Commander, Submarine Force Atlantic

A Transformational Force for the U.S. Navy

Conversion Update

USS Ohio's return to the Fleet was formally recognized
at a ceremony in Bangor, Washington on February 7, 2006

USS Ohio
(SSGN 726)
USS Florida
(SSGN 728)
USS Michigan
(SSGN 727)
USS Georgia
(SSGN 729)
  • ERO Started:
    Nov 2002
  • Conversion
    Nov 2003
  • Returned to
    Dec 2005
  • ERO Started:
    Aug 2003
  • Conversion
    Apr 2004
  • Returned to
    Apr 2006
  • ERO Started:
    Mar 2004
  • Conversion
    Jan 2005
  • Returned to
    Dec 2006
  • ERO Started:
    Mar 2005
  • Conversion
    Oct 2005
  • Returned to
    Sep 2007

Even beyond its baseline mission capabilities,
SSGN offers significant opportunities to develop
and test new weapon delivery systems, sensors, 
and operational concepts that could further
transform naval warfare.


Concept Drawing of SSGN

Guided Missile Submarines

Transformation and the Navy

Well before the events of September 11th, the vision of how the military must change to face future threats effectively, and the value of submarines as part of that fight, were clear.

During the Cold War, we created the first SSBN by enlarging the partially-constructed hull of the then-named Scorpion. In only two years the conversion was complete, the ship was renamed USS George Washington (SSBN-598), and the concept of strategic deterrence was changed forever. Clearly, there is a well-established precedent of converting existing platforms into new ones built on proven concepts and the latest technology.

Today’s “transformation” efforts include advanced sensors and surveillance systems, rapid precision strike, assured access to hostile or denied areas, and a high “tooth-to-tail ratio” (the ratio of combat power to required support).

  • Forward Presence - Utilizing the two-crew concept, the four SSGNs will provide a continuous 2.4 submarines in-theater presence.
  • Strike Capability - Each of the converted submarines will have the capability to launch up to 154 Tomahawk land attack missiles. The SSGNs have 22 missile tubes, which can house seven missiles per tube in Multiple All-Up-Round Canisters (MACs). 
  • Special Operations Capability – SSGNs will have separate, interchangeable canisters for Special Operations Forces (SOF) equipment that can be installed in place of the MACs.  Clandestine insertion and retrieval of SOF operators (via lockout chambers) will be enhanced by the ability of the SSGN to host dual dry deck shelters with SEAL Delivery Vehicles (SDVs) and/or Advanced SEAL Delivery System (ASDS). 
  • Connectivity - SSGNs will be configured for high data rate connectivity using sail-mounted Universal Modular Masts and the Common Submarine Radio Room (CSRR).  The Battle Management Center will also provide the SSGN with the capability to host an embarked joint command element.

Responsive, forward-deployed units, survivable against anti-access threats, and capable of sustained high-volume strike with minimal logistic support, score high in these categories - SSGN is a prime example.

Overview of SSGN Capabilities

Here is a quick summary of the capabilities SSGN brings to Joint Warfare:

  • TRIDENT stealth and reliability, with more than 20 years of service life remaining for each SSGN
  • Large-volume precision strike, with up to 154 Tomahawk and Tactical Tomahawk cruise missiles
  • Sustained Special Forces operations to include insertion, extraction, and support of 102 Special Forces personnel, conditioned and ready, with onboard periods much longer than on SSNs
  • Command center for mission planning and execution
  • Capacity for conducting other SSN missions, such as: intelligence, surveillance, reconnaissance, and targeting; anti-submarine warfare; anti-surface warfare; and mine warfare
  • High-data-rate connectivity and joint command/control capability with a “Virginia-class” advanced SSN radio room and ISR suite
  • 67 percent operational availability by using two crews to achieve a continuous, 2.4-ship deployed presence in support of Combatant Commanders' mission requirements
  • 20 times the payload of an SSN, with large ocean interfaces (22 seven-foot diameter launching tubes, two for SOF lock-out), opportunity for payload experimentation and development


  • Cutaway graphic of the SSGNStealth, endurance, and agility have long enabled nuclear-powered submarines to take sensors and precision weapons into the fray with little or no logistical support. However, in spite of their unmatched supremacy beneath the world’s oceans and their ability to strike with impunity with dozens of cruise missiles, the greatest limitation of today’s attack submarines is payload.
  • Even beyond its baseline mission capabilities, SSGN offers significant opportunities to develop and test new weapon delivery systems, sensors, and operational concepts that could further transform naval warfare. Two examples already envisioned are encapsulated launch of a variety of tactical munitions and deployment of large Unmanned Undersea Vehicles (UUVs) and off-board sensors. Encapsulated launch will send weapons to the surface for dry-launching, using a standardized buoyant capsule and a common interface for loading and communications. This modular approach to payloads will even allow use of “off-the-shelf” weapons, unmanned aerial vehicles, and decoys in support of joint forces. And, by developing large UUVs that make full use of the seven-foot tubes, they can surpass the range, endurance, and payload of small surveillance platforms and take on new missions - even offensive ones.

Strike Capabilities

The SSGN will bring a new dimension to strike warfare. Currently, SSNs with up to two-dozen Tomahawks usually launch missiles in salvos of three or four (16 maximum), while on SSGN a salvo of 32 missiles will represent less than 15 percent of the full load of 154 missiles. Existing submarine Torpedo-Tube Launched (TTL) TLAMs will be converted for vertical launch to provide the required load-outs. Obviously, the number of TLAMs available to deploying SSNs will decrease as a result, but if you consider that a missile on an SSGN is deployed 70 percent of the time, the overall TLAM inventory immediately available to the Combatant Commanders will increase by about 50 to 60 percent. This shift of weapons will also open up some room in SSN torpedo rooms for more torpedoes or alternative payloads, like LMRS and other unmanned vehicles.

Special Operations Forces (SOF)

SEALs have operated from submarines for years. Conversion of the SSBNs USS James K. Polk (SSN-645) and USS Kamehameha (SSN-642) - since inactivated - gave us the space for embarked SEALs to work out and maintain their conditioning for extended periods and to deploy with their equipment. SSGN will not only restore the force’s large, sustainable SOF capability, but will include significant command and control capabilities well beyond those of previous boats. With a dedicated command center and a “Virginia-class” communication system, SSGN will be able to control a Special Forces campaign over a period of months from her covert position. Once on scene, SSGN will deploy Special Forces submerged, either from the SEAL delivery vehicles (SDVs) housed in the dry-deck shelters, or in the Advanced SEAL Delivery System (ASDS) underwater vehicle, which transports SEALs inside a dry environment. SSGNs should prove to be the most advanced covert Special Forces platforms ever.

Mission Agility

The SSGN’s inherent stealth and endurance - as with all nuclear-powered submarines - will enable it to conduct many traditional SSN surveillance or sea control missions, even though it will be optimized for strike and Special Operations Forces because of its immense payload capacity. The SSGN can conduct a wide range of missions in a single deployment. SSGN is a highly flexible multi-mission platform capable of supporting the following operational objectives:
- Assure access to the contested littorals
- Acquire actionable intelligence
- Dissuade and deter by holding vast target sets at risk
- Strike with precision and surprise in support of the JFC's objectives

The mission agility of our nuclear-powered submarines and their broadly trained crews makes them capable of nearly any submarine mission.

Concept of Operations

  • This Weapons Handling Facility is an example of the well-established infrastructure that will make SSGN conversion a success.Dual-crewed SSGNs will deliver these extraordinary warfighting capabilities with unrivaled efficiency. SSGNs will have a deployment cycle similar to TRIDENT SSBNs, with every other crew turnover at a forward-deployed site to achieve a higher operational availability and in-theater presence. A strong, efficient, and well-established infrastructure is required to make this work, and we already have that in the TRIDENT program. Since the TRIDENT maintenance and support systems are located in Bangor, Washington, and Kings Bay, Georgia, it follows that the most cost-effective option for homeporting SSGN will be at those bases. With four SSGN conversions, two will be stationed on each coast to balance support to the EUCOM, CENTCOM and PACOM theaters. Locations for the forward-deployed turnovers will depend on where they are operating.
  • SSGNs will be accountable under current START counting rules, and it is important that SSGN be part of future arms control agreements.
  • Since 1960, SSBNs have guaranteed our security by deterring the use of weapons of mass destruction against the United States. In keeping with the objectives of a transformed Navy, we now have the opportunity to re-deploy these successful ships to make use of their incredible payload, stealth, and endurance in a new deterrent role. With future enemies certain of both our capability and determination - but uncertain about when and from where our new SSGNs might attack, we achieve a powerful, new level of deterrence and open a door to new capabilities and operational concepts yet to be imagined for submerged, survivable platforms.

For more information on SSGN, click here to see the Navy Fact File page