200517 Broken Stud on Windlass

Broken Stud on Windlass
MARS Report 200517

A Company vessel anchored awaiting berthing prospects. The starboard anchor was dropped 5 shackles into the water. The brake was applied and the bar was put across. A few hours later, as a precautionary measure, the Master ordered the Officer of the Watch to slack the cable to 7 shackles in the water. This time, the anchor party walked the anchor slowly out. On completion of this operation, they attempted to apply the brake, the bar was put across and windlass disengaged. After a short while the deck hand reported that he was unable to close the brake. The Chief Officer investigated the matter and found that the brake band-tightening stud was bent and broken (see drawing).

Root Cause:

A root cause analysis was undertaken on the above incident with the following findings:-

1. Although greasing was carried out as per Planned Maintenance, the personnel involved did not check whether these had any affect on the parts being greased. This inaction led to the stud ball-end joints being seized
2. Over a period of time the immobilised stud suffered fatigue failure and broke.

Lessons learnt:

1. Check the moving parts of the anchor windlasses and see whether your vessel does not suffer from the same problem.
2. Make sure that whenever an action is required, the personnel carrying out the operation thoroughly understand the reason for it and consequences of failures.
3. It has to be said here that all actions taken by the vessel in order to investigate and then repair the item were of the highest possible standards.
4. Also proper securing procedures adhered to by the ships staff prevented serious injuries and loss of anchor occurring.