Chieftain tank

The Chieftain FV4201 was the main battle tank of the United Kingdom during the 1960s, 1970s and 1980s. It was one of the most advanced tanks of its era, and at the time of its introduction in 1966 had the most powerful main gun and most effective armour of any tank in the world. The Chieftain also introduced a supine (reclining backwards) driver position, enabling a heavily sloped hull with reduced height. It remained in service until replaced by the Challenger 1.

Chieftain tank
Class Vehicle
Type Armoured Fighting Vehicle
Manufacturer Leyland Motors Limited
Origin United Kingdom - UK (Great Britain)
Country Name Origin Year
United Kingdom - UK (Great Britain) 1966
Country Name Operational Year Retirement Year
Iran (Persia) View
Iraq View
Jordan View
Kuwait View
Oman (Muscat) View
United Kingdom - UK (Great Britain) 1966 View
ManufacturerName Production From Production To Quantity
Leyland Motors Limited View

The Chieftain was an evolutionary development of the successful cruiser line of tanks that had emerged at the end of the Second World War. British engineers had learned during the war that their tanks often lacked sufficient protection and firepower compared to those fielded by the enemy, and that this had led to high casualty levels when faced with the superior German tanks in World War II. The Centurion addressed this to a great degree, combining higher levels of armour and an improved gun, which made it at least equal to any of the contemporary medium tanks. However, the introduction of the Soviet IS-3 heavy tank forced the introduction of their own Conqueror heavy tank, armed with a 120 mm (4.7 in) gun. A single design combining the firepower of the Conqueror's 120 mm gun with the mobility and general usefulness of the Centurion would be ideal.

Leyland, who had been involved in Centurion, had built their own prototypes of a new tank design in 1956, and these led to a War Office specification for a new tank. The General Staff specification drew on experience of Centurion in the Korean War and Conqueror. The tank was expected to be able to engage the enemy at long range and from defensive positions, be proof against medium artillery. To this end, the gun was to have a greater angle of depression than the 8 degrees of Conqueror and better frontal armour. The tank was expected to achieve 10 rounds per minute in the first minute and six per minute for the following four.

The first few prototypes were provided for troop trials from 1959, this identified a number of changes. Changes to address engine vibration and cooling resulted in redesign of the rear hull. This increased the design weight to nearly 50 tons and as such the suspension (which had been designed for 45 tons) was strengthened. Track pads had to be fitted to protect roads from damage and the ground clearance increased. The design was accepted in the early 1960s.

Britain and Israel had collaborated on the development in its latter stages with a view to Israel purchasing and domestically producing the vehicle. Two prototypes were delivered as part of a four year trial. However, it was eventually decided not to sell the marque to the Israelis, which prompted them to follow their own development programme.

In 1957, NATO had specified that its forces should use multi-fuel engines. The early BL Engine delivered around 450 bhp (340 kW) to the sprocket, which meant a top road speed of around 25 mph (40 km/h) and cross country performance was limited. This was further hampered by the Horstmann coil spring suspension, which made it a challenge to drive cross country and provide the crew with a comfortable ride. Due to the cylinder linings being pressure fitted, coolant leaks within the cylinder block were common, resulting in white smoke billowing from the exhaust.

In the late 1970s, engine design changed with the introduction of Belzona which was used to improve the lining seals. Engine output also increased, with later engines delivering some 850 bhp (630 kW) to the sprocket. This meant better performance and an increased speed. However, cross-country performance remained limited.

Several aspects of Chieftain design were trialled by the production of the FV4202 "40-ton Centurion" with a reclined driver position and mantleless gun mounting.

Like its European competitors, Chieftain found a large export market in the Middle East, but unlike Centurion, it was not adopted by any other NATO or Commonwealth country.

Chieftain proved itself capable in combat and able to be upgraded with enhancements, both for overall improvement and to meet local requirements. The marque was continuously upgraded until the early 1990s, when it was replaced by Challenger 1. The final Chieftain version, which was used by the British Army until 1995, incorporated "Stillbrew" armour named after Colonel Still and John Brewer from the Military Vehicles and Engineering Establishment (MVEE), the Improved Fire Control System (IFCS) and the Thermal Observation Gunnery Sight (TOGS). The last British Regiment equipped with Chieftain was the 1st Royal Tank Regiment, which was based at Aliwal Barracks, Tidworth.

The first model was introduced in 1967. Chieftain was supplied to at least six countries, including Iran, Kuwait, Oman and Jordan. An agreement for sales to Israel and local production was cancelled by the British Government in 1969, despite considerable Israeli technical and tactical input into the development of the tank, especially the capacity to operate successfully in desert environments, and the provision for the tank to make good use of hull-down positioning. Two examples were delivered to and extensively trialled by the Israeli Armoured Corps. This experience spurred the creation of the indigenous Israeli Merkava, the development programme of which was led by General Israel Tal, who had worked closely with the British in the Anglo-Israeli Chieftain project. The largest foreign sale was to Iran, which, at the recommendation of General Tal, took delivery of 707 Mk-3P and Mk-5P, 125–189 FV-4030-1, 41 ARV and 14 AVLB before the 1979 revolution. Further planned deliveries of the more capable 4030 series were cancelled at that point.

It was in the Middle East that the Chieftain was to see all of its operational experience. First, it was used extensively by Iran during the Iran–Iraq War of 1980–88, including the largest tank battle of the war, with mixed results as many suffered from chronic engine problems. The Cheiftain remains in service in Iran, the Mobarez tank being a locally upgraded version.

Kuwaiti Chieftains participated in the 1990 Iraq–Kuwait War. The Kuwaiti 35th Armored Brigade fought at the Battle of the Bridges against elements of the Iraqi Hammurabi and Medina divisions before withdrawing over the Saudi border 136 Kuwaiti Chieftains were lost. Only seven tanks managed to survive the war with Iraq.

Type Main battle tank
Place of origin United Kingdom
Service history
In service 1966–present
Used by UK, Iran, Iraq, Jordan, Kuwait,Oman
Wars Iran–Iraq War, Gulf War
Production history
Manufacturer Leyland Motors
Specifications
Weight 55 long tons (62 short tons; 56 t)
Length 35 ft 4 in (10.77 m) – gun forward
7.5 m (24 ft 7 in) – hull
Width 12 ft 0 in (3.66 m)
Height 2.9 m (9 ft 6 in)
Crew 4
Armour Glacis: 120 mm (4.7 in) (72°)
Hull sides: 38 mm (1.5 in) (10°)
Turret: 195 mm (7.7 in) (60°)
Main
armament
L11A5 120 mm rifled gun
Secondary
armament
2 × L7 Machine Gun
Engine Leyland L60 (multifuel 2-strokeopposed-piston compression-ignition)
750 hp (560 kW) 6 Cyl, 19 litres.
Power/weight 11.1 hp (8.3 kW)/ton (at sprocket)
Transmission TN 12
Suspension Horstmann
Ground clearance 1 ft 10 in (0.56 m))
Fuel capacity 195 imp gal (890 l)
Operational
range
500 km (310 miles) on roads
Speed Road: 48 km/h (30 mph)
Off road: 30 km/h (19 mph)

End notes