The United States’ only operational heavy icebreaker suffered both flooding and engine failure during this year’s icebreaking mission to Antarctica.
Despite these challenges, however, the USCGC Polar Star completed its Antarctic mission this week in support of National Science Foundation (NSF) after cutting a resupply channel through 15 miles of ice in the Ross Sea and escorting supply vessels to the continent.
The Polar Star sailed from Seattle in November to assist in the annual delivery of supplies and fuel for NSF research stations in Antarctica, part of a yearly mission known as Operation Deep Freeze. Although the sea ice extent was not as bad as it has been in years past, the vessel at times had to break through ice as much as 10-feet thick. The mission was further complicated by engineering complications, the Coast Guard admitted on Wednesday.
“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.”
The first challenge came on January 11 when the Coast Guard says one of the cutter’s three main gas turbines failed. The crew was able to troubleshoot the turbine by finding a programming issue between the engine and the cutter’s 1970s-era electrical system, and they were able to continue the mission without the turbine.
Later, on January 16, the Coast Guard says the 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, in this case, controlled the flooding using an emergency shaft seal to stop the ingress of water into the vessel. The Coast Guard reports that the crew was able to dewater the engineering space and effect more permanent repairs to the seal to ensure the watertight integrity of the vessel, and there were no injuries as a result of the malfunction.
Although both issues were resolved without need of additional help, the incidents highlight the growing need for the U.S. Coast Guard to modernize its icebreaking capacity.
Built more than 40 years ago, the 399-foot Polar Star is the only operational heavy icebreaker in the U.S. fleet. With a crew of nearly 150 people, it weighs 13,500 tons and uses 75,000 horsepower to break ice up to 21 feet thick.
The Coast Guard is currently in the process of procuring a single new heavy polar icebreaker, however, construction is not expected to begin until 2019 at the earliest, and the necessary funds have still not been appropriated. Delivery of the vessel is not expected until 2023, based on current estimates.
“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.
During this year’s mission, the USCGC Polar Star 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 on January 27 and February 2, respectively.
The Polar Star is expected to return to the U.S. in March 2018.