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 for 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
|
CHARACTERISTICS |
BASELINE SEAWOLF |
SSN 23 DOUBLE HULL |
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 |
SPECIAL
WARFARE |
None |
FLEXIBLE
LI / LO w/ Ocean Interface
DDS
ASDS |
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.
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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.
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