On 2 March 2015, the officer-in-charge of the mooring party on board the LNG tanker Zarga suffered severe head injuries, when he was struck by a mooring rope that parted during a berthing operation, at the South Hook LNG terminal, Milford Haven. The UK Marine Accident Investigation Branch (UK MAIB) issued an investigation report, providing important safety issues, in order to prevent similar incidents from occurring again.
The incident
- The area where the officer was standing was clearly within the snap back zone of the rope but had previously been designated as a safe area.
- The perception on board was that HMPE ropes did not recoil on failure, and the elasticity introduced by the rope’s tail had not been properly assessed.
- The vessel’s mooring lines were not fit for purpose, they did not have the minimum breaking strength specified at build. they were not compatible with the vessels mooring deck fittings and the required working load limit was too high.
- The predominant failure mode, axial compression fatigue, had not previously been associated with HMPE rope failures.
- The rope’s tightly bound jacketed construction increased the likelihood of axial compression fatigue and prevented the crew from inspecting its load bearing core and identifying key discard criteria.
- Guidance provided by the rope manufacturers and shipping industry bodies for the selection and use of high modulus synthetic fibre mooring lines was limited and often contradictory.
Safety issues Recommendations UK MAIB advises several companies, such as Shell International Trading and Shipping Company Ltd, the Oil Companies International Marine Forum, Bridon International Ltd (the rope manufacturer) and Eurocord, to review and enhance their guidance and instructions for the monitoring, Explore more by reading UK MAIB’s full report:
maintenance and discard of HMSF mooring ropes and to improve knowledge on the advantages and limitations they present when used on board ships for mooring line applications.