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Course of events

During a vessel’s stay at port in calm weather, the opportunity arises for carrying out a rescue boat drill. The launching of the rescue boat in this case took place using a davit/winch and single point suspension arrangement incorporating an on/offload release mechanism, including hook and pawl, connected to the boat. After lowering the boat to the water with three crew members on board, and after completing operating tests, the davit connecting link was attached to the hook. Retrieval of the boat commenced and when hoisted to a height about 10 metres above the sea, the boat with crew were suddenly dropped into the water.

Extent of damage

The rescue boat hull was intact, but the extent of possible damage is unknown. Unfortunately, one crew member was seriously injured and taken to hospital. On examination of the release mechanism hook, the tip was found with pieces partly broken off and the pawl deformed. It is not known if the hook and pawl damages were present before this exercise, but the vessel and its equipment were only a few years old when the incident happened.

Probable causes

As part of investigations, the checking of all loose gear revealed that the diameter of the  was less than the recommended dimensions for the release mechanism, even though the rated safe working load was suitable. The manufacturer of the loose gear is different to that of the release mechanism and boat. The damages to the hook and pawl, combined with the smaller link size, increased the gaps between these parts that could affect the link position and cause excessive loads.

It was also clear that operating instructions for hoisting were not strictly followed by the crew, as they had not confirmed the proper placement of the davit connecting link in the hook before hoisting the boat after it was out of the water.