anchor, ship, chain,
cable, anchoring, fouling anchor, deck officers, deckhands, windlass, hawse
pipes, spurling, brakes, buoy, mast, navigators, engine telegraph, seabed,
Anchor winch and chain
Preparing to Anchor
A ship will lay anchor whenever there is going to be a long stop, perhaps waiting for the pilot, or waiting for
berthing space at the wharves, or waiting for the bunkering barge.
Contrary to normal thinking, the anchor itself is
not enough to stop a ship from drifting. The weight of the anchor chain also plays a part in the process of anchoring.
A length of anchor chain of 4 times the depth of water is generally sufficient to prevent a vessel of 10000 tonnes
displacement from drifting.
There is also a method of letting go the anchor and paying out the chain. The ship should be maneuvered to go either
slow ahead or slow astern as the chain is paid out. This is to prevent fouling of the anchor by the chain. If the
vessel is not moving, the chain tends to pile up on the anchor so that it becomes difficult to weigh anchor later on.
The length of chain to use when anchoring depends upon several factors:
Anchoring is a job for the deck officers and deckhands. Normally, it will be done while in port or near the vicinity
of land when the depth of water is comparatively shallow.
- The depth of water
- Length of time it is intended to stay at anchor
- Nature of the holding ground. clay and sand provide good holding ground, but a rocky bottom is unreliable.
- Strength of the tide
- Weather expected and the shelter available at the anchorage
- Type of anchor
- Size and type of vessel
- Space available
Below are some to the steps that are taken whenever a ship anchors:
There is not much to do during anchorage. If the weather is pleasant, some seamen will proceed
to enjoy fishing with their hooks, lines and baits. This is the most suitable time for fishing.
- The deck officer on duty will order steam or electric power on deck. For steam powered machinery, the deckhands will
operate it to turn the windlass over slowly on free gear until warmed up and the cylinders are cleared of water.
- The hawse pipes and spurling pipes are cleared.
- The brakes are checked to be on.
- The bottle screw holding the claws are checked for functioning. These are removed from the chain.
- The windlass is put into gear and the steam valve cracked open so that the chain does not run out as the brake is
- The brake is then unscrewed and the chain led out until the anchor clears the hawse pipes.
- If an anchor buoy is to be used, this should be connected to ensure that sufficient chain is used for the depth of
water in which it is proposed to anchor.
- The brake is checked to be firmly screwed up. The windlass is taken out of gear. The anchor is then ready for letting go.
- Normally the anchor ball is hoisted up on the mast and the anchor lights made ready to be switched on if required.
- The anchor is dropped into the water. This will be communicated to the navigators on the bridge who will communicated
with the engine room via engine telegraph to move the ship dead slow ahead or dead slow astern.
- Once the anchor together with the chain has been laid on the seabed as required, the order will be given to the engine
room - Finish with Engine.