The Transocean Winner semi-submersible drilling unit was under tow in the North Sea, on its way to Malta, when severe weather caused the towline to snap, blowing the rig ashore on a beach in Dalmore, near Carloway earlier in August.

According to the Maritime and Coastguard Agency, Transocean was asked on Friday to use the good weather conditions on scene to take the opportunity to remove non-essential diesel oil and any other potential pollutants from the drilling rig.

The agency on Saturday confirmed that 200 tons hydrocarbons, consisting of mainly diesel oil with small amounts of base oil and brine, was successfully transferred from the rig onto the supply vessel Olympic Orion.

No pollution has been reported or observed. The MCA said it was sending its verification aircraft to overfly the rig and surrounding area. The aircraft was in Inverness on Saturday, waiting for a higher cloud base on site before the flight can be safely carried out.

According to the coastguard, Transocean plans to refloat the rig over the high water on Monday night.

The rig will then be towed to Broad Bay, Isle of Lewis and will remain there until it is in a stable and fit condition to be towed or transported to a suitable repair facility.

Hugh Shaw, the Secretary of State’s Representative for Maritime Salvage and Intervention said: “Good progress is being made in this operation. The plans for the refloat are in place Although this is dependent on the Salvage team being able to recover enough buoyancy to enable the rig to refloat safely.”

Source: Offshore Energy Today