The construction of the next-generation American strategic nuclear missile submarine has officially begun: at the Electric Boat factory in Kwonset Point, the “backbone” of the future submarine has been laid.

Rather than laying an actual backbone at the ceremony, the District of Columbia sponsor, the initials of Congresswoman Eleanor Holmes Norton (D-DC), was welded to a steel plate that would be permanently placed on the submarine in a place of honor.

While official construction has only just begun, General Dynamics says it’s 20 percent complete. This is because the submarine’s design is modular and the main sections are built on various Electric Boats and subcontractors. In 2023, the first of the modules will arrive at the new Electric Boat factory in Groton, Massachusetts, for complete assembly.

The District of Columbia will be the first of 12 planned Columbia-class submarines with ballistic missiles.

The Columbia class will have an all-electric pump unit and will be powered by an advanced nuclear reactor that does not require refueling for the entire life of the hull. In addition to missiles, the Mk will carry 48 torpedoes and will be equipped with an expanded version of the LAB sonar used on Virginia-class attack submarines. The case will also have an acoustic structure for minimal sound signature.

The District of Columbia will be valued at approximately $9.15 billion. Its deployment is scheduled for 2030, and its service life will be 42 years.