It is to replace the Ohio class. Attack subs.
Columbia-Class Submarine: The Largest Submarine Built By The U.S. Navy Is A Big Secret
Columbia-Class Submarine: What Do We Know? Lurking secretly in dark waters around the world and holding potential adversaries at risk of nuclear destruction from unknown locations, US Navy’s nuclear-armed ballistic missile submarines offer the backbone of U.S. strategic deterrence.
Undersea strategic deterrence essentially guarantees second-strike retaliatory catastrophic destruction of any adversary who attacks the U.S. with nuclear weapons, thus preventing war by ensuring the complete annihilation of any country that attacks with nuclear weapons. The promise of total destruction, somewhat paradoxically one might say, keeps the peace.
Columbia-Class Submarine – Lurking Threat
This conceptual premise is why, for many years now, the Pentagon has identified the now emerging Columbia-class nuclear-armed ballistic missile submarines as a number one DoD acquisition priority. After years of science and technology, prototyping, and advanced design specs, the U.S. Navy is now building its first Columbia-class submarine, slated to arrive at the end of the decade.
Designed to replace the aging fleet of Ohio-class ballistic missile submarines, which have performed admirably for decades, well beyond their expected service life, the Columbias will introduce a wide sphere of new technological leaps forward in the realm of the undersea.
The innovations woven into the Columbia-class submarines are numerous. Perhaps the most significant of these innovations is the new, ultra-quiet electric drive propulsion system, replacing legacy hydraulic systems.
Among other things, this new drive propulsion system means that Columbia-class submarines will be much harder to detect than existing Ohios, and therefore be better positioned for clandestine strategic deterrence missions.
An electric drive has other advantages as well, as it enables more onboard electrical power, sufficient to sustain onboard command and control, navigational systems, and the energy necessary for many of its technologies.
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Columbias are also being built with a new X-shaped stern intended to improve both maneuverability and quieting for the submarine. Columbias are also built with a “life-of-core” nuclear reactor, which does not need to be dry-docked for lengthy mid-life refueling procedures.
This massively improves operational tempo, deployability, and mission resilience. It is the reason why the Navy plans to build only 12 Columbia-class boats to replace the current fleet of 14 Ohio-class submarines.
Yet another interesting element of the Columbia-class is that it is being engineered with a handful of innovations now integrated into the U.S. Navy’s Block III Virginia-class attack submarines.
These include the integration of a fiber-optic cable linking periscope sights to command and control centers within the boat, removing the need for submariners to stand directly below a periscope. Depending upon how the cable is configured, Commanders can view periscope images from anywhere within the submarine.
An equally if not more impactful Virginia-class Block III innovation is the “fly-by-wire” navigational system also built into the Columbias.