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SSN-21 Seawolf-class

Seawolf-class submarines were designed to operate autonomously against the world's most capable submarine and surface threats. The primary mission of the Seawolf was to destroy Soviet ballistic missile submariness before they could attack American targets. The Soviet submarines are one of the most survivable elements of their intercontinental ballistic missile arsenal. In addition to their capabilities in countering enemy submarines and surface shipping, Seawolf submarines are suited for battlespace-preparation roles. Incorporation of sophisticated electronics produces enhanced indications and warning, surveillance, and communications capabilities. These platforms are capable of integrating into a battle group's infrastructure, or shifting rapidly into a land-battle support role.

The Seawolf features a strengthened sail, designed to permit operations under the polar ice cap for taking the fight to the Soviets in their own front yard. It sports an eight-tube, double-deck torpedo room to simultaneously engage multiple threats. It incorporates the latest in quieting technology to keep pace with the threat then posed by an aggressive Soviet Union.

The Seawolf has the highest tactical speed of any US submarine. Much much of the design effort was focused on noise reduction, and it is expected that the fully coated boat will restore the level of acoustic advantage which the US Navy enjoyed for the last three decades. The Seawolf's propulsion system makes it ten times more quiet over its full range of operating speeds than the Improved-688 class and 70 times more quiet than the initial generation of Los Angeles 688-class submarines. The Seawolf's quieter propulsion system will also enable it to have twice the tactical speed as the I-688. Tactical speed is the speed at which a submarine is still quiet enough to remain undetected while tracking enemy submarines effectively. Overall, the Seawolf's propulsion system represents a 75-percent improvement over the I-688's -- the Seawolf can operate 75 percent faster before being detected. It is said that SEAWOLF is quieter at its tactical speed of 25 knots than a LOS ANGELES-class submarine at pierside.

With twice as many torpedo tubes and a 30% increase in weapons magazine size over the Los Angeles (SSN 688)-class submarines, Seawolf is capable of establishing and maintaining battlespace dominance. Seawolf's inherent stealth enables surreptitious insertion of combat swimmers into denied areas. SSN 23 will incorporate special-operations force capabilities, including a dry deck shelter (DDS) and a new, specially designed combat swimmer silo. The DDS is an air-transportable device that piggy-backs on the submarine and can be used to store and launch a swimmer delivery vehicle and combat swimmers. The silo is an internal lock-out chamber that will deploy up to eight combat swimmers and their equipment at one time.

Construction of the submarine has relied on a new welding material to join the steel into plates, hull subsections and large cylindrical sections. The Seawolf is the first American attack submarine to use a hull made entirely of high-pressure HY-100 steel -- previous sumarines used HY80 steel. HY-100 steel was first used in submarines in the early 1960s in the Navy's deep-diving SEA CLIFF and TURTLE,, which were capable of reaching depths in excess of 10,000 feet. More recently, the Moray, an advanced conventional submarine designed by the Dutch shipyard R.D.M. (Rotterdamsche Droogdok Maatschappij B.V), incorporated HY-100 steel to achieve an operational diving depth of 300 meters, and an incidental diving depth of 360 meters.

The SEAWOLF program began in the mid-1980s to ensure U.S. submarine superiority over Soviet counterparts well into the next century. The first U.S. attack submarine in decades designed from the keel up to accommodate the latest weapons, sensors, propulsion, and communication advancements, SEAWOLF exceeded expectations during lead ship sea trials in the summer of 1996. The test program included first underwater submergence, acoustics trials, engineering inspections and at-sea training for the crew. Seawolf (SSN 21) was commissioned on 19 July 1997 at Electric Boat Shipyard.

Seawolf was projected to be the most expensive ever built, with a total program cost for 12 submarines estimated in 1991 at $33.6 billion in current dollars. As many as 29 submarines were planned. The Navy's plans for Seawolf would have resulted in spending 25 percent of the Navy's shipbuilding budget on a ship that was designed for threats that vanished with the end of the Cold War. In the 1992 State of the Union address, President Bush [and Defense Secretary Dick Cheney] proposed the rescission of $2,765,900,000 previously appropriated for the procurement of the second and third Seawolfs. Two Seawolf Class submarines were authorized by Congress, which in 1995 agreed to terminate the program at three boats. President Clinton endorsed the construction of SSN-23 as the most cost- effective method of retaining the vitality of the submarine industrial base while bridging the gap to the future New Attack Submarine. The Fiscal Year 1998 $153.4 million budget request was the final increment of funding required for the third SEAWOLF to complete the program. The program continues to be managed within the Congressionally mandated cost cap.

On 10 December 1999 Electric Boat was awarded an $887,113,628 modification to previously awarded contract N00024-96-C-2108 for new efforts on USS JIMMY CARTER (SSN 23) to accommodate advanced technology for naval special warfare, tactical surveillance, and mine warfare operations. Work will be performed in Groton, Conn. (73%); Quonset Point, R.I.. (21%); and Newport News, Va. (6%), and is expected to be completed by June 2004.


Builders General Dynamics Electric Boat Division
Power Plant One S6W reactor
one shaft at with 52,000 shp with pumpjet propulsor

Improved Performance Machinery Program Phase II one secondary propulsion submerged motor
Length 353 feet (107.6 meters)
Draft 35 feet (10.67 meters)
Beam 40 feet (12.2 meters)
Displacement 7,460 ton surface displacement
9,137 tons submerged displacement
SpeedOfficial: 25+ knots (28+ miles per hour, 46.3+ kph)
Actual: 35 knots maximum submerged speed
Actual: 20 knots tactical ["silent"] speed
Operating DepthOfficial: "greater than 800 feet"
Actual: About 1600 feet
Jane's Fighting Ships: 2000 feet
Armament eight 660-mm torpedo tubes
50 Tomahawk cruise missiles or
50 Harpoon antiship missiles or
50 Mark 48 ADCAP torpedoes or
up to 100 mines
Crew 12 Officers; 121 Enlisted


Name Number Builder Homeport Ordered Commissioned Decommissioned
Seawolf SSN-21Electric Boat Groton09 Jan 198917 Jul 19972027
Connecticut SSN-22Electric Boat Groton03 May 199111 Dec 19982028
Jimmy Carter SSN-23Electric BoatBangor29 Jun 1996Dec 20012031
SSN-24[Electric Boat] [#4 through #12 cancelled in 1992]
SSN-25[Electric Boat] [#4 through #12 cancelled in 1992]
SSN-26[Electric Boat] [#4 through #12 cancelled in 1992]
SSN-27[Electric Boat] [#4 through #12 cancelled in 1992]
SSN-28[Electric Boat] [#4 through #12 cancelled in 1992]
SSN-29[Electric Boat] [#4 through #12 cancelled in 1992]
SSN-30[Electric Boat] [#4 through #12 cancelled in 1992]
SSN-31[Electric Boat] [#4 through #12 cancelled in 1992]
SSN-32[Electric Boat] [#4 through #12 cancelled in 1992]
SSN-33[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-34[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-35[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-36[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-37[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-38[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-39[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-40[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-41[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-42[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-43[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-44[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-45[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-46[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-47[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-48[Electric Boat] [cancelled -- 29 boats originally planned]
SSN-49[Electric Boat] [cancelled -- 29 boats originally planned]

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Maintained by Robert Sherman
Originally created by John Pike
Updated Tuesday, May 09, 2000 9:39:23 AM