BY the end of the conflict in Europe 1945, all those on the victorius side had been traumatised by their experience at the hands of German armour, and especially Main Battle Tanks; US, Russian and British equipment seemed to be constantly one or two steps behind the German designers up until the very end of the war, with the heralded arrival of both the FV 4007 Centurion and the M26 Pershing tanks.
Radically different lessons were drawn from this experience, however. The Russians, and later both the French and Germans, saw the future of the MBT in as many 35-45 ton vehicles as possible, with firepower and protection taking second place to speed. The British however took the lessons of both the Western Desert and the Bocage to heart, and decided that a heavily armoured vehicle with massive firepower was the only way to minimise British tank casualties in any future European conflict.
This view was crystallised by the alarming appearance of the Soviet T10 heavy tank in 1955; Weighing 55 tons and carrying a 122mm gun, this final variant of the Iosef Stalin line could penetrate 450 mm thick amour at a range of 2000m, thus outmatching any of NATO's own vehicles. Britain's short-term answer was the FV214 "Conqueror" heavy tank, produced from 1955 to 1958. Conqueror was armed with a 120 mm rifled gun but was both cumbersome and difficult to maintain, and when Centurion tanks were upgunned to 105mm, Conqueror was phased out of service.
Centurion was extremely successful in both British and foreign service, but the Soviet Union was constantly revising and replacing its fleet with newer models. Now cleaving fully to the philosophy that "quantity has a quality all its own", it developed and deployed in rapid succession, the T54, T55 and T62 This series of MBTs were designed for the mass offensive; cheap and easy to build and maintain, relatively fast, and with a 100mm smoothbore gun. The UK's dwindling budget could not afford a fleet to match such vehicles, but it could build a smaller force of well-armoured MBTs, with an accurate and highly-effective long-range gun, that theoretically could survive just long enough to blunt the thrust of the Warsaw Pact hordes flooding across the Inner German Border at the start of World War III.
In 1956, Leyland Motors (who had been the lead designer for the Centurion Mk. 7) had privately built three prototypes, designated the FV4202. This vehicle 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 main battle tank - FV4201 - whose overall specification was issued by The War Office in 1958. Chieftain continued the tradition of British tank names beginning with a 'C' and was manned by a crew of four (driver, gunner, loader and commander). 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 then went over to Germany in late 1962 to commence trials there.
Powered by the Leyland 750bhp six-cylinder diesel/multi-fuel engine it had a top speed of 48 kmh and a range of 500 km. Chieftain also possessed collective NBC protection, and was fitted with self contained air purification, water supply and feeding facilities, so that its crew of four could live 'closed down' in nuclear- or chemically-contaminated environments for anything up to a week.
The hull of the Chieftain was made of both cast and rolled steel sections welded together. The driver sat at the front centre of the hull, with the loader on the left and commander and gunner on the right of the turret. Armor Thickness was in excess of 300mm RHA.
Chieftain was accepted for service in 1963 and entered service in 1967 with the 11th Hussars and 17/21st 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.
Chieftain mounted a Royal Ordnance 120mm L11A5 rifled gun fitted with a Pilkington Optronics laser rangefinder plus 12 (initially 6) individual smoke grenade launchers on the turret; earlier models had a .50" ranging gun as a crude but effective range-finder. In the 1970s, British Army variants 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 (IFCS), ROMOR/"Stillbrew" armour, and the upgraded No. 11 NBC system. It could also be fitted with a dozer blade to dig itself into a fire position.
A 7.62mm L8A1 machine gun was mounted coaxially with the main gun, and a 7.62mm L37A1 machine gun on the commander's cupola. The engine was a Leyland L60 No. 4 Mk. 8A, which generated 750hp and was coupled to a David Brown Defence Equipment TN12 transmission.
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 transmission.
Subsequent to this, in 1974 Iran ordered 1,225 Shir 2s, and as an interim measure prepared to take delivery of 125 Shir 1s, but the whole order was cancelled in 1979 after the Islamic Revolution. The British Army eventually accepted the Shir 1 for service as the Challenger 1.
Jordan also ordered the Shir 1 under the name Khalid, albeit with a number of modifications, including a new Perkins Engines Company Condor V-12 1200 diesel (with 1,200bhp), a DBDE TN37 transmission, and a Howden Aircontrol cooling system. Oman also bought a number of Chieftain Mk. 15s (named Qayd Al Ardh) in the mid-1980s.
During fighting in the Middle East, Iraq captured between approximately 300 Chieftain MBTs from Iran, many of which were undamaged. In 1988, Iraq passed 90 Chieftains on to Jordan amongst a large quantity of military equipment.
There are a number of specialised variants of the Chieftain - some of which are still in service with the British Army. These include the FV4203 Armoured Vehicle Royal Engineer (AVRE), FV4204 Armoured Recovery Vehicle (ARV) and Armoured Repair and Recovery Vehicle (ARRV - a converted ARV with a a hydraulic crane that can lift a complete Challenger MBT power pack and hydraulic track tensioners), as well as the FV4205 Armoured Vehicle-Launched Bridge (AVLB) which can carry one of a range of 5 different deployable tank bridges on its turretless superstructure.
(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.
Chieftain PP1 - Initial production prototype. FV4020 - Design concept vehicle for the Chieftain. Chieftain Mk 1 - Pre-production vehicle - only 40 examples built. Chieftain Mk 1/2 - Mk 1 brought up to Mk 2 standard (training). Chieftain Mk 1/3 - Mk 1 with a new power pack (training). Chieftain Mk 1/4 - Mk 1 with a new power pack and modified RMG (training) Chieftain Mk 2 - Redesigned turret with new cupola. Chieftain Mk 3 - Improved engines, dry-air cleaner element, modified No 15 Mk 2 cupola. Chieftain Mk 3/2 - Improved electrical equipment and air cleaners. Chieftain Mk 3/3 - Mk 3 with ER RMG, laser rangefinder, 720bhp engine & modified NBC pack. Chieftain Mk 3S - Production model of Mk 3/G with turret air-breathing and commander's firing switch. Chieftain Mk 4 - Only two built; greater fuel capacity and minor modifications. Chieftain Mk.5: Final production variant, development of the Mk 3/3 with with powerplant upgrades new full-width nbc pack on rear of turret.
Chieftain Mk.6-11 were incremental upgrades to earlier models. Chieftain Mk 6 - Mk 2 rebuilt to Mk 5 with new power pack and modified RMG. Chieftain Mk 6 AVLB - Converted Chieftain Mk 1/4 gun tanks Chieftain Mk 7 - Mk 3 rebuilt to Mk 5 with improved engine and modified RMG Chieftain Mk 8 - Mk 3/3 rebuilt to Mk 5 with improved engine and modified RMG. Chieftain Mk 9 - MK 6 fitted with IFCS. Chieftain Mk 10 - Mk 7 fitted with IFCS. Chieftain Mk 11 - Mk 8 fitted with IFCS, Stillbrew, TOGS and No 11 NBC system. Chieftain Mk 12 - Mk 5 fitted with IFCS, Stillbrew, TOGS and No 11 NBC system.
Chieftain Mk 5/5K - Kuwaiti Army version.
Chieftain Mk 7/2c - Original Version supplied to Oman in August 1981 Chieftain Mk 15 - Improved Omani Army version, aka Qayd Al Ardh, fitted with BAe L20 sight & GEC-Marconi/Ferranti Type 520 laser rangefinder (delivered 1984-85)
Chieftain Mk 3/3P - Iranian Army version (delivered 1971-78) Chieftain Mk 5/5P - Iranian Army version (delivered 1971-78) FV4030/1 - Improved Iranian Army version (delivered prior to 1978)
Khalid - Version of the Shir 1 supplied to Jordan with CV12 1200hp engine and No 84 sight.
Last updated by WarpSpasm 23 May 05