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.
The role of the 20,600t aircraft carrier is to provide a command headquarters for the task group and to support the operations of the short take off and vertical landing aircraft and helicopters. The ship accommodates over 1,000 crew, including 350 aircrew 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.
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.
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/min 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/min 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/min.
COUNTERMEASURES
The Invincible class is fitted with the Thales Defence Type 675(2) jamming system and a UAT(

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 ship supports nine Harrier aircraft (both the Royal Air Force GR7/GR9 Harrier II and the Royal Navy FA2 Sea Harrier, now operated by the combined RAF/RN Joint Force Harrier), nine Sea King HAS 6 antisubmarine warfare helicopters and three Sea King AEW 2 and ASaC Mk 7 airborne early warning helicopters. FA2 Sea Harrier aircraft will be retired by 2007. Landing trials with the Merlin HM.1 helicopter have taken place on the Ark Royal, which is the first carrier to deploy the Merlin.
The runway is about 170m long with a ski ramp set at 12°. In the hangar deck the aircraft is tethered to the floor using securing chains with tension clamps. Strachan and Henshaw have been contracted to install a replacement aircraft carrier lift system.
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 the Kelvin Hughes Type 1006 navigation radar and HMS Illustrious has the Type 1007, both operating at I-band.
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 28 knots. At the economical speed of 19 knots the range of the ship is 7000 miles.