SSGN Attack Weapons System (AWS)


Ohio class conventional missile delivery system that accommodates concurrent SOF missions
  • AWS reliability
  • AWS accuracy
  • Time to reconfigure strike to / from Special Operations Forces (SOFs)

Primary customers

  • Commander, Fleet Forces Command (CFFC)
  • Combatant Commanders (COCOM)
  • PEO (SUB)
  • PMS-398
  • The SSGN Fleet

Program Summary

After a period of examination and planning, the Navy received a favorable decision from DoD to convert four Ohio class TRIDENT II submarines, that formerly deployed the TRIDENT I (C4) SWS, to a tactical capability. Based on SSP’s long experience with the SWS in this submarine and our proven skills in fire control, launcher, and weapons system integration, SSP was charged with developing the AWS portion of this effort. The AWS includes the fire control and the launcher as well as supporting shore capability for payloads. The SSGN will deploy the Tomahawk weapons system, which SSP will integrate into the submarine. The SSP fire control will leverage Tomahawk fire control development, and the launcher will accommodate a number of Tomahawk missiles in their Multiple All-Up-Round Canisters (MACs) within the envelope occupied by a TRIDENT II missile. The SSGN will have a reconfigured payload comprising fewer Tomahawk missiles but with the addition of Special Operation Forces (SOFs). 

Attack Weapons System

The Attack Weapon System (AWS) is also part of the Navy’s contribution to the offensive strike leg, but as a non-nuclear system. It is being deployed on four guided missile submarines (SSGNs). These submarines are transformational, both physically and conceptually. The SSGN submarines have been converted from TRIDENT SSBNs, originally scheduled to be decommissioned. By capitalizing on the investment already made in these advanced submarines, new conventional land attack strike and special operations capabilities are being provided to the US Navy.

SSGNs can operate in otherwise denied areas to provide unique capabilities that would enable other U.S. forces. These capabilities include carrying up to 154 TOMAHAWK cruise missiles that can be launched at rapid rates, the ability to carry Special Operations Forces (SOF) personnel, and the capability to host swimmer lockouts, Dry Dock Shelters, and Advanced SEAL Delivery Systems (ASDS). The SSGN will also retain the multi-mission capability found in SSNs and provide large volumes for future payloads and mission adaptability. SSP’s role in SSGN is to integrate the TOMAHAWK cruise missile into the TRIDENT submarine, through the design, development, and lifecycle support.

The Tomahawk MissilePhoto: TOMAHAWK Missle Launch

The TOMAHAWK missile is the US Navy’s surface and submarine launched, precision strike standoff weapon. SSGNs can be loaded with either the Block III or the tactical TOMAHAWK Block IV variants. These missiles are designed to fly at extremely low altitudes at high subsonic speeds, and are flown over an evasive route by several mission-tailored guidance systems. In any weather, day or night, TOMAHAWK missiles can fly up to 1,000 miles to deliver payloads with incredible accuracy.

The TOMAHAWK missile, while onboard the SSGN, is encapsulated within the legacy Capsule Launching System (CLS). The CLS provides environmental protection, missile ejection using a gas generator, and an umbilical cable for communication with the shipboard components. This configuration is referred to as the TOMAHAWK All-Up-Round (AUR).

Multiple All-Up-Round Canister (MAC)

The MAC structurally supports seven TOMAHAWK All-Up-Rounds (AURs) or AUR ballast cans, and interfaces with the existing OHIO Class missile tube. The MAC supports the AURs both vertically and radially at the upper flange and provides radial support for the capsule at three specific elevations to align with the exterior AUR shock pads. The MAC also provides an upper seal between itself and the missile tube, and seals between itself and individual AURs or AUR ballast cans. These seals prevent water from entering the missile tube below the MAC.

Attack Weapons Control System (AWCS)

The AWCS consists of an integrated Launch Control System interfaced with the Tactical Tomahawk Weapon Control System and the Captain’s Information and Control Station, having the capability to launch up to 154 missiles from a maximum of 22 missile tubes. The AWCS consists of equipment that includes measurement, conversion, computation, and transmission capabilities to provide data to the TOMAHAWK missiles for platform and computer initialization and flight path presettings. The AWCS also provides power and control to the missile in support of test and missile launch. The AWCS is capable of displaying the readiness status of the weapons system; controlling the operations necessary for mission/engagement and planning; and preparation and initiation of missiles for launch. The AWCS also controls the resources of the ship's support systems to maintain the TOMAHAWK AUR environment, pressurize the submarine missile tube under hatch area and TOMAHAWK AUR, monitor progress of the launch sequence, monitor and control the position of the submarine missile tube muzzle hatch, and monitor the position of the missile tube access door openings.

The Guided Missile Submarines (SSGN)

USS OHIO (SSBN 726), USS MICHIGAN (SSBN 727), USS FLORIDA (SSBN 728), and USS GEORGIA (SSBN 729) has been refueled and converted to SSGNs. They have all been redesignated as SSGNs (e.g., SSGN 726, SSGN 727, SSGN 728, and SSGN 729). The first conversion (USS OHIO) started in November of 2003 and the last ship was completed in FY 08. USS OHIO has the distinction of being the first OHIO Class submarine to be refueled at Puget Sound Naval Shipyard, while USS FLORIDA has the distinction of being the first OHIO Class submarine to conduct both shipyard availability and refueling on the East Coast of the United States at Norfolk Naval Shipyard.

The Future

SSGN, with its tremendous payload capacity, will be able to employ emerging technologies to create an entirely new and affordable capability for the joint force. The conversion process remolds the fleet ballistic missile submarine to perform joint missions never envisioned by the original designers, meeting the CNO’s Seapower 21 vision for a fraction of the cost of developing a comparable capability from the ground up.

SSGN will contribute to the operational concepts of Sea Strike, Sea Shield and Sea Basing through extending the submarine’s reach to gain and sustain battle force access with the employment of SOF and future unmanned vehicles and sensors; development and sharing of knowledge with Combatant, National, and Joint Commanders using onboard equipment, SOF, and future unmannevehicles; extension of homeland defense, deterring conflict and countering weapons of mass destruction with covert organic intelligence, surveillance and reconnaissance, the employment of SOF, and future unmanned vehicles and sensors; and projecting close-in power with surprise through the employment of large volume Tomahawk Strike, SOF, and future submarine launched munitions.

top of page