A 17,000-tonne oil rig which ran aground in Scotland will be loaded on to the back of an enormous ship and carried to Turkey later this month.

The Transocean Winner grounded on Lewis after breaking free from the vessel towing it in a storm on August 8.

The rig was pulled free from the rocks two weeks later and taken to Broad Bay on the far side of the island.

The semi-submersible ship OHT Hawk is due to arrive in the Western Isles in late September and will carry the Transocean Winner to Turkey, where it will be dismantled.

Salvage expert Hugh Shaw, who is in charge of the operation, said: "There will be many technical challenges surrounding the operations

"However, I am satisfied that this is the safest option and it fully meets the requirements to minimise any future risk to safety or damage to the environment."

The colossal OHT Hawk is more than 700ft long, 180ft wide and weighs about 60,000 tonnes.

Its 18,100 horsepower engines give it a range of nearly 29,000 miles, travelling at about 15mph.

The rig was on its way from Norway when it broke free from the tugboat Alp Forward and crashed into the shore near Carloway.

Two of its four fuel tanks ruptured in the collision and spilled about 53,000 litres of diesel into the sea. Most of the pollution is believed to have dispersed harmlessly.

On Monday, the Maritime and Coastguard Agency ruled out the return of a second emergency tug to Scotland despite calls for its reinstatement in the wake of the grounding.

Campaigners handed a petition asking for its reinstatement to ministers in London on Tuesday.