USCGC Polar Star (WAGB-10)

USCGC Polar Star (WAGB-10) is a United States Coast Guard Heavy Icebreaker. Commissioned in 1976, the ship was built by Lockheed Shipbuilding and Construction Company of Seattle, Washington along with her sister ship, Polar Sea (WAGB-11).

Homeported in Seattle, Polar Star and Polar Sea operate under the control of Pacific Area and coordinate their operations through the Ice Operations Section of the United States Coast Guard.

Design
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 have greatly reduced staffing requirements.

Polar Star's three shafts are turned by either a diesel-electric or gas turbine power plant. 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).

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 1-3/4 inches (45 mm) thick in the bow and stern sections, and 1-1/4 inches (32 mm) thick amidships. The hull strength is produced almost entirely from the massive 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.

With such a sturdy hull and high power to back it up, the 13,000-ton (13,200 metric ton) Polar Star is able to break through ice up to 21 feet (6 m) thick and steam continuously through 6 feet (1.8 m) of ice at 3 knots (6 km/h).



Polar Star has other unique engineering features designed to aid in icebreaking. At one point, 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) to an opposing tank in 50 seconds and generate 24,000 foot-tons (65 MN·m) of torque on the ship. This system has since been removed due to maintenance issues.

Duty on an icebreaker is long and strenuous, especially when it involves being away from homeport for up to eight months out of the year. Careful consideration has been given to meet the needs of Polar Star's crew of 15 officers and 126 enlisted. The ship has four sizable lounges, a library, a gymnasium, and a small ship's store. It 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. Bright colors and modern decor differ sharply from traditional military shipboard drabness.

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 at Coast Guard Aviation Training Center, Mobile, Alabama, but POPDIV has since been disbanded due to an overhaul on the HH-65 Dolphin airframe.

Operations
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, vulcanology, oceanography, sea-ice physics and other disciplines.

Operations in the remote, hazardous and unforgiving polar regions make it necessary for the crew of Polar Star to be highly self-sufficient. The crew consists of personnel trained in navigation, engineering, welding, machinery repair, electronics, boat handling, firefighting, damage control, diving, medicine, and nearly every other kind of special skill that could possibly be needed.

Reserve status, overhaul and reactivation
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 June 30, 2006, the USCG placed the Polar Star in "Commission-Special" status in Seattle, WA. This caretaker status required a reduced crew of 34 to keep the ship ready for a possible return to the ice. In 2009, the NSF announced that they would end funding for maintaining the Polar Star

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 the 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.

In March 2010, United States Coast Guard Adm. Thad Allen announced that the Polar Star would receive a $62 million overhaul at Seattle's Todd Pacific shipyard. The United States Coast Guard planned for the overhaul to be complete by December 2012. On 14 December 2012, The United States Coast Guard announced the reactivation of the Polar Star. The overhaul of the Polar Star, completed by Vigor Industrial shipyard (formerly Todd Pacific shipyard), cost US$57 million. The Polar Star will undergo testing in 2013 prior to returning to service.