The US Coast Guard’s only operational heavy icebreaker, the Polar Star, arrived at McMurdo Station, Antarctica, after completing her mission on Feb 6 to cut a channel through 15 miles of Antarctic ice in the Ross Sea and escort supply vessels to the base.
The Polar Star sailed from her homeport of Seattle on Nov 30 last year to assist in the annual delivery of operating supplies and fuel for the National Science Foundation (NSF) research stations in Antarctica during Operation Deep Freeze by carving a navigable path through seasonal and multi-year ice up to 10ft thick.
“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 Captain Michael Davanzo, the commanding officer of the more than 40-year-old vessel.
On Jan 11, the cutter’s progress was slowed after one of her three main gas turbines failed. The crew uses the cutter’s main gas turbine power to break up thick multi-year ice using her propellers. The crew was able to troubleshoot the turbine, finding a programming 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.
On Jan 16, the Polar Star’s shaft seal failed causing flooding in the cutter’s engine room at a rate of approximately 20-gallons a minute. The crew responded quickly, using an emergency shaft seal to stop the flow of freezing Antarctic water into the ship. The crew was able to dewater the engineering space and carry out more permanent repairs to the seal to ensure the watertight integrity of the vessel. There were no injuries to the crew.
The cutter refuelled at McMurdo Station on Jan 18 and continued to develop and maintain the ice channel in preparation for two resupply ships from US Military Sealift Command, the cargo ship Ocean Giant, 15,599gt, and the tanker Maersk Peary, 38,177dwt. The Polar Star escorted the vessels to the ice pier at McMurdo Station, which 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 on Jan 27 and conducted their final escort of the Maersk Peary on Feb 2 and then escorted her safely out of the ice on Feb 6 after her cargo had been transferred.
The Polar Star was due to return to the US last month.