Lifeboat wire rope failure

During a five-yearly 110% load test of a lifeboat, taking place under third party supervision, the forward fall wire failed, resulting in the lifeboat falling and flipping upside down landing in the water below.  There were no personnel onboard during testing and no injuries were reported. The lifeboat was recovered to shore.

What went wrong?

Our member’s investigation noted that during maintenance of the lifeboat davit sheaves, the fall wire was removed by disassembling the three existing bulldog (“Crosby”) clamps on each wire termination on the davit. Once all maintenance works were completed, the fall wire was reinstalled using the original bulldog clamps, which were clamped in the same position as the original termination.

What were the causes?

Close inspection of the wire indicated that the fall wire had slipped through the bulldog clips and released from the thimble on the turnbuckle because:

• The grips were torqued in the exact same position they were before, therefore compromising the structure of the wire which was already flattened/deteriorated;
• The bolt grips were tightened without making reference to any minimum / maximum torque value specification.

Additionally:

• There had been inadequate preparation of the wire for termination;
• Bulldog clips had remained in use  since the installation of the lifeboat, as there was no regulatory or mandatory (Flag state) or company procedural requirement to perform replacement;
• There was no evidence that the bulldog clips were inspected prior to refitting.

What lessons were learned?

• Fall wire inspection, maintenance and termination should be by competent and qualified personnel;
• Consider replacing wire terminations which have Bulldog grips or cable grips (left image) with asymmetrical wedge socket type (right image).

 What actions were taken?

• Checked fleetwide to see whether any similar terminations existed – any lifeboat falls which were found to be secured with bulldog grips were renewed and replaced with the asymmetrical wedge socket type by a competent third party and subsequently certified;
• Flag State was notified at the time of the event, and updated with the outcome of the investigation.

Members may wish to refer to:

• Tombarra fall wire fatality: Updated reports
• Failed shackle on vessel life raft
• High potential near miss – rescue boat davit failure (MSF)