Ohio-Class Cruise Missile Submarine:
The four guided-missile submarines (SSGNs) of the Ohio-class: Ohio, Michigan, Florida, and Georgia — are four of the most heavily armed ships in the world. Each is equipped with 154 cruise missiles and can carry up to four platoons of Navy SEALs.
Originally constructed as ballistic missile submarines, each submarine carried 24 nuclear tipped D-5 Trident submarine-launched ballistic missiles. Under the terms of the START II treaty the United States was left with four excess ballistic missile submarine hulls. Rather than decommission them, the U.S. Navy paid $4 billion to convert them to carry conventionally-armed Tomahawk land attack cruise missiles.
Twenty two of the Trident missile silos were converted to each hold seven Tomahawk missiles. The result is a stealthy cruise missile platform capable of firing 154 Tomahawk missiles, a unique capability that greatly increases the US Navy’s firepower.
The precise loadout of each submarine is classified but includes some mixture of Block III Tomahawk and Block IV Tomahawk missiles. Tomahawk Block III/C has a single 1,000 lb conventional warhead and a range of 1,000 miles. Block III/D has a payload of 166 cluster bomblets and a range of 800 miles. Each missile features multiple navigation methods and can guide itself to target by Inertial Navigation System, Terrain Contour Matching, Digital Scene Matching Area Correlator and GPS.
Tomahawk Block IV/E adds the capability for each missile to conduct reconnaissance, bomb damage assessment and retargeting. The missile can send back an image of the battle area in order, loiter while new target data is drawn up, and then substitute a new target for the old one. The missile is also significantly cheaper than previous Tomahawks.
The remaining two Trident launchers were converted for use by Navy SEALs, and feature lockout chambers for exiting the submarine underwater. The Ohio-class SSGNs can each carry 66 SEAL commandos as well as embark a combination of two midget submarines or Dry Dock Shelters.
The Ohio submarines fired their first missiles in anger on March 19th, 2011 during Operation Odyssey Dawn. USS Florida fired 93 Tomahawks against Libyan military targets. In the future, the cruise missile submarines could be used as mother-ships for Unmanned Underwater Vehicles (UUVs.)