The US Navy has awarded a contract to General Dynamics Electric Boat to perform upgrade works on the nuclear submarine New Hampshire (SSN-778).

Under a $23.7m contract, the company will provide post-shakedown availability services for the submarine, which includes maintenance, repairs, alterations and testing.

The refit work will be carried out in Groton and is expected to begin this month, with scheduled completion in September 2010.

The USS New Hampshire (SSN-778) is the fifth Virginia-class nuclear-powered attack submarine, commissioned in 2008.

General Dynamics Electric Boat in collaboration with Northrop Grumman received contracts to produce a total of 18 Virginia-class submarines of the planned 30 ships.