Page last updated at 20 Jun 2011

Latest Astute class weapons systems ordered

Babcock has recently received the full contract to deliver its weapon handling and launch system (WHLS) for the fifth Astute class submarine new generation nuclear powered attack (SSN) submarine. The system is the first on a UK Royal Navy submarine to use Babcock's advanced air turbine pump and programmable firing valve technology, with a number of important advantages.

Babcock has designed and supplied the WHLS for the first four Astute class boats (Astute, Ambush, Artful and Audacious) under earlier contracts. The latest contract for WHLS equipment for boat 5 follows an earlier contract for the long-lead items, and is accompanied by a long-lead items contract for boat 6.

The Astute class WHLS comprises more than 20,000 components, it is capable of carrying more torpedoes and tube-launched missiles than any previous class of RN submarine, and is smaller, quieter, and more flexible, optimising firing profiles for the range of weapon types that the system can carry.

The handling system comprises equipment to embark, store, reposition and load weapons into the torpedo tubes. Configuration of the weapons within the Weapon Stowage Compartment (WSC) has been carefully developed, resulting in the highest packing density of weapons in the stowage compartment. Weapons are protected in the WSC using a unique method of shock mounting, which provides adaptable protection according to the number of weapons stored on each stowage tier. This improves crew safety and maximises potential for the system to continue to function following a shock event.

The launch system uses an air turbine pump (ATP) to achieve a positive launch firing mechanism. The ATP is an air driven rotary pump that displaces a volume of water to launch a weapon from a torpedo tube. Uniquely, Babcock uses a programmable firing valve (PFV) to control the ATP firing air profile, allowing the system to match the launch requirements precisely to a range of variables including weapon type, boat speed and depth.

The ATP and PFV system on Astute offers significant performance advantages over previous systems, including the water ram systems currently in service with the Royal Navy. As well as being smaller, with space saving benefits, it is more efficient (using substantially less firing air), and has acoustic advantages (lower noise signature), and an extended operational lifecycle. The installation of two ATP/PFV systems per boat, giving independent port and starboard operation, provides operational and reliability benefits.

In weapons trials of the first WHLS on Astute, weapon shapes have been successfully launched from all six tubes as part of ongoing design proving activities.

"All the ATPs were first tested at our launch test facility, including performing water shots and firing weapon shapes to confirm each pump's characteristics, which enabled us to optimise the pumps' performance before fitting to the boat," Babcock Project Director Gavin Borland explained. "This can yield considerable programme and cost advantages to the customer. Further test-firings at sea have also been successfully completed, testing the full functionality of the installed ATPs to launch a range of weapons at a variety of depths and speeds. Astute's WHLS is an advanced, highly capable, and reliable system for a submarine that is said to be the most potent and technologically advanced SSN ever to serve with the Royal Navy."

BAE Systems Head of Supply Chain - Complex Systems, George Teasdale, said: "The signing of the Performance Partnering Agreement (PPA) for the placement of the Boat 5 contract and the Boat 6 long lead opportunity demonstrates the long term commitment between BAE Systems and Babcock. Collectively we are striving for continuous improvements in performance as measured through BAE Systems Supplier Performance Review (SPR) process. Through various relationships management initiatives both BAE and Babcock have adopted a one team approach to meeting the enormous challenges both commercially and technically of supplying such a complex scope of supply as the Weapons Handling and Launch System. The dedication and excellent support provided to the Astute submarine programme by Babcock have enabled the signing of the PPA."

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