Causes and prevention of losing anchor and breaking chain

1. Reasons

1. When anchoring in deep water above 25M, a certain length or a sufficient length of anchor chain is not poured out by the windlass in advance. When anchoring, the anchor and chain are subject to the acceleration of gravity, causing the windlass to fail to brake and the anchor to drop. Even lowering the knife-type chain stopper does not help.

2. When an empty ship is anchored in strong winds or anchored with a heavy load in a sharp top current, the anchor chain is broken by reversing too much, or the inertia is not eliminated early before turning around when anchoring with a heavy load. As a result, the cross-current pressure is too high during the anchoring and U-turn and the chain is broken. .

3. During the anchoring process, the bridge and the bow do not cooperate well or the communication equipment fails.

4. The anchor chain mark is unclear or faded, causing the entire anchor chain to loosen and fall into the sea.

5. I did not know whether there were any obstacles in the anchorage and what the substrate was like, so I dropped the anchor blindly. As a result, I found that the anchor was hooked when lifting the anchor. Although many attempts were made, it was still ineffective and I had to abandon the anchor.

6. Failure to properly tie and lock the chain brake, anchor windlass brake, and lashing wire after sailing. Failure to check after being hit by wind and waves at sea, causing all the anchor chain to loosen, or the anchor to hook on the seabed. Pull off the anchor chain.

7. When sailing in the harbor, in order to evacuate an incoming ship or collide with the dock, the anchor was dropped when the ship’s speed was high and the anchor was not braked in time after it touched the seabed. As a result, the brakes could not be braked and the entire anchor chain slipped out and fell into the water.

8. When anchoring in a sandy place in a river, the anchor is buried deep in the sand due to long-term inability to anchor. It is only discovered when the anchor is lifted. When the anchor cannot be lifted, the anchor has to be abandoned.

9. The outboard flange of the anchor chain hole, commonly known as “LIPS”, is not rounded, and the flat end of the “U” shaped anchor connecting the anchor head is upward. This “U” line is often unloaded when the anchor is weighed. If the anchor is stuck on the “LIPS” and the force is continued to be applied quickly to winch the anchor, the “U” row of unloaders will be pulled apart, and its cross pin will come out and the anchor will fall into the sea. Some ships do not have this phenomenon for ten years, but when the trim is at a certain angle and the anchor is rotated to a certain angle by wind and waves, the above phenomenon will happen coincidentally.

10. There are internal injuries, blisters, and cracks inside the anchor chain, and it will be broken by a slight amount of force.

11. If the anchor is anchored when the wind and current are not favorable, and the chain is loosened before the bow of the ship is straightened, it is easy to cause the chain to cross the bottom of the ship from one side to the other side, causing the bottom of the ship to sit on the chain. If the wind and waves are bumpy, the anchor chain may be broken.

12. When anchored in drift ice, the chain can easily break due to the pressure of drift ice.

13. In extremely cold areas, such as when the temperature is below minus 20°C, the chain will become brittle due to cold. If the chain is loosened too quickly and then braked immediately, the chain may break.

14. When anchoring, there were too few people on the bow of the ship and they failed to report the stress of the chain to the bridge in time. As a result, the bridge failed to take adequate measures and the chain broke. Or the intention is to drop the second anchor to prevent the primary anchor from continuing to slide out at a higher ship speed. However, due to the lack of two people, it is difficult to drop the second anchor in time, which may cause the primary anchor to lose anchor.

15. Causes due to problems with the windlass and anchor equipment, such as the failure of the brake belt of the windlass, the base of the chain stopper and the windlass is not strong due to corrosion, the diameter of the chain has exceeded the limit, the chain ring and its swivel ( Commonly known as Hericium) has cracks, the pin connecting the unloader is loose and other reasons can cause similar accidents.

Post time: May-29-2024