Construction began in Quonset Point and will later transfer to the main Electric Boat shipyard in Groton, Connecticut, with hull sections transported by the specially built Ocean Transport Barge Holland, named after Irish immigrant John Holland, designer of the US Navy’s first submarine. The submarine will be completed and launched in Groton.
The Columbia class will eventually consist of at least twelve submarines, replacing fourteen Ohio-class boats currently in service, four of which were modified to carry Tomahawk cruise missiles and support special operations. The retirement of Ohio-class vessels, each armed with 24 UGM-133 Trident II D5 missiles, is scheduled to begin in 2027, coinciding with the entry into service of the lead ship, USS District of Columbia.
Columbia-class submarines will carry 16 Trident II D5LE ballistic missiles, representing about 70 percent of the United States’ nuclear triad. Once all are commissioned, they are expected to conduct deterrent patrols into the 2080s.
Each vessel will measure 171 metres and displace 20,810 tonnes, making them the largest submarines ever built in the United States, compared with the Ohio class at 170 metres and 18,400 tonnes. Their reactors will not require refuelling during their planned service life, reducing operating costs and maximising patrol endurance.
In addition to ballistic missiles, the submarines will be armed with Lockheed Martin Mk 48 Mod 7 CBASS torpedoes, and equipped with advanced acoustic qualities and modern sensors derived from the Virginia-class attack submarines. A distinctive feature will be the X-shaped stern diving planes, used for the first time on a US nuclear submarine, combined with a pump-jet propulsion system directly driven by an electric motor powered by steam-generated turbogenerators.
