The conical drilling unit Kulluk sits grounded 40 miles (64 kms) southwest of Kodiak City, Alaska in this U.S. Coast Guard handout photo taken January 3, 2012.
An oil drilling rig that ran aground off an uninhabited island in the Gulf of Alaska last week was being towed in stable condition Monday, with no sign of environmental impact or fuel leakage, recovery workers said.
Salvage crews secured tow lines to the Kulluck drillship, a Royal Dutch Shell rig, prior to refloating the 266-foot diameter vessel late Sunday, according to the recovery and response team. They began towing it a few hours later to Kiliuda Bay, where they plan to anchor it.
The escort ships were using infrared sensors to examine the water for any sign of discharge from the vessel, and so far, none had been reported. The Coast Guard plans to send aircraft over the Kulluk at first light, "to look for any signs of sheen, weather permitting."
The rig is carrying about 143,000 gallons of diesel fuel and about 12,000 gallons of lube oil and hydraulic fluid, according to federal on-scene response coordinator, Coast Guard Capt. Paul Mehler.
More than 730 people are now involved in the response and recovery operation, the Coast Guard said.
The Kulluck broke loose of its tether to a tug boat on New Year's Eve in "near hurricane" conditions and ran aground on the sand and gravel shore of Sitkalidak Island, 40 miles southwest of Kodiak City, Alaska, the U.S. Coast Guard said.
U.S. Coast Guard via Reuters
A salvage team aboard the conical drilling unit Kulluk moves lines from an emergency towing system in this U.S. Coast Guard handout photo taken January 2, 2013.
Environmentalists have seized on the accident as proof Arctic Ocean oil operations are too risky. The drilling rig was being moved from its Arctic drilling grounds to Seattle for maintenance, and had passed through the Bering Sea and was set to cross the Gulf of Alaska when the storm hit.
“Oil companies keep saying they can conquer the Arctic, but the Arctic keeps disagreeing with the oil companies,” Rep. Ed Markey, D-Mass., a member of the Natural Resources Committee, said in a statement.
A Shell official said the drilling rig was built with a double-sided hull of reinforced steel that is three inches thick. It recently had undergone $292 million in improvements before being put into service for a short time this summer in the Beaufort Sea off Alaska's north coast.
Sean Churchfield, operations manager for Shell Alaska, said an investigation will be conducted into the cause of the accident. He did not know whether the findings would be made public.
The Coast Guard said it would investigate too and make its findings public.
The Associated Press contributed to this report.
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