The UK’s Marine Accident Investigation Board has released its report on the grounding of the Marshall Islands registered semisubmersible rig Transocean Winner on the Isle of Lewis following the loss of tow from the Dutch registered tug ALP Forward on 8 August 2016.
The report cites three safety issues responsible for the grounding:
The effect of the wind on Transocean Winner led to ALP Forward being incapable of controlling the wind and tow in the severe weather conditions. Without the necessary information, it was not possible for the master to predict the tug’s inability to hold the rig and change his passage plan in time to seek shelter.
The planning of a passage so close to the coast left little sea room for the tug and tow to drift. When ALP Forwardlost control of the tug and tow, it was very likely that Transocean Winner would have grounded even if the tow line had not parted.
The tow line was in a generally poor condition. There was insufficient catenary in the deployed tow line, which led, in the weather conditions, to repeated sudden loadings, resulting in the tow line parting. It is quite possible that a new tow line would have also parted under the same circumstances and conditions.