The US Navy has awarded a modification contract to General Dynamics (GD) Electric Boat to provide three backup photonics masts for Virginia Class submarines.

Under the $32.9m contract, the company will provide non-hull-penetrating photonics masts which will replace the traditional periscopes used on submarines.

Each mast incorporates an HDTV digital colour camera, an infrared camera and a laser rangefinder.

The mast cameras record information digitally before transmitting it through fibre optics into the ship and processing it with on-board image processors.