In 1956, Leyland Motors (who had been the lead designer for the Centurion Mk. 7) built three prototypes, designated the FV4202. It was similar to the Centurion but had only five roadwheels, a new turret that lacked a mantlet and the driver sat in a reclined position to reduce the height of the hull. The last two details were adopted for the new Chieftain main battle tank (FV4201) whose overall specification was issued in 1958. The first mock-up was built in 1959 and the first prototype later the same year. A further six prototypes had been built by April 1962 and during that year crews from the 1st and 5th Royal Tank Regiments came from Germany to help test the new vehicle. Two prototypes of the new Chieftain went over to Germany in December 1962 to commence trials there. The Chieftain was accepted for service in 1963 and entered service in 1967 with the 11th Hussars and 17/21 Lancers. Two production lines for the Chieftain were set up, the first at the Royal Ordnance factory in Leeds (bought by Vickers in 1986), and the second, at the Vickers' plant at Elswick. Around 900 Chieftains were built for the British Army with production being completed in the early 1970s. Iran ordered 707 Chieftains in 1971 (Mk. 3/3(P) and Mk. 5/3(P)) with a number of armoured recovery vehicles and bridgelayers. Iran also took delivery of some 187 improved Chieftains, designated the FV4030/1 which carried more fuel, had improved mine protection and additional shock absorbers as well as electronic control of the David Brown Defence Equipment TN12 transmission. Subsequent to this, in 1974 Iran ordered 1,225 Shir 2s, but as an interim measure ordered 125 Shir 1s but the order was cancelled in 1979 after the Islamic Revolution. Jordan however, ordered the Shir 1 under the name Khalid, which had a number of modifications including a new Perkins Engines Company Condor V-12 1200 diesel (1,200hp), a David Brown Defence Equipment TN37 transmission and a Howden Aircontrol cooling system. The British Army eventually accepted the Shir 2 for service as the Challenger. Oman also bought a number of Chieftain Mk. 15s (named Qayd Al Ardh) in the mid-1980s. The hull of the Chieftain is made of cast and rolled steel sections welded together. The driver sits at the front of the hull, with the loader on the left and commander and gunner on the right of the turret. The Chieftain mounts a Royal Ordnance 120mm L11A5 rifled gun fitted with a Pilkington Optronics laser rangefinder. In the 1970s, British Army Chieftains were fitted with the Thermal Observation and Gunnery Sight (TOGS - which was also fitted to the Challenger), GEC-Marconi fully integrated Improved Fire Control System, Stillbrew armour and the No. 11 NBC system. A 7.62mm L8A1 machine gun is mounted coaxially with the main gun and a 7.62mm L37A1 machine gun is mounted on the commander cupola. The engine is a Leyland L60 No. 4 Mk. 8A diesel, which generates 750hp and is coupled to a TN12 transmission. There are a number of specialised variants of the Chieftain which are still in service with the British Army. These include the Armoured Vehicle Royal Engineer (AVRE designated the FV4203), Armoured Repair and Recovery Vehicle (ARRV) and Armoured Recovery Vehicle (ARV designated FV4204) and Armoured Vehicle-Launched Bridge (AVLB designated FV4205) which carries the No. 8 or No. 9 Tank Bridge.
(Mk. 5) Hull length: 7.52m. Hull width: 3.5m (with skirts). Height: 2.9m. Crew: 4. Ground Clearance: 0.51m. Weight: 55,000kg (combat). Ground pressure: 0.9kg/sq.cm. Max speed: 48km/h. Max range (internal fuel): up to 500km on road. Armament: 120mm rifled main gun, 1 x 7.62mm MG coaxial, 1 x 7.62mm MG on commander's cupola.
BIBLIOGRAPHY
Forty, George. Cheiftain, 1979, 1st Edition, Ian Allen Ltd, Shepperton, Modern Combat Vehicles No. 1.
[/url]