ANCHORAGE, Alaska -- A Coast Guard flight over a drilling rig that was run aground in storm-tossed waters off Kodiak Island in Alaska on New Year's Eve found no signs of a fuel spill, officials said Tuesday.
However officials monitoring the situation said it will take closer inspection to determine what has happened to the mobile drill rig Kulluk, which was intentionally grounded on rocks off the southeast shore of Sitkalidak Island after its tow lines broke during a heavy storm.
The rig, part of Royal Dutch Shell's effort for offshore drilling in Alaska, is carrying about 150,000 gallons of diesel and about 12,000 gallons drilling fluids, officials said. It was being towed from Dutch Harbor in the Aleutian Islands to Seattle for maintenance.
Complicating assessment of the rig and its condition is a North Pacific storm with winds gusting near 70 mph and swells to 35 feet. The storm is abating slowly; the forecast calls for winds to drop to gusts of up to 40 mph with swells up to 20 feet.
The vessel was carrying a skeleton crew of 17 as it was being towed Monday by two vessels -- the Aiviq, a 360-foot anchor handler, and the Alert, a tugboat. The vessels were in the Gulf of Alaska along Kodiak Island, heading for shelter from the storm.
About 4:15 p.m., the drill rig separated from the Aiviq about 10 to 15 miles off shore and grounding was inevitable, Coast Guard Cmdr. Shane Montoya said late Monday during a news conference in Anchorage.
"Once the Aiviq lost its tow, we knew the Alert could not manage the Kulluk on its own as far as towing, and that's when we started planning for the grounding," he said.
The command center gave instructions to the nine tug crew members to guide the drill ship to the place where it would cause the last environmental damage. The tug cut the unmanned ship loose at 8:15 p.m. and it grounded at 9 p.m. near the north tip of Ocean Bay on uninhabited Sitkalidak Island, southeast of Kodiak Island.
"The Alert was not able to do anything as far as towing the Kulluk but tried to maintain some kind of control," Montoya said.
The drill ship drafts 35 to 40 feet of water. The Coast Guard planned to fly out again to plan a salvage operation and possible spill response. It is carrying 150,000 gallons of diesel and about 12,000 gallons of lube oil and hydraulic fluid, Montoya said.
Susan Childs, Shell's on-scene coordinator, said it was too early to know how the vessel would react to the pounding of the storm when it was aground and stationary.
She was optimistic about its salvage prospects and its chances for staying intact. "The unique design of the Kulluk means the diesel fuel tanks are isolated in the center of the vessel and encased in very heavy steel," she said. "When the weather subsides and it is safe to do so, we will dispatch crews to the location and begin a complete assessment."
The Alaska Department of Environmental Conservation said in a situation report it was unknown if there was a release of any oil product.
The Kulluk is designed for extended drilling in Arctic waters and underwent $292 million in technical upgrades since 2006 to prepare for Alaska offshore exploration. The drill ship worked during the short 2012 open water season in the Beaufort Sea off Alaska's north coast. It's ice-reinforced, funnel-shape hull can deflect moving ice downward and break it into small pieces.
Attached to a drilling prospect, the Kulluk is designed to handle waves 18 feet high. When disconnected from a well, it's designed to handle seas to 40 feet. Garth Pulkkinen of Noble Corp., the operator of the drill ship, said it was never in danger of capsizing.