ship handling

Shiphandling/WatchstandingSeminar II

Lesson Contents• Shiphandling Theory

• Laws of Motion• Controllable Forces• Uncontrollable Forces

• Shiphandling• Terminology• Ground Tackle• Getting Underway• Single Screw Characteristics• Twin Screw Characteristics• Tug Handling• Man Overboard Recovery

Shiphandling Theory: Motion

• Various forces acting on the ship create movement.

• Newton’s Laws of Motion1. Unless acted upon by an outside

force:• An object in motion tends to stay in

motion.• An object at rest tends to stay at rest.

2. The resulting motion of an object is the sum of all forces acting on it.

3. Every action has an equal and opposite reaction.

Shiphandling Theory: Forces

• Controllable• Propeller• Rudder• Bow

Thruster/APU• Mooring Lines• Anchors• Tugs

• Uncontrollable• Wind• Current/Tides• Seas• Water Depth

Controllable Forces

Propellers

• Provides the most important source of force on a ship.

• (Usually) makes ship go forward.• Most ships have 2 propellers.• Aircraft carriers / Patrol Craft have

4.• Frigates have 1.

Controllable Forces

Propellers

• Forces resulting from the use of the propellers:• Forward (or reverse) thrust• Side Force

Controllable Forces

Propeller Thrust

• A result of the propeller spinning on its shaft.

• Caused by a pressure differential between the opposite sides of the propeller blade.

Controllable Forces

Propeller Thrust

Rotation ofpropeller blade

Water FlowLow Pressure

High Pressure

PropellerBlade

Resulting Thrust

Controllable Forces

Controlling Propeller Thrust

• Depends on type of propellers• Fixed Pitch Propellers• Controllable Pitch Propellers

Controllable Forces

Controllable Pitch Propellers

• Found on all gas turbine ships and some diesel amphibs

• 0 - 12 kts• shaft rotates at 55 RPM• thrust (speed) controlled by changing

the pitch of the propeller blade

Controllable Forces

Controllable Pitch Propellers

• >12 kts• thrust controlled by changing the

speed (RPM) of the shaft.

• The shaft always spins in same direction whether going forward or backward.

Controllable Forces

Fixed Pitch Propellers• Found on steam ships (carriers, subs,

amphibs)

• Cannot change pitch of propeller

• Thrust (speed) controlled by changing speed of the shaft

• To go backwards, must stop shaft and spin the shaft in the opposite direction.

Controllable Forces

Side Force

• Causes stern to move sideways in the direction of propeller rotation.

Propeller

Controllable Forces

Side Force

SideForce

Bottom

Single ScrewGoing Ahead

AheadAsternTwin Screw

SideForce

SideForce

Controllable Forces

Screw Current

• Consists of two parts• Suction Current - going into the

propeller• Discharge Current (Prop Wash)-

comes out of the propeller

Suction Current Discharge Current

Propeller

Acts on Rudder

Controllable Forces

Rudders

• Used to control ship’s heading by moving the stern.

• To have an effect, must have a flow of water across the rudder.

• Normally this flow of water is the discharge current of the screw.

Controllable Forces

RudderForce

Low Pressure Area High Pressure Area

• Acts a wing

RudderWaterFlow

RudderForce

Low Pressure AreaHigh Pressure Area

Controllable Forces

Propellers / Rudders

• Primary means of controlling the stern

Thrust

Side Force

Rudder Force

Controllable Forces

Pivot Point

• Imaginary point on the ship’s centerline about which the ship pivots

ThrustSide ForceRudder Force

Pivot Point

Controllable Forces

Pivot Point

Ship twisting with no way on.

Controllable Forces

Pivot Point

• Usually located 1/3 the length of the ship from the bow. (Just behind the bridge.)

• Pivot point is not fixed

Controllable Forces

Forces which affectlocation of the Pivot Point

• Headway or Sternway• Ship’s Speed

• Anchors• Mooring Lines• Tugs

Controllable Forces

Wind• Acts on the sail area of the ship

• Exposed superstructure• Hull structure

• Ships tend to back into the wind

• 30kts of wind = 1kts of current

Uncontrollable Forces

Current• Acts on the underwater part of the

ship.

• Creates set and drift.

Depth of Water

• Squat - Occurs a high speeds• bow of a ship rides up onto the bow

wave• stern of a ship tends to sink

• Shallow water effects.

Uncontrollable Forces

SHIP TERMINOLOGY

• Bow• Stem• Forecastle• Hawsepipe• Weather

decks• Draft• Freeboard

• Superstructure

• Pilothouse• Mast• Yardarm• Truck• Stack• Keel

• Shaft• Propeller• Rudder• Stern• Transom• Waterline

Shiphandling

SHIP TERMINOLOGY

Shiphandling

Turning Circle: The path described by a

ship’s pivot point as it executes a 360° turn.

Tactical Diameter (180°)

Final Diameter (360°)

Shiphandling: Terms

Final Diameter

Turning Circle

Kick

Tactical Diameter

Shiphandling: Terms

• Advance• Distance gained toward the direction of

the original course after the rudder is put over.

• Transfer• Distance gained perpendicular to the

original course after the rudder is put over.

Shiphandling: Terms

Advance and Transfer

Advance & Transfer 90° Turn

KickA

dvance

Transfer

Shiphandling: Terms


KickA

dvanc

e

Transfer

Shiphandling: Terms


Kick

Ad

vanc

e

Transfer

Shiphandling: Terms

• Headway• moving forward thru the water

• Sternway• moving backwards thru the water

• Bare Steerageway• the minimum speed a ship can

proceed and still maintain course using the rudders

Shiphandling: Terms

Mooring Lines

123456

BowLine

SternLine

Spring Lines

After BowSpring

Forward BowSpring

After QuarterSpring

Forward QuarterSpring

Shiphandling: Ground Tackle, Mooring Lines

Mooring Lines

• Lines• 1-6• Lines 1 and 6 are thicker than others

• Mooring procedure• fake out lines• safety brief• heaving lines


Mooring Lines

• Terms:• Heaving Line• Tattletale• Fenders• Capstan (p. 188 Seamanship)• Rat Guards (p. 175 Seamanship)


• Stand by lines• Take in the slack• Take a strain

• Heave around• Avast heaving• Hold• Check

• Double up• Single up• Take in

• Slack• Ease• Take to the

capstain

Sequence:

Commands:


Safety

• Battle dress• Snap back zone• Tugs• Pilots ladder


Deck and Pier Fittings

Shiphandling: Ground Tackle

Anchors

• Most common anchor• Standard Navy Stockless

• Most ships have two• Deep water anchor - 14 shots of chain• Normal anchor - 12 shots of chain

• Shot - 15 fathoms (90 feet)

Shiphandling: Ground Tackle, Anchors

Scope of Chain15 fathoms

30 fathoms

45 fathoms

60 fathoms

Shiphandling: Ground Tackle, Anchoring

Scope of Chain

Next to Last Shot

Last Shot


Anchoring

• Approach• Standby• Let Go the Anchor• Reports• P. 194 (Seamanship)• Anchor watch


• Concerns:• Watch the stern/pier• Watch for other

ships• Winds / Currents

• Set on or set off pier?

• Using mooring lines and tugs as necessary to control bow / stern

Shiphandling: Getting Underway, Mooring

The Ideal Approach• Approach on a converging course 10

to 20 degrees from the heading of our berth.

• When parallel, swing the rudder opposite the pier, and stop the ship.

• Stop headway by backing outboard engine.

• “Walk” the ship in by tensioning line 1; “twist” the stern with the engines.


Less than Ideal Conditions

• Being Set On: • Stop parallel to the pier, with 1/2 a

beam width of open water between you and the pier.

• Allow the current to push you onto the pier.

• Being Set Off: • Make your approach at a larger angle

to the pier at a considerable speed.• Be careful not to part your bow line.


• Easier than anchoring• Buoy held securely by several anchors.• Chance of dragging reduced.

• Two methods• Ordinary• Trolley


Requires:MWB / RHIB with boat crewYour shipA buoy

Conning Officer

• Drives the ship’s heading and speed through standard commands (orders) to the helm and leehelm

• Helm - controls the rudder• Leehelm - controls the propellers

Shiphandling: Standard Commands

Basic Format

Conning Officer

Command

Acknowledges Report

Helm / Leehelm

Verbatim Repeat back

(Carries out command)

Report


HELM CONSOLEShiphandling: Standard Commands

ENGINE ORDER TELEGRAPH


MODERN HELM CONSOLE

• Direction: Either left, right or “Rudder amidships”

• Amount: Expressed as a number of degrees of rudder (10, 15, etc.), or one of the following: (nominal values given)• Standard: 15°• Full: 30°• Hard: 35°(maximum rudder angle)


• Course: >10 degree change

COMMANDS TO THE HELMFormat Example

-Direction "Right. . .""Left. . ."

-Amount ". . standard rudder. . ."". . .ten degrees rudder. . ."

-Course ". . .steady course two zero zero."". . .steady on course one one five."


COMMANDS TO THE HELM

• Exception: Course changes of 10° or less:• For small course changes, a specific

rudder angle is not given. This allows the Helm to use up to 10° of rudder to make the course change.

• The standard command is:• Direction: “Come right/left”• Course to steer: “Steer course ___”


OTHER HELM COMMANDS

• Desired action: Increase or decrease rudder angle from a previously ordered angle

• Command:• “Increase your rudder to ________”• “Ease your rudder to _______”

• Note: Anytime a new rudder angle is ordered, a steering/steady course must be repeated if it is desired.


OTHER HELM COMMANDS

• Desired action: Change rudder angle to an equal amount of rudder in the opposite direction

• Command: “Shift your rudder”• Note: Again, if desired, course to

steer must be repeated.


OTHER HELM COMMANDS• Desired action: Steady the ship on

the current heading• Command: “Steady as she goes”

• When given, the Helm immediately determines ship’s head at the instant of the command, and steadies the ship on that course.

• This should normally be given only with the rudder at or near amidships.


OTHER HELM COMMANDS• Desired action:

Determine current ship’s heading

• Command: “Mark your head”• When given, the

Helm immediately determines ship’s head at the instant of the command,and reports it to the Conn.

• Desired action: Warn the Helm to steer more exactly

• Command: “Mind your helm”


HELM REPLY

• Whenever an order to the Helm is given, the Helm repeats the order back to the Conn verbatim.

• This assures the conning officer that the order was heard and understood correctly.


HELM REPLY

• Examples:• The Conn orders: “Right standard

rudder, steady course 260.”• The Helm replies: “Right standard

rudder, steady course 260, aye.”


HELM REPLY

• Order: “Mark your head”• Reply: “Mark my head, aye. 283.”

• Order: “Mind your helm”• Reply: “Mind my helm, aye.”


HELM REPLY

• If the helm does not understand an order from the Conn, the helm will reply:“Orders to the helm”

• The Conn should immediately check his/her order and restate it clearly to the Helm.


REPORT & ACKNOWLEDGEMENT

• Once a desired action is complete, the Helm reports it to the Conn.

• The Conn acknowledges all reports with “Very well’

• If the Conn does not acknowledge a report, the Helm should repeat the report until acknowledged.


EXAMPLES

Order: “Right standard rudder, steady course 298.”

Reply: “Right standard rudder, steady course 298, aye.”

Report: “Sir, my rudder is right standard, coming to new course 298.”

Report: “Sir, steady on course 298, checking 309.”


EXAMPLES

Order: “Come left, steer course 345.”Reply: “Come left, steer course 345,

aye.”Report: “Sir, my rudder is left 5°,

coming to new course 345.”Report: “Sir, steady on course 345,

checking 352.”


EXAMPLES

Order: “Right full rudder.”Reply: “Right full rudder, aye.”Report: “Sir, my rudder is right full,

no new course given.”Report: “Passing 230 to the right.”Order: “Belay your passing heads.”Reply: “Belay my passing heads,

aye.”


EXAMPLESOrder: “Ease your rudder to right 15°.”Reply: “Ease my rudder to right 15°,

aye.”Report: “Ma’am, my rudder is right

15°, no new course given.”Order: “Steady course 143.”Reply: “Steady course 143, aye.”Report: “Ma’am, my rudder is right

15°, coming to new course 143.”


EXAMPLES

Order: “Hard left rudder.”Reply: “Hard left rudder, aye.”Report: “Sir, my rudder is left 35°,

no new course given.”Order: “Shift your rudder.”Reply: “Shift my rudder, aye.”Report: “Sir, my rudder is right 35°,

no new course given.”


EXAMPLESOrder: “Right full rudder.”Reply: “Right full rudder, aye.”Report: “Sir, my rudder is right 30°, no new

course given.”Order: “Rudder amidships”Reply: “Rudder amidships, aye.”Report: “Sir, my rudder is amidships, no new

course given.”Order: “Steady as you go.”Reply: “Steady as you go, aye. Course 098.”Report: “Steady on course 098, checking

107.”


ENGINE ORDERS

• For fixed pitch propellers, ship speed is dependent on shaft rpm only.

• For controllable pitch propellers, ship speed is dependent on shaft rpm and, below about 12 knots, propeller blade pitch.• For gas turbines, the shaft is always

spinning when the engine is on line. “All engines stop” is achieved by a blade pitch of 0°.


ENGINE ORDERS

• Prescribed standard speeds are predetermined ship’s speeds:• “Standard speed” - normally 15 knots• “1/3” - one third of standard speed• “2/3” - two thirds of standard speed• “Full” - speed higher than standard

speed• “Flank” - maximum speed


ENGINE ORDERS

• AheadBell Speed1/3 52/3 10Std 15Full 20Flank Max

speed

Typical Prescribed Standard Speeds

• AsternBell

Speed1/3 52/3 10Full

Max

speed


ENGINE ORDERSFormat Example

-Engines ”All engines. . ."

-Direction ". . ahead full. . ."

". . .back 2/3. . ."

-Speed ". . indicate 108 revolutions for 15 knots."

". . .indicate 072 revolutions and 20% pitch for 3 knots."


ENGINE ORDERS

• Engines: Port, starboard, or all engines. Unnecessary for single screw ships.

• Direction: Ahead, back or stop, and nearest standard speed (except for stop)


ENGINE ORDERS

• Speed: “..indicate ____ turns for __ knots.”, OR“..indicate turns for __ knots.”• For controllable pitch propellers below 12

knots:“..indicate ___ turns and __% pitch for __ knots.”OR, “..indicate pitch and turns for __ knots.”

-Note: If proceeding at a prescribed standard speed, none of this is required.


MANEUVERING COMBINATIONS

• In maneuvering situations, where frequent engine changes are expected, the Conning Officer may set “maneuvering combinations”.

• When set, the Lee Helm answers all bells at the prescribed standard speed increment.

• On ships with an EOT, this is indicated by an RPM setting of “999”.


REPLIES AND REPORTS

• Reply: Verbatim repeatback is required.• Reports: Lee Helm reports when action

is completed.• Note: Every report must include the

complete status of all engines, even if only one was changed.

• Acknowledgement: Conn will acknowledge all reports with “Very well”


EXAMPLES

Order: “All engines ahead standard, indicate 115 revolutions for 16 knots.”

Reply: “All engines ahead standard, indicate 115 revolutions for 16 knots, aye.”

Report: “Ma’am, engine room answers all engines ahead standard, indicating 115 revolutions for 16 knots.”


EXAMPLES

(Continued from previous slide)Order: “Indicate 122 revolutions for 17

knots.”Reply: “Indicate 122 revolutions for 17

knots, aye.”Report: “Ma’am, engine room answers

all engines ahead standard, indicating 122 revolutions for 17 knots.”


EXAMPLES

Order: “Port engine ahead 1/3, starboard engine back 2/3.”

Reply: “Port engine ahead 1/3, starboard engine back 2/3, aye.”

Report: “Ma’am, engine room answers port engine ahead 1/3, starboard engine back 2/3.”


EXAMPLES

(Continued from previous slide)Order: “Starboard engine stop.”Reply: “Starboard engine stop, aye.”Report: “Ma’am, engine room

answers starboard engine stop, port engine ahead 1/3.”


EXAMPLES

Order: “All engines ahead 1/3, indicate pitch and turns for 5 knots.”

Reply: “All engines ahead 1/3, indicate pitch and turns for 5 knots, aye.”

Report: “Sir, engine room answers all engines ahead 1/3, indicating 075 turns and 34% pitch for 5 knots.”


Ship AheadPropeller AheadRudder Amidships

Shiphandling: Single Screw Ships

Ship AsternPropeller AsternRudder Amidships

Ship follows the rudder:Ship will tend into the wind:Ship will tend to port very easilyShip does not tend to starboard easily


Ship AheadPropeller AsternRudder Amidships


Ship AheadBoth Propellers Ahead

Shiphandling: Twin Screw Ships

Ship AheadOne Propeller Trailing

Counteract with rudder


Ship AsternOne Propeller Trailing



Ship AheadBoth Propellers Ahead Different Speeds



Propellers Split


Single Headline

• Simplest Tie-up

• Best to allow tug to push or pull only

• Not good if complex tug maneuvers required.

Shiphandling: Tug Tie-Ups

Double Headline

• Not as simple

• Allows tug to push or pull and complex tug maneuvers


Power

• Most versatile tie-up

• Good for general purpose use

• Holds tug securely to ship.


Recovery Maneuvers

• Williamson Turn• Anderson Turn• Race Track• Y-Turn

Shiphandling: Man Overboard Recovery

Easiest Method?

• Daylight: Anderson• Night: Williamson• Subs: Y backing• Carriers: Racetrack

• Boat / Helo?


Recovery considerations

• Helicopter• average time to ready for takeoff is

10-12 mins

• Small boat• average time to launch 6-8 mins

• Ship• fastest method


Small Boat Considerations

• PPE for boat crews• manning

• coxswain• bow hook• corpsman• boat officer• signalman• SAR swimmer

• 3-5 knots; no sternway


Initial Actions• Applicable for all recoveries:

• Full rudder to side of ship where person fell overboard.

• Full speed.• Throw smoke float, life ring• Keep in sight• Pass the word• 6 short blasts• Mark on chart• Man Boat Deck• Notify other ships, Helos• Receive muster report


Follow-on actions• Notify Captain, TAO and Flag• Hoist Oscar flag (day); turn on red-

over-red pulsating (night)• Notify other ships in company• Gather Vitals from CIC

• Time in water• Water temp and stay time• Bearing and range to man


Right Full Rudder

All Engines Ahead Full

Kicks Stern AwayMan OverboardStarboard Side


Williamson Turn

Shift RudderWhen 60° Off Course


maneuvering

• Williamson

portport starboardstarboard- slow- slow

- good for night- good for night or low visor low vis

60 deg60 deg


Anderson Turn


maneuvering• Anderson

portport starboardstarboard

- fastest- fastest

- most skill- most skill


Racetrack Turn


maneuvering

• Race track

portport starboardstarboard- high speed- high speed

- easier approach- easier approach


Y-Turn


maneuvering

• Y-backing

- poor control- poor control

- keeps ship- keeps ship close to manclose to man


maneuvering

• tear drop

portportstarboardstarboard

- Carriers- Carriers modifiedmodified racetrackracetrack


ship handling

Education

controllable forcesforces

controllable forcesrudders

controllable forcespivot

rudder propeller

force rudder force

motion various forces

ships pivot point

kts shaft