The US Navy has awarded two contract modifications to General Dynamics (GD) to continue development of the common missile compartment and to support nuclear submarine repair work.

Under the first $21m modification contract, subsidiary Electric Boat will acquire, produce and test prototype material and equipment.

The equipment will be used to manufacture the common missile compartment for the UK’s Successor ballistic-missile submarine and the US’s Ohio replacement submarine.

The first contract, with a potential value of more than $692m, modifies a $76m contract announced in December 2008 for a common missile compartment.

Electric Boat will carry out submarine repair work under the second $11.9m contract modification.

The second contract forms part of a basic ordering agreement awarded to the company in 2010 to support submarine repair work.