Columbia-class ballistic missile submarines (SSBNs) are being constructed by General Dynamic subsidiary Electric Boat for the US Navy in collaboration with Newport News Shipbuilding.

Newport News Shipbuilding cut the first steel plate for the lead submarine in class, Columbia (SSBN 826), in May 2019. The boat is scheduled to be delivered in 2027. The US Navy is expected to receive 12 Columbia-class submarines, which will replace its Ohio-class submarines.

The new submarines will support the US strategic deterrent mission, as the SSBN fleet of the US Navy carries 70% of the nation’s operational nuclear weapons.

Columbia-class submarine programme details

The US Navy placed a $5bn detailed design contract with General Dynamics Electric Boat for the Columbia-class submarine programme in September 2017. General Dynamics Electric Boat awarded a $468m subcontract to Newport News Shipbuilding to support the construction of the submarines in December 2017.

Newport News Shipbuilding is responsible for engineering analysis, development of components, detail planning, and technical services.

Electric Boat acts as the prime contractor for the submarine programme, with 80% of the work being performed by Electric Boat and the remaining 20% being delivered by Newport News Shipbuilding. The two shipbuilders will engage multiple vendors and suppliers to perform the work.

Preliminary construction works began at Electric Boat’s facility in Quonset Point, Rhode Island, US, in 2017, while final assembly and trials of the submarines will be performed at Electric Boat’s shipyard in Groton in 2024.

In May 2019, Electric Boat received a $497m contract modification to develop and expand submarine industrial base in support of the Columbia-class and the Nuclear Shipbuilding enterprise.

Design and features

Columbia-class ballistic missile submarines will feature X-shaped stern control surfaces and sail-mounted dive planes. The hull will be covered with an anechoic coating.

The missile compartment will integrate four factory-made missile tubes equipped with a quad pack each. It will be built and assembled in parallel with the hull and integrated into the hull along with decks, other equipment and systems.

Each submarine will measure 170.7m-long and will have a diameter of 13.1m. The submerged displacement of the boat will be 20,810t.

Weapon systems

Each submarine will be installed with 16 missile tubes for launching 16 Trident II D5 (LE) submarine-launched ballistic missiles (SLBM).

Powered by three solid-fuel rocket motors, the three-stage missile can carry up to 14 multiple independently targetable re-entry vehicles with W88 or W76 thermonuclear warheads to a distance of 12,000km.

Sensors fitted to the Columbia-class ballistic missile submarines

The submarines will feature a large aperture bow (LAB) sonar system and can also be outfitted with a submarine warfare federated tactical system (SWFTS) for integrating sonar, optical imaging, and weapons control systems.

The horse-shoe-shaped LAB sonar is made of special composite materials to enhance the transfer of acoustic signals.

Propulsion and performance

The electric-drive propulsion system on board the Columbia-class ballistic missile submarines will include an electric motor driving the propeller of the boat. It is expected to be quieter than a mechanical drive system.

Submarines will use a nuclear reactor to generate energy, which will be converted into electrical power to fuel the electric propulsion motor.

The propulsion system will enable the submarine to sail at a speed of more than 20k and operate at a depth of 800ft.

Each submarine in the Columbia-class is expected to carry out 124 deterrent patrols during its service life of 42 years.