The Polar Sea has been out of service for months with three failed motors, and is now undergoing an initial inspection to determine the cause and extent of damage, said John Lockwood, director of marketing and business development at Todd Pacific Shipyards in Seattle.

The 399-foot icebreaker was docked in early January at the shipyard on Harbor Island in West Seattle. It returned March 31, 2004, from a 5½-month deployment in the Antarctic, breaking ice for ships to resupply McMurdo Research Station, the logistics hub for the U.S. Antarctic Program. Its efforts allowed the delivery of more than 8 million gallons of fuel and 11 million pounds of cargo.

The vessel operates as part of the Coast Guard's Polar Ice Program, which also include its sister ship, the Polar Star, and the icebreaker Healy, all based in Seattle. While the Healy operates primarily in the polar north, the Polar Star and Polar Sea mostly work near Antarctica.

The Polar Sea was built in 1977, and damage to its motors could be the long-term effect of years of operations in ice-covered waters.

"It's just a combination of wear and tear and the extremely adverse environment in which the ships operate each year," Lockwood said of the problem.

The ship's three main electric motors, which drive the propellers, get their power from three gas turbines and up to six diesel engines that help as the cutter plows through ice. The ship's reinforced hull is shaped to ride up on the ice, which breaks under the ship's weight. At a continuous speed, the Polar Sea is capable of breaking ice 6 feet thick, or 21 feet thick if it backs up and rams the ice.

"It's like backing your car up and driving it into a building," said Lockwood, a former rear admiral with the Coast Guard.

During the "open and inspect" process, Lockwood said Todd Shipyards will determine what condition the motors are in and the repairs necessary. He was optimistic the motors can be repaired.

Coast Guard officials said there is no immediate timeline for repairs, nor is there a final cost.

"We are looking at the ship to see what maintenance the ship needs and what alternatives to use," said Lt. Cmdr. Glynn Smith, a public affairs officer with Coast Guard Pacific Area in Alameda, Calif., which oversees the polar program. "We are definitely working to try and achieve some low-cost alternatives."

The Coast Guard deploys an icebreaker each year to Antarctica to break ice and escort supply ships to McMurdo.

In 2003, ice conditions were some of the worst in 50 years, and the Polar Sea required assistance from the Healy to clear a channel to the station. Without the Polar Sea this year, the Russian icebreaker Krasin was brought in to work with the Polar Star, cutting a 94-mile path through ice 10 feet thick in areas.

The ice pack was nearly double its normal 48 mile width after building up behind the world's biggest iceberg that has blocked wind and water currents that usually break up ice floes in McMurdo Sound.

Polar Sea has a crew of about 180 and carries two Coast Guard HH-65A helicopters during polar deployments for science and logistics support. The icebreaker accommodates as many as 35 scientists and technicians and is equipped to function as a scientific platform with five internal laboratories. It has room for an additional seven portable science laboratories on deck.