Columbia-Class: Key Design Features


Design Features

Class overview
Preceded by: Ohio class
Cost: $109.8 billion for 12 boats (FY2021, projected)
Planned: 12
Type: Ballistic missile submarine (SSBN)
Displacement: 20,810 long tons (submerged)
Length: 560 ft (171 m)
Beam: 43 ft (13 m)
Speed: 20+ knots
Diving Depth: 800+ feet
Installed power: Nuclear reactor
Propulsion: Turbo-electric drive, pump-jet
Range: Unlimited
Complement: 155 (accommodation)
Sensors and processing systems:    Enlarged version of the Virginia-class LAB sonar
Armament: 16 × Trident D5

General Characteristics

Although still evolving, the following are some of the characteristics for the SSBN(X) design:

Advanced Capabilities
The U.S. Navy has also stated that "owing to the unique demands of strategic relevance, SSBN(X)s must be fitted with the most up-to-date capabilities and stealth to ensure they are survivable throughout their full 40-year life span."

Additional reported design features include:

Note the offset axis of the X-rudder planes, with alternating rudders slightly more forward.
GDEB image of the stern section of the USS District of Columbia (SSBN-826).
Columbia-Class Stern Section

Common Missile Compartment (CMC)
As part of the US strategic nuclear deterrence plan, Columbia class SSBNs and the Royal Navy’s Dreadnought Class of SSBNs will carry the Trident II D-5 missile for the first portion of their respective operational lives. Since 2008, the United States and the United Kingdom (U.K.) have been jointly developing a common system to house the tubes that will carry these submarine launched ballistic missiles. Each Common Missile Compartment (CMC) will will hold four missle tubes, and is therefore often called a "Quad-Pack". The Columbia class will hold four Quad-Packs (16 tubes) and the Dreadnought Class will use three Quad-Packs. The U.S. missiles are armed with nuclear warheads maintained by the Department of Energy (DOE).

In addition to the missile tubes, the CMC program also provides systems to support the missiles and the launch equipment, including power, cooling, gas venting, and launch hardware and software. The Navy’s Strategic Systems Program is responsible for CMC development efforts.




Workers stand in the four tube "Quad-Pack" built as part of the CMC Program. (GDEB Photo via US Navy)

Columbia-Class Submarine Size
Columbia-Class Submarines will be the largest U.S. Navy Submarine ever built.

It will be larger than the Ohio-class, the current largest submarine, in terms of submerged displacement.

Columbia sub