The International Marine Contractors Association has issued a safety flash about an incident in which a platform supply vessel (PSV) collided with a jack-up rig, causing damage to the PSV.
The incident occurred after transfer of water to the rig. The PSV had been ready to disconnect the hose, but the rig informed the ship that there would be a delay. The PSV was to the windward (weather) side of the rig and the weather was rough, with the wind approximately 22 knots.
A little under an hour after completing transfer of cargo, but while the hose was still connected, the PSV starboard engine and thrusters tripped.
As a result the PSV started to move astern and to starboard. Dynamic positioning control was immediately transferred to manual mode. The hose was dropped in the water. While pulling away to safety, the PSV made contact with the forward leg of the drilling rig.
What went wrong? What were the causes?
- Procedures were not followed. The vessel was working on the weather side as the jack-up rig was not geared up to receive water on the lee side.
- A mechanical seal of a fuel oil pump was damaged suddenly, indicating material failure.
What lessons were learnt? What actions were taken?
- Better management and assessment of risk during simultaneous operations – if required, the vessel should come off and get out of the safety zone.
- While material failure of items can be unpredictable, planned maintenance schedules and manufacturer’s instructions should be followed for critical equipment.