The gale conditions off the Shetland Isles mean their plans are unlikely to get under way until later today at the earliest. Emergency equipment, such as containment booms and dispersant chemicals, was on its way to the islands last night from the oil industry's emergency store in Southampton.
'With the weather like it is, it is not practical to take any immediate action,' George Henderson, of the Shetland Islands Council emergency operation, said last night.
Spray dispersants will be used first - booms for containing oil are best suited to calm conditions. Six Dakota DC3 aircraft, usually based at Inverness and at Coventry, are on stand-by for this purpose. Two Cessna 402 aircraft with remote-sensing equipment on board were also on alert last night. These can track and analyse the oil slick as it progresses. Storm force winds were preventing them from flying into Sumburgh.
As soon as the tanker ran aground, the clean-up became the responsibility of the local authority. Yesterday, the team at the emergency centre set up at Sumburgh airport was still assessing the situation.
Tony Brewster, of Bristow Helicopters, said: 'Quite considerable quantities of oil are leaking out. She is holed beneath the waterline and quite a lot of oil is coming out.'
Mr Henderson said the poor weather was expected to continue, and possibly to worsen, with the wind coming from the south-west directly into the shore. 'Spraying is of little value at the moment because we can't get the oil sprayed at the correct location. Even using aircraft the task is tricky because so much oil is being driven onshore, it is not going seaward. It will be a shore clean-up.'
The Department of Transport said: 'The first line of attack is dispersant spraying from the pollution unit's DC3 aircraft. Conditions at sea are too rough to allow any recovery operations or spraying from vessels. We must assume that all 85,000 tons will be spilt.
'About 40 per cent of the oil can be expected to evaporate. A further 20-30 per cent should disperse in the sea.
'Some oil will undoubtedly come ashore - on rocky shores oil will be washed off and dispersed by waves. Some will get into coves, bays, and beaches, and will need to be cleared up as conditions allow.
'The Marine Pollution Control Unit's equipment will be sent to Lerwick. This includes skimmers, vacuum pumps, and booms. Other equipment is available in the Shetland Isles.
'It is too soon to decide upon a strategy for clean-up. Much depends on the weather and when the oil comes ashore. We have predictions but in these very strong winds and high seas nothing is certain.'
Joe Nichols, technical manager at the International Tanker Owners Pollution Federation, said it was difficult to predict whether the 85,000 tons of oil would leak out. That depended on the position in which the tanker was lying, and the nature of the immediate coastline. 'It is possible to lose the entire cargo, but that is extremely rare.'