Astute-class vessel

The UK Ministry of Defence (MoD) has awarded a contract to Babcock for the delivery of its weapon handling and launch system (WHLS) in support of the Royal Navy’s sixth and seventh Astute-class nuclear powered submarines, HMS Agamemnon (S124) and HMS Ajax (S125).

It follows an earlier contract for long-lead items, worth approximately £55m.

Consisting of equipment to embark, store, reposition and load weapons into the torpedo tubes, the handling system improves crew safety, while the launch system uses an air turbine pump (ATP) to achieve a positive launch firing mechanism.

Designed as an air-driven rotary pump, the ATP launches a weapon from a torpedo tube by displacing a volume of water.

Additional features of the WHLS system include a programmable firing valve (PFV) technology that controls the ATP firing air profile.

The PFV enables the system to match the launch requirements such as weapon type, boat speed and depth.

Each Astute-class submarine will be equipped with two ATP/PFV systems, to offer operational and reliability benefits by providing independent port and starboard operation.

Powered by a Rolls-Royce PWR 2 second-generation nuclear reactor, the 93m-long, 11.3m-wide Astute-class submarines will eventually replace existing Swiftsure and Trafalgar-class vessels for the UK Navy.

"Designed as an air-driven rotary pump, the ATP launches a weapon from a torpedo tube by displacing a volume of water."

Capable of cruising at a submerged speed of 54km/h, the 7,400t Astute-class vessel can also carry a crew of 110 and is armed with 36 torpedoes and missiles, including Tomahawk cruise missiles, Spearfish torpedoes and mines with six 533mm torpedo tubes.

Astute-class vessels also feature UAP4 electronic support measures (ESM) system, two non-hull-penetrating CM010 optronic masts, as well as Successor identification friend or foe (IFF) naval transponder systems.

Under previous contracts, the company delivered the WHLS for the first five Astute-class submarines including HMS Astute (S119), HMS Ambush (S120), HMS Artful (S121), HMS Audacious (S122) and HMS Anson (S123).

The WHLS for the sixth Astute-class submarine is scheduled for delivery in spring 2014.

Image: A Royal Navy’s Astute-class submarine at sea. Photo: courtesy of Babcock International.

Defence technology