The Seawolf class fast attack submarine (SSN 21) was conceived and developed as the replacement for the Los Angeles (SSN 688) and Improved Los Angeles (SSN 688(I)) attack submarines. Using the latest technology available, and building on the lessons learned from not only experience with the 688 boats but with improving Soviet capabilities as well, the Seawolf submarines were intended to be the ultimate undersea warfare platform. Every aspect of the Seawolf improves upon the 688's performance; the 21 boats have a faster top speed, a faster silent speed, an increased weapons loadout as well as twice the compliment of torpedo tubes. Their sonars are more sensitive and their signal and data processing capabilities are considerably more advanced.
The lead boat of the class, the USS Seawolf (SSN 21) was awarded to Electric Boat in January of 1989, with the keel being laid in October of 1989. The submarine was launched in June of 1995 and later commissioned into active service in July of 1997.
Unfortunately, the Seawolf's performance did not come without a price. At approximately $2 billion apiece, the Seawolf was the most expensive submarine ever constructed. Furthermore, with the collapse of the Soviet Union not long after construction began on the Seawolf, the very reason for the class' existence was no longer an issue; the Seawolf became a predator with nothing to hunt. As a result, funding for the program was slashed. Of a proposed 29 boats, only three were constructed (the other two were the USS Connecticut (SSN22) and USS Jimmy Carter (SSN 23) all built at Electric Boat in Groton, CT.) Yet, in what has become something of an ironic twist of fate, the Virginia class submarines (SSN 774) which were developed as a cost effective replacement for the Seawolf and Los Angeles class submarines, have, as a result of a reduced production tempo, an actual cost per unit price of almost $300k more per submarine than the more capable Seawolf boats ($2.3B vs. $2B.)The third member of the Seawolf family, the USS Jimmy Carter, differs significantly from its other two class members. At approximately 100' longer, the Carter incorporates an additional hull section to facilitate R&D (research and development) testing on ROV, special operations support, and advanced warfighting capabilities. The 2,500-ton MMP (multi-mission platform) is nearly as sophisticated as one of the older 688 class boats, and is equipped to operate and evaluate current and prototype undersea equipment. In addition to supporting equipment testing and evaluation, the MMP is also capable of serving as a special operations mission planning and command center, and the submarine itself is capable of berthing up to 50 SOF personnel. In addition to the MMP module, the Carter is also equipped with additional low speed and station keeping maneuvering modules, devices which make it well suited to the same stationary, sea-bottom deployment and recovery operations that were once conducted by the modified Sturgeon class submarine USS Parche (SSN 683.)
The Seawolf class fast attack submarines are 353 feet long (453 feet SSN23), have a beam of 40 feet, and a navigational draft of 36 feet (37 feet SSN23.) Their full load displacement is 9,137 tons submerged (12,139 tons SSN23). Ship?s compliment is 15 officers and 101 enlisted. The Seawolf class submarines have a top speed of 25 knots on the surface and a submerged speed of more than 35 knots. They have a silent cruising speed of 20 knots. The maximum diving depth is in excess of 800 feet. In an effort to improve upon the hull strength, the Seawolf submarines are the first in the Navy to be constructed out of HY-100 (high yield) high strength steel, the same material used to fabricate deep diving research submersibles. To reduce the strength of threat sonar returns, the Seawolf is coated in acoustic (sound absorbing) tiles.
To support SOC operations, the Seawolf class submarines are capable of transporting and launching both the DDS (dry deck shelter) and the SDV (SEAL Delivery vehicle). These submarines are also equipped with an 8-man diver lock out chamber for rapid deployment of swimmers and equipment directly from the submarine.
In an effort to reduce transient noise from torpedo launches, the Seawolf is the first American submarine to feature oversized (660mm vice 533mm torpedo tubes) to enable "swimout" torpedo launches. The "swimout" launch feature enables to torpedo to leave the tube quietly, under its own power, rather than be ejected with a noisy blast of compressed air.
The Seawolf class submarines are powered by a single General Electric S6G nuclear reactor producing 52,000 horsepower. Propulsion is provided by two steam turbines connected to a single shaft with shrouded pumpjet propulsor.
The Seawolf class submarines are equipped with a BQQ-5D bow-mounted active/passive spherical search and attack array, a passive wide aperture flank sonar array, and a BQS-24 high frequency active sonar system for counter-mine and under ice operations. In addition, the submarines are equipped with two towed sonars, the TB-16 "fat line" towed array and the TB-29 low frequency "thin line" towed array.
For surface navigation, the Seawolf uses a BPS-16(v)4 I-band navigation radar.
Command and control systems include the BSY-2 submarine combat system. The BSY-2 integrates sonar/ESM data, target/weapon tracking and weapon targeting and control into a single functional system.
Defensive and electronic warfare systems include the WLY-1 acoustic countermeasures system (an automated threat torpedo detection, classification and tracking system) and the WLQ-4(v)1 electronic signal interceptor.
The Seawolf class submarines are armed with eight 26" (660mm) "swimout" torpedo tubes, mounted amidships, aft of the bow mounted sonar. In a departure from previous designs, the Seawolf submarines are not equipped with VLS tubes. Instead, the Seawolf is capable of carrying a total of 50 tube launched weapons, ranging from Tomahawk cruise missiles, Mk48 mod 6 ADCAP heavyweight torpedoes, Mk50 lightweight ASW torpedoes, sub-launched Harpoon antiship missiles, or as many as 100 Mk60 CAPTOR mines.