General Dynamics' (GD) subsidiary Electric Boat has received an $18.9m contract modification from the US Navy to continue developing the Virginia Payload Module (VPM).

The contract modification is part of an overall engineering contract worth $965m, which was awarded in 2010, to support the Virginia-class submarine programme.

With this contract modification, the cumulative value of the overall Virginia-class Lead Yard Services contract amounts to $1.46bn.

"The hull will be extended by up to 80ft and strike capacity will improved by 230%."

Under the contract, GD will provide two VPM pre-production setups to support the manufacturing start of the VPM payload tubes.

The VPM features four large-diameter payload tubes in a new hull section, which will be inserted in Virginia-class submarines to help retain their stealth and manoeuvrability.

Each of the payload tubes is capable of launching seven Tomahawk cruise missiles.

With the new section, the hull will be extended by up to 80ft and strike capacity will improved by 230%, at a cost increase of less than 15%.

Nearly 28 Virginia-class submarines have been either delivered, are authorised for construction, or are under contract for the US Navy.

The US Navy’s Virginia-class submarines will have a 377ft hull and displacement capacity of 7,800t. They can operate at a speed of more than 25k while being submerged, and can dive to over 800ft deep.

The Virginia-class submarines are designed to detect and destroy enemy submarines and surface ships; engage in intelligence, surveillance, and reconnaissance (ISR) missions; mine warfare and battle group operations.

Image: The US Navy’s Virginia-class submarine, USS John Warner, with its Virginia Payload Tube hatch open. Photo: courtesy of US. Navy photo by Mass Communication Specialist Seaman Casey Hopkins/Released.