House D.J. Ship Handling Theory and Practice

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216 SHIP HANDLING

Passive Tank – ship rolled to Starboard

(stern view). The water volume moves

as indicated in a downhill motion.

Ship now rolling to Port and

the water in the tank has built

up on the starboard side.

This provides a moment which

will oppose the roll velocity.

Ship now at a position of complementing

the roll to port. The water is providing

no moment to the ship.

Ship now rolling to starboard.

The water in the tank on the port

side acts to provide a moment,

again, opposing the roll velocity.

a) b)

c) d)

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This text has been compiled to expand the subject of ship handling procedures and

the varied equipment associated with the task. It is not meant to provide every

answer to every problem which exists in the world of manoeuvring ships. Nor can it

possibly put the years of required experience on the newly qualified Master. It has

been written to provide some insight to the theory, which supports an ever so prac-

tical topic for today’s handlers of the world’s ships.

It is a sad indictment of our training techniques that many Chief Officers gain

their rank and have little opportunity to obtain ‘hands on’ ship handling practice.

Yet as soon as that same Chief Officer is promoted to command, he is immediately

expected to handle the manoeuvring of the vessel, as if he had carried out the task

for years.

This element of the marine industry continues to race through change with new

innovations in hardware being developed on virtually a daily basis. We saw the

changes coming slowly with the advent of the Controllable Pitch Propellers. However,

since that dawn, major inroads into azi-pods, thrusters, high performance rudders,

new hull forms, increased speeds and improved steering concepts have changed the

so-called norms of manoeuvring ships.

It is hoped the text and illustrations of this volume will go some way to help the

young sea-going officer move towards the experience of the established Master.

217

Summary

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Barrass, C.B. (1989) Squatting of Ships Crossing in a Confined Channel, Article in

‘Seaways’ Magazine, November.

Clark, I.C. (2005) Ship Dynamics for Mariners, published by The Nautical Institute.

Henson, H. (2003) Tug Use in Port, 2nd edition, published by The Nautical Institute.

House, D.J. (2002) Anchor Practice: A guide to industry, published by Witherby.

International Marine Organization (2004) SOLAS (Safety of Life at Sea), Chapter V,

published by IMO Publication.

OCIMF (1992) Mooring Equipment Guidelines, 2nd edition, published by Witherby.

Rowe, R.W. (2000) The Ship Handlers Guide 2nd edition, published by The Nautical

Institute.

Schneekluth, H. and Bertram, V. (1998) Ship Design for Efficiency and Economy, pub-

lished by Butterworth-Heinemann.

Watt (1970) Vessel Performance in Confined and Restricted Channels of the St Lawrence

River, An MoT Report.

Willerton, P.F. (1980) Basic Ship Handling for Masters, Mates and Pilots, published by

Newnes.

Williamson, P.H. (2001) Ship Manoeuvring Principles and Pilotage, published by Witherby.

The Maritime and Coastline Agency, Maritime Guidance Notes:

MGN 199 (M) Dangers of Interaction

MGN 301 (M  F) Manoeuvring Information on Board Ship

MGN 308 (M  F) Mooring, Towing or hauling Equipment on all vessels – Safe

Installation and Safe Operation.

219

Bibliography

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Vessel manoeuvring principles

Question 1. What is the approximate position of the vessel’s pivot point, when the

vessel is making headway?

Answer: When the vessel is making headway the position of the ship’s ‘Pivot

Point’ is established approximately 0.25L, from forward (where ‘L’, represents the

ship’s length).

Question 2. When a vessel undergoes ship’s trials, a turning circle to port and to

starboard is usually conducted. Assuming the calm conditions are the same and the

vessel is fitted with a single right-hand fixed propeller, which turn would be com-

pleted tighter and quicker?

Answer: A turn to port would normally be expected to be tighter and quicker than

a turn to starboard, assuming the conditions are the same.

Question 3. When operating astern propulsion, how would the ship’s Master

know that the vessel is actually making sternway through the water?

Answer: Observation of the water surface, from the bridge wing, would indicate

that the stern wake is moving forward towards the midship’s position. This indica-

tion would show the propeller position has moved aft, away from the agitated

water and is actually moving the vessel astern.

Question 4. When is the rudder considered effective?

Answer: When a stream of water is passing aft of the rudder position.

Note

: The reason why the rudder is always placed amidships, when the vessel is operating

astern propulsion, is that it is non-effective when water is moving forward and not passing

the rudder.

221

Self-examiner – Questions

and Answers on ship

handling

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Question 5. When conducting a turning circle, which is the larger diameter

scribed:

a. The tactical diameter?

b. The final diameter?

Answer: The tactical diameter is the larger of the two.

Question 6. If a vessel is required to complete a round turn when engaged opera-

tionally, what features and characteristics would affect the size and quality of the turn?

Answer: The turning ability of a vessel will be directly influenced by the following:

a. Light or loaded condition. When in a light or ballast condition the vessel will be

influenced by the wind and may make considerable leeway.

b. If the vessel is trimmed by the stern, she will generally steer more easily.

c. If the vessel is not upright and carrying an angle of list the turn would take

longer and turning towards the angle of list would increase the turn size. Beam of

the ship will affect the turn. A narrow beam vessel will turn tighter than a broad

beam vessel.

d. Additional factors affecting the turning ability include: depth of water, draught

of ship, speed of vessel and the type of rudder being employed.

Question 7. What shipboard elements are under the control of Masters and

Marine Pilots when involved in practical ship handling?

Answer: The control elements at the disposal of the ship handler include:

a. Engines and propulsion power.

b. Rudder(s) and steering elements.

c. Anchors.

d. Mooring ropes and lines.

e. Tugs when responding to command control.

f. Bow/stern thrust units (if fitted).

Some vessels are now fitted with Double Acting controls and, as such, would

have functional ahead and astern controlling stations, inclusive of Bow Rudder

configuration.

Question 8. What elements are not under control when involved in ship

handling?

Answer: Clearly the weather elements during operations such as: wind, direction

and force; together with state of visibility, tides and current flow, depth of water;

man-made structures such as bridges; geographic obstructions like narrows and

islands, as well as other traffic in the vicinity.

Question 9. When operating astern propulsion with a right hand fixed (RHF)

pitch propeller the ship’s stern will pay off, either to port or starboard because of the

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effects of transverse thrust. Which direction will the stern move when operating

astern with a RHF propeller, rudder amidships?

Answer: When moving astern, rudder amidships and right-hand fixed propeller,

the stern will move to port and the bow will move to starboard, because of trans-

verse thrust effects.

Question 10. What do you understand by the term ‘Headreach’?

Answer: Headreach is described by that distance a vessel will move forward over

the ground, after main engines have been stopped.

Manning and station requirements

Question 1. When involved in manoeuvring the vessel, what personnel would

you expect to be involved in the Bridge Team?

Answer: The Master (Team Leader), the Marine Pilot, the Officer Of the Watch, the

Helmsman, the Lookout(s) and an engine room contact. Additionally, a

Communications Officer and/or a radar observer.

Question 2. When taking up an aft or forward mooring station, what would the

expected duties of the Deck Officer be?

Answer: The Officer in Charge of the station would be concerned with the safety of

everybody aboard and be required to inspect the immediate deck area to ensure that

no obstructions or hazardous situations exist. The Officer in Charge of the station

would further check that all machinery is functioning correctly and that clear commu-

nications are available to the bridge. Heaving lines, stopper arrangements and any

special signals are readily available for use as required. Mooring lines intended for use

should be cleared from drums and flaked on deck ready for running in a safe manner.

Question 3. When picking up the Marine Pilot from a pilot launch, what prepara-

tions should be made ready at the boarding station?

Answer: Assuming that previous communications between the ship and the pilot

launch have been established, the boarding station should have the pilot ladder (or

pilot hoist) deployed and ready at the required operational height above the water

surface. Manropes and stanchions should be rigged. Ancillary equipment such as

lifebuoy and heaving lines should be readily available. Where the operation is to be

carried out at night, the boarding station should be illuminated overside and in the

deck area of boarding.

The Officer Of the Deck, when meeting the pilot, should inspect the rigging and

securing of the ladder and ensure that communications to the bridge are operational

and in good order. Where a pilot hoist is to be used, the hoist and all control func-

tions should be checked before the pilot boards.

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Note

: Where a high climb (over 9 metres) is expected, a combination rig with the accommo-

dation ladder and pilot ladder would be arranged.

Question 4. What international code signal flag should be displayed by the ship,

once the Marine Pilot has boarded and taken the ‘con’?

Answer: The ship should display ‘H’ (Hotel Flag) indicating there is a pilot on board.

Question 5. When a vessel is approaching an anchorage, what preparations

would you expect the anchor party to carry out, before working anchors and cables?

Answer: Assuming that the Master and Chief Officer of the vessel have jointly

agreed the content of the anchor plan, the Officer in Charge of the anchor party

would expect to obtain power on deck and take charge of the forward mooring

deck. The windlass would be inspected, oiled and greased and then turned over to

ensure that the machinery was in good running order and without defects. The

brake system would be checked and if found satisfactory the anchors would be

placed in gear and the securings cleared away. The anchor for use would be walked

back out of the hawse pipe and if it is intended to let go, it would be placed on the

brake and the windlass taken out of gear. The Bridge should then be informed that

the anchor is cleared away and ready to be released.

Where heavy anchors are employed, as with VLCC vessels, it is anticipated that

the anchor will be walked back all the way and not let go, as is common with the

smaller vessel and less heavy anchor.

Relevant lights and signals would be prepared for immediate display, once the

vessel is anchored.

Question 6. A Marine Pilot is to be delivered to the vessel by helicopter. What

preparations would the Heli-deck landing party carry out, prior to commencing a

hoist operation?

Answer: The Heli-Deck party would prepare the hoist/landing deck area prior to

the arrival of the aircraft. All preparations would be as per the ICS Guide to

Helicopter Operations at Sea.

Such preparations would include the lowering of all exposed high rigging in the

area of operation. The deck space and surrounding area would be cleared and any

loose material secured away. A wind sock or signal flags would be displayed to pro-

vide indication of the wind direction to the pilot of the aircraft.

A designated hook handler would be equipped with rubber soled boots, rubber

gloves and an insulated static hook rod, to assist the transfer. Other crew members

of the deck party would be briefed on what not to do. Correct navigation signals to

reflect restrictions in ability to manoeuvre would be displayed and the rescue boat

would be turned out ready for emergency launch, if required.

Question 7. When weighing anchor what relevant reports are passed from the

forward station to the bridge?

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Answer: The direction of which way the cable ‘leads’ is usually indicated through-

out the period of weighing anchor. The bridge would also be informed when the

cable is ‘up and down’ and when the anchor is actually ‘aweigh’. Once the anchor is

clear of the water surface, confirmation that the anchor is ‘sighted and clear’ is usu-

ally communicated to the ship’s Master. Once the anchor is stowed and secured for

sea, stations would normally be stood down. The Officer in Charge of the anchor

operation would be expected to report to the bridge to inform the Duty Officer and

the Master of this fact and cause an entry to be made in the log book.

Question 8. When a vessel is expecting to take tugs fore and aft, what information

will the Officers at these stations require?

Answer: Securing tugs to a parent vessel can be carried out by several methods

and any officer under orders to secure a tug would need to ascertain:

a. Whether the tug’s line or ship’s line is to be employed.

b. What lead is required to secure the tug by.

c. What method of securing to the ‘bitts’ is required (eye or figure eight to bollards).

Question 9. When manoeuvring in close proximity to small craft, like pilot

launches and tugs, what is considered a main danger and hazard?

Answer: Where small crafts of any kind are engaged with a larger, parent vessel

the main danger is from the forces of ‘Interaction’ between the two crafts.

Question 10. Following an emergency incident at sea, like an onboard fire, what

operational stations would you expect to be manned and brought to an alert status?

Answer: With most sea-going emergency incidents, the bridge team would be

called in and the Engine Room would be placed on immediate stand-by. Depending

on the nature of the incident then emergency parties, for damage control, rescue

boat crew, a fire party or first aid party or a combination of these could expect to

take up stand-by positions.

Note

: It must be anticipated that the Master would take the ‘con’ and effect control of the

Navigation Bridge.

Ship manoeuvring operations

Question 1. How could a vessel turn around sharply in a river, where sea room is

limited?

Answer: A vessel can achieve a tight turn by ‘snubbing around’ on the ship’s

anchor. Alternatively, depending on the amount of sea room, the vessel may be able

to carry out a short round turn.

Question 2. What do you understand by the term ‘Dredging the Anchor’?

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