Anchoring & Anchoring Operation
Table of contents
1. Overview
Anchoring is a very important process and refers to dropping and securing the anchor at the seabed to prevent the ship from drifting from its position when waiting for the berth to get vacant or to enter the port.
An anchor is a device similar to a hook attached to a chain called a ship anchor along with the cable holds the ship at its position in reasonable weather conditions against wind and current.
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2. Reasons for Anchoring
When you reach the port, you may need to anchor your ship due to many reasons such as:-
- Before entering the port and waiting for the pilot/berth
- Cargo operation at the anchorage
- Crew change
- Awaiting instructions from owners/ charterers
- To turn the vessel around
3. Parts of the Anchor System
3.1 Anchor
Anchor is the crucial equipment of the ship is used to hold the ship at a stable position during anchoring. There are three anchors on board the ship, two on the forecastle ( one on the port side and the other on the starboard side), and one is a spare anchor used in case one anchor is lost.
3.2 Chain Cable
Chain cables provide enough weight to ensure that the anchor lies horizontally on the sea bed and gets the maximum holding force.
The length of the chain cable ( steel studs) is measured in shackles, one shackle is equal to 27.5 meters. One shackle is also equal to 15 fathoms or 90 feet.
3.3 Hawse Pipe
The main function of the hawse pipe is to guide the chain from the deck level to the outside of the side plating. Hawse pipe is large enough to accommodate the smooth running of the chain
Hawse pipe provides the secure stowage for the anchor. A Hawse pipe is a structure that enables the anchor to drop freely without jamming and damaging the hull.
3.4 Anchor Lashing
The function of the anchor lashing is to secure the anchor when in stowed position. Anchor lashing prevents the anchor from banging into the ship hull, damaging it, and at the worst part from penetrating it. The method of securing the anchor is called Devil’s Claw comprises the wires and bottlescrew arrangement.
3.5 Chain Stopper
The function of the chain stopper is to guide the chain into the hawse pipe. It transfers the chain forces into the ship’s structure when closed. It is built to withstand 80% of the Minimum Breaking Load of the chain.
The most common type of chain stopper is a rolling type or guillotine type.
3.6 Windlass
It is a machine designed to raise or lower the anchor and has one or more cable lifters or gypsy. Gypsy is a deeply grooved drum that engages the link of the chain. Windlass helps the sailor to lower or raise the anchor more efficiently than the manual method.
3.7 Spurling Pipe
The spurling pipe is the opening in the forecastle deck leading to the chain locker, it is the opening that carries the anchor chain from the gypsy to the chain locker.
3.8 Chain Locker
A chain locker is a compartment located on the bow of a ship under the windlass beneath the forecastle deck. A chain locker is a structure used to store the anchor chain when it is not in use. A chain locker can be made watertight to ensure that the water does not enter the chain locker.
3.9 Bitter End
As the name suggests it is the end, the bitter end is the the end of the anchor chain secured at the chain locker or the hull by a quick-release system. The end is secured at the chain locker or collision bulkhead of a vessel. At the bitter end, sludge is kept for the release of the anchor chain at the time of emergency.
These anchoring equipment are located on the forecastle, the most exposed part of the vessel.
4. Anchor Watch Duties
‘Anchor Watch‘ typically refers to a practice used by sailors to monitor their vessel while at anchor. When a boat is anchored, it is important to ensure that it stays in a fixed position and doesn’t drift or drag anchor. An anchor watch regularly checks the vessel’s position to ensure it remains within a swinging circle.
- While at anchor use should exhibit proper light and sound signals.
- Ensure that a proper lookout is maintained, in case of restricted visibility a separate lookout should be maintained with OOW.
- Ensure that the main engine and other machinery are always ready for immediate maneuver.
- Make good use of navigational equipment, and check and verify the ship positions.
- The watchkeeper should keep observing the weather conditions at all times.
- If OOW finds anything unusual then he should notify the master and take necessary actions.
- Personnel on anchor watch should ensure that antipiracy precautions are taken including regular rounds.
- Maintain a continuous listening watch on the VHF channel.
- Necessary entries shall be made in the logbook at the end of each watch.
5. Terms related to Anchoring
5.1 Anchor Cockbill (Anchor is ready for ‘ letting go’)
Anchor is said to be at a cockbill position when it has been lowered out of the hawse pipe and the weight is taken on the brakes and is in readiness for letting go when the order is given.
5.2 Anchor Aweigh
The anchor is said to be ‘Aweigh’ immediately after it is clear of the sea bottom while being picked up. When the anchor is aweigh, the cable will suddenly become taut with a jerk to the ‘up and down’ position.
5.3 Foul Hawse
A ship has ‘Foul Hawse’ if the cables are crossed with each other when the ship is riding to both anchors. A ship has ‘Clear Hawse’ when the cable is clear of each other when the ship is riding to both the anchors.
5.4 Clear Anchor
The anchor is reported as ‘Clear’ as soon as it is entirely out of water. Anchor is reported ‘Clear’ if it is clear of its cable, and of any obstruction such as the height of the rope, any cable, any chain, etc. picked up from the bottom.
5.5 Anchor Dragging
An anchor cable is said to be dragging when it falls to hold the ship in its position and instead drags it along the bottom. This may occur in heavy weather.
6. Conclusion
Using and taking care of the anchoring system is very important for keeping the vessel in position when it is not in motion or stationary. The crew needs to know how to use and secure the anchor properly. We have to regularly check and resolve the problem regarding the anchor for the smooth functioning of the vessel so that everything works well and keeps us secure.
7. Frequently Asked Questions
Q1 What exactly is known as an anchor?
Ans. An anchor is a heavy hooked-like structure that is dropped from the boat or ship to keep it in position when it is not moving.
Q2 What is the purpose of a chain locker?
Ans. The purpose of a chain locker is to store the anchor chain when it is not in use.
Q3 What is anchor lashing?
Ans. Anchor lashings are used to avoid the anchors being lost while underway at sea.
Q4 What is the difference between a hawse pipe and a spurling pipe?
Ans. Hawse pipe and Spurling pipe are completely different things and to be confused with each other-
The hawse pipe leads the anchor chain from the water onto the deck.
Spurling pipe – It carries the anchor chain from the windlass to the chain locker.
Q5 What is windlass?
Ans. It is the equipment used for lowering and raising of anchor during the anchoring operation.
Q6 What is the purpose of the bitter end?
Ans. The bitter end is the end of a rope or chain that fastens to the ship so you don’t lose your anchor.
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