USS Jimmy Carter (SSN-23) Expanding Future SSN Missions

by RADM John P. Davis, USN

"What will the submarine of the future look like?" Over the years, the Navy has posed this question several times to the scientific community. In 1948, for example, the Navy asked the National Academy of Sciences to form a committee on undersea warfare to study the concept of a submarine designed primarily to maximize submerged performance. The Academy returned with recommendations for building a high-speed submarine capable of exceeding 20 knots underwater, based on a teardrop-shaped hull, a single screw, and HY-80 steel for the hull. As a result, USS Albacore (AGSS-569) was born, and the course of submarine design changed irrevocably.

The Defense Science Board, NDIA, and Future Missions
Recently, Department of Defense leadership asked again for help from the scientific community in this area. In 1997, the Under Secretary of Defense for Acquisition and Technology asked the Defense Science Board (DSB) to assess "how attack submarines should serve the nation's defense needs in the 21st century." Subsequently, the DSB Task Force on Submarines of the Future reported back in July 1998 and described the submarine technologies and operational capabilities an SSN of the future should have. The Task Force "firmly reaffirmed" that the next class of submarine should be a large, nuclear-powered ship with substantial internal volume for non-traditional payloads. The term "non-traditional payload" was used to capture a vision larger than that of the conventional torpedoes, missiles, and mines currently carried on submarines. This would include stand-off vehicles, distributed sensors, and leave-behind weapons. The DSB also suggested that "weapon-specific interfaces," such as torpedo and vertical launch tubes, be replaced by larger-aperture openings to the sea and external weapons storage. In parallel, the National Defense Industrial Association (NDIA) also formed a study committee on submarine issues under the auspices of the Naval Sea Systems Command Submarine Technology Directorate (NAVSEA 92). This team studied the technology issues relative to using small submersibles and other off-hull systems as a means of extending the reach of the host submarine to perform sensitive missions without risking the submarine and her crew. The study identified four technology areas for detailed assessment: Signature Control, Launch and Recovery, Long Range Underwater Acoustic Communications, and Compact Acoustic Sensors. In particular, NDIA recommended the study of launch and recovery designs that might reduce the difficulties encountered in using existing submarine torpedo tubes. Our current torpedo tube geometry is unfavorable for the launch and recovery of auxiliary vehicles. The tube faces forward and is canted outward at approximately 15 degrees, which forces the vehicle across the flow arising from the forward motion of the submarine and generates large and complex hydrodynamic forces on the body. Ideally, the committee noted, "a system that is fully integrated into the basic submarine design has the greatest potential for performance improvements with minimal restrictions."

SSN-23 and the Multi-mission Project
The new missions and design concepts outlined by the DSB and NDIA reconfirmed the soundness of the Navy's plan to provide one of the three Seawolf (SSN-21)-class submarines with advanced, versatile multi-mission functionality. The third of the class, USS Jimmy Carter (SSN-23) was chosen to serve as a test bed for studying the evolution of submarine missions in the 21st century. It will support classified research, development, test, and evaluation (RDT&E) efforts for notional naval special warfare (NSW) missions, tactical undersea surveillance, and undersea warfare concepts. The Navy, with funding approved by Congress to complete the Multi-Mission Project, has tasked General Dynamics Electric Boat Division (EB) to provide Jimmy Carter with additional volume and functionality to support new multi-mission opportunities. These changes will have no direct impact on the ship's organic warfighting capability but will give the submarine an enhanced payload capability with a more modular architecture. The required modifications will delay her scheduled delivery by approximately 27 months, until mid-2004, but the ship will be fully operational within a year after delivery.

A Wasp Waist for More Ocean Access
The planned alterations include lengthening the hull behind the sail and inserting an Ocean Interface (OI) section that will support the Multi-Mission Project by opening larger payload apertures to the sea. The resulting modular architecture will allow the ship to be configured for specific missions using interchangeable payloads and tailored support services, yet it will preserve the submarine's core mission capabilities for normal tasking. The OI hull insert is unique, with a horizontal "hourglass" configuration that necks the pressure hull down to a "wasp waist," so that when the section is faired over, significant external volume will be available outside the pressure hull, but still within the skin of the ship. This will allow more flexibility in designing and adding systems and storage, while maintaining a smooth hydrodynamic hull shape with minimal impact on the ship's draft. The OI facilitates more flexible payload interfaces with the water and imposes far fewer constraints on the shape or size of weapons, auxiliary vehicles, and sensors to be deployed from the submarine. The OI supports the launch and recovery of tethered and autonomous vehicles without incurring many of the difficulties of current designs using torpedo tubes. The external volume under the shroud could also contain the necessary support systems for such vehicles. This approach would allow the host submarine to control the vehicle from within the ship without consuming valuable internal space for large cable reels or other support equipment. The OI will also allow the ship to deploy and retrieve a new generation of weapons, countermeasures, and sensors, which can now be developed without the size limitations imposed by torpedo or vertical launch tubes. In addition, Jimmy Carter will be configured with an advanced communications mast to support the high-volume data requirements of network-centric warfare, as well as DSB-recommended auxiliary maneuvering devices for low speed operations in littoral regions.

Full Seawolf Warfighting Capabilities - plus Special Operations
Despite her modification to conduct classified RDT&E, Jimmy Carter will retain all her organic warfighting capability, as shown in the accompanying table. She will support the fleet commander as an attack submarine in conducting undersea warfare, surveillance and reconnaissance, covert special operations, mine warfare, and strike operations, just as her two sister ships do. She will also be available to the Navy to test future concepts for weapons, countermeasures, and non-traditional payloads - tasking that is currently divided among several submarines. In addition to these robust capabilities, Jimmy Carter will also be capable of supporting Special Operations Forces (SOF), with provision for operating the Dry Deck Shelter (DDS) and Advanced SEAL Delivery System (ASDS). Moreover, one of the ship's most important functions will be to support research and development for future Naval Special Warfare (NSW) undersea mobility requirements, tactics, techniques, and procedures. Jimmy Carter had already been programmed to support NSW, but the additional volume and length of the OI provides even greater potential to develop new roles for submarines in special operations. The OI will provide a hangar or garage capability fo
Jimmy Carter brings many new innovations into the submarine design    r locking-in and locking-out future generations of SEAL delivery vehicles, and her reconfigurable cargo area can accommodate dry stowage and access for maintenance. Other internal volume will be available as command and control space for mission planning and monitoring, plus dedicated berthing space for up to fifty SOF Team members. The extra external volume created by the hourglass design allows for stowage of SOF supplies like Combat Raiding Craft, fuel, munitions or delivery vehicles.

Jimmy Carter brings many new innovations into the submarine design    


SPEED 25+ knots 25+ knots
DEPTH 800+ feet 800+ feet
WEAPONS LAUNCH 8 Torpedo Tubes 8 Tubes + 1 Ocean Interface
PAYLOAD ~50 Tube Launched Wpns ~50 Tube Launched Wpns + Flexible
Internal And External Storage
COUNTERMEASURES Fixed External Mounted
Limited Internal Devices
Flexible Internal and External Devices
COMPLEMENT 130 (12 officers) 130 (12 officers) + 50 SOF
PROPULSION S6W PWR, Single Shaft S6W PWR, Single Shaft


Mine Warfare and Tactical Surveillance Concepts
Jimmy Carter will support future concepts of offensive and defensive mine warfare in her ability to launch and recover a wide range of tethered and autonomous vehicles and sensors of varying sizes and shapes. The OI, with its associated electronics and cargo space, will provide the ship enough weight and volume reserve to support a variety of defensive unmanned underwater vehicles (UUVs) and sensors. Significantly, it will not constrain the design of future submarine-launched offensive mines, since future weapons could be carried outboard and launched from the OI. Tactical surveillance from submarines is expanding and may soon include the use of Unmanned Aerial Vehicles (UAVs) and large off-board arrays, facilitated by improving submarine communication capabilities. USS Chicago (SSN-721) demonstrated this concept in a 1996 exercise, when she controlled a camera-equipped Predator UAV while submerged and then relayed remote images to shore in real-time to support SOF operations. In future, the OI could conceivably house not only the means for controlling a UAV, but also launching it. The reconfigurable electronics space will accommodate the additional installed electronics necessary to support auxiliary vehicles, sensor processing and analysis electronics, and a variety of remote environmental sensors.

Jimmy Carter - Our Path to the Future
USS Jimmy Carter (SSN-23) honors the 39th President of the United States and the only U.S. President ever to qualify in submarines. As the last and most advanced ship of the Seawolf class, she will have built-in flexibility and an array of new warfighting features that will enable her to prevail in any scenario and against any threat - from beneath Arctic ice to shallow water. In addition to the organic capabilities she bring to the Fleet, Jimmy Carter will also serve as a real-world springboard for developing and testing a whole new generation of weapons, sensors, and undersea vehicles.


RADM Davis
RADM Davis is from Shelter Island, New York. He graduated from the United States Naval Academy in 1968 and the Naval Postgraduate School in 1969 with a Master of Science Degree in Electrical Engineering.

Following nuclear power training, RADM Davis served on the USS Pogy (SSN-647), USS Daniel Webster (SSBN-626) (Blue), and USS Memphis (SSN-691), later commanding USS Jacksonville (SSN-699) and USS Glennard P. Lipscomb (SSN-685), and serving as Deputy Commander of Submarine Squadron SIX from 1988 to 1989.

Ashore, RADM Davis has been assigned as Head, Undersea and Arctic Warfare Branch, in the Office of the Chief of Naval Operations; Director, Advanced Submarine Research and Development (SEA 92R); and Program Manager of both the Mk 48 ADCAP Advanced Capability Torpedo Program and the Undersea Weapons Program Office (PMS 404).

RADM Davis was selected to Flag rank in 1996 and has been assigned subsequently as the Director, Submarine Technology, at the Naval Sea Systems Command (NAVSEA) and the Program Executive Officer, Submarines. He assumed additional duties at NAVSEA as Deputy Commander, Submarines, in October 1998.