America’s sole heavy icebreaker, the U.S. Coast Guard Cutter Polar Star, returned Monday to its homeport of Seattle following a 105-day deployment to Antarctica that saw on-board fires, ship-wide power failures and other engineering calamities.
The 150-strong Polar Star crew set off on Nov. 27 last year for their sixth deployment in as many years and traveled 11,200-nautical-miles to Antarctica to support Operation Deep Freeze.
Operation Deep Freeze
Deep Freeze is an annual joint military service mission in support of the National Science Foundation, which runs the U.S. Antarctic Program and staffs McMurdo Station, the main U.S. logistics hub in Antarctica. This was the 63rd iteration of the annual operation, which began in 1955.
As in years past, getting the 43-year-old heavy icebreaker to Antarctica was accomplished despite a series of engineering calamities aboard the ship. Commissioned in 1976, Polar Star is operating more than decade beyond her expected 30-year service life. The cutter is scheduled for a service life extension project starting in 2021.
U.S. has only two icebreakers
Upon arrival in McMurdo Sound, Antarctica, the Polar Star broke through 16.5 nautical miles of ice, six to ten feet thick, in order to open a channel to the pier at McMurdo Station. Once the channel was open, the crew refueled Polar Star at McMurdo. At the conclusion of a three day port visit there the ship provided a six-hour familiarization cruise to 156 NSF station personnel.
On Jan. 30, the Polar Star escorted the container ship Ocean Giant through the channel, enabling a 10-day offload of 499 containers with 10 million pounds of goods that will resupply McMurdo Station, Amundsen-Scott South Pole Station and other U.S. field camps for the coming 12 months. The Ocean Giant is an ice strengthened vessel contracted by the U.S. Navy’s Military Sealift Command for Operation Deep Freeze.
Polar Star is one of just two icebreakers currently maintained by the U.S. Coast Guard. The other, the Cutter Healy, is a medium icebreaker based in the Arctic. If a catastrophic event, such as getting stuck in the ice, were to happen to the Healy in the Arctic or to the Polar Star near Antarctica, the U.S. Coast Guard would have no vessels that could be sent to rescue them
By contrast, Russia currently operates more than 50 icebreakers – several of which are nuclear powered.
The Coast Guard is seeking to recapitalize its icebreaking fleet, using a so-called “6-3-1 approach.” Six icebreakers total, three of those to be heavy-duty, and one needed ASAP.
During the transit to Antarctica, one of the ship’s electrical systems began to smoke, causing damage to wiring in an electrical switchboard, and one of the ship’s two evaporators used to make drinkable water failed. The electrical switchboard was repaired by the crew, and the ship’s evaporator was repaired after parts were received during a port call in Wellington, New Zealand.
The impact from ice operations ruptured the cutter’s centerline shaft seal, allowing water to flood into the ship. Ice breaking operations ceased so embarked Coast Guard and Navy Divers could enter the water to apply a patch outside the hull so Polar Star’s engineers could repair the seal from inside the ship. The engineers donned dry suits and diver’s gloves to enter the 30-degree water of the still slowly flooding bilge to effect the vital repairs. They used special tools fabricated onboard to fix the leaking shaft seal and resume ice breaking operations.
The Polar Star also experienced ship-wide power outages while breaking ice in McMurdo Sound. Crew members spent nine hours shutting down the ship’s power plant and rebooting the electrical system in order to remedy the outages.
On Feb. 10, the crew spent nearly two hours extinguishing a fire in the ship’s incinerator room while the ship was approximately 650-nautical-miles north of McMurdo Sound, Antarctica. The fire damaged the incinerator and some electrical wiring in the room was damaged by fire fighting water. There were no personnel injuries or damage to equipment outside the space. Repairs to the incinerator are already scheduled for Polar Star’s upcoming inport maintenance period.
Maintenance cycle repeating
Reserved for Operation Deep Freeze each year, the Polar Star spends the Southern Hemisphere summer breaking ice near Antarctica, and when the mission is complete, the Polar Star returns annually to dry dock in order to complete critical maintenance and repairs in preparation for the next Operation Deep Freeze mission. Once out of dry dock, the ship returns to Antarctica, and the cycle repeats.