Northrop Grumman has received a $635m contract from the US Navy for engineering, design and overhaul support of both the Los Angeles Class and Seawolf Class submarines.

Under the five-year contract, the company will provide planning and engineering for upgrades and modernisation for all new construction, operation and decommissioning of submarines.

The scope of work for the submarines also includes technical support, management of technical manuals, and drawings and design efforts to support modernisation of the ships.

Work will be carried out at the company’s shipbuilding sector in Newport News, Virginia, and is expected to be complete by 2014.