Defective Tightening Nut Makes Lifeboat Launch Impossible

A system is only as good as its weakest link. A recent Mars Report describes an incident in which a lifeboat could not be lowered during a drill due to one small, defective tightening nut.

A summary of what happened:

While at anchor, the deck crew were testing the port and starboard lifeboat davits, lowering the boats to deck level without crew on board, and then raising them back to the stowed position. The starboard boat was lowered and raised without incident.

When the same procedure was attempted with the port lifeboat, the aft davit arm lowered, but the forward one did not. The brake was immediately reapplied and actions were taken to bring the boat back to its secured position.

Investigation Findings

An investigation found that the wire clamp on the davit’s wire rope, which is instrumental in keeping the load balance between the davit arms, had slipped. Further investigation revealed the threads of the clamp’s tightening nut were very worn.

Advice from The Nautical Institute

  • In this case the lifeboat launching was not possible because of one small nut.
  • Practice lowering of lifeboats is best done, if possible, without crew on board.

Mars Reports

This accident was covered in the Mars Reports, originally published as Mars 201971, that are part of Report Number 325. A selection of this Report has also been published in SWZ|Maritime’s December issue. The Nautical Institute compiles these reports to help prevent maritime accidents. That is why they are also published on SWZ|Maritime’s website.

More reports are needed to keep the scheme interesting and informative. All reports are read only by the Mars coordinator and are treated in the strictest confidence. To submit a report, please use the Mars report form.

Author: Mariska Buitendijk

Mariska Buitendijk is one of SWZ|Maritime's journalists as well as the magazine's copy editor.