US icebreaker Polar Star returns home from challenging Antarctica mission
The US Coast Guard’s only heavy icebreaker, USCGC Polar Star, returned to its homeport in Seattle on March 16 after completing a mission plagued by several “engineering challenges”.
The crew of the cutter overcame flooding and engine failure to accomplish their mission supporting operation Deep Freeze, the US military operation to resupply the US Antarctic Program.
Polar Star supported the National Science Foundation (NSF) by cutting a resupply channel through 15 miles of Antarctic ice in the Ross Sea and escorting supply vessels to the continent.
“Although we had less ice this year than last year, we had several engineering challenges to overcome to get to the point where we could position ourselves to moor in McMurdo,” said Capt. Michael Davanzo, the commanding officer of the Polar Star. “Our arrival was delayed due to these challenges, but the crew and I are certainly excited to be here. It’s a unique opportunity for our crewmembers to visit the most remote continent in the world, and in many respects it makes the hard work worth it.”
On Jan. 16, Polar Star’s shaft seal failed causing flooding in the cutter’s engine room at a rate of approximately 20-gallons per minute. The crew responded quickly, using an emergency shaft seal to stop the flow of freezing, Antarctic water into the vessel. The crew was able dewater the engineering space and effect more permanent repairs to the seal to ensure the watertight integrity of the vessel. There were no injuries as a result of the malfunction.
Flooding was not the only engineering challenge the crew of Polar Star faced during their trek through the thick ice. On Jan. 11, their progress was slowed after the one of the cutter’s three main gas turbines failed. The crew uses the cutter’s main gas turbine power to breakup thick multi-year ice using its propellers. The crew was able to troubleshoot the turbine finding a programing issue between the engine and the cutter’s 1970s-era electrical system. The crew was able to continue their mission in the current ice conditions without the turbine.
“If the Polar Star were to suffer a catastrophic mechanical failure, the Nation would not be able to support heavy icebreaker missions like Operation Deep Freeze, and our nation has no vessel capable of rescuing the crew if the icebreakers were to fail in the ice,” said Vice Adm. Fred Midgette, commander, U.S. Coast Guard Pacific Area in Alameda, California. “The crewmembers aboard Polar Star not only accomplished their mission, but they did so despite extreme weather and numerous engineering challenges. This is a testament to their dedication and devotion to duty.”
The cutter refueled at McMurdo Station Jan. 18 and continued to develop and maintain the ice channel in preparation for two resupply ships from U.S. Military Sealift Command, Ocean Giant and Maersk Peary. The crew of Polar Star escorted the vessels to the ice pier at McMurdo Station, an evolution that requires the cutter to travel about 300 yards in front of the supply ships to ensure they safely make it through the narrow ice channel. The crew escorted the Ocean Giant to the ice pier at McMurdo Jan. 27 and conducted their final escort of the Maersk Peary to Antarctica Feb. 2. The crew escorted Maersk Peary safely out of the ice Feb. 6 after supply vessel’s crew transferred their cargo.
Polar Star is homeported in Seattle and carries approximately 150 crewmembers, 1.5 million gallons of fuel and enough food stores to last one year in the ice should it be necessary. Polar Star is 399-feet long, 13,500 tons, 84-feet wide, has a 34-foot draft (same as an aircraft carrier), 75,000 horse power and nine engines (six diesels, three jet-turbines). The ship can break continuously through six feet of ice and up to 21 feet of ice by backing and ramming. The 41-year-old cutter is expected to reach the end of its extended service life by 2023.
The US Coast Guard plans to award a contract for design and construction of a new heavy polar icebreaker in fiscal year 2019.