LONDON — LONDON -- A tanker loaded with 26 million gallons of crude oi was impaled on the rocks off Scotland's remote Shetland Islands last night and, battered by hurricane-force winds and heavy seas, was spilling oil along a rugged, cliff-lined coast that is home to one of Europe's largest sea bird and wildlife colonies.
Rescue tugs and crews flying helicopters into the 80-mph winds managed early yesterday to pluck all 34 crewmen from the decks of the foundering Braer, an 18-year-old tanker operated by a Connecticut company.
Conservationists said they feared an ecological disaster if oil slicks spread into the craggy bays that offer winter sanctuary to birds and sea otters.
The amount of oil that had spilled was not known last night, but an official of the government's Marine Pollution Control Unit in London said crews at the scene reported that the fierce seas appeared to be helping scatter the slick, which consists of a light crude oil that breaks up more easily than heavier oils do.
With little change expected in the severe weather, salvage crews worried that the pounding seas would soon tear apart the single-hulled tanker, spilling its entire cargo along the rocky coast of the Shetlands, a rugged, sparsely populated archipelago about 200 miles north of Aberdeen.
Mike Toogood, the Coast Guard's senior watch officer in Lerwick, the capital, said about 30 percent of the oil was being scattered by the heavy seas and that an additional 40 percent was evaporating, limiting the environmental damage.
But pollution control officials said the 25-foot seas and strong winds were preventing crews from reaching the wreck with booms to contain the oil and detergents to help disperse it.
The spill was the most serious in Britain since the tanker Torrey Canyon ran aground in 1967, spreading 40 million gallons of oil into the Atlantic off Land's End, fouling the coast of southwestern England. The largest oil tanker spill in history took place in 1979 off Trinidad and Tobago when two ships collided, spilling 97 million gallons of oil.
The Shetlands accident is the second major oil spill in Europe in the last five weeks. On Dec. 3, a Greek tanker broke in two and caught fire after it ran aground in stormy weather near La Coruna, Spain, spilling 21.5 million gallons of oil into the sea and contaminating about 50 miles of coastline, although much of the slick was dispersed by waves.
The Exxon Valdez, which ran aground off the coast of Alaska in 1989, spilled nearly 11 million gallons of oil, less than half as much as the Braer carried. But the Alaska spill is regarded as NTC one of the worst ever because it happened in a sheltered sound rather than along a rocky, storm-tossed coastline exposed to the open sea, and because it involved a much heavier, less soluble variety of crude oil than that carried by the Braer.
Lord Caithness, the government's shipping minister, said the ship's engines failed while passing south of the Shetlands. "Had it happened a few miles further down, the ship would have drifted past the Shetlands," he said last night. "It is like hitting a needle in a haystack, tragedy that it is."
He said he expected the tanker's private insurance coverage to fully compensate the government for any environmental damage.
The tanker, which sails under Liberian registry, is operated by Bergval & Hudner Ship Management of Stamford, Conn. Michael Hudner, chief executive for the company, said he regretted the accident and that the company was sending two salvage vessels to help with cleanup operations.
Chris Harbard, a spokesman for the Royal Society for the Protection of Birds, said that because the majority of the island's colonies of sea birds are not expected to migrate to the Shetlands until next month, the number of birds imperiled probably numbers in the thousands, rather than the hundreds of thousands.
Those endangered by the oil are puffins, long-tailed ducks, common loons, eider ducks and shags, which are cormorant-like birds. Mr. Harbard said that since the birds nest on the seaside cliffs, he did not expect the oil to pose a threat to the nesting areas. But the birds feed on the water, many of them by diving for fish.
He said Quendale Bay, where the ship ran aground, also has a population of sea otters, and there were reports yesterday that some otters already had been seen covered with oil.
The Braer was passing east through the international shipping lanes off the southern tip of the Shetlands early yesterday, en route to the Atlantic Ocean and Canada from Norway, when it lost power.