Across the Pond

Our counterparts across the pond in the UK have plans to add 3 fast attack Astute class submarines by 2011. The first one (of which the class is named), the Astute is due to reach the fleet in 2009 after an August 2007 launch. It appears the UK submarine fleet has some aging Swiftsure class submarines that are near the end of their lifespan. The following is some of the specifications of the new class of nuclear powered attack submarines:

MISSILES
The Astute will be equipped with the Tomahawk Block IV (Tactical Tomahawk) cruise missile from Raytheon fired from the 533mm torpedo tubes.
Tomahawk is equipped with the TERCOM terrain contour mapping-assisted inertial navigation system. The terrain contour mapping for use over land combines onboard radar altimeter measurements with terrain mapping data installed in the missile.
Block II added Digital Scene Matching Area Correlation (DSMAC) guidance. Block III improvements include an improved propulsion system and Navstar Global Positioning System (GPS) guidance capability. The GPS provides location and velocity data of the missile for precision targeting.
Tomahawk has a range of up to 1,000 miles and a maximum velocity of 550mph. Block IV includes a two-way satellite link that allows reprogramming of the missile in flight and transmission of Battle Damage Indication (BDI) imagery.
TORPEDOES
Astute will have six 533mm torpedo tubes, and will be equipped with Spearfish torpedoes and mines. There is capacity for a total of 36 torpedoes and missiles.
The Spearfish torpedo from BAE Systems is wire-guided with an active / passive homing head. The range is 65km at 60kt. Spearfish is fitted with a directed-energy warhead.
COUNTERMEASURES
The countermeasures suite will include decoys and Electronic Support Measures (ESM). The The ESM system is the Thales Sensors Outfit UAP(4). Outfit UAP(4) has two multi-function antenna arrays which are mounted on the two non-hull penetrating optronics masts from Thales (formerly Pilkington) Optronics and McTaggart Scott.
Astute Class submarines are to be fitted with the Royal Navy's new Eddystone Communications band Electronic Support Measures (CESM) system, also to be fitted to the Trafalgar Class submarines. The Eddystone system is being developed by DML of Devonport UK, with Argon ST of the USA. It will provide advanced communications, signal intercept, recognition, direction-finding and monitoring capability.
SENSORS
Astute is fitted with I-band navigation radars. The sonar is the Thales Underwater Systems (formerly Thomson Marconi Sonar) 2076 integrated passive / active search and attack sonar suite with bow, intercept, flank and towed arrays. Sonar 2076 has been fitted to three Trafalgar class submarines and entered service in February 2003.
Atlas Hydrographic will provide the DESO 25 high-precision echosounder, to be fitted on the Astute. DESO 25 is capable of precise depth measurements down to 10,000m.
Astute will have two non-hull-penetrating CM010 optronic masts developed by Thales Optronics. McTaggart Scott will supply the masts. The CM010 mast includes thermal imaging, low light TV and colour CCD TV sensors.
Raytheon Systems Ltd has been contracted to provide the Successor IFF (Identification Friend or Foe) naval transponder system for the Astute class.
PROPULSION
The nuclear power will be provided by the Rolls-Royce PWR 2 pressurised water reactor. The long-life core fitted on the PWR 2 means that refuelling will not be necessary in the service life of the submarine.
The other main items of machinery are two Alsthom turbines, and a single shaft with a Rolls-Royce pump jet propulsor, consisting of moving rotor blades within a fixed duct. There are two diesel alternators, one emergency drive motor and one auxiliary retractable propeller. CAE Electronics is to provide the digital, integrated controls and instrumentation system for steering, diving, depth control and platform management.
The PWR 2 second-generation nuclear reactor was developed for the Vanguard Class Trident submarines. Current generations of PWR would allow submarines to circumnavigate the world about 20 times, whereas the latest development of PWR would allow circumnavigation 40 times without refuelling.
The major equipment components in the development of PWR 2 are the reactor pressure vessels from Babcock Energy, main coolant pumps from GEC and from Weir, and protection and control instrumentation from Siemens Plessey and Thorn Automation.