The incident

During the swinging out and lowering of the boat, the davit moved uncontrollably to the full extent of the piston, at which point the piston end cap separated from the piston and the davit carried on falling to the deck.

On coming to a stop at the deck, the shock loading of the fall wire caused it to part and the rescue boat fell into the water. There were no injuries as a result of this incident.

The MSF notes that that this was due to the good practice of lowering the rescue boat unmanned to function test the davit and associated controls before boarding.

 

Probable causes

The davit manufacturer and a local hydraulics expert were both unable to confirm the exact cause of the initial failure, however, a failure of one of the counterbalance valves or failure of the end cap itself were noted as the most probable first point of failure.

 

Actions taken and lessons learned

  • The vessel owner made it mandatory for vessels to complete an unmanned test lowering of the davit and boat, function testing all controls, before conducting manned launch;
  • Replacement of fall wires on rescue boats at 30-month intervals;
  • At the five-yearly thorough examination, maintenance and testing of the rescue boat and davit, replacement of the counterbalance valves and piston end cap;
  • Review of the maintenance and inspection requirements within vessel planned maintenance system (PMS) to ensure alignment with the manufacturer’s recommendations.

Following the accident, the MSF recommended that all companies review their own procedures to asses potential for similar incidents.

It must be noted that the good practice of lowering the rescue boat unmanned to function test the davit and associated controls prior to boarding prevented a possible fatal accident in this incident,

...MSF stressed.