The FV4201 Chieftain was the primary
main battle tank
A main battle tank (MBT), also known as a battle tank or universal tank or simply tank,Ogorkiewicz 2018 p222 is a tank that fills the role of armour-protected direct fire and maneuver in many modern armies. Cold War-era development of more po ...
(MBT) of the
United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
from the 1960s into 1990s. Introduced in 1967, it was among the most heavily armed MBTs at the time, mounting a 120 mm
Royal Ordnance L11 gun, equivalent to the much larger specialist
heavy tank
A heavy tank is a tank classification produced from World War I to the end of the Cold War. These tanks generally sacrificed mobility and maneuverability for better armour protection and equal or greater firepower than tanks of lighter classes.
...
s in service. It was also among the most heavily armoured, with up to that was highly sloped to offer thickness along the line of sight.
A development from the
Centurion MBT, the Chieftain introduced the supine (reclining) driver position to British design allowing a heavily sloped hull with reduced height. A new powerpack and improved transmission gave it higher speed than the Centurion despite being heavier due to major upgrades to armour protection and the armament; this allowed it to replace both the Centurion and
Conqueror heavy tank while performing their roles effectively.
The multi-fuel engine proved to be the design's primary drawback leading to break downs; it was said that the Chieftain was extremely effective if it broke down in a useful location. This led to a series of improved models with new armour, sensors, engines and suspension systems, and these saw sales export success. Among these was the Shir 2 version for
Iran
Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...
, which added
Chobham armour, one of the first British uses of this armour. This order was cancelled due to the
Iranian Revolution
The Iranian Revolution (, ), also known as the 1979 Revolution, or the Islamic Revolution of 1979 (, ) was a series of events that culminated in the overthrow of the Pahlavi dynasty in 1979. The revolution led to the replacement of the Impe ...
in 1979.
It was intended that the Chieftain would be replaced by a new design, the
MBT-80
The FV4601 MBT-80 was a British experimental list of main battle tanks by generation#Third, third-generation main battle tank, designed in the late 1970s to replace the Chieftain (tank), Chieftain tank. It was eventually (and later controversia ...
. When tensions with the
Warsaw Pact
The Warsaw Pact (WP), formally the Treaty of Friendship, Co-operation and Mutual Assistance (TFCMA), was a Collective security#Collective defense, collective defense treaty signed in Warsaw, Polish People's Republic, Poland, between the Sovi ...
rose in 1980,
Vickers
Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in 18 ...
offered a further updated version of the Shir 2 which became
Challenger 1. This could be available years earlier and still met many of the MBT-80 design goals. Challenger deliveries began in 1983, but the Challenger initially proved problematic and the Chieftain remained in front-line service until 1996 with the introduction of the
Challenger 2.
Development
The Chieftain was an evolutionary development of the successful
cruiser
A cruiser is a type of warship. Modern cruisers are generally the largest ships in a fleet after aircraft carriers and amphibious assault ships, and can usually perform several operational roles from search-and-destroy to ocean escort to sea ...
line of tanks that had emerged at the end of the
Second World War
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
. Its predecessor, the
Centurion main battle tank (MBT), is widely considered to be one of the most successful of post-war MBT designs. However, the introduction of the Soviet
IS-3 /
IS-4 heavy tank
A heavy tank is a tank classification produced from World War I to the end of the Cold War. These tanks generally sacrificed mobility and maneuverability for better armour protection and equal or greater firepower than tanks of lighter classes.
...
along with Soviet
T-54/T-55 led to the introduction of the
Conqueror heavy tank armed with a gun. A single design combining the firepower of the Conqueror's 120 mm gun with the mobility and general usefulness of the Centurion was seen as the ideal combination.
Starting in 1950, a series of Concept Research Studies were undertaken "in the search for a design to succeed Centurion".
These involved both a development of the existing Centurion Heavy Cruiser Tank design, as well as a variety of unconventional concepts such as small 1 & 2 man tanks equipped with anti-tank missiles or auto-loading and liquid-propellant guns. in 1954 the decision was taken that "the next UK tank should be an evolutionary one designed to carry an HV gun with a bagged charge ammunition system".
Leyland, who had been involved in the Centurion tank, had built their own prototypes of a new tank design in 1956. Several aspects of the design were trialled by the production of the
FV4202 "40-ton Centurion" with a reclined driver position and mantletless gun mounting. In effect, the FV4202 was a shorter Centurion chassis with a prototype of what would become the Chieftain turret, but armed with the 20pdr gun.
This work led to a
War Office
The War Office has referred to several British government organisations throughout history, all relating to the army. It was a department of the British Government responsible for the administration of the British Army between 1857 and 1964, at ...
specification for a new tank. The General Staff specification drew on the experience of Centurion tanks in the
Korean War
The Korean War (25 June 1950 – 27 July 1953) was an armed conflict on the Korean Peninsula fought between North Korea (Democratic People's Republic of Korea; DPRK) and South Korea (Republic of Korea; ROK) and their allies. North Korea was s ...
as well as that of the Conqueror tank. The tank was expected to be able to engage the enemy at long range, from defensive positions, and 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 would be equipped with better frontal armour. The tank was expected to achieve a firing rate of 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 which identified a number of changes. Improvements to address engine vibration and cooling resulted in a redesign of the rear hull. This increased the design weight to nearly 50 tons and accordingly the suspension (which had been designed for 45 tons) was strengthened. Trackpads 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 (since, at that period of time in the late 1960s, the UK was more friendly towards the Arab states and Jordan than to Israel), which prompted them to follow their own development programme.

In 1957, NATO had specified that its forces should use multi-fuel engines. The early Leyland engine delivered around to the sprocket, which meant a top road speed of around and cross-country performance was limited. Whilst the
Horstmann coil spring suspension reduced the on-road ride-quality compared to tanks with torsion bar suspension, Colonel Peter Hamer of the 11th Hussars commented that "over really bad rough ground it could leave a
Leopard
The leopard (''Panthera pardus'') is one of the five extant cat species in the genus ''Panthera''. It has a pale yellowish to dark golden fur with dark spots grouped in rosettes. Its body is slender and muscular reaching a length of with a ...
for dead".
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 to the sprocket. This meant better performance and an increased speed. However, cross-country performance remained limited.
Design

The design of the Chieftain included a heavily sloped hull and turret which greatly increased the effective thickness of the frontal armour – on the glacis (from an actual thickness of ) and on the turret (from ).
[Richard Ogorkiewicz, ''Cold War, Hot Science: Applied Research in Britain's Defence Laboratories 1945–1990'' (2002), p.128-129, edited by Robert Bud & Philip Gummett, NMSI Trading Ltd, ] It had a
mantletless turret in order to take full advantage of reclining the vehicle up to ten degrees in a hull-down position.
For security reasons early prototypes had a canvas screen covering the mantlet and a sheet metal box mounted over the sloping glacis plate to disguise the configuration of the vehicle.
The driver lay semi-recumbent in the hull when his hatch was closed down which helped to reduce the profile of the forward glacis plate. The commander, gunner and loader were situated in the turret. To the left side of the turret was a large searchlight with infrared capability in an armoured housing.
The original design of the Chieftain tank called for a petrol "V8 Rolls Royce engine".
With a two year delay in the development of the V8 engine - "the decision was taken to drop the V8 and go with a yet to be produced multi fuel engine."
The
Leyland L60
The Leyland L60 was a British vertical six-cylinder Opposed-piston engine, opposed-piston Two-stroke engine, two-stroke multi-fuel diesel engine designed by Leyland Motors in the late 1950s/early 1960s for the Chieftain (tank), Chieftain main ...
engine is a
two-stroke
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a power cycle with two strokes of the piston, one up and one down, in one revolution of the crankshaft in contrast to a four-stroke engine which re ...
opposed piston design intended for
multi-fuel use so that it could run on whatever fuel was available. In practice the engine did not deliver the expected power and was unreliable, estimated to have a 90% breakdown rate but improvements were introduced to address this. Primary problems included
cylinder liner failure, fan drive problems and perpetual leaks due to vibration and badly routed pipework. However, as the engine power improved the tank itself became heavier.
The tank was steered by conventional tillers hydraulically actuating onto external brake discs. The discs worked via the
epicyclic gearbox providing "regenerative" steering. The
Merritt-Brown TN12 triple-differential gearbox was operated motorcycle-style with a kick up/kick down "peg" on the left, which actuated electro-hydraulic units in the gearbox, the accelerator cable was operated by the right foot. In the turret, the loader was on the left and the gunner on the right of the gun with the commander situated behind the gunner. The suspension was of the
Horstmann bogie type with large side steel plates to protect the tracks and provide stand-off protection from hollow charge attack.
The main armament was the
120 mm L11A5 rifled gun. This differed from most contemporary main tank armament as it used projectiles and charges that were loaded separately, as opposed to a single fixed round. The design of the Bagged Charge System was initiated after the earlier Liquid Propellant Gun project had failed due to the injection pump being so large that "no tank could accommodate it".
This led to design studies to find "means of reducing the ammunition size and from this the bagged charge concept emerged".
The charges were encased in combustible bags. Other tank guns such as the 120mm L1 gun on the Conqueror, needed to store the spent shell cartridges or eject them outside. The combustible charges were stored in 36 recesses surrounded by a pressurised
water/glycol mixture – so-called "wet-stowage". In the event of a hit penetrating the fighting compartment, the jacket would rupture soaking the charges and preventing a catastrophic propellant explosion. As there was no shell case, the firing of the charge was by vent tubes automatically loaded from a ten-round magazine on the breech.
Due to the length of the gun, which required balancing, and the need for storage space, the turret has a large overhang to the rear. This contains radios, ammunition and fire control equipment and has further stowage externally.
The gun could fire a wide range of ammunition but the most commonly loaded types were
high explosive squash head (HESH),
armour-piercing discarding sabot (APDS), or practice round equivalents for both types. The Chieftain could store up to 64 projectiles (although the propellant stowage allowed a maximum of 36 charges for APDS rounds). The gun was fully stabilised with a fully computerized integrated control system. The secondary armament consisted of a coaxial
L8A1 7.62 mm machine gun and another 7.62 mm machine gun mounted on the commander's cupola.
An advantage of using two-part ammunition was that in the case of inert rounds like APDS the loader could reach for the next round and hold it in his lap, ready to load while the gunner was acquiring the target and firing. This practice increases the rate of fire but would be hazardous with one-piece ammunition.
Chieftain had an
NBC protection system which Centurion lacked.
An
infantry telephone was fitted to the rear of the tank to facilitate communication with infantry.
The initial
Fire-control system (FCS) was the Marconi FV/GCE Mk 4. A .50-inch (12.7 mm)
ranging gun was mounted above the main gun (with 300 rounds available). This fired ranging shots out to a maximum of , at which point the tracer in the ranging rounds burned out although the high explosive tip still created a visible "splash" on impact. The tank commander had a rotating cupola with nine vision blocks -giving all round view, plus the 7.62 mm machine-gun and an infrared (IR) capable projector coaxial with the weapon. The aiming systems were provided for both the gunner and the tank commander; they had 1x or 10x selectable magnification power, increasing to x15 in the Mk5 and beyond, and they were replaceable with IR vision systems for night operations (3x magnification power). The commander could rotate his cupola to bring his sight onto a target and then engage the mechanism that brought the turret round on to the correct bearing so that the gunner could complete the aiming.
The commander's controls had over-ride capability on those of the gunner.

The left side of the turret had a large searchlight with an electrically controlled infrared filter inside an armoured box, with a relatively long range – up to .
[JP-4 dossier, ''Main Battle Tanks'' (1990), pp.35–36, edited by Ed.Ai. 1990, Florence]
From the beginning of the 1970s, the Mk 3/3 version replaced the ranging gun with a
Barr and Stroud LF-2
laser rangefinder with a range. This allowed engagements at much longer ranges, and also could be linked to the fire control system, allowing more rapid engagements and changes of target.
On later models, fire control was provided by the Marconi IFCS (Improved Fire Control System), using a digital ballistic computer. The upgrade was not finished until the end of 1980, when some examples (but not the majority) had the IR searchlight replaced with TOGS. Many later examples had
Stillbrew armour, intended to defeat Soviet 125 mm tank guns and heavy anti-tank missiles. These became the Mark 10 and then Mk 11 version.
The Chieftain used the TESS (TElescopic Sighting System) developed in the early 1980s that was later sold as surplus for use on the
RAF Phantom aircraft.
Service

During the Cold War, Chieftain tanks were deployed in units of the
British Army of the Rhine (BAOR) in West Germany to defend against a possible Warsaw Pact attack on the country.
Like its European competitors, the Chieftain found a large export market in the
Middle East
The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula, the Levant, Turkey, Egypt, Iran, and Iraq.
The term came into widespread usage by the United Kingdom and western Eur ...
, but unlike the Centurion, it was not adopted by any other
NATO
The North Atlantic Treaty Organization (NATO ; , OTAN), also called the North Atlantic Alliance, is an intergovernmental organization, intergovernmental Transnationalism, transnational military alliance of 32 Member states of NATO, member s ...
or Commonwealth country.
The Chieftain proved itself capable in combat and able to be upgraded, both for overall improvement and to meet local requirements. It 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 Chieftains was the
1st Royal Tank Regiment, which was based at
Aliwal Barracks, Tidworth.
The first model was introduced in 1967. Chieftains were supplied to at least six countries, including
Iran
Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...
,
Kuwait
Kuwait, officially the State of Kuwait, is a country in West Asia and the geopolitical region known as the Middle East. It is situated in the northern edge of the Arabian Peninsula at the head of the Persian Gulf, bordering Iraq to Iraq–Kuwait ...
,
Oman
Oman, officially the Sultanate of Oman, is a country located on the southeastern coast of the Arabian Peninsula in West Asia and the Middle East. It shares land borders with Saudi Arabia, the United Arab Emirates, and Yemen. Oman’s coastline ...
and
Jordan
Jordan, officially the Hashemite Kingdom of Jordan, is a country in the Southern Levant region of West Asia. Jordan is bordered by Syria to the north, Iraq to the east, Saudi Arabia to the south, and Israel and the occupied Palestinian ter ...
. An agreement for sales to
Israel
Israel, officially the State of Israel, is a country in West Asia. It Borders of Israel, shares borders with Lebanon to the north, Syria to the north-east, Jordan to the east, Egypt to the south-west, and the Mediterranean Sea to the west. Isr ...
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
In sailing and warfare, to be hull down means that the upper part of a vessel or vehicle is visible, but the main, lower body (Hull (watercraft), hull) is not; the term hull up means that all of the body is visible. The terms originated with sai ...
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 was led by General
Israel Tal
Israel Tal (; 13 September 1924 – 8 September 2010), also known as Talik (Hebrew: טליק), was an Israel Defense Forces (IDF) general known for his knowledge of tank warfare and for leading the development of Israel's Merkava tank.
Biography
...
, who had worked closely with the British in the Anglo-Israeli Chieftain project. The largest foreign sale was to Iran, who, at the recommendation of General Tal, took delivery of 707 Mk-3P and Mk-5P (the letter P standing for Persia), as well as 187 FV4030-1, 41 ARV and 14 AVLB before the
1979 revolution.
Further planned deliveries of the more capable FV4030-2 (Shir 1) and FV4030-3 (Shir 2) series were cancelled at that point.
It was in the Middle East that the Chieftain was to see all of its operational experience. It was first used extensively by Iran, during the
Iran–Iraq War
The Iran–Iraq War, also known as the First Gulf War, was an armed conflict between Iran and Iraq that lasted from September 1980 to August 1988. Active hostilities began with the Iraqi invasion of Iran and lasted for nearly eight years, unti ...
of 1980–88, including the
largest tank battle of the war, with mixed results as the Chieftain Mk 3/5 suffered from chronic engine problems and low
power-to-weight ratio
Power-to-weight ratio (PWR, also called specific power, or power-to-mass ratio) is a calculation commonly applied to engines and mobile power sources to enable the comparison of one unit or design to another. Power-to-weight ratio is a measurement ...
, making it unreliable and slow when manoeuvering over harsh terrain, which in turn made it prone to breakdowns in the midst of battle or a sluggish target and thus vulnerable to enemy tank fire.
[ After the tank battle at ]Susangerd
Susangerd () is a city in the Central District (Dasht-e Azadegan County), Central District of Dasht-e Azadegan County, Khuzestan province, Khuzestan province, Iran, serving as capital of both the county and the district. The vast majority of i ...
, captured Chieftains of the Iranian 92nd Armored Division
The 92nd Armored Division, also called 92nd Armored Division of Ahvaz or 92nd Armored Division of Khuzestan (), is an armored division of the Islamic Republic of Iran Army, first formed during the reign of the Shah.
In September 1980, among the ...
were taken back to Baghdad for trials. According to Aladdin Makki, the Iraqi Army Corps chief of staff, in a post-war interview, Iraqi sabot rounds "Went through the front armour of the Chieftain and came out the backside". This as well as the Chieftain's poor off-road capability influenced the Iraqis to reject British arms sale propositions, who were at the time courting Iraq for arms sales that included Chieftain MBT's. According to Makki, when the British telephoned the Iraqi director of Armor, Salah Askar, he responded with "We don't want your stupid tanks!" Ra'ad Al-Hamdani, an Iraqi general in the Republican Guard, also expressed negative opinion on the Chieftain's performance in combat, stating "The 16th Iranian Armored Division, which was equipped with Chieftain tanks, lost a battle against the 10th Iraqi Armored Brigade with T-72
The T-72 is a family of Soviet Union, Soviet main battle tanks that entered production in 1973. The T-72 was a development based on the T-64 using thought and design of the previous Object 167M. About 25,000 T-72 tanks have been built, and refu ...
tanks. It is hard for an armored brigade to destroy a division in 12 hours but it happened; it was a disaster for the Iranians". Out of the 894 Chieftain tanks that had started the war only 200 were left by the war's end.
The Chieftain remains in service in Iran, with the Mobarez tank being a locally upgraded version.
Kuwait and the Battle of the Bridges
Kuwait had 143 Chieftains on the eve of the 1990 Iraqi Invasion of Kuwait
The Iraqi invasion of Kuwait, codenamed Project 17, began on 2 August 1990 and marked the beginning of the Gulf War. After defeating the Kuwait, State of Kuwait on 4 August 1990, Ba'athist Iraq, Iraq went on to militarily occupy the country fo ...
. Thirty-seven Chieftains of 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. Kuwaiti 35th Armored Brigade failed to block the Mutla Pass and were ineffective at delaying the Iraqis, however they withdrew into the desert and became part of '' Joint Command Forces East'' during the 1991 Gulf War
, combatant2 =
, commander1 =
, commander2 =
, strength1 = Over 950,000 soldiers3,113 tanks1,800 aircraft2,200 artillery systems
, page = https://www.govinfo.gov/content/pkg/GAOREPORTS-PEMD-96- ...
.
Besides those of the 35th Armored Brigade, the rest of the Kuwaiti Armed Forces' Chieftains (136 tanks) were either destroyed or captured by the invading forces after they had been abandoned by their Kuwaiti crews when their ammunition ran out. After the liberation of Kuwait, the ageing Chieftains were replaced by the Yugoslav M-84
The M-84 is a Socialist Federal Republic of Yugoslavia, Yugoslav main battle tank based on the Soviet T-72. It is still in service with Bosnia and Herzegovina, Croatia, Serbia, Slovenia and Kuwait.
Development and production
Development
The ...
.
Specifications (Mk. 5)
* Crew: 4
* Combat weight: 55 tons
* Overall length: gun forward
* Hull length:
* Height:
* Width:
* Powerplant: Opposed-piston engine
An opposed-piston engine is a piston engine in which each cylinder (engine), cylinder has a piston at both ends, and no cylinder head. Petrol and diesel opposed-piston engines have been used mostly in large applications such as ships, military ...
Leyland L60
The Leyland L60 was a British vertical six-cylinder Opposed-piston engine, opposed-piston Two-stroke engine, two-stroke multi-fuel diesel engine designed by Leyland Motors in the late 1950s/early 1960s for the Chieftain (tank), Chieftain main ...
(diesel, multi-fuel compression ignition)
* Range:
* Maximum road speed:
* Cross-country speed:
* Armour: turret front, RHA (60°)
;Armament
* 120 mm L11A5 rifled tank gun
** Rate of fire: 10 rounds per minute for the first minute and 6 thereafter.
** Elevation: −10 to +20 degree
** Laser rangefinder
* Coaxial L8A1 7.62 mm machine gun
* Cupola-mounted L37A1 7.62mm machine gun
Mark 1 and Mark 2 models had a coaxial Browning .50-inch (12.7 mm) ranging machine guns prior to the introduction of the laser rangefinder on the Mark 3/3 then later the Mark 5 model.
;Equipment
* Twin Clansman VRC 353 VHF Radio sets (1979 onward)
* 1 C42 1 B47 Larkspur VHF radios (pre 1979)
* 2 X 6-barrel smoke dischargers on turret
* Bulldozer blade (optional – fitted to one tank per squadron)
Variants
; FV4201 P1 – FV4201 P7:
:Prototypes. Seven built, L60 Mk 1 or L60 Mk 4, initial vehicles had internal exhaust silencers, short hull, small diameter road wheels. In an attempt at reducing the overall height of the vehicle the original design used road wheels of a smaller diameter which gave insufficient ground clearance. They were later replaced with Centurion road wheels of a larger diameter and by careful re-positioning of their mountings along with adjustment of the idler and final drive mountings resulted in a vehicle height only higher than with the original smaller wheels. Initial vehicle weight ; for later vehicles, 1959-1962
; Chieftain Mk.1
: 40 training vehicles for 1965–1966 with L60 Mk 4 engine, strengthened TN12 gearbox, exhaust silencers moved to external armoured box on hull rear plate, larger 'Centurion' diameter road wheels, re-positioned final drive and idler wheel assemblies, two-piece commander's hatch cover, rubber track pads fitted for road protection in West Germany
West Germany was the common English name for the Federal Republic of Germany (FRG) from its formation on 23 May 1949 until German reunification, its reunification with East Germany on 3 October 1990. It is sometimes known as the Bonn Republi ...
, resilient rubber coaming around engine rear decking to prevent damage from gun with gun depression when turret traversed to the rear, stowage rack added to left rear of turret, dummy stowage 'bin' on front glacis and canvas cover over turret nose to conceal ballistic shapes, weight , Issued to 1 RTR and 5 RTR for troop trials. All Mk.1 to Mk.1/4 vehicles were subsequently to be based at Bovington Camp and Catterick Garrison
Catterick Garrison is a major garrison and List of modern military towns, military town south of Richmond, North Yorkshire, Richmond, North Yorkshire, England. It is the largest British Army garrison in the world, with a population of around 14 ...
. 11 short hull units converted to become Chieftain, Armoured Vehicle-Launched Bridge Mk.6 (CH AVLB Mk 6).
; Chieftain Mk.1/2
: Upgrade of Chieftain Mk.1 to Chieftain Mk.2 standard, fitted with 650 hp L60 Mk 4A2 engine, training use only
; Chieftain Mk.1/3
: Upgrade of Chieftain Mk.1, fitted with 650 hpL60 Mk 5A engine, training use only
; Chieftain Mk.1/4
: Upgrade of Chieftain Mk.1, fitted with 650 hp L60 Mk 6A engine and improved ranging gun, training use only.
; Chieftain Mk.2: First service model with 650 hp L60 Mk 4A2 engine, L11A2 or L11A3 main gun, NBC system fitted to rear of turret, revised turret stowage, one-piece commander's hatch cover, armour removed from searchlight cover, rigid flotation panels replaced by facility for deep wading, road speed , range , weight , first vehicles issued to 11th Hussars at Hohne in West Germany in early 1967, improved L60 Mk 5A engine fitted 1969
; Chieftain Mk.3:Improved 650 hp L60 Mk 6A engine with two-stage air cleaner, improved auxiliary generator ( Coventry Climax H30), better stowage, new No. 15 Mk 2 commander's cupola, road speed improved to , range increased to , weight , 1970
; Chieftain Mk 3/2: Fitted with L60 Mk 7A, 1971
; Chieftain Mk 3/3: Fitted with 720 hp L60 Mk 7A, Improved main gun range finding, provision for Barr & Stroud TLS (Tank Laser Sight) LF2 laser range finder, With the LF2, the Chieftain became the first vehicle to be fitted with such a range-finding system. 1971
; Chieftain Mk 3/G: Chieftain Mk.3 with engine induction through fighting compartment. Prototype only
; Chieftain Mk.3/3P: Chieftain Mk 3/3 for Iran
Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...
, 1973
; Chieftain Mk 3/S: Production version of Chieftain Mk 3/G with commander's firing control
; Chieftain Mk.4
:Chieftain Mk.3 with increased fuel capacity for Israel Defense Forces
The Israel Defense Forces (IDF; , ), alternatively referred to by the Hebrew-language acronym (), is the national military of the State of Israel. It consists of three service branches: the Israeli Ground Forces, the Israeli Air Force, and ...
(IDF). Only two built. 1973. The Chieftain Mk.4 project was halted at the behest of the British Government due to the perceived adverse effect the sale of Chieftain to Israel was likely to have on the balance of power within the region. Of the two Mk.4 vehicles built, one was scrapped, the other "02 SP 27" was fitted with an NCK Rapier crane and used at Kirkcudbright Training Area
; Chieftain Mk.5: Final production variant, L60 Mark 8A, with upgrades to the NBC protection system, weight , 1975
; Chieftain Mk.5/5P: Chieftain Mk.5 for Iran
Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...
, 1975. Engine later upgraded to L60 Mk 10A, 1977
; Chieftain Mk.5/2K: Chieftain Mk.5 for Kuwait
Kuwait, officially the State of Kuwait, is a country in West Asia and the geopolitical region known as the Middle East. It is situated in the northern edge of the Arabian Peninsula at the head of the Persian Gulf, bordering Iraq to Iraq–Kuwait ...
, 1975
In 1975 all British Army earlier Marks of tanks except Mark 1s were upgraded to Chieftain Mk.5 standard as part of the 1975 "Totem Pole" programme. "Exercise Totem Pole" was carried out in six-to-nine phases depending on the Mark of vehicle being modified (Chieftain Mk.5's already had some of the required changes incorporated at the factory) between 1975 and 1979 and included fitment of the Marconi Improved Fire Control System (IFCS), replacement of the searchlight with the Barr & Stroud Thermal Observation Gunnery System (TOGS), along with modifications for using FSAPDS ammunition. Upon completion of each phase the vehicle received an additional suffix to the designation, e.g., "Chieftain Mk.3/S(Y)2" denoting a Mark 3/S having completed the first three phases of "Totem Pole". including addition of Clansman radios, fitting of TLS, fitment of Muzzle Reference System (MRS) upon replacement of L11A3 barrel with L11A5 barrel, and fitment of 750 hp L60 Mark 8A. These vehicles were re-designated Chieftain Mk's.6 to Mk.8.
; Chieftain Mk.6
:Chieftain Mk.2 upgraded to Chieftain Mk.5 standard, 1975
; Chieftain Mk.7
:Chieftain Mk.3 and Chieftain Mk 3/S upgraded to Chieftain Mk.5 standard, 1975
; Chieftain Mk.7C
:Chieftain Mk.3 upgraded to Chieftain Mk.5 standard for Oman
Oman, officially the Sultanate of Oman, is a country located on the southeastern coast of the Arabian Peninsula in West Asia and the Middle East. It shares land borders with Saudi Arabia, the United Arab Emirates, and Yemen. Oman’s coastline ...
; Chieftain Mk.8
:Chieftain Mk.3/3 upgraded to Chieftain Mk.5 standard, 1975
In 1977 the engines of all British Army vehicles were upgraded to the 750 hp L60 Mark 9A, followed by further upgrading with the L60 Mark 11A or L60 Mark 12A in 1978 as part of the 1977 "Dark Morn" and the 1978 "Sundance" programmes. "Exercise Sundance" concerned improvements in engine power, reliability, and other power train improvements, and was carried out in five main phases between 1976 and 1979. These, in themselves, had been preceded by "Dark Morn", "High Noon", and the initial "Fleetfoot" engine development programme which had completed in October 1971. Vehicles on which "Sundance" modifications had been carried out received an additional 'Z' suffix appended to their designations, the "Sundance" engines themselves were signified with a distinctive orange/yellow-coloured upper crankcase.
; Chieftain Mk.9
:Chieftain Mk.6 after completing all phases of "Totem Pole", 1979.
; Chieftain Mk.10: Chieftain Mk.7 after completing all phases of "Totem Pole". Later upgraded with addition of Stillbrew Crew Protection Package which added additional armour to the turret front and turret ring to increase turret frontal protection against HEAT
In thermodynamics, heat is energy in transfer between a thermodynamic system and its surroundings by such mechanisms as thermal conduction, electromagnetic radiation, and friction, which are microscopic in nature, involving sub-atomic, ato ...
rounds, specifically, the improved variants of the Soviet-made RPG-7, etc., and consisted of conventional steel armour mounted on rubber pads to prevent vibration, 1984–86
; Chieftain Mk.11: Chieftain Mk.8 after completing all phases of "Totem Pole". Later upgraded with Stillbrew, 1984–86
; Chieftain Mk.12: Chieftain Mk.5 after completing all phases of "Totem Pole". Later upgraded with Stillbrew, 1984–86
; Chieftain Mk.12/13: Proposed further upgrades, cancelled when the Challenger 1 was introduced.
; Chieftain 800: Re-engined Iranian FV4030/1 Chieftain Mark 5/3P fitted with the Rolls-Royce CV8 TCA engine and the fully automatic TN12 Mk. 5 transmission.
; Chieftain 900: Two Mk. 5/3 (P) were converted by Royal Ordnance Factories by fitting the Rolls-Royce Condor 900E engine and the fully automatic TN12-1000 version of the Chieftain's gearbox, hence the name of Chieftain 900. The two Chieftain 900 prototypes were built in April 1982 and were exhibited the same year at the British Army Equipment Exhibition (BAEE). They were not fitted with real Chobham armour but were mocked up with cosmetic sheet-metal cladding to simulate the Chobham armour package. The project was abandoned by 1986.
; FV4030/1 Chieftain Mk. 5/3 (P) « Persia » : Also known as "Project 4030 Phase 1" or "Improved Chieftain". The Mk. 5/3P featured the Tank Laser Sight (TLS), the Muzzle Reference System (MRS), a fully automatic controller for the TN12 gearbox, a fuel capacity increase, thickened underbelly mine armour and shock absorbers fitted to the front and rear suspension units. 185 vehicles were built between August 1976 and late 1977/early 1978.
; FV4030/2 Shir (Lion) 1: Also known as "4030 Phase 2". This tank formed Phase 2 of the Iranian contract for the supply of a new generation of MBTs (Phase 1 being for an Improved Chieftain). This project began in 1974. Shir 1 incorporated the Chieftain hull front and turret casting. The rear of the hull was reconfigured to accept a new power pack comprising Rolls-Royce CV12 (a turbocharged V12 four-stroke diesel engine), David Brown TN37 transmission and new cooling group. An improved bogie suspension (Super Horstmann), new final drives and tracks were included. The first vehicle-ran in April 1977 and no production deliveries had taken place when the project was cancelled in February 1979.
; Khalid: Also known as "4030 Phase 2 Jordan". The sale of 274 MBTs was negotiated with Jordan in June 1979 following the cancellation of the Iranian contract. The Khalid tank is based on the Shir 1 design with the addition of the Integrated Fire Control System (IFCS), Tank Laser Sight (TLS) and the No 84 Day/Night Sight. The first 125 were reworked Shir 1s and the remaining 149 were new production tanks. The order has been completed, the first being delivered in July 1981.
;FV4030/3 Shir 2: Also known as "'4030 Phase 3'" Iranian variant. The Shir 2 represented a completely new-MBT incorporating Chobham armour (renamed "Pageant" to avoid diplomatic incident with the US government) to the hull and turret, with the rear of the hull similar in design to the Shir 1. The fire control, gun control and automotive systems were the same as Shir 1 with the following exceptions: Automotive - the option of adopting hydrogas suspension and command & control, the new No 84 commander's (PPE) day/night sight. The project began in 1974 and the first vehicle ran in October 1978. The production order was for 1,200 MBTs and production release given for 250 before cancellation in February 1979. Not delivered, the Shir 2 tanks became FV4030/4 Challenger 1 tanks after reworking at ROF Leeds.
; Mobarez Tank:Iranian upgraded version of Chieftain. :
;Chieftain/ T95: Development of the FV4201 Chieftain allowed for the interchangeability of guns with the U.S. T95 tank by means of exchanging turrets. The project was discontinued because of numerous problems with training crews to master two artillery systems. Equipped with a 90mm T208 (rifled) gun.
;FV4211: Test vehicle using Chieftain automotive sub systems (including the L60 engine), embodied in a new aluminium hull and turret structure incorporating Chobham Armour (CA) for the first time. The project began in October 1969. A feasibility study was completed by February 1970 which led to MVEE being asked to design and produce a prototype within a year. This timescale was achieved, the MVEE produced the first prototype in February 1971. Although the project was officially discontinued in 1972, research work within MVEE continued until 1974. A paper study on a Mk. 2 version was carried out and was considered during the FMBT (Future Main Battle Tank) studies in 1974.
; FV4204 ARV/ARRV: Armoured Recovery Vehicle, Armoured Recovery and Repair Vehicle.
; FV4205 AVLB Mk5: Bridge-laying vehicle
; Chieftain AVRE (CHAVRE): Armoured Vehicle Royal Engineers, twelve early "Willich Chieftain AVRE" vehicles converted by 32 Armoured Engineer Regiment and 21 Engineer Base Workshop of the Royal Engineers, Willich, 1987, remaining 48 ex MBTs converted by Vickers Defence Ltd, 1991, to be a British Army combat engineering variant used by the Royal Engineers
The Corps of Royal Engineers, usually called the Royal Engineers (RE), and commonly known as the ''Sappers'', is the engineering arm of the British Army. It provides military engineering and other technical support to the British Armed Forces ...
.
; Chieftain Fascine Layer: Four turret-less vehicles specially converted for laying fascine
A fascine (pronounced ) is a rough bundle of wikt:brushwood, brushwood or other material used for strengthening an earthen structure, or making a path across uneven or wet terrain. Typical uses are protecting the banks of streams from erosion (a ...
s
; Chieftain Marksman: Self-propelled anti-aircraft gun version, equipped with the Marksman twin gun turret.
; Chieftain Mineclearer: Mine-clearing development.
; Chieftain Sabre: Twin 30 mm AA turret.
; Chieftain SID: Chieftain Signature Integration Demonstrator.
:Two vehicles modified from Chieftain Mk.12 for TRIGAT trials aimed at reducing battlefield reflectivity and emissions
; Chieftain Crazy Horse: Mobile Range Hard Target.
:Modified from Chieftain Mk.1 with gun removed and incorporating Skyleader radio control. Remotely controlled range target for use with inert rounds. Used in conjunction with modified Alvis Stormer command vehicle. One built. 1987.
; Weapon Carriers: The Chieftain chassis was adapted to mount air defence weapons ("Marksman" 2 x 35 mm cannon) and a 155 mm howitzer in a number of variants.
Operators
Current
* : 100 Chieftain Mk3/Mk5 and 20 ARV in 2004. In the 1970s, Iran's Pahlavi government ordered and received 792 Chieftains including 707 Mark 3/3P and 5P MBTs, 71 Chieftain ARVs (fitted with Atlas cranes), 14 AVLBs, and 187 FV4030.
* : 27 delivered 1981–85.
Former
* : Used from 1965 to 1995.
* : 274 Khalid delivered between 1981 and 1985 + 90 MK3/5 (captured Iranian tanks) from Iraq. In storage.
* : 50-75 tanks, captured from Iran, in service with Iraqi Army in 1990. Most upgraded to Khalid-level, with air conditioning for the crew and reinforced armour and night vision.
Evaluation-only
* : Two prototypes for evaluation .
* : One Chieftain was tested alongside a Leopard tank between 15 January and 22 March 1968 by the ''Detachement ter Beproeving van Voertuigen'' ("Detachment for Testing of Vehicles") of the Royal Netherlands Army
The Royal Netherlands Army (, KL) is the Ground warfare, land branch of the Netherlands Armed Forces. Though the Royal Netherlands Army was raised on 9 January 1814, its origins date back to 1572, when the was raised making the Dutch standing a ...
; the tank was allocated British registration number 03 EB 81 and Dutch number KZ-99-65. The Leopard was eventually selected largely because of the Chieftain's poor construction quality, especially the engine, which leaked so much oil that the engine compartment turned black.
See also
Tanks of comparable role, performance and era
*
* (Early models)
*
*
*
*
* : Approximate Soviet equivalent
Notes
References
;Citations
;Bibliography
*
*
*
External links
FAS.org
Chieftain Tank
{{Authority control
Main battle tanks of the United Kingdom
Cold War tanks of the United Kingdom
Military vehicles introduced in the 1960s
Main battle tanks of the Cold War
History of the tank