Anchoring a Important Aspect of Shipboard Operation!!!
After a long sea voyage a ship arrives in a port or near a port area and may have to anchor the ship. This may be because of customs, immigration and cargo formalities or due to non-availability of a berth. A ship may be required to anchor for receiving stores, provisions, bunkers, crew change, surveys, repairs, awaiting port clearance. A ship may also be forced to take shelter at an anchorage due to unfavourable weather in the open sea.
The anchors of the ship are like claws and their function is to hold on to the seabed so that the ship stays in one place and not drift under the influence of winds or currents.
"TAKE GOOD CARE OF YOUR ANCHORS AND THEY WILL COME TO YOUR HELP WHEN NEEDED"
Berthing alongside and unberthing operations involve almost the full ship’s complement. The deck officers and crew attend to the forecastle and poop deck.
The engine room staff attends fo the main engines and other equipment. The and Master is on the bridge usually being guided by a pilot assisted by a helms man and another officer. Tugs may be required to push/pull/nudge and to cajole the ship o desired angles and positions.
Your Sullen Face On
Leaving a Good Port will
Brighten Up Again When
You See What Is Waiting
For You In The Next Port
Parts of the anchor, chain, windlass and chain locker.
A normal merchant ship will have two anchors; one fitted on each side of its bow, hence called “bower anchors”. In addition to these, a spare anchor is kept secured on the main deck in case one of the bower anchors requires replacement due to loss or damage. On modern ships Anchors are “STOCKLESS’.
Lugged Shackle
Anchor Chain
Anchor chain Depending on the size of the ship, mainly its length, the bower anchors will be fitted with anchor chains of certain lengths. A medium size ship 15000 DWT would generally have 10 shackles. (1 shackles=15 fathoms=27.4 m).
A VLCC may have up to 15 shackles (410.00 m). One end of the chain is secured in the chain locker and is called the “BITTER END”. On the other end is a `D’ type shackle attached to the bower anchor. The ‘bitter end’ will be secured such that in an emergency it can be released quickly to let go the whole anchor chain.
Kenter Shackle
Typical electric windlass with warping drum (winch drum)
The windlass is a machine primarily provided to handle the anchor chain either as a means of letting the anchor cables run out or haul it in again.
The prime mover could be an electric motor or even steam/hydraulic type; the two (port &starboard) ‘gypsies’ heave or lower the cable. The gypsy will rotate freely and pay out cable to anchor a ship. The gypsy gear has to be engaged to heave up the anchor. The warping drums will rotate with the gypsy in gear or with the gypsy gear disengaged.
A bow stopper arrangement between the windlass ‘gypsy’ and hawse pipe holds the cable mechanically to take the strain off the brakes when the vessel is riding on her anchor.
Process of lashing and unlashing anchors.
The anchor chain has to be well secured while the ship is at sea. This ensures that the flukes are resting tightly against the shell plating. This ensures that the anchor does not have a play against the ship’s side plating when the ship is rolling or pitching or the sea is rough.
Additionally precautions have to be taken to avoid sea waves and water entering the chain lockers.
Following is a step-by-step method recommended for securing the anchors after they are hove up tight: –
a) Ensure that the windlass brake is tightly secured. The bow stopper is placed in position and the windlass is out of gear.
b) Reave the anchor lashing steel wire rope through one of the chain links or alternatively place the devil’s claw on the cable.
c) If the wire is used connect bottle screw and screw the bottle screw up tightly.
d) Put the hawse pipe and spurting pipe steel plate covers in position.
e) Cover these plates with a canvas cloth.
f) The spurting pipe must be additionally coated with a good protective coat.
Process for engaging and disengaging the windlass system
► Request the engine room for power to the windlass system. (Usually called “forward deck power”)
► Ensure that a spike, small hammer, sledge hammer, crowbar, can filled with Lub oil,goggles and a torch (at night) are near the windlass area.
► Make sure that the brakes are on.
► Remove the anchor lashings leaving the ‘bow stopper on.
► Turn the windlass over slowly to a position. Where the gears can be engaged.
► Put one anchor in gear and turn windlass ‘in’ to take the weight of the anchor.
► Remove the bow stopper.
► Open the brake.
► The windlass gear in now engaged. You can now lower the anchor out of the hawse pipe to the water level if required.
► When ordered to lower, lower the anchor slowly clear of the hawse pipe.
► Screw brake tightly home, turn windlass such as to take the weight of the anchor on to the brakes only.
► Take the windlass out of gear. The anchor is now ready to let go by releasing the brake.
Importance of securing spurling pipe covers weathertight.
The Department of Trade and Industry (UK), now Maritime Safety Agency, drew attention to the following two incidents where the ingress of water through spurting pipes was a contributory cause to these ships becoming casualties. in the first case, referred to below, the ship foundered resulting in loss of life.
Case 1
A loaded ship on passage from Holland met with heavy weather in the English Channel. The canvas covers to the spurting pipes were torn away and the chain locker and forecastle store became flooded. The ship being already down by the head the additional flooding was sufficient to bring the weather deck under water thereby placing the air pipes and subsequently the cargo hatchways in jeopardy. Progressive flooding occurred and eventually the ship was lost.
Case 2
The second ship also outward bound from Holland encountered heavy seas, which were sufficient to break the cement, which had plugged the starboard spurting pipe. Seawater thus gained access to the chain locker and the forward stores space producing trim by the head and bringing the foredeck awash. Fortunately, the Master took early action and returned to port where the spurling pipes were re-cemented.
In the first case the mere fitting of canvas around the spurting pipes was not sufficient but had close lifting supported the canvas steel plates or a more efficient means of preventing the ingress of water provided the casualty would have been avoided. The second case showed that the quantity of cement used must be adequate not only to plug the spurling pipes but also to prevent lateral movement of the cable within them.
Various markings on the anchor chain.
Cable markings
When anchoring, it is important to know how much cable has run out. The chain is therefore marked at each joining shackle. First shackle is marked by a piece of seizing wire, flexible and thin galvanised iron wire, on the first studded link on both sides of the shackle.
Second shackle is marked by a piece of seizing wire on the second studded link on both sides of the shackle.
Third shackle is marked by a piece of seizing wire on the third studded link on both sides of the shackle, and so upto the last shackle. in addition, since the seizing wire markings cannot be easily seen at night, a system of marking by white paint is also employed. Different ships have different systems. For example, some ships paint all the joining shackles and the links, which have seizing wire marking. Whereas other ships do not paint the joining shackle at all but paint all the studded links on both sides of the shackle, upto the links which have seizing wire markings.
Anchoring terminology & anchoring terms.
The following are a few of the expressions used in anchoring and as assistant to the officers who may be in charge of the forecastle cable-party you will do well to acquaint yourselves with all of them, for misunderstood order from the bridge may give rise to some undiplomatic language.
| Term | Meaning |
|---|---|
|
Wind rode |
A vessel is so described when she is riding head to wind |
|
Tide rode |
A vessel is so described when she is riding lead to tide |
|
Lee tide |
A tidal stream which is setting to leeward or downwind. The water surface has minimum of chop on it, but the combined forces of wind and tide are acting upon the ship. |
|
Weather tide |
A tidal stream which is setting to windward or upwind. The water surface is very choppy, but the forces of wind and tide are acting in opposition on the ship |
|
Shortening-in |
The cable is shortened in when some of it is hove in board. |
|
Growing |
The way the cable is leading from the hawse pipe, e.g. a cable is growing aft when it leads aft. |
|
Short stay |
A cable le is at short stay when it is taut and leading down to the water close to the vertical. |
|
Long stay |
A cable is at long stay when it is taut and leading down to the water close to the horizontal. |
|
Come to, Brought up, Got her Cable |
These are used when a vessel is holding to her anchor and the cables. |
|
Snub the Cable |
To stop the cable running out by using the brake on the windlass. |
|
Range the cable |
To lay out the cable on deck, or wharf, or in a dry dock etc |
|
Veer the cable |
Walk back or to pay out cable using the windlass motor. |
|
Walking back the anchor |
To lower the anchor under power. |
|
Surge cable |
To allow cable to run out freshly, without using the brake or the windlass motor. |
The Anchor
| Term | Meaning |
|---|---|
|
A cockbill |
Used to describe the anchor which has been lowered clear of the hawse pipe and is hanging vertically |
|
Foul anchor |
Used to describe an anchor which is caught in an under water cable, or which has brought old hawsers to the surface with it. |
|
Up and down |
The cable is up and down when it is leading vertically to the water. |
|
Foul hawse |
When both anchors are out and the cables are entwined or crossed. |
|
Open hawse |
When both anchors are out and the cables lead broad out on their own bows |
|
Clearing anchors |
Anchors and cables are cleared away when the securing gear on deck is removed. |
|
Nipped cable |
The cable is nipped when an obstruction, such as stem or hawse-pipe lip, causes it to change direction sharply. |
|
Render cable |
The cable is rendered when the brake is loosely applied so that the cable runs out slowly. |
The procedure for anchor work
► Request the engine room for power on deck.
► Take to the forecastle head a spike, hammer, crowbar, oilcan, goggles portable VHF set and at night a torch.
► Take off the hawse pipe covers. Let go the lashing in the chain locker.
► Make sure that the brakes are on and the windlass is out of gear.
► Turn the windlass over slowly and oil the moving parts. On a steam windlass, the drain cocks must all be opened to drain the water. The cocks may then be closed again.
► Put one anchor in gear. (See that gears are clear to engage first)
► Remove the devils claw and any other lashings.
► Remove the compressor bar and the cement and the covers or other filling from the spurting pipe.
► Make sure that the weight of the anchor is held by the brake and that the gears although in, are clear. Take out of gear.
► Prepare the other anchor using the same routine. (5, 6 & 7). 10.
► Inform the Officer concerned and the bridge on VHF that the anchors are ready for lowering clear of the hawse pipe.
► Place one anchor in gear.
► When ordered to lower away by the Officer, take off brakes and lower slowly until the anchor is out of the hawse pipe.
► Screw the brake tightly home and take out of gear.
Letting go the anchor
Wear goggles. (The anchor cable when running out may throw mud rust etc. and hence the protection) Let go the brake when ordered and brake as required after the anchor has hit the bottom.
One man to strike the bell to indicate the number of shackles that have gone out. e.g. first shackle, 1 bell, sixth Shackles, 6 bells, etc.
When sufficient cable has been paid out and when the cable is riding easy the ship is “brought up”. Inform the bridge. Put on the compressor bar and screw the brake tightly home, Hoist the anchor ball or anchor lights.Return the gear to the store.
Weighing the anchor
► Take to the forecastle head a hammer or crowbar, hose, oilcan, VHF portable set and at night a torch. Couple up the hose to the deck hydrant, lead it to the hawse pipe and open the hydrant. (A number of ships have built in arrangement for washing the cable as it is hove in.)
► Request the engine room for power and water on deck.
► Make sure the windlass is out of gear and the brakes are on.
► Turn windlass over slowly and oil the moving arts. On a steam windlass the drain cocks must all be opened and the water allowed to drain before the cocks are closed again.
► Put the anchor in gear (see that the gears are clear to engage.)
► Send a man to the chain locker with a light. He shall ensure that the cable is lying clear and there is no other obstruction in the chain locker.
► Remove the compressor bar and when ordered to do so, take off the breaks and commence heaving in the cable. See that the hose is running and have a man to wash the cables as it comes in. Inform the man in the locker that you are about to heave away. He shall arrange the cables so that they fall in a heap. Another man should stand by the bell to ring the shackles as they come in. Inform the bridge the status of the cable on VHF.
► When the anchor is aweigh i.e. the anchor is off the ground and the cable is vertical take down the anchor ball or anchor light and ring the bell rapidly to indicate that the anchor is aweigh.
► When the anchor is hove home, inform the man in the locker. He shall now come out of the chain locker and inform the officer in charge that he has come out. This precaution is necessary or else the man may have suffered injury and it would not be noticed. Apply the brake tightly and insert the compressor bar. Ease the gears and take the windlass out of gear. Stop the water, close the cock and uncouple the hose. Return the gear.
Accident prevention
► Be sure the brake is tightly home and the gears eased before taking the windlass out of gear.
► Do not leave the windlass in gear.
► Wear goggles when letting go the anchor.
► Do not go in the chain locker to stow the cable.
► Do not use chain hooks in the chain locker
► See that the spurting pipes are made properly weathertight.
► When it is necessary to let go an anchor or pay out cable and a man is in the locker (as might happen when mooring) The order “Stand clear in the locker” must be given, replied to and carried out before the anchor or cable is allowed to run out.