Invincible Class Aircraft Carriers, United Kingdom

The first-of-class HMS Invincible aircraft carrier was built by Vickers Shipbuilding and Engineering (now BAE Systems Marine) at Barrow-in-Furness. The ship was commissioned in July 1980. The two sister ships HMS Illustrious and HMS Ark Royal, both built at the Swan Hunter Shipbuilders yard in Wallsend, were commissioned in 1982 and 1985.

Since the end of the Cold War, the primary role of the 20,600t aircraft carriers has changed from sea control to maritime force projection, to include maritime strike, littoral manoeuvres and command and control of land operations. The vessels now embark a Tailored Air Group (TAG), consisting of Joint Force Harrier (JFH) aircraft and Sea King and Merlin helicopters.

The ship accommodates over 1,000 crew, including 350 air crew with 80 officers. It also has capacity for an additional 500 marines.

The vessels were armed with a Sea Dart twin launcher, installed on the forecastle of the ship near the ski ramp. However, the missile system has been removed from all three carriers and the flight deck extended, to provide more capacity for aircraft and enable take-off for RAF Harrier GR.7/9 aircraft. HMS Invincible completed a refit in March 2003. Illustrious completed refit at Babcock's Rosyth yard in November 2004.

In March / April 2003, HMS Ark Royal was deployed as part of the UK task force in support of Operation Iraqi Freedom. On board were Merlin HMA1 and Sea King ASaC Mk 7 helicopters, the first operational deployment of these aircraft.

Ark Royal completed a refit in September 2006 which included the fitting of better aviation facilities, an enhanced communications mast, SCOT 5 satellite communications system, Bowman command and control communications system, electronic charting and towed sonar decoy system. The refit allows the vessel to take on additional commando and helicopter carrier roles as well as maritime strike, and command and control platform.

Ark Royal can now carry up to 400 troops and RAF Chinook helicopters, as well as Army Apaches and Navy Sea King and Merlin helicopters. Ark Royal officially rejoined the fleet in December 2006 and began a two-month period of sea training in January 2007 before returning to active service.

HMS Invincible was decommissioned in August 2005. However, she has not been withdrawn from service and will remain available to the Navy until 2010.

COMMAND SYSTEMS

The combat data system is BAE Systems ADIMP with communication links Link 10, Link 11 and Link 14. Following refit, HMS Invincible has had the combat system upgraded to the same standard as Illustrious and Ark Royal, with new multi-function consoles and flat-panel colour displays. The secure satellite communications system, the Astrium (formerly Matra Marconi) SCOT, has the capacity to handle data rates up to 2Mb/s.

BAE Systems is upgrading the combat data system on Illustrious and Ark Royal with Link 16, for anti-air warfare control and aircraft direction, and a new IFF (Interrogation Friend or Foe) tracking capability.

GUNS

HMS Ark Royal is armed with three Mark 15 Phalanx close-in weapon systems (CIWS) from Raytheon and General Dynamics. Each Phalanx CIWS has one 20mm M61A1 Vulcan Gatling-principle gun which fires 3,000 rounds a minute at a range of 1.5km.

HMS Invincible and Illustrious each have three Thales Nederland (formerly Signaal) Goalkeeper CIWS. Goalkeeper's Gatling principle 30mm gun provides a maximum firing rate of 4,200 rounds a minute with a range of 1,500m.

All three carriers are also equipped with two GAM-B01 20mm guns from Oerlikon-Contraves and BAE SYSTEMS, which have a maximum range of 2km and firing rate of 1,000 rounds a minute.

COUNTERMEASURES

The Invincible class is fitted with the Thales Defence Type 675(2) jamming system and a UAT(8) electronic support measures system also supplied by Thales Defence (formerly Racal).

The ship's decoy system is the Royal Navy's Outfit DLJ with Sea Gnat. There are eight 130mm six-barrel launchers produced by Hunting Engineering. Chemring and Pains Wessex produce the Sea Gnat chaff and infra-red decoys.

AIRCRAFT

The Tailored Air Group (TAG) is composed of up to 24 aircraft including up to nine combined RAF/RN Joint Force Harrier GR7/GR9 aircraft. The Royal Navy FA2 Sea Harrier aircraft were progressively withdrawn from service from March 2004 and the last squadron was decommissioned in March 2006.

The TAG includes a mix of helicopters, depending on role: Sea King ASaC Mk 7 airborne early warning helicopters, Sea King and Chinook support helicopters and Merlin HM.1 anti-submarine helicopters.

The runway is about 170m long with a ski ramp set at 12°. In the hangar deck the aircraft are tethered to the floor using securing chains with tension clamps. Strachan and Henshaw have been contracted to install a replacement aircraft carrier lift system. Selex Sensors & Airborne Systems (formerly Galileo Avionica) was contracted to supply the SPN-720 precision approach radar for the landing of Harrier GR9 aircraft on Ark Royal and Illustrious in February 2005.

SENSORS

The BAE Systems Type 909 G/H-band fire control radar, which provided target tracking and illumination for the Sea Dart missile, has been removed from the three carriers. BAE Systems Type 996 surface search radar antennae is mounted very high on the tower between the two funnels. HMS Ark Royal has Type 992.

Both radars operate at E and F-bands. BAE Systems Type 1022 air search radar operates at D-band. HMS Invincible and Ark Royal are equipped with Kelvin Hughes Type 1006 navigation radar and HMS Illustrious has Type 1007, both operating at I-band.

Ark Royal and Illustrious are being fitted with the Galileo Avionica SPN-720 precision approach radar to provide landing guidance for the Harrier GR9 aircraft.

Qinetiq, with Babcock Design & Technology, has been awarded a contract to provide an advanced technology mast communications and radar mast for HMS Ark Royal. The sensors and antennas will be housed within the structure, protected from the environment. The mast is due to enter service in late 2005.

The sonar system is the hull-mounted Type 2016 active / passive search and attack sonar by Thales Underwater Systems (formerly Thomson Marconi Sonar).

PROPULSION

The ship is powered by COGAG (Combined Gas turbine And Gas turbine), consisting of four Rolls-Royce Olympus TM3B gas turbine engines generating 97,000hp, providing a speed of 28kt. At the economical speed of 19kt the range of the ship is 7,000 miles.

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