House D.J. Ship Handling Theory and Practice

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The vessel should be manoeuvred to bring the inner mooring buoy abeam of the

break of the foc’stle head and off the port bow, passing a head line through a centre

lead to the mooring boat for running and securing to the buoy. If a centre lead (bull-

ring) is not fitted, two separate rope eyes, one from each bow, must be sent.

106 SHIP HANDLING

Hold ship’s position against current flow

by means of engines

Once head line is fast, stop

engine and allow vessel to

drop astern of head buoy.

Use mooring boat to pass

stern line via centre lead

to mooring buoy aft

Once moored to

the buoys, slip

wires should be

rigged and run to

the buoys at both

the fore and aft

ends

Mooring to buoys – procedure (tide ahead)

1. Stem the tide. If the tide is astern, then go past the buoys and turn the vessel short

round to stem the tide. Position the vessel off the forward buoy. Use the engines

to hold station. Pass all the forward headlines to the buoy.

2. Once the headlines are secured, reduce the engines and let the tidal effect take the

vessel astern, paying out the forward lines as required. When the lines are at the

correct length, hold on to let the vessel swing easy between the line of buoys.

3. Make fast forward and stop engines. Send away the stern mooring lines to the aft

buoy and make them fast.

4. Slip wires should then be passed to the buoys at each end, once all fast fore and aft.

Securing mooring lines to buoys

Various ports around the world employ different practices for securing the soft eyes

of mooring ropes to mooring buoys. The easiest method is to have sufficient num-

bers of mooring shackles to send away with each eye, which will permit each rope

to be separately connected to the ring of the buoy.

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An alternative securing method is to use manila lashing tails, of suitable length, to

lash in place a toggle passed through the rope’s bight and wedged across the rope

eye. Where no toggle is available, the sides of the rope eye can be lashed together

under the rope’s bight.

ANCHOR OPERATIONS AND DEPLOYMENT 107

Buoy A

Buoy B

No wind no tide

To moor between buoys, to end facing the opposite way.

The vessel should approach ‘Buoy B’ at a fine angle on the starboard bow and

pass a head line, via a mooring boat to be secured to the ring of the buoy. Once the

mooring boat is clear, the rudder should be placed hard to starboard with main

engine at half ahead. The head line will act as a spring causing the stern of the ves-

sel to be forced upwards towards ‘Buoy A’.

Use the same mooring boat to pass a stern line towards ‘Buoy A’. Care should be

taken not to foul the stern line with the propeller action. Once the line is secured

onto the buoy, heave the stern of the vessel into a position of alignment between the

two buoys.

Tidal conditions

If the mooring is to be attempted with a right hand or left hand fixed propeller, in

tidal conditions the vessel should approach ‘Buoy B’ as described in the previous

example.

Wait for the tide to turn, provide the vessel with a sheer, by use of the rudder and

tend the forward mooring as the vessels swings on the tide, to place the stern close to

‘Buoy A’. Once in the outward facing position, pass the stern moorings to ‘Buoy A’.

Where a ship is equipped with twin propellers or CPP and Bow Thrust (and/or

stern thrust), it would not be anticipated that the ship would have to wait for the

tides to turn, to complete the mooring.

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1. Single up to the forward slip wire. As the vessel is held in position with water

flowing past the rudder, the ship is still steerable.

2. Helm hard to starboard and the stern could expect to swing outside the line of

buoys.

3. Engines ahead, let go the forward line and clear the buoys.

Departing the Buoys (Tide Astern)

108 SHIP HANDLING

Departure from Mooring Buoys (Tide Ahead)

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1. Single up to slip wire fore and aft.

2. Slack the forward line. Engines astern, if the stern swings to port with the trans-

verse thrust, then let go the forward line. Allow the vessel to drop astern.

3. Stop engines, let go the aft line. Then engines astern again to clear the buoys.

4. With adequate clearance, stop engines. Engines ahead and apply helm as required.

NB. Do not attempt to bring the vessel back between the buoys.

Departing the Buoys (Tide Astern)

When the vessel does not swing with the transverse thrust effect (see previous example).

ANCHOR OPERATIONS AND DEPLOYMENT 109

Hanging off a ship’s anchor

There may be occasions when it is necessary to hang off the anchor, as when moor-

ing to buoys or in a situation of establishing a ‘Composite Towline’ (see towing

chapter). In the majority of cases and depending on the design of the vessel, the

anchor is far too heavy to be cleared and physically hung off by wires. If the oper-

ation has to take place at all, it would be carried out with shore side crane facilities or,

alternatively, hung off in the hawse pipe by its own anchor securing devices.

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If hanging off in the hawse pipe, the bare end of cable would then expect to be

deployed via the centre (Bullring) lead (if fitted). Clearly, where a centre lead is not

a feature, an alternative mooring strategy would have to be employed.

Previously, vessels with anchors of under 10 tonnes could contemplate hanging

the anchor off at the break of the for’cstle head. However, heavy duty wires and

associated shackles would have to be available. In the modern day, where ships are

carrying anchors in excess of 20 tonnes, the practicalities make such an operation

dangerous and foolhardy.

Rigging slip wires (to mooring buoys)

The objective of rigging slip wires to mooring buoys is functional to allow the vessel

to control the departure time of the vessel, independent of shore side linesmen.

The wire is rigged as a bight passing through the ring of the mooring buoy, with

both parts of the slip secured aboard the mooring deck of the mother ship. Slip wires

are generally rigged both fore and aft (ropes are not generally used).

Preparation

1. The wire should be flaked the length of the foredeck.

2. The eye of the wire should be reduced by seizings to allow it to be passed

through the ring of the mooring buoy easily.

3. Have a strong messenger line ready flaked to run with the slip wire.

4. Pass both the slip wire and the messenger separately overside towards the water

surface, ready to be picked up by a mooring boat.

Operation

The vessel would be expected to be secured by mooring ropes at each end prior to

attempting the rigging of slip wires.

a) Pay out one end of the slip wire and one end of the messenger with some slack on

each, into the stern part of the mooring boat.

b) Men in the mooring boat would normally coil slack to each line in the sternsheets

of the mooring boat to permit flexible operations.

c) The boat would move towards the buoy to permit one man (Buoy jumper) to land

on the buoy and pass the reduced eye of the slip wire through the ring of the buoy.

d) Once the eye has been passed through the ring then the messenger can be

secured to the eye, to permit pulling the slip wire back to the vessel.

e) As the wire is brought on board the messenger can be detached and both parts of

the bight can be turned up on bitts. This will allow either part of the slip wire to

be released as and when by the deck crew without calling out shoreside labour.

Precautions

When operating with mooring boats, the personnel in the boat should be wearing

lifejackets. If lifejackets are not visible then the mooring officer should offer the use

of ships lifejackets for this operation.

110 SHIP HANDLING

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When passing the slip wire, the eye should be passed from the upward side of the

buoy ring, as this will avoid the eye ‘Lassooing’ the ring when letting go. When secur-

ing the parts of the slip wire, it is recommended that eyes at the ends are not placed

over bitts, but ‘figure 8s’ used for ease of release.

Use of kedge anchor

Kedging is described as the movement of the vessel astern, by means of an anchor or

anchors, laid aft of the vessel. Where a ship is equipped with a stern anchor arrange-

ment the employment of its use as a stream anchor, to kedge the ship astern, would

not be seen as a difficult operation. Unfortunately, many vessels are not so equipped

and if the need to conduct a kedging operation became necessary, limited options

may include the use of the ship’s spare anchor (if carried).

Spare anchors on board the vessel are meant to substitute for the loss of a main bow

anchor, and as such would probably be extremely heavy. To carry out such an anchor

astern of the vessel, with the view to kedging the vessel astern, would probably

require the use of a tug or similar craft to carry the anchor out and deploy it well aft.

Such an operation would usually be employed in a situation where a vessel has run

aground into shallows and is attempting to re-float into deeper water. It must be con-

sidered as extenuating circumstances for a ship’s Master to even consider trying to

kedge the vessel astern. With anchor sizes of large tonnage exceeding 20 tonnes, clearly

the practicalities of lifting and deploying such a weight would pose obvious problems.

The use of a ship’s lifeboats for carrying out an anchor is not recommended; the

sheer weight of a 20 tonnes plus anchor would not give a great deal of safe freeboard

to a ship’s lifeboat, if so employed, especially if the weight of chain or anchor warp

is also included. Such an operation could only be remotely considered with anchors

weighing 5 tonnes or less, and even then the operation would be precarious.

Practically speaking, the option to carry out anchors of over 5 tonnes would have

to be undertaken by a tug or other similar large craft which could lift and sustain the

heavy load. Such a vessel would also require safe means of releasing the anchor

when at the position of deployment.

The procedure of ‘Kedging’ would not generally be undertaken as a stand alone

operation. In order to be successful the prudent use of ballast would be employed.

Possibly a tug would also be used and the state of the tides with the prevailing

weather would warrant consideration.

The foul hawse

The disadvantage of mooring with two anchors is the risk of fouling the anchor cables

about each other. This is generally caused by poor watchkeeping practice when a

change in the wind direction could result in the vessel swinging in opposition to the

lay of the cables.

There are several ways to clear the entwined cables:

a) Use the ship’s engines to turn the ship in the opposite direction to the fouled

turns at the time of slack water.

ANCHOR OPERATIONS AND DEPLOYMENT 111

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b) Engage a tug, to push the vessel around in opposition to the turns, although this

method would incur some expense for employing the tug.

c) Use a barge or other similar floating receptacle, break the sleeping cable, and lower

the end into the barge. Proceed to pull the barge with the cable, around the riding

cable to clear the fouled turns (the ship’s boats could provide motive power to

manoeuvre the barge).

d) Break the sleeping cable and dip the end about the riding cable, using easing

wires from each bow.

It should be noted that to carry out option (d) is a lengthy process, and could only be

considered with relatively small anchors. Adequate safe working loads on respective

wires would need to be considered with this method. It is also very lengthy, and

would have to be managed within the period of the turn of the tide, i.e. 6 hours. This

option should be avoided whenever possible, in favour of a more practical alternative.

Attempting to use the engine and turn the vessel about the riding cable (option

(a)) would be difficult for a single screw ship but would probably be more viable

with twin screws and/or, bow/stern thruster units.

Breaking cables

In any operation where the anchor cable is to be broken, it should be realized that this

element alone can expect to take some considerable time. Kenter Joining Shackles are

easily separated within the dry dock environment, but when the vessel is operational

at sea, the exercise to punch and drift the ‘spile pin’ can be fraught with difficulties.

Clearing the foul hawse – (breaking and dipping cables)

Procedure

1. Heave up on both anchor cables to bring the foul turns visible above the surface

of the water.

2. Lower the ship’s boat and lash the two anchor cables together, with a manila

rope lashing, in a position below the turns.

3. Pass a preventer wire, on a bight, through the sleeping cable and secure on deck

(the preventer is rigged as a safeguard against loss of the chain end, a 24 mm

wire minimum, is recommended for use with the average size of anchor).

4. Walk back on the sleeping cable to bring the next joining shackle on deck for-

ward of the windlass.

5. Pass an easing wire from the warping drum to a shackle position on the sleeping

cable. Position and rig separate dipping wires from each bow.

6. Break the joining shackle on deck and pay out the easing wire to lower the chain

end, clear of the ‘hawse pipe’.

7. Pass the dipping wire from the bow in opposition around the riding cable and

shackle to the broken chain end. Lead the dipping wire to a second warping

drum and heave the wire and the chain end around the riding cable, slacking

back on the easing wire.

8. Continue to heave on the dipping wire to bring the end of cable on deck and it

will be observed one half turn of the foul has been removed. Detach the easing

112 SHIP HANDLING

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wire, leaving it in position in the ‘hawse pipe’, ready to recover the chain end

once all foul turns have been removed.

9. Continue to use alternate dipping (easing) wires to remove each half turn of the

foul.

10. With the last half foul turn remaining in the cables, re-secure the easing wire

from the hawse pipe and heave the broken chain end up on deck for reconnect-

ing the joining shackle.

11. Once the chain is re-joined clear the preventer.

12. With the aid of a manhelper and knife secured to the end, cut the manila lashing

to separate the cables. It would be beneficial to put strain on the lashing by

increasing the tension on the anchor cables.

13. Recover the boat and secure the forward mooring deck.

ANCHOR OPERATIONS AND DEPLOYMENT 113

Sleeping cable

Riding cable

Manila lashing

Dipping easing

wire (1)

Easing

wire to

chain end

Windlass

Prenentor

Dipping

easing

wire (2)

Clearing the foul hawse. Anchor securing fitments left out for clarity.

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Introduction, tug engagement and operations; Bollard pull, towlines care and use, har-

bour towage; Girting the tug and use of ‘Gob Rope’; Towing fitments and towlines,

ocean towing, towing methods, composite; Bridle and towing by double units; Towing

signals.

Introduction

There are a variety of tug types employed within the marine industry. They include

the ocean-going salvage tug down to the smaller harbour traction tug, engaged in

and around ports and harbours. Ship handling situations warrant tug use either in a

pulling or a pushing mode in numerous situations. The large VLCC or ULCC tankers,

for instance, would experience great difficulty in attaining and departing their berths

safely, without the assistance of probably at least four tugs.

Entering docks, turning into rivers and engaging in tight manoeuvres, tends to be

that much easier and safer with tugs engaged. This is especially so with the large

ocean-going vessels that may have limited manoeuvring aids and be restricted to a

right hand fixed propeller only.

Marine pilots tend to work closely with tugs and, in the majority of cases, tug

masters recognize the authority of the parent vessel and the navigational ‘con’. How-

ever, tugs can only be considered as being under control when the tug(s) is responding

directly and to the desires of that person in command of the operation. Circumstances

may make a deviation from the intended movements necessary, but such actions,

related to the tug, are not necessarily helpful to the overall operation.

By the very nature of any environment where tugs are engaged, heavy duty oper-

ations are envisaged. Towing springs and similar weight bearing ropes are inherently

dangerous to personnel who may have to work in close proximity. Full safety aspects

should be applied at all times throughout tug operations. Effective communications

must be maintained between relevant parties and contingency plans should be in

place to reduce the likelihood of accidents throughout this high risk activity.

115

Operations with tugs

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