General Dynamics Electric Boat laid the keel of the US Navy's first Columbia-class nuclear-powered ballistic missile submarine (SSBN) on Saturday, June 4.
The future USS District of Columbia belongs to a class of SSBNs that will be the largest submarines ever built in the United States. Each boat will have a length of 560 feet (170 metres) and a displacement of 20,810 tons (18,878 tonnes) while armament will include 16 ballistic missiles and improved Mk 48 torpedoes.
The future District of Columbia and its sisters will replace the navy's 14 remaining Ohio-class SSBNs beginning in 2027.