown of the internal.

modulus is to be considered at each different strength laminate

of the member.



b. Moment of Inertia

The moment of inertia of each longitudinal, stiffener, transverse

web, stringer or girder, including the plating to which it is

attached, is to be not less than given by the following equation

2 6 0 1 D S - e3

4psem 4

k4E 4E

where:

p,s, and i are as given in 9B.1.2

0.015 for bottom, side, deck and bulkhead internals

0.020 for superstructure front and house front internals

tensile or compressive modulus, in N /mm2 (kgf/mm2,psi)

representative of the laminates used in the moment of

inertia calculation.

c. Shear AreaThe web area, A, of the member is to be not less than given by

the following equation

7.5pst 08psf1 - cm = in2

t

where:

p,s,and re as given in 9B.1.2

98.5 Stanchions

93.5.1 eneral



Supports under stanchions are to be of sufficient strength to

distribute the loads effectively. tanchions above are to be

arranged directly above stanchions below wherever possible; wherethis is not possible, effective means are to be provided for

transmitting the loads to supports below. Stanchions in double

bottom tanks and under the tops of deep tanks are to be metal and

of solid cross section. Stanchions are in general not to be used

in the bottom or double bottom structure where subjected to high

impact loads in service.

93.5.2 tanchion Load

The load on a stanchion is to be obtained from the following equation:

W = pbs kN(tf) = 4.064pbs Ltf

W = load in kN (tf, Ltf)

b = mean breadth in m or ft of area supported

s = mean length in m or ft of area supported

design pressure in kN/m2 (tf/m2, psi) given in Section 8. Where a

stanchion supports two or more decks, p is to be the design

pressure for the deck at the top of the stanchion plus the sum ofthe design pressures for all complete decks and one-half the

design pressure for all tops of deck-houses above the deck being

directly supported.

93.5.3 ermissible Load

The load a stanchion may carry is to be equal to or greater than the

load on the stanchion obtained in 98.3.2. his permissible load is to

be obtained from the following equations.

a. Mild Steel Stanchions

The adoption of aluminum-alloy test values higher than given in Table

4.1 will be subject to special consideration.



9B.5.4 RP Stanchions

Normally FRP is not considered to be a material suitable for stanchions.

If for special reasons FRP stanchions are contemplated, they will be

subject to specially consideration.

9B.5.5 upport by Bulkheads

. Bulkheads supporting girders or bulkheads fitted in lieu of stanchions

are to be stiffened to provide supports not less effective than required

for stanchions.

TABLE 9B.1

DESIGN STRESSES



ALUMINUM STEEL FRP

Bottom Longitudinals 0.55 ay/0.46 s , 0.80 ay 0.50 c

Side Longitudinals 0.55 cy/0.46 , 0.72 ay 0.40 cu

Deck Longitudinals 0.55 ay/0.46 u 0.50 ay 0.40 au

House/Superstructure Stiffeners 0.70 ay/0.58 , 0.70 ay 0.33 cu

Bottom Transverse and Girders 0.55 ay/0.46 c, 0.80 ay 0.33 a,

Side Transverse and Girders 0.55 r y/0.46 u 0.80 a, 0.33 a,

Deck Transverse and Girders 0.70 cy/0.58 u 0.70 o, 0.33 a,

W.T. ulkhead Stiffeners 1.00 ay/0.83 au 1.00 a, 0.55 0,

Tank Bulkhead Stiffeners0.60 oy/0,50 u 0.75 ay 0,33 ou

W.T. ulkhead Webs and Stringers 0.75 cy/0.62 cu 0.75 ay 0.50 cu

Tank Bulkhead Webs and Stringers 0.60 cy/0.50 Cu 0.75 Cy 0.33 Cu

c r y = yield strength, unwelded condition, in N/mm2 (kgf/mm2, psi)

Cu = ultimate tensile strength, in N/mm2 (kgf/mm2, psi)

for aluminum, the value in the welded condition is to be used.

SECTION 10



HULL SCANTLINGS, DISPLACEMENT CRAFT

10.1 Application

This section applies to crafts having maximum speed in knots less than

2.36j (1.30j) where L is the length in m (ft) as defined in 2.1.

Part A lating

10A.1 Aluminum and Steel

10A.1.1 eneralThe bottom shell is to extend to the upper turn of bilge or to

the chine. n general the side shell is to be of the same

thickness from its lower limit to the gunwale. All openings are

to have well rounded corners. The thickness of sea chest, where

installed, is to be not less than required for the bottom shell.

Thick plating of sufficient breadth is to be fitted around

hawsepipes to prevent damage.

10A.1.2 hickness

The thickness of the plating is to be not less than given by thefollowing equations:

a All Plating

qh l/qht = 2 mm = 0.08 in

272 95

b Strength Deck and Shell Plating

2.5 with transverse framing, .2/s .0

SMR- required hull- girder section modulus given in Section 11

SMN- proposed hull-girder section modulus of midship section



After all other requirements are met the thickness is in general

not to be less than 4.0 mm (0.16 in) for aluminum and 2.5 mm(0.10 in) for steel.

Shell thickness in way of skegs, rudder horns and shaft struts is

to be at least 50% greater than the required thickness for the

bottom shell from equations a and b. uitable framing

reinforcement is to be provided in way of shaft struts and

rudders horns.

10A.3. iber Reinforced Plastic

10A.3.1 General

The shell, decks and bulkheads may be either single skin or sandwich

construction. here both are used a suitable transition is to be

obtained between the two.

The bottom shell is to extend to the chine or upper bilge turn.

A suitable transition is to be obtained between the bottom and side

shell plating. The thickness in way of the keel is to be at least 50%

greater and in way of shaft struts and skegs it is to be at least 10 0%greater than the required thickness for bottom shell, given in equation

10A.3.3, a, b or c and actual frame spacing. uitable framing

reinforcement is to be provided in way of shaft struts and rudder

horns.

The shell, deck or bulkhead laminates may be bi-directional,

having essentially same strength and elastic properties in the two in-

plane principal axes of the shell, deck or bulkhead panels or the

laminate may be uni-directional, having different strength or elastic

properties in the two principal axes of the shell, deck or bulkheadpanels. onding angles, flanges or tapes are to have strength and

10A.3.3 ingle Skin Laminate

a With Essentially Same Properties in 0° and 90 ° Direction

The thickness of the shell, deck and bulkhead plating is to be not less than



given by the greatest of the applicable equations in the following.

1 ll Plating

t = 0.015sc Vkhql mm = 0.084sc j i 1 4 7 in.

2 ll Plating

t = 0.0518 sc 3. 1 k 1 hq2 mm = 0.034sc 3Vki q in.

3 trength Deck and Shell

t = k3(C1 + 0.261, Vgi mm = k3(C1 0.0031L m

4 trength Deck and Bottom Shell, Within 0.66L Amidships, L > 30.5m

(100 ft)

Where:

t = —.-Kb

0.6a.SMa MM orECSM A

Kb is defined in 10A .1.2

Ec, SM„ SMA are as defined in 9A.3.3a

S = maller dimension of plate panel, in mm or in,

c = orrection factor for curved plating, (1- A/s), not to be

taken less than 0.70A = istance in mm or in measured perpendicular from the chord

2.

1.= 0.015sc Vksh c li mm t = 0.0084sc Ilkshch in.



t = 0.015sc Vkihqi 1lE- e t = 0.084sc likth qEs

Where s and h are as defined above and

ks = co- efficient for plate panel aspect ratio, obtained from Table9A.1A.

ke = co- efficient for plate panel aspect ration, obtained from

Table 9A.IA.

= greater dimension of rectangular plate panel in mm or in, equal

to s for square panelsE, = flexural modulus of laminate in N/mm2 (kgf/mm2, psi) in the

direction parallel to s

Et = flexural modulus of laminate in N/mm2 (kgf/mm2, psi) in thedirection perpendicular to s

F5 = flexural strength of laminate in N/mm2 (kgf/mm2, psi) in thedirection parallel to s

F = flexural strength of laminate in N/mm2 (kgf/mm2, psi) in thedirection perpendicular to s

10A.3.4 andwich Laminate

a. With Essentially Same Properties in 0° and 90° Direction

In general the inner and outer skins are to be similar in reinforcing form,in lay-up, and in strength and elastic properties, each having also not

greatly dissimilar tensile and compressive strengths and modulii. Special

consideration will be given where this is not the case. In general, single

skin laminate is to be used in way of the keel, shaft struts, skegs, and

rudder horns, deck fittings, bolted connections and other areas ofconcentrated local loads. Alternatively, cores effective in flexure and

= required moment of inertia, in cm 4 or in4

q3 = 124/au SI units (12.6/cu MKS units, 18000/au US units)



q4 = 7580/ETc SI units (773/ETC MKS units, 1.1x106/ET C US units)

auo= tensile strength of outer skin in N/mm 2 (kgf/mm2, psi)

cr= compressive strength of inner skin, in N/mm2 (kgf/mm 2, psi)

ETC= 0.5(ET Ec)

ET = mean of tensile modulii of inner and outer skins, in N /mm 2 (kgf/cm2,

psi)

Ec = mean of compressive modulii of inner and outer skins, in N/mm2

(kgf/cm2, psi)

b. With Different Properties in 0° and 90° Direction

Where the stiffness is greater in the panel direction perpendicular to s

than that in the direction paralles to s, the section modulus about the

neutral axis of the strip of sandwich, 1 cm (1 in) unit width, are also to

be not less than given by the following equations whichever is greater.

1 In direction parallel to s

SM© = 5.2x10- 7(sc)2 ks h q3 cm3, Mo = 0.000016(sc)2 ks h q3 in3

2 In direction parallel to i

SM, = 5.2x10- 7(sc) k hql m3 M, = 0.000016(sc)2 k h q3 n3

Cruos

Cruoe

tensile strength of outer skin, in N /mm2 (kgf/mm2, psi) in


tensile strength of outer skin, in N/mm 2 (kgf/mm2, psi) in



Crui s

cull =

direction parallel to £

compressive strength of inner skin, in N/mm2 (kgf/mm2, psi) in


compressive strength of inner skin, in N/mm 2 (kgf/mm 2,psi) in

direction parallel to i

c Shear Strength

The thickness of.the core and skins of a sandwich laminate are to be notless than given by the following equation. Special consideration will be

given where cores differing from those in 4.11 are proposed.

d, dc =k4 vhsm or in

2

Where:

do =

d, =

v =

k4 =s =

h=t

overall thickness of sandwich, excluding gel coat, in mm or in

thickness of core, in mm or ins.

co-efficient varying with plate panel aspect ratio, given in

Table 9A.6.Where the elastic properties of the skins are

different in the principal axes, v is to be taken not less than

0 50.01(0.001, 0.44) in SI (MKS, US) units

lesser dimension of plate panel, in mm or in.

design head as given in Table 8.2.design stress, in N/mm2 (kgf/mm2, psi), is 0.50 times the minimum

t os thickness of outer skin in mm or in.

t is thickness of inner skin in mm or in.

--



Part B nternals

103.1 Aluminum and Steel

103.1.1 eneral.

Structural arrangements and details are to be in accordance with

Sections 6 and 7. Where different strength alloys are used, for the

stiffener, longitudinal, transverse web, girder etc and for the plating

to which it is attached, the section modulus is to be determined in way

of each different strength alloy.

108.1.2 trengthThe section modulus of each longitudinal, beam, frame stiffener,

transverse web, stringer and girder together with the plating to which

it is attached, (see 3.5), is to be not less than given by the

following equation.

SM — 7.8 chs.22 q cm3 M — 0.0041 chs.22 q in3

The section modulus of collision bulkhead stiffeners is to be 25%

greater than the values given above.

Where:

c .85 for bottom longitudinals, superstructure and deckhouse

bhd stiffeners0.70 for all other shell members and for members of tank

boundaries, including double bottom tank members- 0.64 for strength deck longitudinals amidships, 0.48



(0.048L + 3.6) 0.00058L + 0.14) A-in

Where L and q are as defined in 108.1.4a.



c. Open Floors

The bottom frames and inner bottom frames are to be as required in

108.3.1.

d. Inner Bottom Plating

Inner bottom plating is to be not less than obtained from the following

equation

t 0.033L + 0.008s) fiTmm t 0.0004L + 0.008s) Ain

Where L and q are as defined in 108.1.4.a

frame spacing in mm or in

108.3 Fiber Reinforced Plastic

10B.3.1 eneral

The structural arrangements and details are to be in accordance withSections 6 and 7. These requirements may also apply to plywood in

which case the requirements and the different strength and elastic

properties are to be considered for each of the different materials in

the composite section

Laminates may be bi- directional, having comparable strength and elastic

properties in the two, in-plane, principal axes of the panel or they

may be uni-directional, having dissimilar strengths and elastic

properties in the two, in- plane, principal axes of the panel. Bondingangles, flanges or tapes are to have strength and elastic properties

the direction parallel to the internal to balance the strength and stiffness

of the high strength and high modulus plies in the flange or crown of the

internal.



108.3.3 trength and Stiffness

The section modulus and moment of inertia of each longitudinal, stiffener,transverse web and girder including the plating to which it is attached is

to be not less than given by the following equations

SM = 22.91 chse q3 cm3 M = 0.0119 chse q3 in3

I = 34.85 chst3 q5 cm3 = 0.0022 chst3 q5 in3

Where c,h,s and t are as given in 108.1.2

q3 = as defined in 10A .3.4a.

q5 = 6890/E SI units (703/8 MKS units, 1.0x106/E US units)

E = the modulus of elasticity of the cured laminate, in the direction

parallel to the member, in N/mm2 (kgf/mm2, psi) where the member or plating

to which it is attached are constructed of different modulii laminates, E is

the base value used in the inertia calculation of the member.

108.3.4 roportions

The thickness of webs and flanges are to be in accordance with 78.1.3.

108.5 Stanchions

108.5.1 General

Stanchions in displacement craft are to meet the requirements in

98.5 using in lieu of 98.5.2 the stanchion load as defined in

108.5.2.

TABLE 10.1

ALUMINUM AND STEEL INTERNALSMINIMUM WEB DEPTH



Aluminum teel

mm in) m in)

Bottom Shell .5(0.14) .5(0.10)

Side Shell .0(0.12) .00(0.08)

Strength Deck .5(0.10) .80(0.072)

TABLE 10.2

FIBER REINFORCED PLASTIC

FACTORS C1 k3

C1 3 3

mm (in) ottom Shell ide Shell Deck

3.0(0.12) .0 .90

Consideration will be given to values of CI and k3 for vessels

limited to service in relatively sheltered waters.

SECTION 1

LONGITUDINAL STRENGTH

11.1 General

•



The hull girder section modulus is to be in accordance with the requirements

of this section. The equations are, in general, valid for vessels having

breadths B not greater than twice their depths D as defined in Section 2.

Vessels whose proportions exceed these limits will be subject to special

consideration.

11.3 Longitudinal Hull Girder Strength

11.3.1 . Section Modulus, All YachtsThe required hull girder section modulus SM at amidships is to be not less

than given by the following equation.

SM = 0.01C1L2B(Cb+0.7)(CQ) cm2- t (in2-ft)

where

CI 3.65(L/10)2-20.37(L/10)+37.38 2 < 25m

0.57(L/10)2-5.47 (L/10)+19.38 5 < 45m

• .30 5 < 61m

C1 .0144 [3.65 (L/32.8)2-20.37 (L/32.8)+37.881 39 5 L < 82 ft

0.0144 [0.57 (L/32.8)2-5.47(L/32.8)+19.38] 2 < 148 ft

0.0144 [6.30] 48 5 L < 200 ft

• ength of yacht in m or ft as defined in Section 2

breadth in m or ft as defined in Section 2

Cb = lock coefficient at design draft, based on the length,

L, measured on the design load waterline. Cb is not to

be taken as less than 0.45 for L 5 35 m (115 ft) or 0.6

N/mm2 kgf/mm2 , psi)

Q for fiber reinforced plastic

- 400/au SI units, 41 /au MKs units, 58000/au

US units.

----



(7u inimum ultimate tensile or compressive strengthwhichever is less in N/mm2 (kgf/mm2, psi),

verified by approved test results.

See 5.3.6h 3 and 4.

b. ection Modulus, High Speed Yachts

Where the vessel speed exceeds 25 knots, the hull-girder

section modulus is also to be not less than obtained by the

following equations, whichever is greater.

SM Lw

Cy

(128 YF 78 YCGg

50) CQ cm2 -Win2ft)

r

SM =ALw (78 Ycs 28 YA 50) CQ cm2- m (in2 ft)

Cy

Where

A maximum displacement in metric tons or long

tons

Lw = length of design waterline in m or ft

YF ertical acceleration at forward end, average

1/1 0 highest, m/sec2 (ft/sec2)

Cy 1320 SI and MKS units or 8380 US unitsYCG vertical acceleration at longitudinal center of

K 4000 for steel

-

1333 for aluminum

-

180 for fiber reinforced plastic, basic laminate



Special consideration will be given for fiber reinforcedplastic laminates differing from the basic laminate, see4.5.4.

11.3.2 ection Modulus Calculation

In general, the following items may be included in the

calculation of the section modulus and inertia provided they

are continuous or effectively developed within the midship

0.4L , have adequate buckling strength, and are gradually

tapered beyond the midship 0.4L.

Deck plating (strength deck and other effective decks)

Shell and inner bottom plating

Gunwale angle or its equivalent, bulwark

Plating and longitudinal stiffeners of longitudinal

bulkheads

All longitudinals of deck, sides, bottom, and inner bottom

In general, the net sectional areas of longitudinalstrength members are to be used in the hull girder sectionmodulus calculations. he section modulus to the deck orbottom is obtained by dividing the moment of inertia by the

distance from the neutral axis to the molded deck at side

amidships or base line, respectively. Where a continuous

bulwark or long deckhouse or superstructure is considered as

part of the hull girder, the section modulus to the deck is

obtained by dividing the moment of inertia by the distance

from the neutral axis to the top of the bulwark, deckhouseor superstructure.



SECTION 12

Keels, Stems, Stern Frames and Shaft Struts



12.1 Materials

12.1.1 Ordinary Strength Steel

The requirements in the following subsections are based on

ordinary strength steel. or other materials see 12.1.2 and

12.1.3.

12.1.2 Other MetalsUnless otherwise specified, the required section modulus and

inertia for steels other than ordinary strength or aluminum is to

be not less than those obtained from the following:

SM = SM, x Q

I = I, x E5/E0

where

SM, I = required section modulus nd inertia. nless

specifically stated otherwise, the properties about the

minor axis (axis perpendicular to h or w) are to be

used.

SM5,15 = Section modulus and inertia obtained from the dimensions

given for ordinary strength steel.

Q =s defined in 11.3.1

12.5 Stems

12.5.1 ar Stems

Where bar stems are used, their thickness and widths are not to be less



than obtained from the following equations.

t 0.625L + 6.35) mm 0.0075L + 0.25) in

w 1.25L -1- 90) mm 0.015L + 3.5) in

t equired thickness in mm or in.

w - required width in mm or in.

L - as defined in 12.3.

This thickness and width are to be maintained between the keel and

design load waterline. Above the design load waterline they may be

gradually reduced until the area at the head is 70% of that obtained

from the equations.

12.5.2 ast or Forged Stems

Cast or forged stems of special shape are to be proportioned to provide

strengths at least equivalent to those of bar stems; all joints and

connections are to be at least as effective as would be required on

equivalent bar stems.

12.5.3 late Stems

Where plate stems are used, they are to be not less in thickness than

the bottom shell plating as obtained in Section 9.

12.7 Stern Frames

12.7 1 nner Posts

12.7.2 loors in Way of Stern FrameThe stern frame posts are to be attached to floors having suitable

thicknesses and depths sufficient for welded attachments.



12.7.3 ast, Forged, or Fabricated Stern FramesCast, forged, or fabricated stern frame posts of special shape are to be

at least equal in strength to bar-type stern frame posts, and all joint

connections are to be at least as effective as would be required onequivalent bar-type stern frames. All connections to the stern framesin the vicinity of the shoe pieces are preferably to be either rabbeted

or flush-butted with backing bars where necessary.

12.9 Shoe Pieces

Shoe pieces are to have a width approximately twice the depth. The

section modulus about the vertical axis of the shoe piece is to be not

less than the value obtained from the following equation.

2 — cAV2. /1000 cm3 (in3)

where

2y — required section modulus, at any section of the shoe piece

cY

= a coefficient varying with speed, from Table 12.1

A total area of rudder, in square meters or square feet

V design speed in knots with the vessel running ahead at the

maximum continuous rated shaft rpm and at the designed

waterline.— horizontal distance, in mm or tn., between centerline of

rudder stock and the particular section of the sternframe

12.1 3 Shaft Struts

12.13.1 eneralShaft struts may be of V or I type. The thickness of the strut barrel

or boss is to be at least one-fifth the required diameter of the tail



shaft. pecial consideration will be given to the use of materials

other than steel or aluminum. The following equations are for struts

having streamline cross-sectional shapes. Other methods of determining

scantlings will be considered.

12.13.2 idth and Thickness

The thickness and width of each strut arm is to be not less than those

obtained from the following equations:

a. V strut

t= 0.365d — 2.27 d

b. I strut

t— 0.515d — 3.22 d

where

t thickness of strut (minor axis)

w — width of strut (major axis)

d — required diameter of ABS grade 2 steel tail shaft in mm or in.

Where the included angle of V strut is less than 450, the sizes in

12.13.2a above will be specially considered.

12.13.3 trut Length

The length of the longer leg of a V strut or the leg of an I strut,

measured from the outside of the strut barrel or boss to the outside of

the shell plating, is not to exceed 1 0.6 times the required diameter of

the tail shaft. Where this length is exceeded, the width and thickness

TABLE 12.1

Values of c



Intermediate values of c are to be obtained by interpolation

Speed, V 10

Metric Units

c without an

11 12 13 14 15 > 16

outer post .054 1.811 1.617 1.464 1.339 1.235 1.138

Inch/Pound Units

c without anouter post .296 0.261 0.233 0.211 0.193 0.178 0.164

SECTION 13

Rudders



13.1 General

All vessels are to be provided with an approved steering system.

The use of speed, direction, or pitch variation of specially

designed propelling units as a means of steering will be

specially considered. Effective rudder stop is to be provided.

13.3 Materials

Steel materials for rudder stocks, frames, pintles, crossheads,

tillers, quadrants, etc., are to be in accordance with the Rules

for Building and Classing Steel Vessels. The surfaces of rudder

stocks in way of exposed bearings are to be of noncorrosive

material. Where rudders are of aluminum the material is to be in

accordance with the Rules for Building and Classing Aluminum

Vessels. Special consideration will be given to aluminum rudder

stocks and fiber reinforced plastic rudders and rudder stocks.Material specifications are to be indicated on the plans.

13.5 Unbalanced Rudders

This subsection applies to rudders having their area located

totally abaft the axis of rudders.

13.5.1 pper Rudder Stocks

Rudder stocks above the top pintle are to have diameters not less

than obtained from the following equation.



mean distance in mm or in. of the bolt centers from thecenter of the system of bolts.

The minimum distance between the bolt holes and the edges of the

coupling flanges is to be two- thirds the diameter of the bolts.



c Flanges Where flanges are used as couplings, the minimum

thickness of each flange is to be 0.255. If keyways are cut in

the flanges, the thickness of each flange is to be increased by

an amount equal to the keyway depth. Special consideration will

be given where bolts and flanges are of different materials.d Vertical Couplings Where a vertical scarphed coupling is

used, the minimum length of scarph and the minimum width of

scarph at top and bottom is to be 2.5S. The minimum thickness of

scarph is to be 0.13S.

13.7 Balanced Rudders

This subsection applies to rudders having part of their area

located forward of the axis of rudder.

13.7.1 Upper Rudder Stocks

Rudder stocks above neck bearings are to have diameters not lessthan obtained from the following equation. Where an upper pintle

is provided at the top of the rudder, the upper stock may extendto the top of the rudder.

S = 21.66c /kRAV2 mm = 0.26c /kRAV2 in

S = required diameter of upper stock in mm or in.

c, k, A ,V,R = as defined in 13.5.1

In addition, the upper stock is not to be less in diameter

R — 0.25 (a -4 - 2 6 1 )2) with efficient bottom

bearings

- a + j a2 b without bottom bearings

a

-

vertical distance in m or ft from the center of the



neck bearing to the centroid of Ahorizontal distance in m or ft from the rudder axis

to the centroid of A

The stock of a balanced rudder having efficient neck

and bottom bearings is to be the full diameter for at least

two-thirds of the distance from the neck to the bottombearing. The diameter may be gradually reduced below this

point until it is 0.7551, at the bottom bearing of the

rudder.The lower stock in the bottom bearing is to comply

with the requirements of 13.9 for a pintle in the samelocation. Where the diameter of, the ,-lower stock in thebottom bearing is less than the diameter-of' the-lower stock

at the bottom of the rudder, a suitable transition is to beprovided. The bearings are to be.bushedp,and the bushing is

to be effectively secured against movement.

The stock of a balanced rudder having no bottom

bearing is to be the full diameter to the underside of thetop rudder arm if a single-plate rudder, or to the top ofthe rudder if a built-up rudder. The diameter may be

gradually reduced below this point until it is O.33S1 at the

bottom. The length of the neck bearing is to be 1.551, and

the bearing is to be bushed and the bushing is to be

effectively secured against movement. ower stocks forbuilt-up rudders may be omitted provided the strength of the

rudder in torsion and bending is equivalent to that required

for the lower stock.

13.9 intlesPintles are to be of steel. Where rudders or rudder stocks

are of aluminum, pintles are in general to be of austentic

stainless steel, or other approved material.

The pintle diameters are to be not less than given by



the following equation.

d = c Vc1 j kA

where V,k,A and c are as defined in 13.5.1 and

d equired diameter of pintle in mm or in.

- 4.52 (0.054), 3.67 (0.044) and 3.18

(0.038) for rudders having two,

three or four pintles

respectively.

The depth of the pintle boss is to be not less than

1.2d. intles are to extend for the full depth of the

gudgeons; the top pintle is to be placed as high as

practicable. In general, pintles are to be fitted as taper

bolts; there is to be no shoulder on the pin and the nuts

are to be fitted with efficient locking devices. here

steel pintles of 90 mm (3.5 in.) diameter and greater are

required and are protected by sheathing shrunk onto the

pintle, the diameter may be measured over the sheathing.

13.11 ingle Plate Rudders

13.11.1 hickness

Single- plate rudders with upper stock diameters S measuring

76 mm (3 in.) or less are to have plating thicknesses not

less than obtained from the following equation.

13.11.2 udder Arms

a Spacing The distance between centers of rudder

arms is not to be greater than obtained from the following

equation.



h m 2.5S + 950 mm - 2.5S + 37.5 in.

where

h - maximum allowable spacing of arms in mm or in.

S - required upper stock diameter in mm or in.

Where the distances between rudders arms is less than

given by the above equation, the thickness t, will be

subject to special consideration.

b Section Modulus The section modulus, SM, of the

rudder arm in way of the forward and after edges of the

stock is not to be less than obtained from the following

equation

SM .8(S-50) q cm3 SM .24(5- 2) q in.3

where

S equired upper stock diameter, m mm or in, as given

in 13.5.1q s defined in 13.11.1.

c Breadth The breadths b of the arms may be tapered

forward and aft of the maximum breadths required to meet the

above section modulus; however, the breadths at the leading

and trailing edges of the rudder are not to be less than

obtained from the following equation

(0.00142V jr4- 0.20 ) c1 . 5

t required thickness in side plating and diaphragms,

in mm or in

A,V,c - as defined in 13.5.1

q as defined in 13.11.1



The distance between centers of the diaphragms is not

to be greater than obtained from the following equation.

S = 585 .41V mm - 23 .029V

where

Sp - distance between centers in mm or in.

V and A are as defined above

The thickness of the plating is to be increased at the

rate of 0.015 mm for each millimeter (0.015 in. for each

inch) of spacing greater than given by the equation, and may

be reduced at the same rate for lesser spacing.

Diaphragms are to be attached to the side plating by

fillet welds consisting of 75 mm (3 in.) increments spaced

150 mm (6 in.) between their centers. Where the interior of

a rudder is inaccessible for welding, it is recommended that

the diaphragms be fitted with the flat bars and the plating

be connected to these flat bars by continuous or slot welds.

Double-plate rudders are to be watertight. Means for

draining them are to be provided.

Special consideration will be given to fiber reinforcement

plastic rudders.

SECTION 14

Closing Appliances, Bulwarks, Rails, Ventilators and Freeing Ports.

14.1 rotection of Openings in Weather Decks. Superstructures and



Deckhouses.

14.1.1 xposed Hatch Covers and Doors

Exposed hatch covers and doors are to be weathertight with proper

securing arrangments. n general they are to be permanently and

efficiently connected to the structure in which they are fitted.

Openings are to be framed to provide support for the closing appliances

and associated structure.

All doors are to be operable from both sides. Hatch covers intended for

escape purposes are also to be operable from both sides.

Hatch covers and doors are in general to have strength equivalent to

that required for the structure in which they are located, except that

standard type doors and hatches may be approved for particular

applications on the basis of satisfactory experience in that service.

Hatch covers and doors are in general to be constructed of steel,

aluminum or other approved material such as fiber reinforced plastic.

Hatches are to be gasketed and secured by clamping devices; depending on

location, degree of protection and height above design waterline.

Doors, other than those in exposed machinery casings, may be considered

for approval without clamping devices and gaskets, provided they can be

effectively secured.

Detail plans need not be submitted for doors and hatch covers that are

maintained under ABS type approval program.

14.3 Portlights and Windows

14.3.1 Portlights

Portlights fitted below the main weather deck or in superstructure and

house side plating are to be of substantial construction and provided



with efficient watertight steel, aluminum or other approved material

inside deadlights, permanently attached to the frame. xcept that

depending on the type, size and thickness of the portlight and on the

intended service and where the portlights are recessed into the hull,

consideration will be given to not fitting deadlights. Portlights may

be of the opening type with hinge pins of non-corrosive material.

Portlight frames are to be of steel or other approved material and are

to be attached to the hull by through bolts or equivalent. ower

edges of portlights are not to be below a line parallel to the main

weather deck at side with its lowest point located above the design

water line at a distance equal to either 2.5% of the vessel breadth or

500 mm (19.5 in) whichever is greater. ortlights in way of the

machinery space are in general to be of the non-opening type.

Depending on portlight material and thickness and on service, portable

deadlights may be required for portlights on the front bulkheads.

Other details are to be as given above.

Consideration will be given also to the acrylic or polycarbonate

portlights.

The thickness of portlights of tempered or toughened glass is to be

not less than given in Table 14.2. here applicable, portlight

thicknesses are to comply with appropriate Administration

requirements.

TABLE 14.2

THICKNESS OF TEMPERED OR TOUGHENED GLASS PORTLIGHTS

L

Location 4m 79 ft) 5 m (49.2 ft) 15 m (49.2 ft)



A 0.40d 0.033d 0.02d

B 0.33d 0.025d 0.02d

C 0.025d 0.020d 0.02d

d = diameter between inner edges of the portlight frame

For calculation of required thickness on limited service vessels, d is not to be

taken less than 250 mm (10 in.).

Location . ide shell below main weather deck

B. Superstructures or deckhouses on main weather deck

C. Deckhouses above location B.

The thickness is to be not less than 5 mm (0.20 in)

14.3.2 indows

Windows in deckhouses and in the front and ends of superstructures are to be

suitably framed and effectively secured to the adjacent structure. Frames are

to be of metal or other approved material. Depending on window size and

thickness and on intended service, portable storm shutters may be required. The

window glazing is to be of tempered or toughened glass, consideration will also

be given to acrylic and polycarbonate material. The glazing is to be set into

the frame in a suitable, approved packing or compound. The thickness is to be

not less than given in a, or b.below, whichever is greater.

a. t = .9 s k m (ins)

TABLE 14.3

VALUES OF k

Fronts of Superstructures or Deckhouses on Main Weather Deck

At 0.1L from Forward t 0.5L & Aft



L y - 1.5m(4.92 ft) 3.Om(9.84 ft) 1.5m(4.92 ft) 3.0 m(9.84 ft)

12.2m 40 ft) .009 .009 .009 .009

24.4 m (80 ft) .013 .009 .01 .009

36.6 m (120 ft) .018 .014 .015 .012

48.8 m (160 ft) .020 .016 .016 .01461.0 m (200 ft) .022 .018 .018 .015

Generally in association with storm shutters

Fronts of 2nd Tiers of Superstructures or Deckhouses Above Main

Weather Deck

At 0.1 L from forward t 0.5L & Aft

L y .5m(4.92 ft)

12.2m 40 ft) .007

24.4 m (80 ft) .01336.6 m 120 ft) .016

48.8 m 160 ft) .01861.0 m (200 ft) .019

3.Om(9.84 ft) 1.5m(4.92 ft)

0.007 .0070.009 .01

0,013 .0125

0.015 .0140.016 .015

3.0 m(9.84 ft)

0.007

0.008

0.011

0.01250.013

Deckhouse Sides

At 0.1 L from Forward t 0.5L & Aft

L y - 1.5m(4.92 ft) 3.0m(9.84 ft) .5m(4.92 ft) .0 m(9.84 ft)

12.2m 40 ft) .006 ,006 .006 .006

24.4 m (80 ft) .009 .006 .008 .006

36.6 m (120 ft) .013 .010 .011 .008

TABLE 14.4

, e / S

5.0 .75

4.0 .74

3.0 .71



2.0 .61

1.0 .275

- greater dimension of window panel, in mm or ins

S - lesser dimension of window panel, in mm or ins.

14.3.3 ests

All windows and portlights are to be hose tested after

installation.

14.5 Bulwarks and Guard Rails

14.5.1 ocation and Heights

Bulwarks or guard rails or a combination of both, are in general

to be provided on exposed decks and on exposed tops of

superstructures and deckhouses.

The height of bulwarks or rails, or combination of both, is to be

not less than 750 mm (30 in). Lesser heights may be considered

with regard to location and hazards involved. In exposed areas

not traversed in the normal operation of the vessel, where it is

not practical to fit bulwarks or guard rails, hand or grab rails

may be considered.

14.5.2 ulwarks

Also, consideration may be given to guard wires provided means

are provided to maintain each wire taut at the designed spacing.

14.7 Freeing Ports

14.7.1 eneral

Where bulwarks on exposed main weather decks form wells, ample



provision is to be made for rapidly freeing the decks of water.

a. Basic Area

The basic freeing port area on each side of the vessel for each

well on the main weather deck, in cases where the sheer in way of

the well is standard or greater than standard (Standard sheer as

defined in the International Convention on Load Lines, 1966), is

to be obtained from the following equations:

A = Ke

where

A =freeing port area m2 or ft2

K =0.07 (0.23) for L > 24m (78 ft)

=0.035 (0.115) for 2m (39 ft)

=by linear interpolation for intermediate length

e = length of bulwark on one side in m of ft, but need not exceed

0.7L

b. Correction for Height

Where the bulwark height exceeds 1.2m (47 in.), freeing-port area

is to be increased by 0.0004 m2 per meter (0.04 ft2 per foot) of

bulkwark length for each 0.1 meter (3.9 in.) difference in

height. Where the bulwarks height is less than 0.9m (36 in.) in

height, the freeing port area may be decreased by the same ratio.

Breadth of deckhouse, rea of freeing ports inhatchway or trunk in elation to the total area of

relation to the breadth he bulwarks

of vessel

40% or less 0%



75% or more 0%

The area of freeing ports at intermediate breadths is to be

obtained by linear interpolation.

14.7.3 Open Superstructures

In vessels having superstructures which are open at either or

both ends, adequate provision for freeing the space within such

superstructures is to be provided, and the arrangements are to be

subject to special approval.

14.7.4 Details of Freeing Ports

The lower edges of the freeing ports are to be as near the deck

as practicable. Two-thirds of the freeing port area required is

to be provided in the half of the well nearest the lowest point

of the sheer curve. All such openings in the bulwarks where they

exceed 230 mm (9 in.) in depth, are to be protected by rails or

bars spaced approximately 230 mm (9 in) apart. here shutters

are fitted to freeing ports, ample clearance is to be provided to

prevent jamming. inges are to have pins or bearings of non

corrosive material and in general are to be located at or near

the top of the shutters. f shutters are fitted with securing

appliances, these are to be of approved construction and easily

operable from a redily accessible position.

14.9.2 Vessels Receiving Freeboard Assignment

Vessels whose service requires load line assignment are to comply

with the requirements in the International Convention on Load

Lines. See 1.11.



SECTION 15

WELDING AND FABRICATION

15.1 General

15.1.1 Hull Welding



Welding in hull construction is to comply with the requirements

of this section, unless specially approved otherwise. n all

instances welding procedures and filler metals are to produce

sound welds having strength and toughness comparable to the base

material.

15.1.2 lans and Specifications

The plans submitted are to indicate clearly the proposed extent

of welding to be used in the principal parts of the structure.The welding process, filler metal and joint design are to be

shown on the detail drawings or in separate specifications

submitted for approval. These are to distinguish between manual

and automatic welding. The builders are to prepare and file with

the Surveyor a planned procedure to be followed in the erection

and welding of the important structural members.

15.1.3 Workmanship and Supervision

The Surveyor is to satisfy himself that all welders and welding

operators to be employed in the construction of vessels to be

classed are properly qualified and are experienced in the work

proposed. he Surveyor is also to be satisfied as to the

employment of a sufficient number of skilled supervisors to

ensure a thorough supervision and control of all welding

operations. nspection of welds is to be carried out to the

satisfaction of the Surveyor. See 15.5.10.

15.1.4 Welding Procedures



15.3.4 ack WeldsTack welds of consistently good quality, made with a suitable filler

metal, as intended for production welding and deposited in such a manner

as not to interfere with the completion of the final weld, need not be

removed, provided they are found upon examination to be thoroughly clean

and free from cracks, porosity or other defects. Defective tack welds



are to be removed and tack welds with objectionable contours should be

tapered or removed before final welding.

Preheat may be necessary prior to tack welding when the materials to be

joined are highly restrained, see also 1 5.5.2. Special consideration is

to be given to use the same preheat as specified in the welding

procedure when tack welding higher- strength steels, particularly those

materials which are quenched and tempered, see also 15.5.2. These same

precautions are to be followed when making any permanent welded

markings.

15.3.5 un-on and Run-off TabsWhen used, run-on and run-off tabs are to be designed to minimize the

possibility of high-stress concentrations and base-metal and weld- metal

cracking.

15.3.6 tud WeldingThe attachment of pins, hangers, studs and other related items by stud

welding may be approved at the discretion of the Surveyor. Prior to

actual production work, trial stud welds are to be destructively tested

to demonstrate their suitability for the intended application. The use

of stud welding for structural attachments is subject to special

approval and may require special procedure tests appropriate to each

application.

15.3.7 luminum Construction Temporary Back-up Plates and Tapes

forming is such that base plate properties are changed beyond acceptable

limits, appropriate reheat or stress relief treatments are to be used to

re-establish acceptable properties. Hot forming of 5000 series aluminum

alloys is generally conducted at temperatures between 260°C and 425° C

(500°F and 800°F). Hot or cold forming is not to be performed in the

structures of any aluminum alloy unless supporting data is presented to

the Surveyor's satisfaction indicating that significant deleteriousmaterial property changes will not result. ppropriate temperature



-control methods are to be used in all hot forming and stress relieving

operations. In hot forming or stress relieving, exposure of the 5000

series alloys to the 65C (150F) to 205C (400F) temperature range is to

be minimized by the use of appropriate cooling techniques.

b. Steel

Steel is not to be formed between the upper and lower critical

temperatures; forming in the range between 205C (400F) and 425C (800F)should be avoided. If the forming temperature exceeds 650C (1200F) for

as-rolled, controlled rolled, thermo-mechanical control rolled or

normalized steels, or is not at least 28C (50F) lower than the tempering

temperature for quenched and tempered steels, mechanical tests are to be

made to assure that these temperatures have not adversely affected the

mechanical properties of the steel.

15.5 Production Welding

15.5.1 nvironment

Proper precautions are to be taken to insure that all welding is done

under conditions where the welding site is protected against the

deleterious effects of moisture, wind and severe cold.

15.5.2 reheat

15.5.3 ost Heat

a. AluminumWeldments of work hardenable 5000 series and similar aluminum alloys are

not to be post weld heat treated unless the procedures have been

specially approved. here use of a heat treatable alloy has been



approved, any postweld heat treatment proposed is to be as established

in procedure qualification tests.

15.5.4 ccessibilityAssembly and welding is to be arranged to provide sufficient

accessibility to the joint by the welder, the welder equipment, and for

inspection.

15.5.5 equenceWelding is to be planned to progress symmetrically so that shrinkage on

both sides of the structure will be equalized. The ends of frames and

stiffeners are to be left unattached to the plating at the sub-assembly

stage for a distance of about 300 mm (12 in.) until connecting welds are

made in the intersecting systems of plating, framing and stiffeners at

the erection stage. Welds are not to be carried across an unwelded

joint or beyond an unwelded joint that terminates at the joint being

welded unless especially approved.

15.5.6 ack Gouging

a. luminumChipping, routing, milling, grinding or other suitable methods are to be

employed at the root or underside of the weld to obtain sound metal

before applying subsequent beads for all full penetration welds.

b. teel

For the 5000 series and similar alloys the heating and cooling through

the sensitizing range of 65C - 205C (150F - 400F) is to be as rapid as

practicable.

c. Steel

Fairing by heating or flame shrinkage is to be kept to an absolute

minimum when higher-strength steels are involved, due to inducement ofhigh local stresses and the possible degradation of the mechanical



properties of the base material.

15.5.8 ow Hydrogen Electrodes or Welding Processes

a. Steel

The use of low- hydrogen electrodes or welding processes is recommended

for welding all higher- strength steel and may also be considered for

ordinary-strength steel weldments subject to high restraint. When using

low-hydrogen electrodes or processes, proper precautions are to be takento ensure that the electrodes, fluxes and gases used for welding are

clean and dry.

15.5.9 eld Soundness

Finished welding is to be sound and thoroughly fused throughout itscross section and to the base material. Welds are to be crack free and

reasonably free from other injurious defects such as lack of fusion or

penetration, slag inclusions and porosity. The surfaces of welds are to

be visually inspected and are to be regular and uniform with a minimumamount of reinforcement and reasonably free from undercut and overlap.

15.5.10 nspection of Welds

a. General

1) isual Inspection isual nspection uring

construction is to consist of inspecting the surface appearance of welds

for the existence of cracks and injurious arc strikes, porosity, cold

laps and other flaws or defects. The surface of the welds is to be

Bureau's separately issued publication Rules for Nondestructive

Inspection of Hull Welds, or other approved acceptance standards.

iv) Weld Plugs or Samples The practice of taking weld plugs or

samples by machining or cutting from the welded structure is not

recommended and is to be considered only in the absence of other

suitable inspection methods and is to be subject to the special approvalof the Surveyor. When such weld plugs or samples are removed from the



welded structure, the holes of cavities formed are to be properly

prepared and welded, using a suitable welding procedure approved by the

Surveyor and as established for the original joint.

b. SteelSome steels, especially higher-strength steels, exhibit a tendency to

delayed cracking. When welding these materials, consideration is to be

given to delaying the final nondestructive testing to accommodateoccurrence and detection of such defects.

15.5.11 epair Welding

a. eneral

Defective welds and other injurious defects, as determined by visual

inspection, nondestructive test methods, or leakage under hydrostatic

tests, are to be excavated in way of the defects to sound metal and

corrected by rewelding, using a suitable repair welding procedureconsistent with the material being welded. Removal by grinding of minor

surface imperfections may be permitted at the discretion of the

attending Surveyor.

b. teelSpecial precautions, such as the use of both preheat and low-hydrogen

electrodes, are to be considered when repairing welds in higher-strength

steel, material of thick cross section or material subject to high

In general, use of double-Vee in lieu of single-Vee joints and the

narrowest root gap practicable is recommended to minimize distortion.

For both single-Vee and double-Vee joints, the weld metal at the root on

the reverse side of a weld made without permanent backing is to be

removed to sound metal by an approved method before applying subsequent

weld passes.



Permanent backing straps of a suitable aluminum alloy, tack welded or

otherwise held in place behind the joint may be used for single-Vee butt

welds. leaning, removal of oxides and fit-up of the backing strap

should be adequate to prevent root defects. The backing bar is to be

fitted so that a minimum space exists between the backing bar and plates

to be joined. C onnections in the backing bar are to be made with full-

penetration welds. Upon completion of welding, the backing strap may

become an integral part of the joint. Permanent backing straps are notrecommended where crevice corrosion is of concern. For use under these

conditions, all edges of the backing straps are to be completely welded.

b. Steel

Manual welding using stick electrodes may be ordinarily employed for

butt welds in members not exceeding 6.,5 mm (1/4 in.) in thickness

without beveling the abutting edges. Members exceeding 6.5 mm (1/4 in.)

are to be prepared for welding in a manner acceptable to the Surveyor by

using an appropriate edge preparation, root opening and root face (land)to provide for welding from one or both sides. For welds made from both

sides, the root of the first side welded is to be removed to sound metal

by an approved method before applying subsequent weld passes on the

reverse side. Where welding is to be deposited from one side only,

using ordinary welding techniques, appropriate backing (either permanent

or temporary) is to be provided. The backing is to be fitted so that

spacing between the backing and the members to be joined is in

accordance with established procedures. nless specially approved

Special welding techniques employing any of the above mentioned basic

welding processes will be specially considered, depending upon the

extent of the variation from the generally accepted technique. Such

special techniques include one-side welding, tandem-arc welding and

open-arc welding. The use of gas tungsten-arc welding will also be

subject to special consideration, depending upon the application and

whether the process is used manually or automatically.



15.9 Fillet Welds

15.9.1

a. eneral

Fillet welds may be made by an approved manual, semi-automatic or

automatic process. The sizes of fillet welds are subject to approval in

each case, and are to be indicated on detail drawings or on a separate

welding schedule.

b. luminum

In terminating a weld, either continuous or intermittent, crater filling

by back stepping is recommended to provide a sound ending for each

fillet.

15.9.2 ee Connections

In general, the required size and spacing of the fillets is to be as

given in 15.9.3. Special consideration will be given where there is a

substantial difference between the thickness of members being connected.

Where the opening between members exceeds 1.0 mm (0.04 in.) and is not

greater than 5 mm (3/6 in), the size of the fillets is to be increased

by the amount of the opening. Spacing between plates forming tee joints

is not to exceed 5 mm (3/16 in)

15.9.3 illet Sizes and Spacing

Tee connections are to be formed by continuous or intermittent fillet

in calculating weld factors, the leg length of matched fillet weld is to

be taken as the designed leg length or 0.7tpi .0mm (0.7 t o l -4- 0.08

in) whichever is less.

Where it is intended to use continuous fillet welding, the leg size of

fillet welds is to be obtained from the above equations taking s/2 equal

to 1.



For intermittent welding with plate thicknesses less than 7 mm (0.28 in)

welds are to be staggered.

15,9.4 illet Weld Arrangements

a. ntersections

Where beams, stiffeners, frames, etc, are intermittently welded and pass

through slotted girders, shelves or stringers, there is to be a pair of

matched 75 mm (3 in) intermittent welds on each side of each suchintersection and the beams, stiffeners and frames are to be efficiently

attached to the girders, shelves and stringers.

b. nbracketed End Attachments

Unbracketed beams, frames, etc. and stiffeners of watertight and tank

bulkheads and superstructure and house, fronts are to have double

continuous welds for length at each end equal to the depth of the member

but not less than 75 mm (3 in.)

Unbracketed stiffeners of nontight structural bulkheads, deckhouse

sides, superstructure and deckhouse after ends are to have a pair of

matched 75 mm (3 in) intermittent welds at each end.

c. racketed End Attachments

Frames, beams, stiffeners etc. are to be lapped onto the bracket a

length not less than 1.5 times the depth of the member, and are to have

continuous fillet welds all around, lapped end connections of

times plate thickness. Plugs and slots are not to be filled with welded

deposit.

15.11 Bi-Material Joints and Raying Surfaces

15.11.1 i-material JointsTechniques required for joining two different materials will be subject



to special consideration. he use of explosion bonding may be

considered depending on the application and the mechanical and corrosive

properties of the joint. Such joints, when used, may be required to be

appropriately painted, coated, wrapped or protected by other methods to

prevent galvanic corrosion. Where aluminum is to be joined to other

materials, each Laying surface is to be suitably coated to minimizecorrosion. In addition, when one or both sides of an aluminum or steel

connection to dissimilar metal joints are exposed to weather, sea wateror wet spaces, a minimum of 0.5 mm (0.02 in.) of suitable insulation is

to be installed between Laying surfaces and extended beyond the edge of

the joint. on-welded oil or water stops are to be of plastic

insulation tape or equivalent which would provide a suitably corrosion

resistant system. Special consideration is to be given to connections

of aluminum or steel to wood.

15.11.2 aying Surfaces - Aluminum to Aluminum

Aluminum faying surfaces that will be exposed to the weather, sea wateror other corrosive environments are to be suitably coated to minimize

crevice corrosion in way of the faying surfaces.

15.13 Filler Metals

15.13.1 eneralFiller metals are to be of a type suitable to produce sound welds that

have strength, ductility and corrosion resistant properties comparable



FIGURE 15.1

.

L mmori w a

Chainedl-taggered 1-w---S

w = leg size in mm or in. = throat size in mm or

TABLE 15.1

Weld Factor C

(D.C. = double continuous)



Structural Members luminum teel

Floors, Bottom Transverses and

Bottom Girders

To Shell

Bottom forward 3L/8, V>25 knots .25 .25

Bottom forward L/4, V<25 knots .18 .16

In way of propellers and

shaft struts .25 .25 DC

In machinery space .20 .20

Elsewhere .16 .14

To Inner Bottom or Face Bar

In machinery space

To Inner bottom elsewhere

To face bar elsewhere

0.25 DC

0.140.14

0.25 DC

0.12

0.12

Fldors and Bottom Transverse

TABLE 15.1

Weld Factor C (continued)




Frames

To Shell

Bottom forward 3L/8, V>25 knots

Bottom forward L/4, <25 knots

0.25 DC

0.18

0.25 DC

0.16

In way of propellers and shaft struts 0.25 DC 0.25 DC

Elsewhere 0.14 0.12

End Attachments 0.50 DC 0.50 DC

Girders, Transverses and Stringers

To Shell 0.16 0.14

Deck and Bulkheads

Clear of Tanks 0.16 0 . . 1 4In way of Tanks 0.18 0.16

To Face Bar 0.14 0.12

End Attachments 0.50 DC 0.50 DC

Beams and Stiffeners

To Deck 0.14 0.12

To Tank Boundaries and House Fronts 0.14 0.12

TABLE 15.1

Weld Factor C (continued)




Engine Foundations

To Plating and Face Bar .50 DC .50 DC

Bulkheads and Tank Boundaries

Non-Tight, Internal .16 .14Watertight, or exposed .38 DC .38 DCTank .40 DC .40 DC

Decks

Non-Tight, Internal .25 .25

Weathertight .38 DC (1) .38 DC (1)Strength Deck .38 DC (1) .38 DC (1)

Rudders

Diaphragms to Side Plating

Vertical Diaphragms to Horizontal

Diaphragms, clear of Mainpiece

Horizontal Diaphragm to Vertical

0.300.50 DC

0.50 DC

0.30

0.50 DC

0.50 DC

TABLE 15.2a

Filler Metals for Welding Aluminum Alloy—

Sheet Plate, and Extrusions

Recommendations in this table apply to gas shielded-arc weld-



ing processes.

Filler metal alloys 5183, 5356 and 5556 may be used inter-

changeably provided that strength, ductility and corrosion

resistance are suitable for the service conditions.

Base

Metal

Alloys 5083 5086 5454 5456 6 61

5083 5183 5356 5356 5183 53565086 5356 53b6 5356 5358 5356

5454' 5356 5356 55541 5.358 5356

5456 5183 5358 5356 5556 5358

6061 5356 5358 53562 5356 40432

Notes

1 5454 aluminum alloy welded with 5554 filler metal is generally

recommended for service applications above 65C (150F) such as

for smoke stacks and engine room enclosures.

2 5183 or equivalents may be used.

TABLE 15 . 2b

Filler Metals for Welding Aluminum

Alloy Castings To Castings and Plate

SECTION 16

EQUIPMENT

16.1 General

All vessels are to be provided with anchors, and cables or wire rope.



The anchors and their cables or wires, are to be connected and

positioned, ready for use. Means are to be provided for stopping each

cable as it is paid out, and the windlass is to be capable of heaving in

-either cable or wires. uitable arrangements are to be provided for

securing the anchors and stowing the cables or wires. The inboard ends

of the cables or wires of bower anchors are to be secured by efficient

means. Subsection 16.3 is provided as an optional requirement for the

symbol 0 which is not compulsory for classification.

16.3 Equipment Weight and Size for Optional®

16.3.1 Anchors and ChainsAnchors and chains are to be not less than given in Table 16.1 and the

numbers, weights and sizes of these are to be based on the equipment

number obtained from the following equation. Special consideration will

be given where anchoring and mooring conditions are specified.

Metric UnitsY Equipment Number .269LBD + 0.179/bh + X 0.135/1b1h1

Inch/Pound UnitsY Equipment Number — 0.0075LBD + 0.0050/bh + X 0.00375/01121

L — length of vessel as defined in Section 2

B breadth of vessel as defined in Section 2

16.3.3 Wire Rope

Where the cable is wire rope in accordance with Table 16.1,

rope is to be 6 X 19 standard steel or of equivalent strength.

of chain in accordance with 16.3.4 is to be installed between

rope and the anchor.

16.3.4 Nylon Rope

the wire

A length

the wire



Where the cable is nylon rope, a length of chain is to be installed

between the rope and each anchor. The length and diameter of chain to

be used with each diameter of nylon rope follow.

Nylonhain Nylon hain

16.5

Diameter Length Diameter Diameter Length Diameter

mm m n t n

9.5 1.2 6.5 3/8 4 1/4

11.0 1.5 8.0 7/16 5 5/1612.5 1.8 9.5 1/2 6 3/8

16.0 2.4 11.0 5/8 8 7/1619.0 2.4

12.5 3/4 8 1/2

Where cordage with natural or man-made fibers other than nylon is

proposed, the diameter of the cordage will be subject to special

consideration.

Anchor Types

16.5.1

16.7 nchor Handling

Satisfactory arrangements are to be provided for handling the

anchors and cables. he windlass or other approved device for

paying out and heaving in the cables is to be of good andsubstantial make, and suitable for the size and type of cable to

be used. Care is to be taken to insure fair leads to and from



this device. It is to be well bolted down to a substantial bed,

and deck beams below it are to be extra strength and properly

supported.

16.9 awse Pipes

Where fitted, hawse pipes are to be of ample size and strength;

they are to have full, rounded flanges and the least possible

lead in order to minimize nip on the cables; they are to be

securely attached to thick doubling or insert plates. hen in

position they are to be hose-tested with a water pressure at the

nozzle of not less than 2.06 bar (2.1 kgf/cm2, 30 psi). awse

pipes for stockless anchors are to provide ample clearances; the

anchors are to be shipped and unshipped so the Surveyor may be

satisfied that there is no risk of an anchor jamming in the hawse

pipe.

16.11 rotection of Hull Structure

The hull structure is to be suitably protected both internally

and externally against damage by handling or stowing the anchors,

cable or wire, or during mooring.

TABLE 16.1

Equipment for Yaching Service Vesses

For intermediate values of the equipment number use equipment complement in

sizes and weights given for the lower equipment number in the table.

ST , METRIC UNITS



Equip-meat

NUTTE-

her

Anchors Cable

Number

Ma s sper

Anchor

kg

Total

Length

m

Diameter mm

Chain

Wire

Rope

Nylon

Rope

15 2 18 55.0 6.5 6.5 9.5110 2 22.5 55.0 6.5 6.5 9.5115 2 27 55.0 8.0 8.0 11.012.0 2 32 73.0 8.0 8.0 11.0Y30 2 38 91.5 , . . ,a.59512.5

Y40 2 46 110.0 9.5 9.5 12.5

150 2 55 119.0 11.0 11.0 16.0160 2 64 128.0 11.0 11.0 16.0Y70 2 73 137.0 11.0 11.0 16.0Y80 2 82 146.0 12.5 12.5 19.0

190 2 91 155.5 12.5 12.5 19.0Y100 2 102 164.5 1.2.5 12.5 19.0Y120 2 116 183.0 12.5 12.5 19.0

TABLE 16.1

Equipment for Yachting Service Vessels

ror inter ediate values of the equipment number use equipment complement

in sizes and weights given for the lower equipment number in the table.



Inch/Pound Units

Equip-

ment

Num-ber

Anchors Cable

Number

Ma s s

perAnchor

lb

Total

Lengthfathoms

Diameter in.

ChainWireRope

NylonRope

Y5 2 40 30 14 38

Y10 2 50 30 14 14 38

Y15 2 60 30 516 516 716Y20 2 70 40 °16 516 716Y30 2 85 50

Y40 2 100 60 3/83 / 8

1/

Y50 2 120 65 716 716 58

Y60 2 140 70 716 716 58Y70 2 160 75 716 7/16 58

Y80 2 180 80 12

Y90 2 200 85 12 12 34

Y100 2 225 90 1//'

SECTION 17

CORROSION PREVENTION AND PROTECTIVE C OATINGS

17.1 Aluminum

17.1.1 eneral

Aluminum alloys intended for hull construction are to be used



generally only under conditions that will not induce excessive

corrosion. here exposure to environments that would induce

excessive corrosion is expected, suitable coatings, tapes,

sacrificial anodes, impressed-current systems or other corrosion

prevention measures are to be used. hen tapes are used for

corrosion protection, they are to be non-wicking and non-water

absorbing. rease containing graphite is not to be used withaluminum, instead, zinc or other suitable base grease is to be

used. See also 15.3.3a.

17.1.2 oatings

Coatings are to be applied in accordance with the manufacturer's

instructions, and are to be preceded by appropriate cleaning and

possibly chemical conversion of surfaces as may be required in

accordance with the manufacturer's recommendations. Coatings are

to be free from voids, scratches or other imperfections that arepotential sites for localized corrosion.

The composition of coatings is to be compatible with aluminum.

Coatings containing copper, lead, mercury or other metals that can

induce galvanic or other forms of corrosion are not to be used.

Zinc chromate coatings may be used. Insulating coatings intended

to prevent galvanic corrosion are not to contain graphite or other

conducting materials.

Bearing Areas

Bearing areas such as engine beds, pump foundations, propeller

shafts, rudder and other appendages of metals other than aluminum

are to be suitably isolated by such means as nonmetallic bearing

casings, nonconductive packing (not containing graphite or other

conductors) or suitable tapes and coatings. Alternative methodsfor minimizing corrosion at these locations will be specially

considered. icking-type tapes or water-absorbing packing



materials such as canvas should not be used. The metals used for

such applications are to be selected to minimize galvanic effects;

stainless steels are to be considered. he use of copper-base

alloys such as brass or bronze is generally not recommended where

galvanic corrosion is of concern, and these materials may only be

used when specially approved. In those cases where the use of

dissimilar metals cannot be avoided, or where galvanic corrosion

is of concern, such as in wet tanks, a suitable sacrificial anode

or impressed current system should be installed.

17.1.4 aying Surface between Aluminum and Non-metals

Aluminum in contact with wood or insulating-type materials is to

be protected from the corrosive effects of the impurities in these

materials by a suitable coating or covering. Concrete used with

aluminum is to be free of additives for cold weather pouring.

Preformed glass insulation is recommended for piping insulation.

Any adhesives which may be used to connect insulation to aluminum

are to be free of agents that would be corrosive to aluminum.

Foaming agents harmful to aluminum, such as freon, are not to be

used for insulating foams. Areas where dirt or soot are likely to

collect and remain for prolonged periods are to be protected from

pitting corrosion by the use of coatings or other suitable means.

17.1.5

arrangements are to be submitted for review. Anodes are to be in

accordance with ASTM or other recognized standard. hen

impressed current systems are used, adequate precautions are to

be taken that the negative voltage is not excessive.

17.1,8 tray Current Protection

Precautions are to be taken when in dock to prevent stray

currents from welding power or other sources from adversely

affecting the aluminum. henever possible, the cathodic



protection system of the vessel should be in place and operating

when the vessel is in the water. A.C. power sources are to be

insulated from the hull. or battery and other D.C. power

sources, grounding is to be avoided if possible. here safety

considerations require grounding to the hull, the negative pole

is to be connected to the hull.

17.3 Fiber Reinforced Plastic

17.3.1 GeneralCured gel-coat resins and lay-up resins are to be highly

resistant to water and other liquid absorption; appropriate

materials, lay-up, and lay-up procedures are to be used and

manufacturers recommendations followed to attain this. are is

to be taken in the use of lamminates containing carbon fibers so

that they are not close to or do not induce galvanic corrosion

with metal fittings.

17.3.2 TanksIn water, fuel oil, or other approved tanks, the resins used are

to be compatible with the contents of the tanks, the contents of

the tanks are not to affect the cured properties of the tank

laminate. he cured laminate is to be highly resistant to

absorption of the liquid, and is not to have harmful,

SECTION 18

PROPULSION, STEERING GEAR, AND AUXILIARY MACHINERY

18.1 General

18.1.1 Certification Requirements

All machinery of 135 horsepower and over is to be in accordance

with the applicable requirements of the Rules for Building and

Classing Steel Vessels , except the design of a unit which has



demonstrated satisfactory service experience for the intended

application will be specially considered. Machinery of less than

135 horsepower is to be designed, constructed, and equipped in

accordance with good commercial practice, but need not be

inspected at the plant of the manufacturer, and will be accepted

subject to satisfactory performance witnessed by the Surveyor

after installation. or all engines, their mounting in vessels

is to be in accordance with the engine manufacturer's

recommendations. Particular attention is to be given to proper

mounting in fiberglass vessels.

18.1.2 ervice

Unless otherwise stated, the requirements in the following

sections are applicable to motor pleasure yachts (see 2.31) not

exceeding 45.7 m (150 ft) in length. These requirements consider

the reduced operating hours and lighter loads associated with

such craft. If it is intended to operate the yacht in a more

rigorous service, the Rules for Building and Classing Steel

Vessels Under 90 m (295 ft) would apply.

18.1.3 Power Rating

The vessel's rated power is considered a continuous duty service

within the constraint of these Rules. he pleasure craft rating

can be considered the rated power for the purpose of these Rules

the internal volume exceeds 0.14 m3(5 ft

3) and the temperature exceeds

the following values.

Fuel oil 6C (1 50F)

Lubricating oil 0C (200F)

Liquids, except fuel and lubricating oils 49C (300F)

Steam, gas, or vapors 490 (300F)

Boilers, pressure vessels, cylinders and heat exchangers not indicated

may be accepted on the basis of manufacturer's data indicating pressure



and temperature ratings and suitability for intended service.

Overpressure protection is to be provided and the installation is to be

to the satisfaction of the Surveyor.

18.5 orsional Vibrations

For vessels fitted with unusual propulsion arrangements or engines

without vibration dampers, a torsional vibration analysis of the

propulsion system is to be submitted. This is not required for vessels

under 20 m (65 ft) in length or for installations essentially the same

as previous designs which have proven satisfactory.

18.7 ngine Exhaust Systems

18.7.1 nstallationEngine exhaust systems are to be so installed that the vessel's

structure cannot be damaged by heat from the systems. Exhaust

pipes of several engines are not to be connected together but are

to be run separately to the atmosphere unless arranged to prevent

the return of gases to an idle engine. Exhaust lines from fired

units such as furnaces or boilers and engine exhaust lines are not

to be connected unless specially approved as in cases where the

heat exchange units are arranged to utilize the waste heat from

18.9 rial

Before final acceptance, the entire propulsion system installation is to

be operated in the presence of the Surveyor to demonstrate its

reliability and sufficiency to function satisfactorily under operating

conditions and its freedom from dangerous vibration at speeds within theoperating range.



18.11 teering Gear

18.11.1 eneral

Steering systems are to be in accordance with the applicable

requirements of the Rules for Building and Classing Steel

Vessels except that for vessels with a required upper rudder

stock diameter less than 230 mm (9 in.) the following alternativerequirements may be applied as appropriate. The use of thruster,

cycloidal, or similar propelling units using speed, direction, or

pitch variation as a means of steering will be specially

considered.

18.11.2 lans

Detailed plans of the steering arrangement, including machinery,

controls, instrumentation, power supplies, piping systems, and

pressure cylinders, are to be submitted for approval. The ratedtorque of the unit is to be indicated in the data submitted for

review.

18.11,3 ain Steering GearMain steering gear are to be at least capable of putting the

rudder from 35 degrees on one side to 35 degrees on the other side

with the vessel running ahead at maximum continuous shaft rpm and

at the design waterline. For vessels with a required upper rudder

b When non-power operated mechanical main steering gear is used

c When steering is accomplished by positioning the propulsion

unit.

18.11.5 Protection

The main steering gear is to be protected from the weather and

the auxiliary steering gear is to be so protected as to permit

satisfactory operation in bad weather.

18.11.6 Power-gear Stops



Power gears are to be provided with positive arrangements for

stopping the gear before the rudder stops are reached. hese

arrangements are to be synchronized with the rudder stock or the

position of the gear itself rather than with the steering-gear

control systems.

18.11.7 Mechanical Steering Gears

a eading-block Sheaves Leading-block sheaves are to be

of ample size, about twice the diameter of the rudder stock for

chain with pins about three times the area of the steering

chains; these blocks are to be placed to provide as fair a lead

to the quadrant as possible and to avoid acute angles. arts

subject to shock are not to be of cast iron. or sheaves

intended to be used with ropes, the radius of the grooves is to

be equal to that of the rope plus 0.8 mm (0.0313 in.), and the

sheave diameter is to be not less than fourteen times that of the

rope.

b uffers Steering gears other than the hydraulic type

are to be designed with suitable buffer arrangements to relieve

the gear from shocks to the rudder. Spring buffers used with

chain-and-rod type of steering gear are to be so designed that

they will not close solid at seven-eighths of the proof load of

the required chain and the carrier is to be marked to show the

a on-standard Fittings Fittings which are not

constructed to a recognized standard will be subject to special

consideration. lans showing details of construction, material

and design calculations or test results are to be submitted for

review.

b plit Flanges Split flanges are not to be used in

steering gear systems.



c traight Thread 0 Ring Connections Straight thread 0

ring type connections may be used for connection to equipment

such as pumps, valves, cylinders, accumulators, gauges, and

hoses. Such connections are not to be used for joining sections

of pipe.

18.11.9 Steering Gear Controls

a ain Steering Control Control of the main steering

gear is to be provided on the navigating bridge and in the

compartment containing the steering gear or power units. If the

space in the steering gear compartment is insufficient for

operation, the control may be installed in an adjoining space or

from the open deck (see 18.11.5). If electrical, there are to be

two independent means of control from the navigating bridge.

Electrical power is to be supplied from the power unit motor

controller, or from the main switchboard.

b uxiliary Steering Gear Control Where the auxiliary

steering gear is power operated, it is to be provided with a

control system operated from the navigating bridge and this

control system is to be independent of the control system for the

main steering gear.

Control System Disconnect Means are to be provided to

normally connected to it and which operate simultaneously. The

circuits for each steering gear motor are to be separated

throughout their length as widely as practicable.

b rotection

1 hort Circuit Protection Each steering gear feeder is to be

provided with short-circuit protection located at the main

switchboard.

Protection against excess current including starting current, if

provided, shall be for not less than twice the full load current



of the motor or circuit protected and shall be arranged to permit

the passage of appropriate starting currents.

2 ndervoltage Release Power unit motor controllers and other

automatic motor controllers are to be fitted with undervoltage

release.

18.11,11 rials

The steering gear is to be tried out on the trial trip in order to

demonstrate to the Surveyor's satisfaction that the requirements

of the Rules have been met. The trial trip is to include the

operation of the following, as applicable.

a he main steering gear, including a demonstration of hard

over to hard over performance, with vessel running ahead at

maximum continuous shaft rpmb uxiliary steering gear performance, and transfer between

main and auxiliary steering gear

c he power units including transfer between power units

d The steering gear controls, including transfer of control,

and local control

e The rudder angle indicator

f The motor indicators as required by 18.1 1.9e.

g The piping systems. See 18.1 1.8.

SECTION 19

Shafting and Propellers

19.1 eneral

Propulsion shafting and propellers are to be surveyed during manufacture

in accordance with the applicable requirements of the Rules for



Building and C lassing Steel Vessels , except that for vessels below45.7m (1 50 ft) in length or multiple screw vessels below 61m (200 ft) in

length the following alternative requirements may be applied. he

following requirements apply for design and survey.

SHAFTING

19.3 ail Shaft, Tube Shaft, and Line Shaft Diameters

Full details of tailshafts, tube shafts, line shafts, couplings andcoupling bolts including material specifications are to be submitted for

review. he least diameter of shafting is to be obtained from the

following equations.

D — 100 K 3 f H/R) [C1/ 1 1 2)]

C 1 ° ° 317.4(23.8, 2.10)

C2° 160(16.3, 23180)

D required shaft diameter in mm (in.) for all shafts

K haft design factor (see Tables 19.1 and 19.2)

H power at rated speed in kilowatts (hp, HP

hp- metric horsepower Metric units 1 hp — 0.735 kW)

HP— inch/pound horsehower Inch/lbs units 1 HP — 0.746 kW)

b. tainless Steel Clad he post machining thickness of

stainless steel clad liners to be fitted to tailshafts or tube

shafts for vessels in salt water service is not to be less than

one-half that required for bronze liners or 4.75 mm (0.1875

inches) whichever is greater.The thickness of liners other than bronze or stainless steel clad

will be subject to special consideration.

19.5.2 hickness Between Bearings

The thickness of a continuous bronze liner between bearings is to



be not less than three- fourths of the thickness t determined by

19.5.1.

19.5.3 ontinuous LinersContinuous liners are to be one piece or, if made of two or morelengths, the joining of the separate pieces is to be done by an

approved method of fusion through not less than two- thirds the

thickness of the liner or by a rubber seal.

19.5.4 it Between BearingsIf the liner does not fit the shaft tightly between the bearing

portions, the space between the shaft and the liner is to be

filled by pressure with an insoluble noncorrosive compound.

19.5.5 aterial and Fit

Liners are to be of a high-grade composition, bronze or other

approved alloy, free from porosity and other defects, and are to

prove tight under hydrostatic test of 1.0 bar (1 kgf/cm2 15 psi).

All liners are to be carefully shrunk or forced upon the shaft by

pressure and they are not to be secured by pins.

19.5.6 fter-end Seal

Effective means are to be provided to prevent water having access

to the shaft at the part between the after end of the liner and



b ower Transmitted by Combination Prestress and Shear Where

the power is transmitted by a combination of fitted bolts (not

including dowels) and prestressed non-fitted bolts, the components

are to meet the following criteria:

Fitted Bolts The shear stress under the maximum torque

corresponding to the worst loaded condition, is to be notmore than 50% of the minimum specified tensile yield

strength of the bolt material.



2 on-fitted Bolts The factor of safety against slip, under

the maximum torque corresponding to the worst loaded

condition and the specified bolt tension, is to be at least

1.6 for inaccessible couplings and 1.1 for accessible

couplings.

19.7.3 langes

The thickness of coupling flanges is not to be less than the

minimum required diameter of the coupling bolts or 0.2 times D (as

defined in 19.7.1), whichever is greater. The fillet radius at

the base of a coupling flange is not to be less than 0.08 times

the actual shaft diameter; special consideration will be given to

fillet of multiple radii design. In general, the surface finish

for fillet radii is not to be rougher than 1.6 pm (63 pin.) RMS.

For the fillet radius for tail shaft to propeller coupling flange,see Table 19.2, Note 5.

19.7.4 emountable Couplings

Couplings are to be made of steel or other approved ductile

material. The strength of demountable couplings and keys is to be

equivalent to that of the shaft. Couplings are to be accurately

fitted to the shaft. Provisions for resisting thrust loading are

to be provided.

a ropeller Forward End - Where exposed to seawater, the

propeller assembly is to be sealed at the forward end with a well-

fitted soft-rubber packing ring and

b ropeller aft End - A fairwater cap filled with suitable

sealing material or equivalent sealing arrangement is to be

provided at the aft end of the propeller.

c Non - corrosive non - pitting Alloys - The sealing in (a) and (b)

is not required where the tailshaft is fabricated of corrosion



resistant pitting-resistant alloy unless required by the

manufacturer.

The key is to fit tightly in the keyway and be of sufficient size

to transmit the full torque applied to the shaft at rated speed.

The forward end of the keyway is to be so cut in the shaft as togive a gradual rise from the bottom of the keyway to the surface

of the shaft. Ample fillets are to be provided in the corners of

the keyway and stress concentrations are to be reduced as far as

practicable. For key details, see 19.23.

19 11 ail Shaft Bearings

19.11.1 ater-lubricated Bearings

a ood Bearings resinous, dense hardwood) The length ofthe bearing, next to and supporting the propeller, is to be not

less than four times the required tail-shaft diameter.

b ynthetic Bearings rubber, reinforced resins, plastic

materials) The length of the bearing, next to and supporting thepropeller, is to be not less than four times the required tail

shaft diameter.For a synthetic bearing design substantiated by experimental tests

to the satisfaction of the Bureau, consideration may be given to a

shaft diameter. The length of bearing may be less provided the

nominal bearing pressure is not more than 0.60 N/mm2 (0.0611

kgf/mm4, 87 psi) as determined by static bearing reaction

calculation taking into account shaft and propeller weight which

is deemed to be exerted solely on the aft bearing, divided by the

projected area of the shaft. The minimum length, however, is not

to be less than 1.5 times the actual diameter.Where the material has demonstrated satisfactory testing and

operating experience, consideration may be given to increased

bearing pressure.



19.11.3 elded Overlays

Journal buildup with a weld overlay of stainless steel or other

alloy is to be carried out at an approved facility in accordance

with an approved procedure. (See latest edition of ABS Guide for

Repair and C ladding of Shafts).

PROPELLERS

19.13 General

The propellers need not be designed and constructed in accordancewith these requirements provided they do not exceed 1.5m (60

inches) in diameter and are part of a manufacturer's standard

product line. n such instances, neither the Surveyor's

attendance for material testing and inspection nor the design



review will be required.

The following requirements apply to propellers which exceed 1.5m

(60 in) in diameter.

19.15 Material and Testing

19.15.1 Propeller Material

The material of the propeller is to be tested in the presence of

the Surveyor in accordance with requirements of Part 2, Chapter 3

of the latest edition of the Rules for Building and Classing

Steel Vessels or to other approved specifications. The finished

propeller is to be inspected by the Surveyor before installation

at the manufacturer's plant and after installation.

19.15.2 Stud Material

The material of studs securing detachable blades to the hub is to

be of Grade 2 steel or other approved material and is to be

tested in the presence of the Surveyor in accordance with the

requirements of Part 2, Chapter 3 of the latest edition of the

Rules for Building and Classing Steel Vessels. he finished

studs are to be inspected by the Surveyor.

b. Controllable-pitch Propellers

t0 . 3 5 = K2VAH CRN ± 1.09BK/C mm (in)

A = 1.0 + (6.0/20.7) + 320.35

B = (4900wa/N) (R/100)2 (D/20)3

C = (1 .6P 0.35) (Wf-B)

t0,25 = required thickness at the one-quarter radius in mm or in.



t0,3 5 = required thickness at the 0.35 radius in mm or in.

K1= 1067 (915,41)

K2= 857 (735,32.8)

H = power at rated speed in kilo- watt (hp,HP)

hp= metric horsepower

HP= inch/pound horsepower

R = rpm at rated speed

N = number of blades

2. 2 5 - - - itch at one-quarter radius divided by propeller

diameter

P0.35 = itch at 0.35 radius divided by propeller diameter,

corresponding to the design ahead conditions

20.7 = itch at seven-tenths radius divided by propeller

diameter, corresponding to the design ahead conditions

W = xpanded width of a cylindrical section at the 0.25 or

0.35 radius in mm or in.

a = xpanded blade area divided by the disc area

D = ropeller diameter, in m or ft

K = ake of propeller blade in mm/m or in. /ft multiplied by

D/2 (with forward rake, use minus sign in equation; with

aft rake, use plus sign)

f,w = aterial constants from the following table



shaft. The recess formed at the small end of the taper by the

overhanging propeller hub is to be packed with red lead putty or

rust preventative compound before the propeller nut is put on.

19.27 aterjets

19.27.1 eneral

Full details are to be submitted for the force transmitting partsof waterjet units including material specifications. For vessels

over 20m (65 ft) the units are to be manufactured under Surveys.

Certified mill certificates are to be provided for the components



of the steering section. The material tests for the impellers,

shafts and couplings are to be witnessed by the Surveyor.

Hydraulic cylinders are to be manufactured and surveyed in

accordance with the Rules for Building and C lassing Steel Vessels.

Waterjets used in aluminum vessels are to be suitable to preclude

galvanic corrosion.

19.27.2 esign

Design basis and stress calculations for the impellers, shafting,

steering mechanism, and reversing mechanism are to be submitted to

substantiate the suitability and strength of component parts for

the intended service. For the purpose of design review the stress

calculations are to cover the worst case condition for each

component. The factor of safety for the above components is not

to be less than 2.0 when determined by the following equation;

- Ss + Sa

U

nor less than 4.0 when determined by the following equation:

FS N M U

E

FS

19.27.4 eversing Mechanisms

Astern thrust is to be provided in sufficient amounts to secure

proper control of the vessel in all normal circumstances. he

reversing mechanism is to provide for reversing at full power,

19.27.5 mpeller Bearings

Antifriction bearings are to have a B10 life of at least 80,000

hours



U

•

TABLE 19 1

Shaft Design Factor for Lineshafts, Thrust Shafts, and Oil Distribution Shafts

Design natures

In wait

of axial

Munn? H Nth earings

sides of sed as

rtopeshlort typo

Turbine Drives

Integral haul fit ransverse ame:gain:11 hrust traight

flange oupling eyways oles lots ollars earings ections



Elecitie Drives

Mosel Drives through

slip couplings

(electria or

hydraulic) 0.05 0.05 1.001 1.015 I II 1.015 1.015 0.05

Diese l drives 1.0 1.0 1.1 1.1 1.2 1.1 1.1 1.0

Noise

I Ceotnelde features other Iltan those listed will he specially con- Diameter of bore not more than 0.3 x D.

*Were lengthof the slot not more than idth of the slot not

2 After a length of not less than 0.2 x D from the end of the ore than 0.2 x D, whereby D Is calculated with k 1.0.

keyway, the shaft diameter may ho reduced to the diameter

calculated for straight sections.

MINA radii In the transv erse section of the bottom of the keyway

are to be not len than 0.0125 x D.

TABLE 1 9.2

Shaft Design Factor K for Tail Shafts and Stern Tube Shafts

Tails shafts may be reduced to stern tube shaft diameter forward of the

bearing supporting the propeller. The inboard end of tailshafts or tube

shafts is to be designed the same as line shafts, with shaft design

factors in accordance with Table 19.1.



Propeller attachment method 1

Keyless

Stern ttachment tern

Propulsion ube y shrink ube

type onfiguration eyed2 fit4 langed hafts7 8

Oil lubricated

bearings 1.26 1.22 1.22 1.15

Water lubri-

cated bear-

ings with

continuous

shaft liners

or equiva-

lent 1.26 1.22 1.22 1.15

Water lubri-

cated bear-

ings with

noncontin-

All

All

All

SECTION 20

Pumps and Piping Systems

20.1 Application

Pumps and piping systems are to be in accordance with the applicablerequirements of the Rules for Building and Classing Steel Vessels

except where vessels are below 45.7 m (150 ft) in length, the

following alternative requirements may be applied.



20.2 Piping Groups

To distinguish between detail requirements for the various systems,

the piping on shipboard is divided into two groups.

GROUP I in general includes all piping intended for working

pressures or temperatures in various services as follows.

Service ressure emperature

bar kgs/cm12, psi) (F)

Vapor and Gas

Water

Lubricating OilFuel Oil

Hydraulic Fluid

over 10.3 (10.5, 150)

over 15.5 (15.8, 225)

over 15.5 (15.8, 225)over 10.3 (10.5, 150)

over 15.5 (15.8, 225)

over 343 (650)

over 177 (350)

over 204 (400)over 66 (150)

over 204 (400)

GROUP II includes all piping intended for working pressures and

temperatures below those stipulated under GROUP I, and in addition

such open-ended lines as drains, overflows and vents.

20.3 General

bData The plans are to consist of a diagrammatic plan

of each system accompanied by lists of material giving

size, wall thickness, maximum working pressure and

material of all pipes and the type, size and material of

valves and fittings. omplete construction details

(plans) are to be submitted for valves and fittings that

are not constructed to recognized standards.

20.3.2 Testing

After installation, all piping is to be tested to maximum

working pressure in the presence of the Surveyor.



20.3.3 nstallation Details

a Support Pipes, valves and operating rods are to be

effectively supported.

b Pipes Near Switchboards The leading of pipes in the

vicinity of switchboards is to be avoided as far as

possible. When such leads are necessary, care is to be

taken not to fit flanges or joints over or near the

switchboards and provision is made to prevent any leakage

from injuring the equipment.

c ulkhead, Deck or Tank-Top Penetrations Where pipes

are carried through watertight bulkheads, decks or tank tops,

arrangements are to be made to insure the integrity of the

watertightness of the structure.

d rass Piping Components in Salt Water Systems Where

brass is used, only alloys with a zinc content of 15 percent orless or which contain dezincification inhibitors such as tin,

antimony, arsenic are to be used in saltwater systems

e lastic Pipe Rigid plastic pipe will be specialy



considered for piping systems of less than 10.3 bar (1 0.5 kgf/cm',

150 psi) or less than 177C (350 F) for application other than

bilge piping in the machinery space, lubricating-oil, fuel oil and

fire piping upon submission of the physical characteristics of the

material. Where systems are connected to the sea, the sea valveand its connection to the shell are to be metallic.

The hydrostatic bursting pressure for rigid plastic pipe is to be

at least five times the maximum working pressure for thermoplastic

pipes and four times the maximum working pressure for reinforced

thermosetting resin pipes. he wall thickness for plain-end

thermoplastic pipe is not to be less than Schedule 40 N.P.S. and

the wall thickness for threaded thermoplastic pipe is not to be

less than Schedule 80 N.P.S. he wall thickness of reinforced

thermosetting resin pipes is to be in accordance withmanufacturer's standards based on burst test data.

f ose Flexible metallic and nonmetallic hose may be

installed throughout in systems such as sanitary drains, potable

water, and fresh water cooling for non-vital equipment. Where

hose passes through watertight bulkheads, it is to be connected

to a rigid sleeve of the same material as the bulkhead and the

sleeve is to be fitted with a readily accessible valve at each

The hose is to be adequately supported to prevent any strain on

the joints and prevent undue sagging. Soft supports or supports

with rubber or other suitable lining are to be used to ensure the

hose is not damaged. Contact with sharp edges of structure or

equipment is to be avoided. The hose is not to be subjected to

torsional deflection (twisting) under normal conditions. J oining

the hose sections is to be with suitable factory assembled or

supplied end fitting connections that will not damage the hose.

The use of rubber hoses which are not provided with factory

assembled end fittings will be considered for non-combustible

liquid service in pipe sizes up to 11 4.3 mm O.D. (4 in. N.P.S.) in



accessible locations. Such hoses are to be secured by means of at

least two stainless steel hose clamps at each end. Such clamps

are to be at least 12mm (0.5 in) wide and are not to be dependent

on spring tension to remain fastened.

g ipe Wall Thicknesses Pipe wall thicknesses are to be

in accordance with an approved recognized standard. For pipe with

an operating temperature over 177 C (350 F) or working pressure

over 10.3 bar (10.5 kgf/cm2, 1 50 psi), the thicknesses are to be

in accordance with the Rules for Building and Classing Steel

Vessels .

20.5 ilge System

20.5.1 General

All self-propelled vessels 20 m 65 ft) in length or greater are

to be provided with two power-driven bilge pumps, one of which may

be attached to the propulsion unit. A direct bilge suction led

directly from the main machinery space bilge to the suction valve

chest of the largest pump is to be provided in the main machineryspace.

20.5.2

Submersible bilge pumps located in bilge wells may be used in

individual compartments provided the vessel will remain stable

with the most sensitive of such compartments flooded. In addition

to these submersible pumps, one bilge pump is to be installed in

the main machinery space complying with the above capacity

requirements. second bilge pump of at least one half this

capacity is also to be fitted.

20.5.3 Size of Bilge Suctions

The least internal diameter of bilge suction pipes is to be that

of the nearest commercial size within 6 mm (0.25 in.) of the

diameter determined by the following equations or the above



minimum, whichever is greater.

1. ain Line or the diameter of main-bilge line

suctions in branch systems and direct bilge suctions to the pumps:

d — 25 + 1.68 iL (B+D) mm d — 1 (B+D) in.

2500

2. ranch or Submersibles Pump Lines For the equivalent

diameter of the combined branch suctions to a compartment or

submersible pump lines:

d — 25 + 2.16 jc (B+D) mm d— 1 lc (B+D) in.

1500

d internal diameter of pipe in mm or in.L — length of vessel on load water line in m or ftB — breadth of vessel in m or ft

D — molded depth to main deck in m or ft

c — length of compartment in m or ft

20.7 ent, Sounding, and Overflow Pipes



readily accessible or capable of being manually operated

from a readily accessible location.

20.13 Lubricating-011 Systems

20.13.1 General

The lubricating-oil piping is to be entirely separate from

other piping systems. Where oil coolers are provided thesea suctions are to be arranged to minimize the

probability of blanking off the cooling water.

20.13.2 Oil Filters



Oil filters are to be provided on all engines.

20.15 Cooling-Water System

20.15.1 GeneralDrain cocks are to be provided at the lowest point of all

jackets and a relief valve is to be fitted in the main

line to the jackets to prevent excessive pressure unless

the pumps are of the centrifugal type so designed that the

pressure delivered cannot exceed that for which the piping

is designed. For vessels over 20 m (65 ft), means are to

be provided to ascertain the temperatures of the

circulating water at the return from each engine and to

indicate that the proper circulation is being maintained.

20.15.2 Sea Suctions

For vessels 20 m (65 ft) in length and over at least two

independent sea suctions are to be provided for supplying

water to the engine jackets or to the heat exchangers.

The sea suctions are to be located so as to minimize the

possibility of blanking off the cooling water.

installation and complete assembly, the system is to be

leak tested at operating pressure using air. After the

system has been repaired for any leakage problems, all

appliance valves are to be closed and the cylinder shutoff

valve opened. After the gauge registers that the system

is pressurized, the cylinder valve is to

be closed. he gauge pressure reading is to remain

constant for at least 15 minutes.

20.19 Steering Gear Piping

See 18.11.8.



Section 21

Electrical Installations

21.1 eneral

Electrical installations are to be in accordance with requirements

in 21.3, 21.5, 21.29, 21.31, 21.33 and other applicable

requirements of the Rules for Building and Classing Steel

Vessels , except that where the aggregate generator capacity does

not exceed 75 kw the alternative requirements in 21.7 through



21.27 may be applied. lectrical installations in machinery

spaces with gasoline engines will be specially considered.

21.3 lans and Data

Plans are to be submitted in triplicate. Data to be submitted are

to include a complete feeder list giving for each feeder and

branch circuit, the load, wire size, and voltage drop for the

longest run of each size of cable, type of cable, rating or

setting of circuit breakers, rating of fuses and switches and

interrupting capacity of circuit breakers and fuses.

The following drawings/calculations are to be submitted.

Electrical one line diagram

Electrical switchboards and panelboards

Electrical power and lighting systems

Emergency electrical systems

Internal communication system

Alarm systems

Navigating lights

Propulsion control system



are to be provided with at least two generators. These generators

are not to be driven by the same engine. The capacity of the

generator set or sets is to be sufficent to carry the necessary

load essential for the propulsion and safety of the vessel, and

minimum comfortable conditions of habitability with any one

generator set in reserve. Vessels having only one generator are

to be provided with a battery source to supply sufficient lighting

for safety.

21.9.2 rotection

Generators of less than 25 KW not arranged for parallel operation

may be protected by fuses. All generators of 25 KW and over are



to be protected by a trip-free air circuit breaker providing

longtime over-current protection not exceeding 15% above either

the full-load rating of continuous-rated machines, or the overload

rating of special-rated machines. The shutting down of the prime

mover is to cause the tripping of the ship service generator

circuit breaker.

21.11 torage Batteries

21.11.1 ocation

Storage batteries are to be located in well-ventilated areas as

high above the bilges as possible and as far away as practicable

from potential sources of ignition.

21.11.2 nstallation

Lead-acid storage batteries are to be installed in liquid-tight

trays lined with lead or other suitable materials. lkaline

storage batteries are to be installed on suitable insulating

supports, and when metal cell containers are used these are to be

protected against conducting materials that can cause short-

circuiting between the containers and between the containers and

21.13 ables

21.13.1 onstruction

Cables are to have copper conductors constructed and sized in

accordance with a recognized standard and are to be of the

stranded type, except sizes not exceeding 1.5 mm2 (16 AWG) may

have solid conductors.

21.13.2 nstallation

All wiring is to be run as high as possible above the bilges, and

cable runs are to be made without splices and be as straight and



accessible as practicable. Cables installed in machinery spaces

are to have an insulation with a temperature rating of not less

than 75C. They are to be effectively supported and secured, and

protected against mechanical damage. Cables exposed to moisture

are to be moisture-resisting jacketed (impervious-sheathed). Allcable entrances in exposed locations and all penetrations through

watertight decks and bulkheads are to be made watertight.

21.15 istribution Boxes and Panels

21.15.1 onstruction

Distribution boxes and panels are to be of noncombustible material

and are to be preferably of the dead-front type. They may be of

metal or of nonconductive material. If of metal, they are to begrounded in accordance with 21.5.6. ll terminal strips, fuse

blocks, switches, and similar equipment are to be of

noncombustible high-dielectric-strength insulating material.

21.15.2 nstallation

Distribution boxes and panels are to be installed in dry

accessible, and well-ventilated areas. Not less than 610 mm (24

in.) clearance is to be provided in front of distribution boxes

21.17 Electric Protective Devices

21.17.1 eneralAll conductors are to be protected in accordance with 21.17.2.

Feeder and branch circuits for lighting, heating or ship's service

power are to have each ungrounded conductor protected by a circuit

breaker or fuse of suitable interrupting capacity. ircuitbreakers are to be of the independent-arm or trip-free type.

Circuit breakers may be equipped with time trips, instantaneous

trips or trips consisting of both time over-current and

instantaneous features.



21.17.2 ver-current Protection Devices

a ating Fuse rating and ratings (or settings, if adjustable)

of time- delay trip elements of circuit breakers are not to exceed

the rated current capacity of the conductor to be protected exceptas otherwise permitted for motor branch-circuit protection. f

the standard ratings and settings of over-current devices do not

correspond with the rating and setting allowed for conductors, the

next higher standard rating setting may be used, but not exceeding

150% of the allowable current carrying capacity of the conductor.

Except as otherwise permitted for motor branch-circuit protection,

adjustable-trip circuit breakers of the time-delay or

instantaneous type are to be set to operate at not more than 150%

of the rated capacity of the conductor to be protected.

b ndication The rating or appropriate setting of the

overload protective device for each circuit is to be permanently

indicated at the location of the protective device.

21.17.3 rotectionBranch lighting circuits are to be protected by over-current

protective devices rated or set at not more than 30 amperes. The

21.19 mergency Source of Power

All vessels having only one generator are to be provided with a

source of emergency electrical power sufficient to supply

emergency lighting for at least 6 hours. The power source may be

any one of the following:

a n automatically connected or manually controlled standard

battery; or

b n automatically or manually started generator; or



c elay-controlled, battery-operated lanterns.

21.21 avigating Running Lights

Mast head, port, starboard, and stern lights when required are to

be controlled by a running light indicator panel. A fused-feeder

disconnect switch is to be provided; the rating of the fuses is to

be at least twice that of the largest branch fuse and greater than

the maximum panel load.

21.23 istribution Cables

21.23.1 eneralAll electric cables for power, lighting, communication, control,

and electronic circuits are to have insulations suitable for a

conductor temperature of not less than 75C. The rated operating

temperature of the insulating material is to be at least 10C

higher than the maximum ambient temperature likely to exist, or to

be produced, in the space where the cable is installed. Electric

cables are not to enter oil tanks. Cables are to be installed in

such a manner that stresses on the cable are not transmitted to

21.23.3 Cables behind Sheathing

Cables may be installed behind sheathing, but they are not to

be installed behind or imbedded in structural insulation; they

are to pass through such insulation at right angles and are to

be protected by a continuous pipe with a stuffing tube at one

end. For deck penetrations this stuffing tube is to be at the

upper end of the pipe and for bulkhead penetrations it is to

be on the uninsulated side of the bulkhead.

a able Supports and Bends Cables are to be adequately

supported. Supports for cables are to be spaced not more than

610 mm (24 in.) apart in both horizontal and vertical

directions. ables grouped in a single support are to be



limited to two banks except for turnouts. ables running

transversely to the underside of beams are to be supported in

cable racks or the equivalent. Cables are not to be bent to a

smaller radius than 6 diameters (8 diameters for armored

cable).

b eck and Bulkhead Penetrations here cables pass

through watertight, firetight, or smoke-tight bulkheads or

decks, the penetrations are to be made through the use of

approved stuffing tubes, transit devices, or pourable

materials which will maintain the watertight, firetight or

smoke-tight integrity of the bulkheads or decks.

Additionally, each stuffing tube, transit device, or pourable

material is not to damage the cable physically or throughchemical action or heat build-up. When cables pass through

nonwatertight bulkheads where the bearing surface is less than

6.4 mm (0.25 in.), the holes are to be fitted with bushings

having rounded edges and a bearing surface for the cable of at

least 6.4 mm (0.25 in.) in length. Where cables pass through

deck beams, or similar structural parts, all burrs are to be

removed in way of the holes and care is to be taken to

eliminate any sharp edges.

21.25 plicing of Electrical Cables

a ocation Electric cables are to be installed in continuous

lengths between terminations; however, approved splices will be

permitted when necessary to extend existing circuits for a vessel

undergoing repair or alteration. Splicing procedure and location

of splices are to be submitted for approval.

b nstallation All splices are to be made after the cable is

in place and are to be accessible for inspection. The conductor

splice is to be made using a pressure type butt connector by use

of a one-cycle compression tool.



21.27 ermanent Watertight Fixtures

Permanent watertight fixtures are to be corrosion-resistant and

are to be used where exposed to the weather or splashing water.Lighting fixtures of this type are to be rendered watertight by

means of glass globes protected by substantial guards. Watertight

lighting fixtures are not required for any interior locations

except for refrigerated compartments or where exposed to splashing

water.

21.29 ridge Control of Propulsion Machinery

21.29.1 eneralThe following are applicable for vessels over 20 m (65 ft).

21.29.2 ontrol Capability

Under all sailing conditions, including maneuvering, the speed,

direction of thrust and, if applicable, the pitch of the propeller

are to be fully controllable from the navigating bridge. This

control is to be performed by a single control device for each

independent propeller, with automatic performance of all

21.29.5 Local Control

It is to be possible to control essential machinery and

the propelling machinery locally in the case of failure in

any part of the automatic or remote control systems.

21.29.6 Bridge Control Indicators

Indicators for the following are to be fitted on the

navigating bridge.

a Propeller speed and direction where fixed pitch

propellers are fitted.

b Propeller speed and pitch position where controllable



pitch propeller are fitted.

c An alarm is to be provided to indicate low starting

air pressure and is to be set at a level which stillpermits main engine starting operation.

21.31 rials

21.31.1 Ship s Service

All auxiliary apparatus is to be tried under working

conditions. ach generator is to be run for a time

sufficient to show satisfactory operations. When two or

more generators arranged for parallel operation areinstalled, parallel operation with all possible

combinations is to be demonstrated. Each auxiliary motor

necessary to the operation of the vessel is to be run for

a time sufficient to show satisfactory performance. All

main switches and circuit breakers are to be operated but

not necessarily at full load. he operation of the

lighting system, heaters, etc., is to be demonstrated

satisfactorily. The entire installation is to operate to



SECTION 22

Fire Extinguishing Systems

22.1 ire Pumps

22.1.1 umber of Pumps

Two power-driven fire pumps are to be installed, one of which may

be attached to the propulsion unit. Where vessels are less than



20 m (65 ft) in length, one power-driven, which may be an attached

unit, and one hand-operated fire pump are to be provided.

Sanitary, bilge and general-service pumps may be accepted as fire

pumps.

22.1.2 apacity

The capacity of each fire-pump is to be in accordance with thefollowing.

Vessel Length

Below 20 m (65 ft)

20 m (65 ft) or greater

but below 30.5 m (100 ft)

30.5 (100 ft) or greater

Minimum Capacity

5.5 m3/hr (25 gpm)

11.0 m3/hr (50 gpm)

14.3 m3/hr (66.6 gpm)

If a fixed fire extinguishing system in excess of that required by

22.5 is installed in the machinery spaces, a fire main may not be

be fitted with nozzles suitable for spraying water on oil or with

dual-purpose nozzles.

22.5 ixed Systems

For all vessels, fixed fire extinguishing systems are to be fitted

for spaces containing any of the following:

oil fired furnace

b uel oil units used for the preparation of oil fuel for

delivery to an oil-fired boiler or for the preparation for

delivery of heated oil to an internal combustion engine.



c nternal combustion machinery when the aggregate total power

output is not less than 375 KW (500 HP) and the vessel is

not less than 500 gross tons.

In general fixed fire-extinguishing systems are to comply with the

Rules for Building and Classing Steel Vessels.

22.7 xe

One fire axe is to be provided on each vessel 20 m (65 ft) and

over.

22.9 ortable Extinguishers

Portable extinguishers are to be provided in the quantities and

locations indicated in Tables 22.1 and 22.2.

TABLE 22.1

TABLE 22.2

Portable and Semiportable Extinguishers

Space lassification uantity and LocationSafety AreasCommunicating -II or B-II in each main corridor

corridors ot more than 46m (150 ft)

apart. (May be located

in stairways.)



Radio room -II in vicinity of exit.

AccommodationsSleeping accommo- - II or B- I in each sleeping

dation ccommodations space,

Where occupied by more

than 4 persons.)

Service SpacesGalleys -II or C-II for each 230 m

2 (2500

ft') or fraction

thereof for hazardsinvolved.

Storerooms -II or B-II or each 230 m2 (2500

ft ) or fraction

thereof located in

vicinity of exits,

either inside or

SECTION 24

SURVEYS AFTER CONSTRUCTION

24.1 Conditions for Surveys after Construction

24.1.1 amage to hull, machinery or equipment, which affects or may

affect Classification, is to be submitted by the Owners or their



representatives for examination by the Surveyor at first opportunity.

All repairs, found necessary by the Surveyor, are to be carried out to

his satisfaction. Nothing contained in this section or in a rule or

regulation of any government or other administration, or the issuance ofany report or certificate pursuant to this section or such a rule or

regulation, is to be deemed to enlarge upon the representations

expressed in subsections 1.1 through 1.9 hereof and the issuance and use

of any such reports or certificates are to in all respects be governed

by subsections 1.1 through 1.9 hereof.

24.1.2 otification and Availability of SurveyThe Surveyors are to have access to classed vessels at all reasonable

times. The Owners or their representatives are to notify the Surveyorson all occasions when a vessel can be examined while out of water in

drydock or on a slipway.

The Surveyors are to undertake all surveys on classed vessels upon

request, with adequate notification, of the Owners or their

representatives and are to report thereon to the C ommittee. Should the

Surveyors find occasion during any survey to recommend repairs or

further examination, notification is to be given immediately to the

24.1.4 nnual Classification SurveysAnnual C lass Surveys of Hull and Machinery are to be made within three

months either way of each annual anniversary date of the crediting of

the previous Special Periodical Survey of Hull or Machinery or original

construction date.

Special Annual Survey - When Annual Survey is part of a vessel's

Hull Classification notation, all the requirements of Hull Special

Periodical Survey, except for tank testing, are required each year for

the first three years of each four- year cycle. At the fourth year, acomplete Special Periodical Survey, including tank testing, is required.

24.1.5 ntermediate SurveyIntermediate Surveys are to be carried out within six months either way

of the midpoint between date of build and Special Periodical Survey-Hull



No. 1, and midway between each subsequent Special Periodical Survey ofHull.

24.1.6 pecial Periodical Surveysa pecial Periodical Surveys of Hull and Machinery are to be

completed within three months either way of a date four years

after the date of build or after the crediting date of the

previous Special Periodical Survey, except as noted below.

Alternatively, a year of grace for completion of the Special

Periodical Survey may be granted upon satisfactory completion of

the Year of Grace Survey as noted in 24.1.8. The interval between

Special Periodical Surveys may be reduced by the Committee. If a

Special Periodical Survey is not completed at one time, it will be

credited as of the completion date of the survey but no later than

five years from date of build or from the date recorded for the

previous Special Periodical Survey. Special consideration may be

given to Special Survey requirements in the case of vessels ofunusual design, in lay-up or in unusual circumstances.

Where the Special Periodical Survey is commenced more than three

months prior to the due date, the entire survey is normally to be

again for survey approximately five years from the date of its

survey. or Continuous Surveys, a suitable notation will be

entered in the Record and the date of completion of the cyclepublished. If any defects are found during the survey, they are

to be dealt with to the satisfaction of the Surveyor.

b n addition to the foregoing, at a survey approximately 2-1/2

years after entering service and after each subsequent Continuous

Hull Survey has been credited; vessels will require equivalent ofan Intermediate Survey as indicated in Section 24.1.5.

c t a survey approximately four years after each Special Continuous

Survey of Hull has been credited, thickness gaugings as required

for the forthcoming Special Periodical Survey, that are

accessible, are to be taken.



24.1.8 ear of Gracea o be eligible for the year of grace to complete the Special

Periodical Survey within one year after the due date, the vesselis to be presented for survey within three months either way of

the Special Periodical Survey due date. he requirements for

surveys to qualify for a period of grace will normally include

those thickness gaugings required for the forthcoming Special

Periodical Survey, that are accessible, and may also require

drydocking.

b f the survey is satisfactory, the completion of the Special

Periodical Survey may be deferred for a period not exceeding

twelve months, provided the whole Special Periodical Survey issatisfactorily completed within five years from date of build or

from the date recorded for the previous Special Periodical Survey.

24.1.9 ailshaft Surveys

a ater Lubricated Bearings: Unprotected carbon steel tailshafts

are to be surveyed at least once every three years for single-

screw vessels and four years for vessels fitted with multiple

screws.

Consideration will be given to any special circumstances which

might modify the requirements of a) and b) in particular cases.

24.1.10 oiler SurveysWaste-heat or fired auxiliary boilers intended for working pressures

above 3.4 bar (3.5 kgf/cm2, 50 psi), are to be surveyed at intervals not

exceeding 2- 1/2 years; however where requested by the Owner and at the

discretion of the Surveyor after an external examination of the boilers

and review of operating and feedwater records, an extension of the

auxiliary or waste-heat boiler surveys of up to six months may be

granted.

24.1.11 ay-up and Reactivation

a he Bureau is to be notified by the Owner that a vessel has been



laid-up. This status will be noted in the Record, and surveys

falling due during lay- up may then be held in abeyance until the

vessel reactivates. ay-up procedures and arrangements for

maintenance of conditions during lay-up may be submitted to the

Bureau for review and verification by survey.

b n the case of vessels which have been laid up for an extendedperiod (i.e., six months or more) the requirements for surveys on

reactivation are to be specially considered in each case, due

regard being given to the status of surveys at the time of the

commencement of the lay-up period, the length of the period andthe conditions under which the vessel has been maintained during

that period.

c here the lay- up preparations and procedures have been submitted

to the Bureau for review and verified by Annual Lay- up Surveys,consideration may be given to deducting part or all of the time in

lay-up from the progression of survey intervals.

d or vessels returning to active service, regardless of whether the

Bureau has been informed previously that the vessel has been in

lay-up, a Reactivation Survey is required.

24.1.14 elding and Replacement of Materialsa rdinary and Higher Strength Structural Steels: elding or

other fabrication performed on structural steels is to be in

accordance with the requirements of Section 15.

b pecial Materials: elding or other fabrication performed on

other steels of special characteristics or repairs or renewals ofsuch steel or adjacent to such steel is to be accomplished with

procedures approved for the special materials involved. he

procedures are to take into account the information provided under

paragraph 3.1 and be in accordance with the requirements of

Section 1 5.

c ubstitution and Alterations: Substitutions of steel differing



from that originally installed or alteration of original

structural configuration is not to be made without approval by an

ABS Technical Office.d elding is not to be performed on aluminum alloys of the hull

structure nor repairs or renewals commenced on such plating or

adjacent to such plating without thorough and careful reference to

the recommendations contained in Section 15. ubstitution of

aluminum alloys differing from those originally installed is not

to be undertaken without approval.

24.2 Drydocking Surveys

At each Drydocking Survey the keel, stem, stern frame, rudder,propeller, and outside of side and bottom plating are to be cleaned as

necessary, examined and placed in satisfactory condition together with

bilge keels, thrusters, exposed parts of the stern bearing and seal

assembly, sea chests, rudder pintles and gudgeons together with their

respective securing arrangements. or those vessels constructed of

aluminum underwater plating in close proximity to dissimilar metal is to

be examined both internally and externally as far as practicable. All

3 atches fitted with mechanically operated steel covers including

cover plating, stiffeners, cross joints, gaskets, cleats and dogs.

Exposed steel hatch covers are to be examined to confirm

structural integrity and capability of maintaining

weathertightness. Where significant wastage of hatch covers is

noted, thickness gauging is to be carried out and renewals made as

necessary. Proper operation and functioning of hatch cover andsecuring arrangements to be confirmed.

b rotection of other openings

1 atchways, manholes, and scuttles in weather and superstructuredecks.



2 achinery casings, fiddley covers, companionways and deckhousesprotecting openings in weather or enclosed superstructure decks.

3 ortlights together with deadcovers,

4 entilators, air pipes together with flame screens, scuppers anddischarges serving spaces on or below the weather deck.

5 atertight bulkheads, bulkhead penetrations, end bulkheads of

enclosed superstructures, and the operation of any doors in same.

6 eathertight doors and closing appliances for all of the above

including stiffening, dogs, hinges and gaskets. Proper operation

of weathertight doors and closing appliances to be confirmed.

c reeing ports together with bars, shutters and hinges.d Protection of the crew: guard rails, lifelines, gangways, and deck

houses accommodating crew and guests.

e Anchoring and mooring equipment.

unprotected spaces used for salt-water ballast are to be

internally examined.

At each Intermediate Survey, after Special Periodical Survey No.

2, all spaces used for salt-water ballast which do not have full

and effective corrosion control are to be internally examined and

dealt with as above.

b allast Spaces W ith Full Corrosion Control Where tanks or other

spaces used for salt-water are represented as fully protected, thecontinued effectiveness of such corrosion control arrangements is

to be verified at each Intermediate Survey.

24.5 Special Periodical Surveys - Hull

24.5.1 pecial Periodical Survey No. 1



Special Periodical Survey No. 1 is to include compliance with all Annual

Survey requirements, and the Surveyors are to satisfy themselves, by

examination in position, that all means of protection to openings are ingood condition and are readily accessible. Effect also is to be given

to the following requirements:

a he vessel is to be placed in drydock or upon a slipway and all

items of 24.2 examined.

• he vessel is to be gauged in accordance with Table 24.1.

c he rudder is to be examined. The condition of the carrier andsteadiment bearings and the effectiveness of the stuffing boxes

are to be ascertained.d The holds, tanks, voids, peaks, bilges and drain wells, engine and

boiler spaces, are to be cleaned out and the surfaces of the

framing and plating are to be examined.

e All decks and watertight bulkheads are to be examined.

f The cement or other composition on the inner surface of the bottom

plating is to be carefully examined and sounded to ascertain if it

is adhering satisfactorily to the plating.

approved, provided the Surveyor is satisfied with the internal and

external condition of the tanks and associated structure. The

testing of double bottoms and other spaces not designed for the

carriage of liquids may be omitted, provided an internal

examination is carried out together with an examination of the

tanktop and, in the opinion of the Surveyor, testing may be

waived.

k he Surveyor is to see that a thick steel plate is securely fixed

below each sounding pipe for the sounding rod to strike upon, indry places and in those tanks which are accessible for internalexamination.

The decks are to be examined and deck compositions are to be

examined and sounded, but need not be disturbed if found to be

adhering satisfactorily to the plating.

The hawse pipes are to be examined. Anchors and chain cables are



to be ranged, examined and the required complement and condition

verified.

When spaces are insulated in connection with refrigeration, thelimbers and hatches are to be lifted and enough lining is to beremoved from all spaces to enable the Surveyor to satisfy himself

as to the general condition of the plating and framing in way of

the insulation.

o xposed hatch covers not fitted with tarpaulins are to be hose

tested or otherwise proven weathertight.

In any part of the vessel where wastage is evident or suspect, the

Surveyor may require thickness gauging and repair of the affected

parts. See Table 24.1 .q n addition, the following requirements 1 through 4 apply to those

vessels constructed of reinforced plastic:

1. The framing and holds, hull laminate of the 'tween deck,

deep tanks, peaks, bilges and drain wells, and machinery spaces

are to be cleaned and examined. inings, ceiling, tanks, and

portable ballast are to be removed as considered necessary by the

b lating, in way of deck house or superstructure portlights is to

be examined. In this and any other part of the structure wherewastage is evident or suspect, the Surveyor may require thickness

gauging in order to obtain the actual thickness of material.

c he anchor cables are to be ranged and examined together with

anchors, chain locker, and holdfasts. hain cables are to be

renewed in cases where it is found that the links have been so far

worn that their mean diameter is 12% below the original requirednominal size. Where structural alterations to the vessel have had

the effect of so increasing the equipment requirements as to bring

the vessel into a higher numeral, the original chain cables may be

used until their mean diameter has been reduced 12% below the

nominal diameter of the larger cable required by the higher

numeral.




Special Periodical Survey No. 3 is to include compliance with allrequirements for Special Periodical Survey No. 2. The vessel is to begauged in accordance with Table 24.1 .

24.5.4 pecial Periodical Surveys No. 4 and 5

These surveys are to be at least as comprehensive as Special Periodical

Survey No. 3. The vessel is to be gauged in accordance with Table 24.1.


This survey is to be at least as comprehensive as Special PeriodicalSurvey No. 4. The vessel is to be gauged in accordance with Table 24.1.

24.5.6 pecial Periodical Surveys Subsequent to No. 6These surveys are to be at least as comprehensive as Special Periodical

Survey No. 6. The vessel is to be gauged in accordance with Table 24.1.

24.6 Annual Surveys - Machinery

e Testing of all means of communications between the navigating

bridge, the machinery control positions, and the steering gear

space, as well as the alternative position, if fitted.

f Bilge pumping system and bilge wells including operation of pumps,

remote reach rods and level alarms, where fitted.

g Boilers, pressure vessels, and their appurtenances externally,

including safety devices, foundations, controls, relieving gear,

high-pressure and steam escape piping, insulation and gauges.

h Electrical machinery, the emergency sources of electrical power,the switchgear, and other electrical equipment.

i ire-extinguishing apparatus required for Classification as

outlined in Section 22.

Testing of remote, centralized or automatic control systems, if

fitted, necessary for the safe operation of the vessel.

k esting of fire and high water level alarms, if fitted, in



machinery spaces.

24.7 Special Periodical Surveys - Machinery

24.7.1 arts to be ExaminedAt each Special Periodical Survey effect is to be given to the following

requirements.

a ll openings to the sea, including sanitary and other overboarddischarges, together with the valves connected therewith, are to

be examined internally and externally while the vessel is in dry

dock; and the fastenings to the shell plating are to be renewedwhen considered necessary by the Surveyor. or those vessels

constructed of aluminum insulating material in joints of shellconnections between dissimilar metals is to be examined and

renewed if necessary.

b umps and pumping arrangements, including valves, piping and

strainers are to be examined. The Surveyor is to be satisfied

with the operation of the bilge system, including an internal

g eduction gearing is to be opened and examined as considered

necessary by the Surveyor in order to confirm the condition of the

gears, pinions, shafts, bearings and lubrication system.

Alternative means of ascertaining the condition of epicyclic

gearing will be specially considered.

h n examination of the fire extinguishing apparatus required for

Classification as outlined in Section 22 is to be made in order

that the Surveyor may satisfy himself as to its efficient state.i xamination of anchor windlass including operational check and

test of the brakes.

24.7.2 nternal-combustion Engines

a n addition to the foregoing applicable requirements, cylinders,



cylinder heads, valves and valve gear, fuel pumps, scavenging

pumps, and superchargers, pistons, crossheads, connecting rods,

crankshafts, clutch, reversing gear, and compressors,intercoolers, and such other parts of the main and auxiliary

machinery as are considered necessary are to be opened out for

examination. Tie rods are to be re-tensioned as necessary, engine

entablature bolting checked for tightness, and crankshaft

deflections of low-speed- type engines measured. Parts which have

been examined within the previous twelve months need not be

examined again, except in special circumstances. pecial

consideration as to the intervals for requiring Special Surveys

may be given for main engines with bores 300 mm (11.8 in.) orunder provided the engine is maintained under a manufacturer'sscheduled maintenance program. he records of the program,

including lubrication servicing, are to be made available to the

Surveyor. Periodical overhauls, required by the manufacturer'sscheduled maintenance program, are to be witnessed by the Surveyor

and will be accepted for completion of the cycle.

b ir reservoirs are to be examined and their relief valves proven

insulators, which are to be free from dust or oil in order to

prevent creepage to ground.

d The insulation resistance of each propulsion unit is to be

measured and found equal to the requirements noted above for

auxiliary generators and motors. In order to further evaluate

these insulation-resistance readings, it is recommended that a

separate log be kept of insulation-resistance measurements taken

frequently at regularly scheduled intervals. Humidity, ambient

temperature, and condition of the machine are also to be noted.Any large and abrupt decrease in insulation resistance, when

compared with those recorded in the log, is to be further

investigated and corrected.

e Alternately, a log of insulation resistance values is to be made

at the beginning of the survey and insulation resistance is to be

measured again at the end of the survey; a comparison is to be



made between the measured value and the log made at the beginning

of the survey. ny large or abrupt decrease in insulation

resistance is to be further investigated and corrected.

24.7.4 uxiliary Apparatus

a ittings and connections on main switchboards and distribution

panels are to be examined, and care is to be taken to see that no

circuits are overfused.

b ables are to be examined as far as practicable without undue

disturbance of fixtures.

c ll generators are to be run under load, either separately or inparallel; switches and circuit breakers are to be tested.

d All equipment and circuits are to be inspected for possible

development of physical changes or deterioration. The insulation

resistance of the circuits is to be measured between conductors

and between conductors and ground and these values compared with

those previously measured. ny large and abrupt decrease in

insulation resistance to be further investigated and either

defects being discovered, such other parts as may be considered

necessary are to be opened and examined.

24.7.6 xamination at Shorter IntervalsIf it be found desirable, upon inspection, that any part of the

machinery should be examined at a shorter intervals than specified

above, it will be necessary for Owners to comply with the Committee' s

requirements in this respect.

24.7.7 reventative Maintenance TechniquesVessels which have an approved program of preventative maintenance may

be given special consideration as to the details and intervals for

examination of machinery.

24.8 Tailshaft Surveys



24.8.1 apered Tailshaft Survey DetailsThe survey for shafts with water-lubricated bearings consists of

removing the propeller and drawing in and examining the shaft in itsentirety, and during each survey, the shaft is to be examined by a

surface crack-detection method (such as magnetic particle or dye

penetrant) all around the shaft from the after edge of the liner for

one-third of the length of the taper, including forward end of keyway(if fitted).

The survey for shafts with oil-lubricated bearings may be effected

as described above. Alternatively, at the discretion of the Surveyor,

and on the basis of satisfactory service record, lubricating oil

analysis records, bearing wear-down, and the condition of the inboardand outboard seal assemblies, the survey may consist of removing thepropeller to expose the forward end of the taper, and examination by a

surface crack-detection method (such as magnetic particle or dye

penetrant) all around the shaft of the forward portion of the tapersection, including end of keyway (if fitted).

24.8.3 llowable Bearing Weardown

a ater-lubricated Bearings Other than Rubber: here

machinery is located amidships, the after bearing is to be rebushed when

it has worn down to 6.4 mm (0.25 in.) clearance in the case of shafts

229 mm (9 in.) or less in diameter, 7.95 mm (0.3125 in.) clearance where

the diameter is above 229 (9 in.) but not more than 305 mm (12 in.), and

9.53 mm (0.375 in.) clearance where the shaft exceeds 305 mm (12 in.) in

diameter. In cases where machinery is located aft the maximum clearance

is to be one grade less than the foregoing.

b ater - lubricated Rubber Bearings: Water- lubricated rubberbearings are to be rebushed when any water groove is half of the

original depth, or whenever the clearance exceeds the limits as given

above for wood bearings, whichever occurs first.

c il- lubricated Bearings: Oil-lubricated bearings are to be



rebushed when the weardown exceeds the manufacturer's recommendations.

24.9 Boiler Surveys

Parts to be examined

a t each survey the boilers, superheaters, and economizers are to

be examined internally (water-steam side) and externally (fire

side).b oiler mountings and safety valves are to be examined at each

survey and opened as considered necessary by the Surveyor.

c he proper operation of the safety valves is to be confirmed at

each survey.

d hen considered necessary by the Surveyor, the boilers and

superheaters are to be subjected to hydrostatic pressure test.

ci S

TABLE 241

T A B LE OF M I NI M UM RE QUI RE M E NT S FOR T HI C K NE SS GA UGI NG

Spec ial

Spec i a l Spec ial Spec ial Periodical

Per iodica l Periodical Periodical S u r v e y N o . 4

Survey No. 1 Survey No. 2 S u r v e y N o . 3 a n d Su bseq u en t

1) Areas considered suspect ) Areas considered suspect ) Areas considered suspect ) Areas considered suspect

by the Surveyor, throughout y the Surveyor, throughout y the Surveyor, throughout y the Surveyor, throughout

the vessel. he vessel. h e v e s s e l . h e v e s s e l ,

2) Two girth belts of shell and

deck within the midship half-length

together with internals In way as

d e e m e d n e c e s s a r y b y th e S u r v e yo r .

2) Three girth belts of shell and

deck within the midship hall-length,

together w i th in terna ls In way.

3) Two wind-and-water s trokes, por t and



starboard, for the m idsh ip ha l f - length.

4) A N ex po sed m a i n dec k a n d su pers t ruc t u re

dec k p la t ing.

5) Flat kee l p la t ing fun length, p lus

extensive b ot tom plat ing.

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