The Seawolf
was conceived as a faster, better-armed eventual replacement for
the Los Angeles class nuclear-powered attack submarines. The first
of class, the Seawolf (SSN21), was ordered from the Electric Boat
Division of General Dynamics, Connecticut, in January 1989 and
commissioned in July 1997. Connecticut (SSN22) was commissioned in
December 1998. The third, Jimmy Carter (SSN 23), is to be modified
to improve payload carrying and underwater manoeuvrability. The
alterations to the design will include modifications to the ballast
control, mission management spaces and the creation of a flexible
ocean interface known as a "wasp waist", which will enable the
deployment and recovery of payloads without the use of torpedo
tubes. Other additions include a new high capacity communications
mast and ROV handling system. The Jimmy Carter was launched in June
2004 and commissioned in February 2005.
The Seawolf
was a product of the Cold War, conceived to maintain the USA’s
acoustic advantage over Soviet submarines. With the end of the Cold
War and the change of emphasis to littoral operations, the cost of
the Seawolf submarines was judged prohibitive and the programme was
curtailed in favour of the smaller and cheaper Virginia Class New
Attack submarines.
DESIGN
The
Seawolf’s modular design introduces important improvements and
innovations. It has greater manoeuvrability than the Los Angeles
Class, space for later upgrades and weapons developments, and
better sonars.
The Seawolf
has a submerged displacement of 9,137t dived (12,139t for the Jimmy
Carter), and 8,060t surfaced. Full acoustic cladding has been
installed. It has a maximum speed of 35 knots dived, and a "silent"
speed of 20 knots. It has a crew of 116 personnel, including 15
officers. With a diving depth of 610m, it has been designed with a
sub-ice capability, with retractable bow planes.
COMBAT SYSTEM
The combat
data system is a Lockheed Martin BSY-2 with a network of some 70 or
so 68030 Motorola processors. This being replaced by the Raytheon
AN/BYG-1 combat system. Weapons control is managed by the Raytheon
Mk 2 fire control system.
MISSILES
Like the
improved Los Angeles class, the Seawolf does not have any external
weapons. The submarine is armed with both the land-attack and
anti-ship version of the Tomahawk missile from Raytheon. The
land-attack Tomahawk has a range of 2,500km. A TAINS (Tercom Aided
Inertial Navigation System) guides the missile towards the target
flying at subsonic speed at an altitude of 20m to 100m. Tomahawk
can be fitted with a nuclear warhead which is not normally carried.
Block III improvements include an improved propulsion system and
Navstar Global Positioning System (GPS) guidance capability. The
anti-ship Tomahawk missile is equipped with an inertial guidance
and an active radar and anti-radiation homing head. The range is up
to 450km.
First
underwater launch of the new Raytheon Tactical Tomahawk Block IV
missile took place in November 2002. Block IV includes a two-way
satellite link that allows reprogramming of the missile in flight
and transmission of Battle Damage Indication (BDI) imagery. The
missile entered service with USN surface ships in September
2004.
The Seawolf
class also carry the Harpoon anti-ship missile from Boeing.
Sub-Harpoon uses active radar homing to deliver a 225kg warhead.
The range is 130km and the speed is high subsonic.
TORPEDOES
Seawolf has
eight 660mm torpedo tubes for launching torpedoes and missiles. 50
missiles/torpedoes are carried. The Gould Mk-48 ADCAP torpedoes
combat both high-performance surface ships and fast deep-diving
submarines. The torpedo has a 267kg warhead. It is capable of
operating with or without wire guidance and uses either or both
active and passive homing. Range is 50km (active) and 38km
(passive)
COUNTERMEASURES
Countermeasures include the Northrop Grumman WLY-1 torpedo decoy
system and a GTE WLQ-4(V)1 electronic countermeasures (ECM)
system.
SENSORS
The
submarine's sonar suite is the BQQ 5D with bow-mounted
active/passive arrays and wide aperture passive flank arrays. Also
fitted are TB-16 surveillance and TB-29 tactical towed arrays,
which will be replaced by the TB-29A thin-line towed array being
developed by Lockheed Martin, and BQS 24 active sonar for close
range detection.
The Seawolf
submarines are being upgraded with the Lockheed Martin
AN/BQQ-10(V4) sonar processing system under the Acoustic-Rapid
Commercial-Off-The-Shelf Insertion (A-RCI) programme.
BPS 16
radar, operating at I-band, is fitted for navigation.
PROPULSION
The
nuclear-powered Seawolf has a GE PWR S6W reactor system, two
turbines rated 52,000hp (38.8MW), a pumpjet propulsor, a single
shaft, and one secondary propulsion submerged motor.