General Dynamics (GD) Electric Boat has been awarded a $115.3m contract modification to provide additional lead-yard services for the US Navy's Virginia-class nuclear-powered attack submarines.

The new cost-plus-fixed-fee contract follows the original $431m deal that was awarded last year, and will also see the company carry out various development studies and design efforts relating to the vessels.

GD have agreed to provide lead-yard services for the US Navy submarines to help maintain, update and support the vessel’s design, as well as related drawings and data for each ship.

The contractor will also be responsible for providing all the engineering and related lead-yard services required for the direct maintenance and support of the Virginia-class vessels' specifications.

"The new cost-plus-fixed-fee contract follows the original $431m deal that was awarded last year, and will also see the company carry out various development studies and design efforts."

The development studies will primarily focus on the submarine’s design and design improvements, preliminary and detail component and system design, as well as the integration of system, design, test, logistics and production engineering.

In addition, GD will carry out all the research and development work necessary to evaluate new technologies for potential installation on-board the US Navy vessels, including the Virginia Payload Module.

The majority of the work is set to be conducted in Groton, Connecticut, while the remaining tasks will be carried out in Newport and Quonset Point in Rhode Island, US.

Work on the project is expected to be completed by October.

GD Electric Boat has also secured a $40.65m undefinitised contractual action (UCA) for a previously awarded contract to perform Phase II of the Virginia-class main propulsion machinery (MPM) control system redesign, as part of a separate development.