USCGC Polar Sea (WAGB-11)

USCGC "Polar Sea" (WAGB-11) is a United States Coast Guard Heavy Icebreaker. Commissioned in 1978, the ship was built by Lockheed Shipbuilding and Construction Company of Seattle along with her sister ship, "Polar Star" (WAGB-10).

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

Machinery

"Polar Sea" is an outstanding Polar icebreaker with exceptional hull design, power, strength and weight. The design, which was the result of three years of research and testing, incorporates a number of innovative features that affect nearly every aspect of operations. Equipment on board is highly sophisticated. "Polar Sea" 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 Sea'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 (13,425 kilowatts) and the gas turbine plant a total of 75,000 shaft horsepower (56 MW).

"Polar Sea" has other unique engineering features designed to aid in icebreaking. An installed heeling system can rock the ship to prevent getting stuck in the ice. The system consists of three pairs of connected tanks on opposite sides of the ship. Pumps transfer a tank's contents of 35,000 US gallons (132 m³) to an opposing tank in 50 seconds and generate 24,000 foot·tons force (65 MN·m) of torque on the ship. That goes a long way in rocking "Polar Sea" loose from any tight spots.

Hull design and strength

"Polar Sea" 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 designed to ram ice is 1¾ inches thick (44 mm) in the bow and stern sections, and 1¼ inches thick (32 mm) amidships. The hull strength is produced almost entirely from the massive internal support structure. "Polar Sea'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 Sea" 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 Sea" is able to ram her way through ice up to 21 feet (6.4 m) thick and steam continuously through 6 feet (1.8 m) of ice at 3 knots (6 km/h).

Crew

Operations in the remote, hazardous and unforgiving polar regions make it necessary for the crew of "Polar Sea" 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. 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. There is a crew of 15 officers and 126 enlisted. The ship has four sizable lounges, a library (recently converted), a gymnasium (in an engineering space), and a small ship's store. It also has its own U.S. Post Office, satellite pay telephones, amateur radio equipment, photo lab, and movie library.

Missions

"Polar Sea" 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 Sea" 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.

Aircraft carried

"Polar Sea" carries 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 comes from the Polar Operations Division at Coast Guard Aviation Training Center, Mobile, Alabama.

Notable operations

In nautical history, "Polar Sea" holds several notable records. It is one of only three ships that has ever completely transited the Arctic Ocean and circumnavigated North America. On August 22 1994, Polar Sea was one of first two North American surface vessels to reach the North Pole.

Refit plans

On March 25, 2008 the "Navy Times" described options for the refit or replacement of the older Polar Class vessels.cite news
url=http://www.navytimes.com/news/2008/03/coastguard_icebreakers_032408w/
title=CG steps up bid to rescue icebreaker funding
publisher=Navy Times
author=Philip Ewing
date=Tuesday March 25, 2008
accessdate=2008-03-01
quote= [http://www.webcitation.org/query?url=http%3A%2F%2Fwww.navytimes.com%2Fnews%2F2008%2F03%2Fcoastguard_icebreakers_032408w%2F&date=2008-06-17 mirror] ] The four options laid out were::

On June 16, 2008 the US Coast Guard announced that the Polar Sea would undergo a $6.3 million refit in the Todd Shipyards in Seattle.cite news
url=http://www.earthtimes.org/articles/show/todd-shipyards-corporation-announces-us,434571.shtml
title=Todd Shipyards Corporation Announces U.S. Coast Guard Exercise of Option on Overhaul of USCGC Polar Sea (WAGB-11)
publisher=Earth Times
date=June 16, 2008
accessdate=2008-06-01
quote=] The refit was expected to be completed by September 2008.

References

External links

* [http://www.uscg.mil/pacarea/cgcpolarsea USCGC Polar Sea home page]
* [http://www.uscg.mil/datasheet/icepolr.asp Polar Class Icebreaker vessel vital statistics]