Why the Seawolf-Class are special submarines: Those who have watched the film adaptation of Tom Clancy’s first best-selling novel, The Hunt for Red October, will remember that the two submarines that were the center of the story were a Soviet Typhoon-class ballistic missile (SSBN) that was being shadowed by a US Los Angeles-class fast attack nuclear (SSN) design.
Back then, US naval planners had realized that there was a future in which the boats that the Soviet Navy would introduce in the future and that the Los Angeles design would not be practical for forever.
Their solution was to develop the next attack sub, the Seawolf-class.
Design work on this submarine began in 1983, and the original fleet planning called for constructing up to 29 in this class.
In the meantime, however, the Cold War came to an end well before the first ship in this class could be commissioned.
By the time the first boat, the Seawolf (SSN-21), was in service, the calculation was that this submarine was no longer required in the numbers originally envisioned.
In the end, only three of these subs were built.
History and Details: The Seawolf-Class
This first boat was commissioned on 19 July 1997 and is significantly more powerful than any other submarine.
It has proven to be a high-speed and extremely quiet sub.
It is also equipped with several advanced weapon systems and highly advanced sensors.
The Seawolf is not equipped with any Vertical Launch Systems (VLS), which are the standard fit for most attack submarines.
Instead, Seawolf-class subs have eight torpedo tubes and have space for up to 50 weapons in the torpedo room.
The second boat, the USS Connecticut (SSN-22), is the same configuration as the first proceeding model and was commissioned one year later.
Both of these turned out to be the most expensive submarines built to date with the exception of the French Triomphant-class.
USS Jimmy Carter: A Special Seawolf-Class Submarine
The third ship of the class, USS Jimmy Carter (SSN-23), has a 100-foot hull extension designated the multi-mission platform (MMP).
This hull section could accommodate additional payloads based on advanced technologies or systems still in development.
The MMP space was created by inserting an additional Ocean Interface (OI) section, which was designed and installed by General Dynamics Electric Boat division.
This manner of an extension to the hull is somewhat like a section inserted into an aircraft when adding new on-board and extending the length of the fuselage.
As it is in the aircraft business, this kind of modification is referred by shipbuilders sometimes refer to as “the plug.” This extra space in this additional section was used for various special missions and the equipment needed to support them. The OI section also included a larger payload opening to the sea beyond the normal diver’s tank and could also be used as an underwater hangar.
This latter modification has led to the assumption that remains unconfirmed that the special hangar and the other additional space was so that this one sub could carry out performing highly-classified missions that were detailed in the 1998 non-fiction book, Blind Man’s Bluff.
The sub was later awarded Presidential Unit Citations (PUC) for actions taken in the 2011-2012 time frame but the specifics of those missions remain classified.
Unique Aspects of the SSN-23 USS Jimmy Carter
This OI section which is unique to the SSN-23 is reported to have also featured a specialized set of “Auxiliary Maneuvering Devices” that are fitted fore and aft of the section.
Their function is not officially detailed. However, informed speculation is that this maneuvering hardware would permit the boat to maintain position over a designated target area even in situations involving odd currents – somewhat like how a helicopter can hover over a fixed area.
The SSN-21 also has an advanced set of sensors. These are accompanied by an Advanced Communications Mast (ACM).
A detailed description of the OI section provided in an industry assessment describes the OI section as follows:
The inserted section “reportedly has an ‘hourglass’ configuration, which narrows the interior pressurized hull down to a thinner four-foot-wide passage or ‘wasp waist’ running its length. Normal sub pressure is maintained inside the wasp waist passage. The passage creates a space for crew members to pass through, as well as any operational equipment that must remain in the pressurized area of the sub, such as end-to-end pipes or cables.”
“The space between the wasp waist and the outer hull is the OI hanger area (also called the ‘aquarium’) , which is filled with seawater and kept at sea pressure. This large MMP area outside the pressure hull, but still within the skin of the ship, is ideal for flexible payloads and naval special warfare (NSW) missions. This internal MMP design keeps a smooth hydrodynamic hull shape that has minimal impact on the ship’s draft, while providing a place for any next-generation systems needed in the future.”
Seawolf-Class: A Story in Pictures
PUGET SOUND, Wash. (Sept. 11, 2017) The Seawolf-class fast-attack submarine USS Jimmy Carter (SSN 23) transits the Hood Canal as the boat returns home to Naval Base Kitsap-Bangor. Jimmy Carter is the last and most advanced of the Seawolf-class attack submarines, which are all homeported at Naval Base Kitsap. (U.S. Navy photo by Lt. Cmdr. Michael Smith/Released)
The Seawolf-class fast-attack submarine USS Connecticut transits the Pacific Ocean during Annual Exercise. ANNUALEX is a yearly bilateral exercise with the U.S. Navy and the Japan Maritime Self-Defense Force.
The first of a revolutionary new class of fast attack submarine, the Seawolf (SSN-21). Shown during construction at the Electric Boat Division of General Dynamics Corporation in Groton, Conn. She was christened by Margaret Dalton, wife of Secretary of the Navy John H. Dalton, on June 24, 1995.
Seawolf-Class Submarine USS Seawolf. Image Credit: Creative Commons.
An artist’s concept of the nuclear-powered submarine SEAWOLF (SSN-21).
Seawolf-class Submarine. Image Credit: Creative Commons.
About the Author: Reuben F. Johnson
Reuben F. Johnson is a survivor of the February 2022 Russian invasion of Ukraine and is now an Expert on Foreign Military Affairs with the Fundacja im. Kazimierza Pułaskiego in Warsaw. He has been a consultant to the Pentagon, several NATO governments and the Australian government in the fields of defense technology and weapon systems design. Over the past 30 years he has resided in and reported from Russia, Ukraine, Poland, Brazil, the People’s Republic of China and Australia.
