SSGN Transformation

Electric Boat designed and converted the first four Ohio-class (Trident) ballistic missile submarines into SSGNs, multimission platforms optimized for conventional strike and special operations warfare.

Electric Boat completed the conversion of the Trident submarines, the USS Ohio (SSGN726), USS Florida (SSGN728), USS Michigan, and the USS Georgia (SSBN729). The ships were converted in conjunction with their mid-life refuelings at Puget Sound Naval Shipyard in Bremerton, Wash., and Norfolk Naval Shipyard in Portsmouth, Va. They provide the U.S. Navy with its first truly transformational platform.

All four ships have rejoined the fleet and are in active service.

Electric Boat, the designer and builder of all 18 ships of the Ohio class, was awarded a $1.4 billion contract in 2002 for the design and construction of the SSGN modifications.

Considered a prime example of military transformation initiatives, SSGNs can carry up to 154 strike missiles and are able to sustain more than 66 Special Operations Forces personnel. SSGNs also serve as platforms to develop and test new weapons systems, sensors and operational concepts that could further transform naval warfare, including large unmanned undersea vehicles, unmanned aerial vehicles and off-board sensors.

Ship statistics

18,750 tons (submerged)
560 feet
Hull Diameter:
42 feet
35 feet
25+ knots
Diving Depth:
800+ feet
154 Tomahawk strike missiles; Mark 48 anti-submarine torpedoes
15 officers, 139 enlisted crew members and 66 Special Operations Forces personnel