The British Chieftain tank
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 FV 4201 Chieftain

Main battle tank (1966)
United Kingdom - around 2280 built in all

A difficult task, do better than the Centurion

The Chieftain was a development on the legendary Centurion, which defined the standard of MBTs in the fifties, and dominated the battlefield in the Middle East during most of the cold war. However the FV4201 built by Leyland Motors was a brand new main battle tank aimed at exceeding all expectations placed on the design. Its main rifled Royal Ordnance L11A5 120mm gun was specifically tailored and became the new standard in OTAN. Its cross-country speed was better than the Centurion and it can maintain it longer than the lighter Leopard I in this respect.


The Chieftain originated from a British Leyland design for a new tank dating from as early as 1950, when the War office stated a replacement for the Centurion as the Medium Tank No 2. Two main features had to be included: A brand new L11 120mm main gun. A new thicker sloped armour which was capable of dealing with new Soviet HEAT and other AT rounds. The new Leyland L60 engine .

For at least twenty years the "magic triangle" speed-armour-armament was not achieved as well as for the Centurion. The hull was Some features included a mantle-less turret allowing a superior depression angle. The turret was well sloped and roomy, allowing the loader, commander and gunner to be comfortably housed. A large infra-red searchlight was installed on the left side of the turret. Smoke grenade launchers were mounted on the front of the turret, while the rear received a large gallery to house spare parts and magazines, acting as an extra protection. Large storage bins were also mounted on the tracks covers, and from 1966, additional side skirts were mounted to protect the main part of the tracks.

Main Characteristics

The Mk.I was equipped with the Leyland L60, an ingenious two-stroke opposed piston design for multi-fuel use. But this engine proved unreliable and not powerful enough to allow speeds close to those achieved by the Centurion, with an average 18.64-21.74 mph (30-35 km/h). The motor was enhanced several times, and issues were fixed while it became far more powerful, although additional armour and equipment added weight at the same time. In 1974 the newly introduced Belzona variant gave 850 hp, which was a great improvement compared to the original BL with 450 bhp. The final speed was around 48 km/h (29.82 mph) on road. However the muzzle velocity and accuracy of the main L11A5 rifled gun easily compensates for this lack of mobility. With years of tactical exercises and well-understood limitations, the Chieftain proved a formidable asset in the British army arsenal. The turret was fitted since the beginning with a coaxial L7 and later L8A1 7.62 mm (0.30 in) machine-gun, with a second one in commander's cupola and a Marconi FV/GCE Mk.IV A cal.50 (12,7 mm) ranging gun was mounted over the main gun, capable of ranges up to 2400 meters (1.49 mi). Ammunition comprised HESH (high explosive) and APDS (armour-piercing). 62 rounds were carried. The large rotating commander's cupola had nine openings, a periscope, an infra-red projector with up to x8 magnification power and an alternative IR vision system. The turret main IR range-finder was coupled with an armoured searchlight capable of lighting targets at 0.62-0.93 miles (1 to 1.5 km). The Chieftain was fitted with a complete NBC system.

Lineage, variants and evolution

The first 1965 forty Mk.I batch was so slow that they were quickly reclassified as training tanks. In 1967 Mk.II's were fitted with a more powerful 650 hp engine. This was the first main service version. The later Mk.III was another service model fitted with additional equipments. The Mk.V of 1970 was the final, mass-produced version with a new 850 bhp engine and NBC protection. The 1979 Mk.VI-9 was an upgraded version. All previous tanks were fitted to this new standard which introduced Clansman radios and many other improvements. The Mk.X was mostly an improvement of the turret armour, the Stillbrew crew protection package, and most tanks were upgraded to this standard by 1985. The Mk.XI was another upgrade, including the TOGS (Thermal Observation and Gunnery System) and a laser range-finder in 1988-90. Another upgrade was cancelled as the Challenger entered service. Other British-only variants included the Chieftain 900 with Cobham armour and a handful of FV4204 ARV (armed recovery vehicle) and FV4205 AVLB (bridge-layers), AVRE for the Royal British engineers, the Chieftain Marksman, a twin-gun anti-aircraft version, the Sabre, with a twin 30 mm version, and a mine clearer version.

Chieftain Mk.X at Bovington
A Chieftain Mk.X at Bovington


The Chieftain, like the Centurion before, was largely exported to the Middle East, although it was not adopted by any country within NATO. The first main export variant was the Khalid Shir (Lion) also known as the 40302PJ for Jordan, which included the running gear of the Challenger Mk.I, and later the Shir 2 upgraded at Leeds for Iran, with a reworked rear which allowed to mount the Rolls Royce CV8 engine of the Challenger. The Jordanian Shir 1 comprised 274 tropicalized tanks which were delivered from 1980 to 1985. The Shir 2 was basically an improvement of the Chieftain Mk.V and was built exclusively for Iran which still remains today in first line service, this was upgraded locally and known as the Mobarez. Other variants of the Chieftain were sold to Iran from 1975 to 1979, with 707 Mk-3P and Mk-5P, 125-189 FV-4030-1, 41 ARV and 14 AVLB being delivered, and fighting during the Iran-Iraq war. Other tanks were exported to Iraq (30), Kuwait (267 from 1976 to 1995), and Oman (27). All these are still in first line service. Many Kuwaiti tanks were destroyed during the Iraqi invasion of 1990, and avenged by British Chieftains during Operation Desert Storm.

A test-bed for the Challenger

The Challenger was planned in 1985 to replace the Chieftain, but was largely based on the latter. Technological improvements were mostly new electronic and numeric device and range-finders, communication system, ammunition loading, updated armour and a much more powerful Rolls-Royce engine. The latter provided a much needed greater speed, although the mechanical gear train and hull were basically unchanged since the Chieftain. The first tanks were delivered in 1990.
FV4201 prototype in 1965
FV 4201 prototype in 1965, without storage boxes and side skirts.
chieftain mk1
Chieftain Mk.I main battle tank. The first production version Mk.I in the seventies. They were upgraded and still in existence in 2000 as training tanks.
chieftain mkIII
The Chieftain Tank Mk.III in its urban livery from 1985. The Mk. III was the main upgraded version of the British army. Many of these remained first line until 1995.

chieftain Mk.V 4th RTR
Chieftain Mk.V from the 4th battalion Royal Tank Regiment stationed near Tilworth in 1984.

Chieftain Mark XI BATUS, equipped with TOGS fro the British Army training Suffield, early 1990s.


Chieftain MBT at RAF base Manby, 1990s.
Chieftain MBT at RAF base Manby, 1990s.

FV 4201 specifications

Dimensions : 35.43/24.6 x 11.48 x 9.51 ft (10.8 oa/7.5 m x 3.5 m x 2.9 m)
Total weight, battle ready 55 tons (11000 Ibs)
Crew 4 (commander, driver, gunner, loader).
Propulsion British Leyland diesel BL 40, 450-650 bhp, later BL 60, 695 bhp
Speed 48/30 km/h road/cross-country (29.82/18.64 mph)
Range/consumption 500 km (310.68 mi)
Armament One L11A1 120 mm (4.7in) with Marconi cal.50 gun
One coaxial 7,62 mm L8A1 (0.3 OTAN) machine-gun
One cupola mounted AA L37A1 7,62 (0.3 OTAN) machine-gun
Armour turret front 7.6in, glacis 4.72in, sides 1.37in (195/120/35 mm)
Ammunition used Antipersonal HESH, armour-piercing APDS.
Total production 900 for Great Britain alone, up to 1381 export variants



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