Up to 10 tonnes of oil poured into the Irish Sea after a ship crashed into a wind turbine.
The 40 metre-long OMS Pollux vessel collided with one of the turbines at Dong Energy’s Walney Offshore Windfarm on Thursday morning.
The ship, owned by Danish firm Offshore Marine Services, was refused entry to Barrow docks because its engine was leaking diesel oil as a result of the collision.
The ship was able to move under its own steam and the crew was told to await further instruction in waters away from environmentally-sensitive areas.
The Maritime and Coastguard Agency then arranged for a small plane to fly over the ship, to assess the extent of the leak, and reported a surface sheen up to 10 metres wide and around 0.7 nautical miles in length trailing the vessel.
But, unlike heavier forms of fuel, the MCA said marine gas oil should evaporate or disperse naturally.
A spokesman for Dong, who said there was no damage to the turbine, said: “An incident occurred on Thursday morning at the Walney Offshore Windfarm 15km from Barrow off the Cumbrian coast.
“While carrying out routine inspection work, the dive vessel OMS Pollux collided with one of the wind turbines at about 8.15am when an anchor cable broke.
“None of the 18 crew on board were injured, however the vessel sustained some damage and was leaking fuel oil.”
A spokesman for Liverpool Coastguard said the ship had been told to wait off the coast of Liverpool, while a decision was made about the vessel.
After a 36-hour wait, circling in the Irish Sea, the ship was allowed to enter the docks and arrived at Birkenhead at 3pm yesterday.
A spokesman for Offshore Marine Services said: “We can confirm the vessel had an incident at the Walney windfarm resulting in an oil leak. Everyone onboard is safe and no injuries occurred.
“We have received good support from Liverpool Coastguard and the vessel is now in port of Liverpool for repair.”
The Marine Accident Investigation Branch has been notified about the collision and will publish a report in due course.