USCGC Polar Star (WAGB-10)

Polar Star uses four different methods of electronic navigation to overcome the difficulties of high-latitude operations, and a computerized propulsion control system to effectively manage six diesel-powered propulsion generators, three diesel-powered ship's service generators, three propulsion gas turbines, and other equipment vital to the smooth operation of the ship. The extensive use of automation and low maintenance materials has greatly reduced staffing requirements.[4]

Polar Star's three shafts are turned by either a diesel-electric or gas turbine prime mover. Each shaft is connected to a 16-foot (4.9 m) diameter, four-bladed, controllable-pitch propeller. The diesel-electric plant can produce 18,000 shaft horsepower (13 MW), and the gas turbine plant a total of 75,000 shaft horsepower (56 MW).[4]

Polar Star has sufficient hull strength to absorb the high-powered ice breaking common to her operations. The shell plating and associated internal support structure are fabricated from steel that has especially good low-temperature strength. The portion of the hull designed to break ice is 1.75 inches (44 mm) thick in the bow and stern sections, and 1.25 inches (32 mm) thick amidships. The hull strength is produced almost entirely from the internal support structure. Polar Star's hull shape is designed to maximize icebreaking by efficiently combining the forces of the ship's forward motion, the downward pull of gravity on the bow, and the upward push of the inherent buoyancy of the stern. The curved bow allows Polar Star to ride up on the ice, using the ship's weight to break the ice.[4]

The 13,000-ton (13,200-metric ton) Polar Star is able to break through ice up to 21 feet (6.4 m) thick by backing and ramming, and can steam continuously through 6 feet (1.8 m) of ice at 3 knots (5.6 km/h).[4]

Polar Star alongside her sister ship USCGC Polar Sea near McMurdo Station, Antarctica.

In the past, an installed heeling system could rock the ship to prevent getting stuck in the ice. The system consisted of three pairs of connected tanks on opposite sides of the ship. Pumps transferred a tank's contents of 35,000 US gallons (133 m³ (4,700 cu ft)) to an opposing tank in 50 seconds and generate 24,000 foot-tons (65 MN·m) of torque on the ship.[4] This system has since been removed due to maintenance issues.

The crew of 15 officers and 126 enlisted have access to four sizable lounges, a library, a gymnasium, and a small ship's store. The ship also has its own U.S. Post Office, satellite pay telephones, amateur radio equipment, a computer lounge (for Internet access, distance learning, et cetera), and movie library.

Polar Star can accommodate two HH-65 Dolphin helicopters during major deployments. They support scientific parties, do ice reconnaissance, cargo transfer, and search and rescue as required. The Aviation Detachment used to come from the Polar Operations Division (POPDIV) at the Coast Guard Aviation Training Center in Mobile, Alabama, but POPDIV has since been disbanded due to an overhaul on the HH-65 Dolphin airframe.

The upward angle of Polar Star's bow is designed so that the hull rides up onto the ice surface during icebreaking operations. Subsequently the ship's weight and forward motion combine to fracture the ice.

Polar Star has a variety of missions while operating in polar regions. During Antarctic deployments, the primary missions include breaking a channel through the sea ice to resupply the McMurdo Research Station in the Ross Sea. Resupply ships use the channel to bring food, fuel, and other goods to make it through another winter. In addition to these duties, Polar Star also serves as a scientific research platform with five laboratories and accommodations for up to 20 scientists. The "J"-shaped cranes and work areas near the stern and port side of ship give scientists the capability to do at-sea studies in the fields of geology, volcanology, oceanography, sea-ice physics, and other disciplines.[4]

The crew consists of personnel trained in navigation, engineering, welding, machinery repair, electronics, boat handling, firefighting, damage control, underwater diving, medicine, and other special skills.

Under a 2006 law, since the vessels were designated primarily as research vessels, the National Science Foundation pays for and runs the United States' ice breaking vessels, using Coast Guard crews. On 30 June 2006, the USCG placed Polar Star in "Commission-Special" status in Seattle. This caretaker status required a reduced crew of 44 to keep the ship ready for a possible return to the ice. In 2009, the NSF announced that they would end funding for maintaining Polar Star.[7]

A 26 February 2008 report by the Congressional Research Service estimated a US$400 million cost for a 25-year service life extension refit for Polar Star, a US$56 million cost for an 8 to 10-year service life extension refit or US$8.2 million cost for a single season service life extension refit.[7]

In March 2010, United States Coast Guard Admiral Thad Allen announced that Polar Star would receive a $62 million overhaul, to be complete by December 2012.[8] On 14 December 2012, The United States Coast Guard announced the reactivation of Polar Star. The overhaul of Polar Star took four years and was completed by Seattle's Vigor Industrial shipyard (formerly Todd Pacific shipyard), cost US$57 million. The 34-year-old ship would undergo testing in 2013 before once again plying the frozen Arctic regions. Polar Star was back in operation in late 2013, and assigned to Antarctic operations as part of Operation Deep Freeze in early 2014.[9]

The icebreaker was dispatched from Sydney on January 4, 2014 to attempt a rescue of the Russian research ship Akademik Shokalskiy and Chinese icebreaking research vessel Xuě Lóng trapped at that time in Antarctic ice, the former since 24 December 2013.[10] However, on 8 January 2014 the Australian Maritime Safety Authority confirmed that Polar Star had been released to scheduled duties as both vessels had broken free and were proceeding to open water.[11]

In February 2015 Polar Star was involved in the rescue of the Australian fishing vessel Antarctic Chieftain, towing the ship and 27 crew to safety, through ocean ice and snow nearly 20 feet (6.1 m) deep in the Southern Ocean.[12]

In February 2017, fire crews from Polar Star were made available to help the New Zealand Fire Service and NZDF Fire Crews in fighting against the Christchurch Port Hills Fires in Christchurch, New Zealand.

Polar Star is the only ship in the United States' fleet large enough to break the heavy sea ice to access McMurdo, the U.S. research station in Antarctica.[13] However, as of 2017, this 40-year-old vessel is sometimes referred to as a "rust bucket" by members of her crew, signalling a need for further overhaul or replacement.[14] Some spare parts have become so hard to find that crew members are reportedly sourcing them from eBay.[15]

During the 2017-2018 Antarctic season Polar Star suffered serious technical problems. On January 11, 2018 one of the cutter's three main gas turbines failed; although these are used to provide the power required for breaking up multiyear ice, local conditions allowed the ship to continue with only two turbines. Five days later a shaft seal failed, flooding the engine room; the crew were able to effect repairs and pump out the flooded space. The supply mission to McMurdo was successfully completed.[16]

On February 10, 2019 the crew of Polar Star battled a nighttime blaze for almost two hours before it was extinguished. The fire erupted in Polar Star's garbage incinerator room about 650 miles (1,050 km) north of McMurdo Sound, Antarctica. No one was injured.[17]

• This article incorporates text from the public domain Dictionary of American Naval Fighting Ships.
•  This article incorporates public domain material from websites or documents of the United States Coast Guard.
• U.S. Department of Homeland Security. United States Coast Guard Historian's Office

• Baker, A. D. (1998). The Naval Institute Guide to Combat Fleets of the World 1998–1999. Annapolis, Maryland, USA: Naval Institute Press. ISBN 1-55750-111-4.
• Moore, John (1985). Jane's Fighting Ships 1985–86. London: Jane's Yearbooks. ISBN 0-7106-0814-4.

Wikimedia Commons has media related to USCGC Polar Star (WAGB-10).

• 399-foot Polar Class Icebreakers (WAGB) vessel statistics
• Arctic Exploration Online