General Dynamics Electric Boat (GDEB) has received a contract modification from the US Navy for the Columbia-class ballistic missile submarine (SSBN) programme.

Total value of the new modification contract is approximately $313.9m.

The modification is to the integrated product and process development (IPPD) contract previously awarded by the US Naval Sea Systems Command.

As part of the latest contract, GDEB will support the industrial base development and expansion for the construction of the Columbia-class submarines.

The company will also support efforts related to acquisition, production and delivery of strategic weapon support system kits for the UK.

Additionally, GDEB will continue to work in collaboration with its sub-contractors and vendors to boost the production capability to meet the increased requirements related to the Columbia-class SSBN programme.

GDEB president Kevin Graney said: “Ballistic-missile submarines are the critical, survivable leg of our nation’s nuclear arsenal and Columbia is the Navy’s top acquisition priority.

“We are grateful for the steadfast trust and support the navy and Congress have in Electric Boat as we continue the work, we began 15 years ago to deliver Columbia and the next 60 years of deterrence for our nation.”

The 560ft-long Columbia-class submarines will feature a life-of the-ship fuel core, which will provide sufficient power for the submarine’s entire service life. It will increase the deployment period of the submarine.

GDEB is under contract with the US Navy to construct Columbia-class submarines to replace the Ohio-class ballistic submarines.

In 2020, the company received a contract for constructing the first and second SSBN of the Columbia-class.

The company is expected to handover the first submarine to the US Navy in 2027.