Marine Safety Forum issues safety flash after vessel hits rigProjects and Operations // October 7, 2005
The Marine Safety Forum in the UK has issued a 'Safety Flash' after a supply vessel made contact with a rig while working alongside.
The vessel was in a position 15m from the platform leg, heading into wind and weather. After nine minutes the distance to the leg had decreased to 7-8m and in manoeuvring to increase the distance from the leg, the navigating officer took the vessel ahead to clear the leg. The stern then swung towards the leg and contact was made.
In its root cause analysis of the incident, the Form said that when the vessel set up in Poscon, 150m west of the platform, the navigating officer transferred from manual at the forward console to manual at the aft console to settle the vessel on required heading and then into Poscon at the aft console.
However, he forgot to set the rudders to amidships; the two rudders were set 15 to 20 degrees to starboard. He then took the vessel alongside the platform for cargo operations. On arrival at the platform, he pressed the cancel rudder button on the Poscon console, still failing to notice that the rudders were set to starboard.
The action of the SSW swell on the bow and with the rudders set as they were, while
maintaining position under the crane using ahead movements on the main engines,
caused the vessel to slowly close in on the platform and when he pushed the vessel
ahead to move away from installation, the rudders caused the stern to swing towards
the platform and contact was made.
"The cause was human error," noted the Marine Safety Forum:
1. Failing to put rudders amidships upon completion of manoeuvring at aft console.
2. Failure to cancel rudders from Poscon at 150m and perform environmental
tests with vessel as would be set up alongside.
3. Failure to spend sufficient time on the environmental checks.
4. Failure to notice when at the platform that rudders were not amidships prior to