Following a tragic accident during a routine drill procedure, a National Accident Investigation body approached consultancy experts from The Test House (TTH), to carry out a confidential failure investigation into the cause of the failure. During the drill, a life boat was being recovered and hoisted when the forward fall wire parted, causing the life boat to swivel on the aft hook. The hook failed and the boat plummeted 20 metres, rotating as it fell, and eventually hitting the water upside down. One crew member was thrown out from the lifeboat as it entered the water, and two crew members managed to escape from the upturned lifeboat by their own efforts. The remaining five crew members were subsequently removed by local divers and were declared deceased at the scene.
Assured by TTH’s reputation and integrity, and its long history of mechanical testing expertise, the marine company was confident that the investigation would uncover the exact cause of the failure. TTH holds UKAS accreditation in the fields of NDT, mechanical testing, metallurgical testing and corrosion testing.
Initially TTH completed a thorough, comprehensive and multi-disciplinary report that covered receipt inspection of the failed wire rope, a visual examination at the parted site, a scanning electron microscope (SEM) examination, metallographic examination, hardness testing and break load testing. The TTH provides a range of preparation techniques for metallurgical examination of metals, alloys, backed up by comprehensive photographic and digital imaging capabilities.
The failure investigation found that the strength of the rope had been below the original certified value. There were clear areas of poor condition, showing open lay, internal rusting and wire breaks. There had been an apparent failure to maintain a suitably protective level of lubricant at the sheave location when the rope was left under tension to stow the lifeboat. There was also an apparent failure to monitor the ropes deteriorating condition consistently using a regular and effective inspection procedure.
Having completed the failure analysis, TTH were then able to work with the client to identify effective safety and maintenance procedures for future use, to minimise all risks to the company and its crew. The National Accident Investigation Body’s, Marine Safety Investigation Unit (MSIU) issued a ‘Safety Alert’ which concluded the cause of the failure. The MSIU findings including The Test House investigation report and safety alert can be found at:
Report No. 05/2014 Thomson Majesty