USCGC Polar Star (WAGB-10) - Design

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 ramming 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 design to ram 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; then the bow is levered through the ice like a giant sledgehammer.

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 ram her way 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.