The Marine Safety Forum (MSF) has published Safety Alert 19-07 relating to a rescue boat davit failure during the boat’s periodic launch and testing.
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.
What went wrong?
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.
What actions were taken? What lessons were learnt?
- 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.
Note: the above actions were applicable to the submitting vessel owner in relation to their own maintenance and use of rescue boats and davits. The MSF recommends that all companies review their own procedures to asses potential for similar incidents.