FV4201 Chieftain Mark 11C Main Battle Tank (E1996.2025)
Chieftain was one of the first true Main Battle Tanks, designed to replace both medium and heavy tanks in front line service. However it also incorporated a lot of revolutionary design features, some of which did not work as well as expected. For example, in order to reduce height the driver lies in a reclining position and changes gear with his foot. The gun uses a self-combusting, bagged charge in place of a brass cartridge case and the tank is powered by a multi-fuel engine.
The engine was a Leyland design, developed from a pre-war German diesel aircraft engine. It has six vertical cylinders containing twelve opposed pistons, working on the two-stroke principle. Although essentially a diesel it was capable of running on a variety of fuels. The TN12 gearbox, offering six forward speeds and two reverse, includes a triple-differential steering system.
Late production Chieftains were continually upgraded. This Mark 11 would have been built as a Mark 5, with an uprated engine, which was subsequently fitted with Improved Fire Control System (IFCS), Thermal Observation and Gunnery System (TOGS) and the additional Stillbrew armour on the turret front and around the driver's hatch. Chieftain served with the British Army into the early nineties and enjoyed modest success on the export market in the Middle East.
Precise Name: FV4201 Main Battle Tank, Chieftain Mark 12
The Chieftain was the British Army’s first Main Battle Tank, that is a single type of tank that replaced both heavy tanks (such as the FV214 Conqueror, see E1965.16.1) and medium tanks like the Centurion (See E1975.39).
Design studies began in the early 1950s and some experimental vehicles were produced to evaluate particular technical features. One of the most important was the ’40 ton Centurion’ (FV4202) which introduced a semi-reclining position for the driver and a main gun mounting without an external mantlet. The first of these features was intended to reduce the overall height of the tank; the second made the gun mounting less vulnerable.
The prototype Chieftain was shown to the press in the summer of 1961. The design emphasised firepower and protection. Following extensive trials the Chieftain Mark 2 entered service with the 11th Hussars in the autumn of 1966. The Chieftain introduced a number of innovations, some of which gave considerable trouble in service. The driver sat in a semi-reclining position to reduce the tank’s height and changed gear with his foot. The L11 120mm gun used a self-combusting bagged charge instead of a brass cartridge case: the gun proved to be highly successful.
The engine, the Leyland L60 specially developed for the Chieftain, was a different story. It had six vertical cylinders each containing 2 opposed pistons working on the two-stroke principle. A diesel, it was capable of running on a variety of fuels. The engine was intended to produce 750bhp; early versions managed 585bhp. Eventually the engine delivered 720bhp but it continued to be chronically unreliable. After extensive modifications reasonable reliability was eventually achieved. The L60 was coupled to a TN12 gearbox and transmission with six forwards and two reverse speeds.
The Chieftain was continually upgraded during its’ service life. This particular tank, a Chieftain Mark 12, was originally manufactured as a Mark 5. It was subsequently fitted with a laser range finder; a computerised fire control system (IFCS), thermal sights (TOGS) and additional compound armour on the front of the turret and around the driver’s hatch (so-called Stillbrew armour). The L60 engine was continually modified and improved to increase its’ output and reliability. The end result of all these changes was a very formidable AFV. It is currently displayed outside the main entrance to the museum alongside one of the Challenger 1 prototypes.
The Chieftain hull was used for a range of specialised AFVs, including armoured recovery vehicles (ARV and ARRV), bridge layers (AVLB) and combat engineering tanks (AVRE). In all more than 2200 Chieftains of all types were manufactured by the Royal Ordnance Factories and Vickers Ltd.: 900 of these served with the British Army while the remaining 1,300 tanks were exported to Iran, Jordan, Kuwait and the Oman.
The Museum’s Mark 12 served with the 10th Hussars, the 4th Royal Tank Regiment, the 4th/7th Royal Dragoon Guards, the Royal Hussars and the 2nd Armoured Delivery Squadron, all in BAOR. Iranian Chieftains engaged Iraqi tanks during the Iran-Iraq war while Kuwaiti Chieftains fought the Iraqi army during the invasion of Kuwait in 1990.
Chieftain gun tanks were withdrawn from front-line service with the British Army during the late 1980s and early 1990s. However Chieftain recovery and combat engineering vehicles served with the British Army during the operations to liberate Kuwait in 1991 (Desert Storm). The Tank Museum also has a Chieftain Mark 10 on display, (see E1993.61.3).
Summary text by Mike Garth V1.1