Seamanship Techniques 2011 E Part 2 pps

The holding power of this common anchor will be, roughly speaking, three to four times its weight, depending on the nature of the sea Shank Gravity band Forelock Stock Fluke Arm Crown Pe

years before seeing a bill through Parliament, in 1876, which resulted in

the Merchant Shipping Act The Act gave the Department of Trade and

Industry, as we now know it, the right of inspection, to ensure that a

vessel should not be overloaded beyond her Plimsoll mark or line

Samuel Plimsoll championed the improvement of conditions for the

seafarer, and became the President of the Sailors and Firemens Union in

his later years

Assigning a Vessel’s Loadline

The assigning of a vessel’s loadline by the Department of Trade or other

similarly approved assigning authority is carried out in accordance with

the Loadline Rules, which were set and devised by the International

Conference on Loadlines

The calculation regarding the freeboard and consequently the position

of loadlines will be dependent on the type of vessel and its length, ships

being divided into two types, ‘A’ and ‘B’

Type ‘A’ – Vessels designed to carry only liquid, bulk cargoes, e.g

tankers

Type ‘B’ – All other vessels not governed by the Type ‘A’ definition

The assigning of the freeboard will be governed by many factors and it

is not within the scope of this text to detail the loadline rules (Additional

information is obtainable from Murray-Smith, ‘The 1966 International

Conference on Loadlines’, Trans R.I.N.A., 1969.)

With the exception of pleasure yachts, warships and the like, all

British ships and the majority of vessels of other maritime nations over

80 net registered tons are obliged to be marked with statutory loadlines,

to ensure that they are not overloaded Various authorities assign loadlines

on behalf of the British Government, e.g Det Norske Veritas (DNV),

Lloyds Register (LR), Department of Trade (DT)

A loadline certificate must be displayed in a prominent place aboard

the vessel The certificate is valid for five years, but an annual survey is

Figure 1.32 Alternative tonnage marks.

Positions and marks,

not drawn to scale

to the loadline disc.

300 mm

All lines 25 mm thick

Optional tonnage mark

for fresh or tropical

Such software can be beneficial in producing the ships stability data, together with anticipated stress factors throughout the ships length.

TF F

T S W W

Starboard side

450 mm

300 mm

540 mm 1

48thLD

FWA

V N

LTF LF

Assigned lumber draught (LD)

Figure 1.33 Timber loadlines.

held to ensure that the conditions of assignment and the loadline marksremain unchanged

Should the loadline be submerged through the overloading of thevessel, so contravening the regulations then the master or owner is liable

to a fine of £1000.00 plus £1000.00 for every cm or part of 1 cm loaded The upper edge of loadline marks are the recognised mark levels.The loadline itself (Figure 1.31) is punched into the shell plate andpainted a distinctive colour, usually white or yellow on a dark background.Owners of vessels may make application to the Maritime and CoastguardAgency for a vessel to be assigned an alternative tonnage Gross andregistered tonnages are assigned not only for the upper deck but also forthe second deck, excluding the ’tween deck space, so treating the seconddeck as the upper deck level

over-Once an alternative tonnage has been assigned the tonnage mark(Figure 1.32) will be carved on each side of the vessel below the seconddeck and aft of the loadline disc Should the vessel be so loaded as tosubmerge the alternative tonnage mark, then the normal gross and registeredtonnage will apply Should the state of loading leave the mark visible,then the modified tonnage values will remain valid

1

48th

1

ANCHOR WORK

With the many different types of vessel employed in the marine industry,

it is only to be expected that anchors and their associated equipment

have changed considerably over the years From the forerunners used by

the ancient Greeks to the present day, purpose and design have been

dictated by the needs of the industry

ANCHORS

Admiralty Pattern Anchor

Sometimes referred to as a ‘fisherman’s’ anchor, this design is still popular

within the fishing industry (Figure 2.1(a)) It has been in use for many

years, but because it has difficult stowage characteristics, e.g it cannot be

stowed flat with the stock in position, it has been followed by more

manageable designs Once let go, the stock, lying at right-angles to the

direction of the arms/flukes, causes a fluke to dig into the sea bed This

leaves the remaining fluke exposed, and the cable may often foul it when

the vessel swings When the anchor is not in use, the forelock in the

stock can be unshipped, permitting the stock to be stowed parallel to the

shank

The holding power of this anchor is generally considered to be very

good indeed The design is such that the stock is longer and heavier than

the arms This lends itself to the theory that the stock will be dragged flat

along the sea bed, causing one of the flukes to bury itself The angle of

the stock would also be expected to turn the flukes in the direction of

the sea bed as the anchor strikes the bottom It is interesting to note that

the longer the shank on these anchors the better it holds

The weight of the stock must be equal to 25 per cent of the weight

of the anchor itself Some stocks are designed straight if the weight of the

anchor is over 12 cwt (610 kg), but a bent stock, as indicated in Figure

2.1(a) would be encountered on anchors below this weight

The holding power of this common anchor will be, roughly speaking,

three to four times its weight, depending on the nature of the sea

Shank Gravity band

Forelock Stock

Fluke Arm Crown

Pea or bill (a)

Shank Hollow fluke Knuckle Hinge pin Stops (b)

Figure 2.1 Admiralty pattern anchor (above) and (below)

Admiralty cast anchor type 14 (AC14).

Stock

bottom It is unlikely to be seen on board merchant vessels, exceptpossibly as a lifeboat anchor or as a kedge anchor The weight in anyevent would rarely exceed two tonnes

The Stockless Anchor

This is by far the most popular anchor in general use today its principalparts are shown in Figure 2.2 The head of the anchor is secured to theshank by a hinged bolt which allows the arms to form an angle of up to

45° with the shank Further rotation of the arms are prevented by thehead meeting the shank, at the built-in stops The head of the anchor iscomprised of the flukes, the arms, and the crown which are manufacturedfrom cast steel, whereas the shank is made of cast steel or forged iron.The hinge bolt and the shackle are made of forged iron The stocklessanchor’s greatest advantage is its close stowing properties and is easilyhoused in the hawse pipe when not in use It is easily handled for allanchor operations, and made anchor beds (used with the close stowinganchor) obsolete

The overall size of these anchors will vary between individual ship’sneeds but the head must be at least three-fifths of the total weight of theanchor Holding power again varies depending on the nature of thebottom but, as a rule of thumb, it may be considered to be up to threetimes its own weight The mariner should be aware that the rotationaction of the moving arm may cause the anchor to become chokedwhen on the sea bed so that the arms/flukes are not angled to the fullamount and therefore losing the holding power effect

Admiralty Cast Anchor

Used extensively as a bower anchor for warships, this anchor, because ofgood holding properties, is becoming very popular with the merchantservice (Figure 2.1(b)) With the increase in size of ships – the largetankers of today, for example – shipowners required an anchor withgreater holding power The AC Type 14, as it was called, was developed

in the United Kingdom and has the required properties Tests showedthat it had more than twice the holding power of a conventional stocklessanchor of the same weight With such an obvious advantage, LloydsClassification Society granted a 25 per cent reduction in regulationweight The holding properties of this anchor are directly related to thefluke area, the angle of which operates up to 35° to the shank The angle

of the flukes is made possible by a similar operation as with the stocklessanchor, in which a hinge pin passes through the shank in the crown ofthe anchor

CQR

Illustrated in Figure 2.3, the CQR sometimes referred to as a share’ anchor or, in the United States, just as a plough anchor It isgenerally used as a mooring anchor, especially for the smaller type ofvessel Holding power is again dependent on the type of ground that the

‘Plough-Head of the anchor Fluke

Arm

Anchor crown shackle

Figure 2.2 Hall stockless anchor.

Figure 2.3 CQR anchor (above), Danforth anchor (below).

anchor is bedding into but has been found to be very good It also has

extremely good resistance to drag Like the Admiralty Pattern, it is

difficult to stow The design has been modified since its invention to

incorporate a stock, and is often used as a mooring anchor (Figure

2.28(b)) The CQR was a British invention by scientist Sir Geoffrey

Taylor, who was a man with little boating experience The invention

showed that the application of basic principles can sometimes improve

on practical experience Small-boat owners tend to have the choice of

two anchors on the market, namely the Danforth and the CQR Both

anchors have reasonable holding power but the Danforth may have a

tendency to drag whereas the CQR will not

For easier handling and stowing the Danforth would be more popular,

but if it is decided to use an anchor for the job it was meant for,

preference is generally given to the CQR

Danforth Anchor

Generally accepted as a small-boat anchor, this anchor dominates the

American boat market (Figure 2.3) A stock passes through the head of

the anchor, allowing it to be stowed easily in a similar manner to the

stockless anchor Holding power is about 14.2 times its own weight The

anchor is of American design, and the idea of the stock being passed

through the crown of the anchor as opposed to the top of the shank

demonstrates a practical solution to the stowage problem The stock in

this position prevents the anchor being fouled on its own cable Holding

properties are good but not as good as the CQR’s, and it has a tendency

to drag or glide until the flukes bite into the sea bed The action of this

anchor is similar to that of the stockless anchor, where the tripping palms

catch and cause the flukes to be angled to the shank With the Danforth

anchor, the tripping palms are generally situated closer to the centre line

of the anchor Once tripped, the spade-shaped flukes will tend to dig

into the bottom

All anchors over 168 lb (76 kg) in weight must be tested and issued with

a test certificate The weight of any anchor for the purpose of the rules

and regulations governing anchors and cables shall:

(a) for stockless anchors include the weight of the anchor together with

its shackle if any, and

(b) for stocked anchors, the weight of the anchor including its shackle,

if any, but excluding the stock

Drop Test (cast anchors)

Any part of an anchor over 15 cwt is subjected to a percussion test by

being dropped both end on and side on from a height of 12 ft on to an

iron or steel slab After that, the piece must be slung and hammered all

over by a 7 lb sledgehammer A clear ring must be produced to show that

no flaw has developed during the percussion test

T ABLE 2.1 Proof loads for anchors

Weight Proof Weight Proof Weight Proof Weight Proof Weight Proof Weight Proof

The Bending Test (cast anchors)

An additional piece of metal, 20 cm long, is cast with the piece to be

tested, and is cut away for the purpose of the bending test This piece will

be turned down to 2.5 cm in diameter, and bent cold by hammering

through an angle of 90° over a radius of 3.75 cm The casting will be

deemed sufficiently ductile if no fracture appears in the metal

All anchors are subject to the proof strain (Table 2.1), and subsequent

proof load, but only cast steel anchors will be subjected to percussion,

hammering, and bending tests Wrought iron, or forged steel anchors are

not subjected to these tests as they are forged from red hot slab by

hammering All other anchors will also be annealed

Each anchor must carry on the crown and on the shank the maker’s

name or initials, its progressive number, and its weight The anchor will

also bear the number of the certificate, together with letters indicating

the certifying authority (Figure 2.4)

After the test on the anchor is completed, an anchor certificate will be

awarded The certificate will show the following:

Type of anchor

Weight (excluding stock) in kilogrammes

Weight of stock in kilogrammes

Length of shank in millimetres

Length of arm in millimetres

Diameter of trend in millimetres

Proof load applied in tonnes

Identification of proving house, official mark and government mark

Number of test certificate

Number of tensile test machine

Year of licence

Weight of the head of the anchor

Number and date of drop test

Anchor cable over 12.5 mm in diameter is accepted for testing at an

approved testing establishment in lengths of 27.5 m (1 shackle of cable)

The manufacturer will provide three additional links for the purpose of

the test These three links will be subjected to a tensile breaking stress,

and if this proves to be satisfactory, then the total length of the cable will

be subjected to a tensile proof test, the tests being carried out on approved

testing machines If two successive links break, the cable is rejected

Before the test on chain cable is carried out, the supervisor will satisfy Figure 2.4 Marks on cable X (certificate Number);YYY (certifying Authority).

X

Y Y Y

himself that the quality of the material from which the cable is manufacturedmeets with the requirements of the anchor and chain cable regulations.After a successful test on chain cable a certificate is awarded, stating:Type of cable.

Grade of cable

Diameter in millimetres

Total length in metres

Total weight in kilogrammes

Length of link in millimetres

Breadth of link in millimetres

Tensile breaking load applied in tonnes

Tensile proof load applied in tonnes

Number and types of accessories included

The certificate issued shall also show:

A serial number

Name of the certifying authority

Mark of the certifying authority

Name of the testing establishment

Mark of the testing establishment, if any

Name of the supervisor of tests

The certificate is signed on behalf of the certifying authority

Accessories

Anchor shackles, and joining shackles are all ordered together with anyadditional fittings for the size of cable they are intended to work and beassociated with These accessories must be subjected to similar tensileload and proof load tests as the cable

Material of Manufacture

Wrought iron, forged mild steel, cast steel, or special quality forged steelare used Wrought iron is weaker than the other three materials, and isexpensive to produce; consequently it is rarely seen on present-daymerchant ships Types of cable are shown in Tables 2.2 and 2.3

Size of Cable

The size is measured by the diameter of the bar from which the link ismanfactured Aboard a vessel the size could be obtained from the chaincable certificate, or callipers could be used to measure the actual cable

The Kenter Lugless Joining Shackle, manufactured in nickel steel, is themost popular method of joining shackle lengths of the anchor cabletogether The shackle has four main parts, as shown in Figure 2.5 The

T ABLE 2.2 Types of chain cable

27.5 m = 15 fathoms = 1 shackle length

kg/mm2

1a Wrought iron Fire welded 31–41

1b Mild steel Fire welded 31–41

1c Mild steel Flash butt welded 31–41

1d Mild steel Flash butt welded 41–50

2a Steel Flash butt welded

or drop forged 50–65

3a Steel Flash butt welded

or drop forged 70 min

T ABLE 2.3 Stud link chain cable

two main halves interlock with the stud forming the middle of the link

All parts are held together with a tapered spile pin This spile pin is made

of steel and is driven into the shackle on the diagonal A lead pellet is

then forced into the inverted dovetail recess to prevent the pin from

accidentally falling from the shackle

The manufacture of the shackle in nickel steel prevents corrosion and

the parts becoming frozen together It allows the shackle to be ‘broken’

with relative ease when either the cable is to be end-for-ended or

shackles are to be tested When breaking the shackle, remove the spile

pin by using a punch and drift (Figure 2.15) If the lead pellet has not

been prised out first, be careful that it is not forced out by the percussion

effect of the drift driving the spile pin, for it may emerge with considerable

force A back stop should be provided to prevent persons being injured

by the lead pellet being expelled from the recess

Once the spile pin is removed, the stud can be extracted; the two

halves of the shackle can then be separated by means of a top swage

obtained from the manufacturer When the shackle is reassembled, care

must be taken to ream out the dovetail recess, so that no residual lead is

left inside Should this not be done, then the next lead pellet inserted will

not spread out and obtain a grip inside the recess

The construction of the Kenter shackle is such that it is larger than

Spile pin

the common links but not by so much that it will not fit into the snug

of the gypsy of the windlass or cable holder However, care should betaken that it does not lie flat on the gypsy and cause jamming.The main advantage of this type of joining shackle is that open endlinks are not required, as with the ‘D’ lugged joining shackle In addition,all shackle lengths are the same, which ensures smoother working in thesnugs of the gypsy The shape of the Kenter lends itself to cable working,especially around and over the bow, and the tendency for it to catch iscomparatively rare As with other accessories, these shackles are tested,but because of their type of manufacture in nickel steel, they are notheat-treated

The ‘D’ lugged joining shackle is used extensively for joining the cable

to the anchor in more modern vessels In the past this type of shacklewas used, as the Kenter lugless joining shackle is used today, in thejoining of the shackle lengths of cable together If it is to be used for thispurpose, the rounded crown part of the shackle should always faceforward, so that it does not foul the anchor when letting go

It should be noted that the anchor crown shackle and the ‘D’ joiningshackle face the opposite way to all other ‘D’ joining shackles in thecable The mariner should be aware that the anchor, together with theinitial joining shackle, is walked out of the hawse pipe prior to letting go(except in some cases of emergency) Consequently, the anchor crownshackle would not foul, but should other joining shackles be facing inthis manner, there would be a distinct possibility of the lugs of theshackle catching on a snag in the letting-go operation

When using these types of shackle between cable length, each cablelength must have an open link at the ends This is necessary to allow thepassage of the lugs through the cable

The construction of the ‘D’ lugged joining shackle is illustrated inFigure 2.6, where it may be seen that the bolt, generally oval in shape, ispassed through the lugs and across the jaw of the shackle A tapered spilepin of steel, brass or wood holds the bolt in position, a lead pellet beinghammered home into a dovetail recess chamber to keep the spile pinfrom accidently being expelled The spile pin should be tapered to a ratio

of 1:16, and wooden pins are made of ash or solid bamboo Whenbreaking the ‘D’ joining shackle, the bolt will be hammered from theunlipped end, causing the wooden spile pin to shear

Should the spile pin be made of steel, then this must be expelled byusing a punch and drift in a similar manner to that described for theKenter shackle The steel pin is generally found in the ‘D’ shackle joiningthe anchor cable to the anchor When assembling these shackles, it iscustomary to give the bolt a smear of tallow to allow easy ‘breaking’ at

a later date Should the shackle become jammed and difficult to break,then it can be heated about the lugs This will cause the lugs to expand,allowing the withdrawal of the bolt

Figure 2.6 ‘D’ lugged joining shackle.

Crown

Clear Lead pellet

Tapered

spile pin

Bolt Dovetail

chamber

Jaw

Lug

SECURING AND STOWAGE OF ANCHORS

Alternative methods of securing anchor to cable are illustrated in Figure

2.7, and the operation of the cable in anchoring in Figure 2.8 There are

many different designs of hawse pipe (Figure 2.9) in commercial use

with the modern merchant vessel and the warship The general arrangement

is such that the axis of the pipe does not exceed 45° from the vertical;

however, the most suitable angle is that which allows the easy lowering

and restowing of the anchor Many hawse pipe arrangements are recessed

into the shell plate This not only reduces drag effect, especially on high

speed vessels, but should contact with another vessel or quay occur,

damage is considerably reduced

Many of the modern anchors, e.g AC14 and Bruce (see Figure 2.27),

have incorporated an anchor bed or special stowage frame fitment about

the entrance to the pipe This usually facilitates smoother operation

when letting go and better securing for the anchors when not in use

Securing the bitter end of the anchor cable is illustrated in Figures 2.10

and 2.11, the fo’c’sle head in Figure 2.13 and anchor securing in Figure

2.13 Figure 2.15 lists chain cable accessories

Open end link

Enlarged link

Two (or more) link attachment

‘D’ type end shackle

Alternative 2

Open end link Enlarged link Common link

Three link adapter piece Anchor Anchor crownshackle

Kenter shackle

Common link

Kenter shackle

Figure 2.7 Securing anchor to cable.

Cable drum gypsy Windlass

Warping drum

Devil’s claw Windlass

bed

Spurling pipe

Stores Hatch

To remainder of cable

Cable locker

Forepeak of vessel

Figure 2.8 Operation of cable in anchoring.

NB The devils claw shown in Figure 2.8 is shown for display purpose and would not normally be secured when the anchor is deployed.

Deck plateDoubler

Figure 2.9 Arrangement of hawse pipe.

STEAM WINDLASS OPERATION

The following is a typical list of checks to be carried out before a steamwindlass can be operated safely You should consider what modifications

to the list are needed to operate the type of windlass on your currentvessel if it is different

1 Inform the engine room of the requirement for steam to operatethe windlass

2 On the way to the windlass, ensure that the main deck steam-linevalve is open (this may in fact be in the engine room), and draindeck line

3 Check that the windlass stop-valve is open (usually found underthe bed of the windlass inside the forecastle head), and ensure anylashings in the chain locker are removed

4 Open the drain cocks of the cylindrical steam chests (normallytwo cocks per chest)

5 Ensure that the windlass operating valve is closed (stop–start control)

6 Wait until pure steam issues from the drain cocks – not a mixture

of steam and water

7 Close the drain cocks, and steam is now at the windlass head readyfor use

8 Ensure that the brake is firmly applied and that the windlass is out

of gear

9 Turn the windlass over by operating the start–stop valve

10 Oil ‘moving parts’ as necessary to facilitate smooth running (obviouslyoil is applied to a stationary windlass for safety reasons)

Windlasses, winches and capstans are illustrated in Plates 4–8

Once power has been obtained on deck, and the windlass has been oiledand checked, the anchors must be made ready to ‘let go’ This operationmust be carried out carefully and systematically to ensure that the ‘lettinggo’ operation will run smoothly If a proper routine is established whentime is not limited, the anchoring procedure is more likely to go smoothlyand quickly when an emergency occurs

Once deck power is obtained, the following operations are carried out:

1 Check that the windlass brake is on and holding and that thewindlass is in gear

2 Remove the hawse pipe covers

3 Remove the devil’s claw

4 Remove any additional lashings

5 Remove the bow stopper, guillotine or compressor

6 Take off the brake and walk the cable back a short distance inorder to break the cement pudding inside the spurling pipe.Modern ships often have spurling pipe covers instead of cementseals If fitted these should be removed

7 Clear away old cement and throw overside

Bulkhead

Bulkhead stiffening

PORT

Split pin to prevent accidental

removal of retaining pin

Open link

Anchor cable

Anchor cable retaining pin– this pin will be

removed in an emergency If the pin is

removed while there is tension on the anchor

cable, the operation will be difficult and

DANGEROUS.

Figure 2.11 Alternative method of securing bitter end.

An external fitment is situated outside

and usually above the chain locker The

hinge cover when in position prevents

removal of the locking pin holding the bitter

end of the cable This method allows the

cable to be slipped without any person being

ordered into the locker The locking pin is

removed by a simple sliding motion once

the hinged cover has been lifted The cable

is then released and the bitter end is allowed

to fall back into the locker.

Figure 2.10 Internal securing of bitter end of anchor

cable by Use of clench system inside cable locker.

In some cases the link may pass through

the bulkhead, the pin being placed on the

other side It is not then necessary for a

man to enter the chain locker at all in

order to slip cable.

Watertight hinged cover

Holding bar

or locking pin

Open link Chain cable

Brake handle

Pay out direction Band brake Floating link Brake tension applied Floating end of brake band

8 Walk back on the cable until the anchor is out, clear of the hawse

pipe and above the water surface, then heave a few links back to

ensure cable will run

9 Screw the brake on hard and check that the brake is holding

10 Take the windlass out of gear, leaving the anchor holding on the

brake Check that it is out of gear by turning power on briefly

Report to the Bridge that the anchor is on the brake and ready for

letting go

Cable holders (Figure 2.16) are often fitted to large merchant vessels as

an alternative to the windlass, and, with recent developments, may be

seen on passenger vessels They have also been popular with warships for

some considerable time because they are compact and lie low on the

deck

Early models employed a cable drum (gypsy) without the valuable

addition of warping facilities Modern versions include a warping drum

geared to the centre-line axle This can subsequently be de-clutched

when working anchor cables A separate braking system is incorporated

in each cable holder, similar to that fitted to the windlass

Anchor securing arrangements are similar, except that the bow stopper

is usually situated closer to the hawse pipe than to the cable holder A

devil’s claw or slipping arrangement is sited between the bow stopper

and the holder

Where cable holders are used, the lead of cable is always close to the

deck To prevent excessive wear to deck plating from cable friction, a

‘Scotsman’ is a common fixture to provide the required protection

Variations of combined capstan/cable holders are available on the

commercial market, powered by steam or, more commonly, electricity

Roller type fairleads Hawse pipes

(with cover plates)

(Additional wire or chain lashings to anchor cable)

Compressor (Guillotine bar) bow stopper Bitts

Windlass

Devil’s claw Warping drum Windlass brake

Spurling pipes Cable

Figure 2.13 Fo’c’sle head anchor and cable arrangement

As with other similar deck machinery, additional strengthening of deckareas about operational sites is required to accommodate excessive load.

The preliminaries to the operation include careful scrutiny of the chart

of the area where the vessel is proposing to anchor, and consideration ofthe depth of water and the holding ground with the view to determiningthe amount of cable to use (Figure 2.17) The amount will be determined

by the following:

1 Depth of water

5 Pneumatic windlass showing band brake controls

exposed and anchor cable passing over gypsy and

entering spurling pipes.

6 Single barrel hydraulic mooring winch, with 5 tonne

to 40 tonne pull at design speed of 15 to 10 revolutions

per minute, depending on size and weight of material

being heaved.

7 Double barrel anchor-handling/towing winch of a type extensively fitted in offshore supply vessels Designs include a four-speed range and automatic fail-safe hydraulic braking systems.

8 Hydraulic capstans before being fitted, showing underdeck motor, single drum and vertical capstan.

(a)

Bracing claw (Optional) Roller

releasing roller bowstopper, manufactured and produced by

Clark Chapman Ltd (b)

Self-holding and automatically releasing track bowstopper.

Cable Bottle screw

Drift for expelling pins

Figure 2.15 Chain cable accessories.

Figure 2.17 Amount of cable to use when anchoring.

Vessel Hawse pipe Water surface

2 Type of holding ground, good or bad

3 Length of time the vessel intends to stay at anchor

4 Sea room available for circle of swing

5 Expected weather conditions

6 Strength of tide, if any

7 Draught and amount of hull exposed to the wind

8 Type of anchor and its holding power

These factors will vary with each case and previous experience; however,

as a general rule, four times the depth of water may be taken as aworking minimum This would change, say, if the holding ground wasbad, the weather deteriorating, and you were expected to remain atanchor for a long period of time

The Anchor Plan

An anchor plan should be established between the interested parties,namely: The Ships Master/Captain or Offshore Installation Manager(OIM), the Officer in Charge (OiC) of the anchor party, or the Master

of Anchor Handling Vessel (AHV) It would be expected that these keypersonnel would inform relevant crew members through an establishedchain of command, regarding relevant criteria

In the construction of any anchor plan the following items must beworthy of consideration:

1 The intended position of anchoring of the vessel

2 The available swinging room at the intended position

3 The depth of water at the position, at both High and Low watertimes

4 That the defined position is clear of through traffic

Warping drum

Chain reliever Snug

Scotsman

Cable holder Brake

Deck level

Spurling pipe Underdeck strengthgirders Hawse pipe

Figure 2.16 Cable holders.

5 That a reasonable degree of shelter is provided at the intended

position

6 The holding ground for the anchor is good and will not lend to

‘dragging’

7 The position as charted is free of any underwater obstructions

8 The greatest rate of current in the intended area of the anchorage

9 The arrival draught of the vessel in comparison with the lowest

depth to ensure adequate under keel clearance

10 The choice of anchor(s) to be used

11 Whether to go to ‘single anchor’ or an alternative mooring

12 The position of the anchor at point of release

13 The amount of cable to pay out (scope based on several variables)

14 The ship’s course of approach towards the anchorage position

15 The ship’s speed of approach towards the anchorage position

16 Defined positions of stopping engines, and operating astern

propulsion (single Anchor Operation)

17 Position monitoring systems confirmed

18 State of tide ebb/flood determined for the time of anchoring

19 Weather forecast obtained prior to closing the anchorage

20 Time to engage manual steering established

When anchoring the vessel it would be usual practice to have

com-munications by way of anchor signals prepared for day and/or night

scenarios Port & Harbour Authorities may also have to be kept informed

if the anchorage is inside harbour limits or inside national waters

NB Masters or Officers in Charge, should consider that taking the vessel into an

anchorage must be considered a Bridge Team operation.

Single Anchor – Procedure

The master, or pilot, should manoeuvre the vessel to the desired position,

and take all way off, so that the vessel is stopped over the ground She

should be head to the wind and/or tide, and have her anchor walked

back out of the hawse pipe, on the brake ready for letting go The Bridge

should be informed that the anchor is on the brake of the windlass, or

cable holder, and is ready for the order to ‘let go’

The engines should be operated to give stern way to the vessel The

Master should check overside and see the stern wake, about half-way up

the vessel’s length, and know that stern way is being made through the

water, before giving the order to ‘let go’ The officer in charge of the

anchor party should order the brake to be taken off and allow the cable

to run out with the weight of the anchor The idea is to lay the cable out

in length along the sea bottom, and not cause it to pile up on itself

The officer in charge should start to apply the brake once enough

cable has run out to prevent it falling on top of the anchor The procedure

is to check on the cable periodically, by applying the brake, while the

vessel drops astern, either under engine power or through the action of

the tide, and lays the required length of cable

Communication from the fo’c’sle head to the Bridge should be

maintained by walkie-talkie, loud hailer/phone, or by the ringing of theship’s forward bell.

Bell Signals

When heaving in the cable or letting go, the bell should be struck oncefor every shackle’s length, e.g three shackles, three strokes of the bell.When the anchor breaks clear and becomes ‘anchor aweigh’, then arapid ringing of the bell will indicate to the Bridge that the anchor isaweigh Prudent Chief Officers tend not to ring anchor aweigh until theanchor is sighted and the flukes clear the water, in case the anchor hasbecome fouled in any way with, say, warps or power cables

Marking of Anchor Cable

As the anchor is let go, the officer in charge of the anchor party willrequire to know the amount of cable being paid out Each shackle lengthwill be identified by the joining shackle, which is a larger link than theother links of the cable The individual shackles will be distinguished bythe number of studded links either side of the joining shackle In theexample given in Figure 2.18 the fourth shackle is used, and the fourthstudded link from the joining shackle will be bound around the studwith seizing wire This identification by means of seizing wire will beseen to mark the fourth shackle on both sides of the joining shackle.Seizing wire is used to enable the officer in charge to feel about the stud

of the link and so locate, by his sense of touch, how far away the markedlink is from the joining shackle – very useful during the hours ofdarkness Seizing wire is used because it is quite robust and will stand afair amount of wear and tear when the anchor is being let go, whereasthe paint mark (see below) may tend to chip, or flake off, after a shortperiod of time

The length of cable between the seizing wire portions is painted abright distinctive colour, e.g white, so that each shackle length mayeasily be located and acknowledged when operating anchors during thehours of darkness Some ships often paint the joining shackle a differentcolour to highlight the position of the joining shackle

If a ‘D’ lugged joining shackle is used to join cable lengths together(Figure 2.18(b)), then open links are found either side of the ‘D’ shackle.These open links must not be counted in the marking of the cable withseizing wire Only studded links away from the joining shackle are to becounted

Anchor cables should be checked whenever an opportunity presentsitself, as in dry dock where the cables can be ranged along the bottom

of the dock and inspected with ease

The term ‘clearing away’ means preparing the anchor to let go, thoughdifferent ships have different ways of operating Most vessels are nowequipped with hawse-pipe covers – sliding metal covers which must be

Figure 2.18 Marking anchor cable: (a) fourth shackle

of cable; (b) second shackle length by means

of ‘D’ lugged joining shackle Open links

on either side of the joining shackle are

ignored for the purpose of marking cable

in this case.

(a) Kenter lugless

‘D’ lugged joining shackle Seizing wire Common

link

removed in order for the cable to run clear Anchor lashings may be

attached to the bow stopper claw or secured from deck lugs through the

cable itself These must be released and cleared away, as with the devil’s

claw, if fitted The compressor or guillotine bar should be removed from

the cable, together with any lashings which may have been applied inside

the cable locker

Past and Present Practice

A lashing in the cable locker served to stop the cables banging together

when the ship was at sea In bygone days the sailors used to sleep in the

fo’c’sle head area, and the banging cables tended to keep them awake

Hence they were lashed secure

The more up-to-date thinking is that if the cable is lashed the chance

of a bight of cable being buried by the remainder of the pile of cable in

the locker will be reduced This was especially so in the early days of

non-self-stowing cable lockers

Another reason, which is now by far the most popular, is that when

the spurling pipes are sealed with cement, this cement plug and seal

would be prevented from cracking up, when the vessel was in a seaway,

by the secure lashing of the two cables together inside the cable locker

Mariners should be aware that the practice of lashing cables in the

locker is no longer common practice on modern vessels

Spurling pipes must be sealed, but hinged slide design steel plates are

now by far the most popular method of making them watertight Should

these steel plates not be fitted, then a pudding plug, made up of rags or

cotton waste, should be forced into the aperture of the spurling pipe

Cement mix, of four of sand to one of cement, should be poured over

the pudding, about the anchor cable This cement cover should be of

such thickness that any movement of the anchor cable in the spurling

pipe would not cause the cement to break The purpose of the pudding

is to stop the cement from dropping through to the cable locker, and also

to give it something to set on

Anchor A-Cockbill

When the anchor is hanging vertically from the hawse pipe, with the

flukes turned into the ship’s side (Plate 9) In this position it will not

stow correctly in the hawse pipe

Anchor Aweigh

The anchor is said to be ‘A-Weigh’ at the moment it is broken out of the

ground and clear of the sea bed

Anchor Buoy

A buoy used to indicate the position of the ship’s anchor when on the

Anchor Coming Home

When the anchor is being drawn towards the ship in the operation ofheaving away, by means of the windlass or cable holder/capstan, theanchor is said to be coming home Instead of the ship being drawntowards the anchor, the reverse is happening

Anchor Dragging

The anchor is said to be dragging when it is not held in the sea bed It

is said to bite well when it has a good hold in the ground The vessel is

‘dragging her anchor’ if she moves her position while dragging theanchor over the sea bed

‘got her cable’ are sometimes used to mean the same thing The officer

in charge of an anchor party will know when the vessel is brought up,

by the cable rising up from the surface towards the hawse pipe when thebrake is holding it The vessel should then move towards the anchor,causing the cable to drop back and make a catenary (Figure 2.19)

Cat the Anchor

The anchor is said to be catted when hung off, from what used to becalled the clump cathead More modern vessels will be fitted with a pipelead set back from the line of the hawse pipe and used for the purpose

of ‘hanging off an anchor’ Found in practice when mooring to buoys bymeans of mooring shackles with the cable

draws back towards the holding anchor

Figure 2.19 A vessel brought up.