May 21, 2005
Rudder cracks found in Alaska Class tankers
BP's two new double-hulled Alaska Class tankers are out of service following discovery of cracks in the rudders of both vessels.
The Anchorage Daily News reports Anil Mather--president of Alaska Tanker Co. which operates the ships--as saying that the cause of the cracks remains a mystery.
The Anchorage Daily News story, reported by Wesley Loy, says that Alaskan Frontier is expected to be out of service for several weeks pending repairs to cracks in both its rudders.
Alskan Frontier was the first of the Alaska Class ships to be delivered by NASSCO. It entered service last August.
Divers discovered the rudder cracks during a scheduled inspection of the Alaskan Frontier last Saturday, the Anchorage Daily News quotes Mathur as saying. The inspection turned up several cracks in its rudders, the largest measuring 9 feet long, says the newspaper.
A subsequent check of the newer sister ship, the Alaskan Explorer, found three cracks on one of its rudders, the longest measuring 15 inches.
Alaskan Frontier and Alaskan Explorer are the first of four Alaska Class tankers ordered from NASSCO. Two sister ships are under construction at the yard and BP has options for two more.
The ships' design places strong emphasis on environmental safety and redundancy. In addition to a double-hull, the ships have twin diesel-electric propulsion systems in segregated engine rooms, two propellers and twin rudders. Cargo piping is installed in the cargo tanks instead of on-deck to reduce the chance of accidental oil spills. They are built to ABS class.
The Anchorage Daily News story quotes Mathur as commenting that "when you come up with brand new designs, you can have new problems."
"The important thing was, this was not a catastrophic failure," Mathur is quoted as saying. "This is embryonic. The problem has been caught very, very early."
The newspaper says the Alaskan Explorer is expected to return to service by week's end, once the cracks are repaired. As a precaution, a tug will escort the unladen ship when it enters Prince William Sound.
Repairs to the Alaskan Frontier will take longer. Reportedly, the ship will likely will be out of service until July.