M26E1

Chieftain Mk 10

Chieftain Mk 5

Challenger Mk.2

Chieftain Mk 10

Chieftain Mk 5

Challenger Mk.2

Britain

VI Rank

Battle rating:

AB	RB	SB
9.0	9.0	9.0

Class:

Medium tank

Research:190 000

Purchase:520 000

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This page is about the British medium tank Chieftain Mk 10. For other uses, see Chieftain (Family).

Description

The Chieftain Mk 10 is a rank VI British medium tank with a battle rating of 9.0 (AB/RB/SB). It was introduced in Update 1.71 "New E.R.A.".

The Chieftain Mk 10 is the first vehicle available in the British main research tree with APFSDS available for research, significantly improving the vehicle's gun performance once unlocked.

General info

Survivability and armour

The Chieftain Mk.10 sports identical hull armour to the earlier variants, however the turret is augmented with Stillbrew composite armour, providing near-complete frontal protection when in hull-down positioning, with the exceptions of the small area around the gun breech and a small section of visible turret ring. The Chieftain's Stillbrew package offers extremely effective protection against most kinetic rounds, with only rounds available on vehicles such as the T-80B and Type 90 able to penetrate it.

The vehicle's hull armour should be considered essentially non-existent relative to the weaponry it faces; in most cases a hull shot will result in penetration.

Armour types:

• Stillbrew composite armour (turret front, turret ring)
• Cast homogeneous armour (hull front, turret)
• Rolled homogeneous armour (hull sides, hull rear, hull roof, turret roof)
• Aluminium (side skirts)

Armour	Front	Sides	Rear	Roof
Hull	70-127 mm (40-79°) Front glacis 76.2 mm (40-45°) Lower glacis 200* mm (0-45°) Turret ring	88-220 (8-30°) + 13 mm Front Top 50 mm (1-31°) Center Top 37 mm (30°) + 13 mm Rear Top 37 (10°) + 13 mm Bottom	37 mm (1-7°)	13-28 mm
Turret	125-250 + 80-150* mm (2-81°) Turret front 100-220 mm (1-53°) Gun mantlet	45-196 mm (1-65°)	45 mm (1°)	50.8 mm Front 25 mm Rear
Armour	Sides	Roof
Cupola	150 mm	25 mm
Composite armour*	Front	Sides	Rear	Roof
Hull	Turret ring: 200 mm Kinetic 200 mm Chemical	N/A	N/A	N/A
Turret	Turret front: 450 mm Kinetic 500 mm Chemical	N/A	N/A	N/A

Notes:

• Suspension wheels and tracks are 20 mm thick.
• Belly armour is 16 mm of RHA.
• Stillbrew armour at turret ring is pure 200 mm CHA.
• Stillbrew armour on turret front is composed of (80 to 150 mm CHA) + (60 mm rubber) + (150 to 250 mm CHA).

Mobility

Game Mode	Max Speed (km/h)		Weight (tons)	Engine power (horsepower)		Power-to-weight ratio (hp/ton)
	Forward	Reverse		Stock	Upgraded	Stock	Upgraded
Arcade	54	13	57.2	1178	1,450	20.59	25.35
Realistic	49	12		672	760	11.75	13.29

The Chieftain Mk 10's mobility is extremely sub-par, particularly when considering the vehicles it will face regularly - such as the Leopard A1A1 or the AMX-30 Super. While the vehicle is technically capable of a maximum of 48 km/h in RB/SB, the lacklustre power and the Chieftain Mk 10's significant weight result in this speed being essentially unattainable except in on-road downhills.

As such, Chieftain Mk 10 players should not rely on their mobility for anything; rather they should make their way to positions with good visibility and attempt to maintain ranged engagements only, relying on their turret armour.

Armaments

Main armament

The L11 120mm Rifled Cannon is reasonably competitive at the Chieftain's rank, although it does suffer from a somewhat mediocre reload time. The weapon is extremely accurate, particularly once utilising the L23 APFSDS round, and performs admirably in ranged engagements. The weapon's default APDS and HESH rounds can be used to good effect against most targets, given careful aim and target selection.

120 mm Ordnance BL Tk. L11					Turret rotation speed (°/s)					Reloading rate (seconds)
Mode	Capacity	Vertical	Horizontal	Stabilizer	Stock	Upgraded	Full	Expert	Aced	Stock	Full	Expert	Aced
Arcade	53	-10°/+20°	±180°	Two-plane	21.4	29.6	36.0	39.8	42.2	9.7	8.6	7.9	7.5
Realistic					13.4	15.8	19.1	21.1	22.5

Ammunition

Penetration statistics
Ammunition	Type of warhead	Penetration @ 0° Angle of Attack (mm)
		10 m	100 m	500 m	1,000 m	1,500 m	2,000 m
Shell L31A7	HESH	152	152	152	152	152	152
Shot L15A3	APDS	320	315	305	294	280	270
Shot L23	APFSDS	410	408	405	400	390	380

Shell details
Ammunition	Type of warhead	Velocity (m/s)	Projectile Mass (kg)	Fuse delay (m)	Fuse sensitivity (mm)	Explosive Mass (TNT equivalent) (g)	Normalisation at 30° from horizontal	Ricochet
								0%	50%	100%
Shell L31A7	HESH	670	17.1	0.4	0.1	5,248	+0.0°	73°	77°	80°
Shot L15A3	APDS	1,370	7.6	N/A	N/A	N/A	+1.5°	75°	78°	80°
Shot L23	APFSDS	1,535	3.89	N/A	N/A	N/A	+1.5°	76°	77°	80°

Smoke shell characteristics
Ammunition	Velocity (m/s)	Projectile Mass (kg)	Screen radius (m)	Screen deploy time (s)	Screen hold time (s)	Explosive Mass (TNT equivalent) (g)
L34	670	17.1	20	5	25	50

Ammo racks

Full ammo	1st rack empty	2nd rack empty	3rd rack empty	4th rack empty	5th rack empty	6th rack empty	Visual discrepancy
53	__ (+__)	__ (+__)	__ (+__)	__ (+__)	__ (+__)	__ (+__)	__

Optics

Chieftain Mk 10 Optics
	Default magnification	Maximum magnification
Main Gun optics	X8.0	X10.3
Comparable optics	___

Machine guns

The Chieftain's two machine guns are not powerful, but can be used as deterrent for close air support and may be used to destroy incoming ATGMs, with a bit of luck.

7.62 mm L37A1
Mount	Capacity (Belt capacity)	Rate of fire (shots/minute)	Vertical guidance	Horizontal guidance
Commander's cupola	2,000 (100)	650	-10°/+50°	±120°

7.62 mm L8A1
Mount	Capacity (Belt capacity)	Rate of fire (shots/minute)	Vertical guidance	Horizontal guidance
Coaxial	6,000 (200)	600	N/A	N/A

Usage in battles

The Chieftain Mk 10 plays similarly to the Mk 3/Mk 5 - ideally taking long-ranged engagements from hull-down positions, or when forced into shorter-ranged engagements avoiding exposing the vehicle as much as possible. Fortunately, the Stillbrew addition on the Mk.10 significantly reduces the risks of exposing the turret, with the composite capable of deflecting most kinetic rounds it will face - although the armour package is not invulnerable to chemical rounds; some powerful HEAT rounds and most late ATGMs will easily punch through it. Augmenting the vehicle's ability further is the (researchable) access to L23 APFSDS, which significantly improves the L11's long range efficacy. Despite these improvements, the Chieftain still suffers from mediocre mobility and care must be taken to ensure one does not get engaged while the vehicle is moving, as the ability to quickly move into cover is often not an option.

Specific Adversaries

T-64B/T-80B: The Chieftain is susceptible to the T-64B and T-80B at close to medium ranges, where their highest-performance APFSDS rounds or their ATGMs are capable of punching through the Stillbrew armour. As such, when forced to engage either of these vehicles try to force mistakes by staying in cover, encouraging them to move within your firing line rather than attempting to brute-force your way through them.

Leopard 2K: The Leopard 2K is a dangerous adversary due to its speed and ability to move quickly and potentially flank the Chieftain Mk.10, as well as its 650mm HEAT round which the Stillbrew will not reliably protect against. The Leopard is however fairly easy to destroy due to its essentially non-existent armour - although don't underestimate the ability for the sharp angles to bounce rounds.

AMX-40: The AMX-40 is a threat to the Chieftain Mk.10 for similar reasons to the Leopard 2K; as with the Leopard, be wary of flanks and the power of the AMX-40's APFSDS.

Modules

Tier	Mobility		Protection	Firepower
I	Tracks		Parts	Horizontal Drive
II	Suspension	Brake System	FPE	Adjustment of Fire	NVD
III	Filters		Crew Replenishment	Elevation Mechanism	Shot L23	Smoke grenade
IV	Transmission	Engine		L34	Laser rangefinder	Artillery Support

Pros and cons

Pros:

• Stillbrew composite armour makes a hull-down Chieftain essentially impervious to all but the best kinetic rounds. It is also resistant to most rank VI chemical rounds and early generation ATGMs. Due to this, the tank is a nightmare to fight with outdated tanks for many nations, as not many tanks can even scratch its turret directly to begin with
• The L23 APFSDS round is very powerful and will have little trouble penetrating most vehicles at the Chieftain's rank
• 10° of gun depression
• Reasonably fast reload time for a 120mm with a base time of 9.5s and a best time of 7.5s
• Reasonable reverse speed
• Receives a Laser Rangefinder as a Tier 4 modification, the first British vehicle this is available on

Cons:

• Stillbrew composite armour does not provide particularly good chemical protection against upgraded rank VI ATGM, which means, that while it can often allow Chieftain Mk 10 to ignore ATGM attacks from tanks like Begleitpanzer 57, KPz-70 or M551 and maybe even some attacks from unskilled IT-1 operator, in up-tier or against specialized rank VI ATGM tanks and tanks, which can carry advanced ATGM ( like BMP-1, BMP-1 (DDR), BMP-2, Type 89, Warrior, Etc.), the tank commander must be much more cautious
• While turret is near invulnerable to shells with poor flight characteristics, it still retains a glaring weakspot in form of cupola, which can be penetrated and obliterated by almost any APHE, sometimes even from light tanks such as Begleitpanzer 57, resulting in full crew knockout. Because of this, Chieftain Mk 10 is usually forced to keep their enemies away, even when going to the frontline
• Very poor mobility characteristics, much slower than most medium tanks it have to face
• Hull armour is negligible, comprised only of Cast Homogenous armour, which means that it is even weaker, than what it looks like
• Hull penetration will often result in ammunition detonation as ammo is strewn throughout it

History

Concept

The idea of a "universal tank" began in Britain in 1944 when Montgomery and other influential people began advocating for a more standardized tank to replace the cruiser and infantry tank classes used on the field. Efforts did not start until after World War II under the General Staff designation A45, with development starting just as the new cruiser tank Centurion started to enter military service. The A45 was cancelled in 1948 after development troubles and its inability to be used as a "universal" platform. Ironically, the Centurion proved to be a better "universal tank" platform than the A45.

Development

The Centurion tank series was very successful in British and its allies' service, but the development of new Soviet armour such as the IS-3 and T-54/55 caused the British tank arms race to take another leap forward. Development on the Centurion's successor began in 1951 under the name Medium Gun Tank No. 2. The project's priority was gun and armour, but with mobility to be equal to the Centurion's and weight of fewer than 45 tons. The weight limit caused a program known as the Concept Study Programme to commence in order to find ways to keep the tank under that weight limit yet meet all the armour and firepower specifications. One of the concepts that came out was the usage of bagged charges, which was already in use on naval ships but was a new concept for tank ammunition. Thus, a gun using the bagged charge propellant system began development in 1954, along with a new specification by General Staff that the Medium Gun Tank No.2, now known as FV4201, uses a conventional four crew tank with a turret and a better gun and armour than the Centurion. Though the Conqueror heavy tank was one such response to the firepower requirement, limited production cut that to only 200 units built.

The biggest bump to the firepower of the FV4201 was the recommendation of a 120 mm calibre tank cannon. Though the Conqueror used a 120 mm, the new one would incorporate more innovative features such as the bagged charges. Other design features added was the usage of a Rolls-Royce V8 engine, an auxiliary engine, an automatic gearbox, and a reclining seat for the driver. The reclining seat was a very new feature in tank design as it reduced the vehicle's hull height and thus gave it a lower profile. Leyland Motors was assigned to be the main designer for the tank despite their commitment to the Centurion production lines. The manufacturing process of the tank was decided to be cast rather than welded. In 1957, several specifications added to the FV4201 impeded its attempt to fit in the specifications. A bigger turret was designed and it mounted IR equipment for night fighting. Troops requested more frontal and turret side armour, which along with the turret change caused an increase in the tank's overall weight. A controversial decision was also made in 1957 by NATO that tanks should have multi-fuel engines. The FV4201 installed a new engine conforming to these standards in 1958, a German engine derived from a Junkers Jumo aviation engine. This extended development time since the engine compartment had to be redesigned to fit the engine, raising the total tank weight to 50 tons. The engine, designated the L60, was received with a mixed reception by the Royal Armoured Corps (RAC) and other users due to its novel features. Britain stayed as the only user of a multi-fuel engine in the Cold War as many other nations found the concept impractical and abandoned it.

As the FV4201 finalized its prototype stages, General Staff sent a revised specification for it. The tank was to have the firepower of the Conqueror with the mobility of the Centurion, an armour that maximizes the protection-weight ratio, a weight limit at 45 ton with a top speed of 26 mph and an operating range of 300 miles. The first wooden prototype was made in March 1959, with full prototypes ordered in June 1959 for troop trials. Vickers-Armstrong and Royal Ordnance Factory shared the manufacturing process and the first prototypes were built in January 1960. The first two prototype FV4201 was trialled in Germany alongside their new Leopard 1. The greatest issue with the FV4201 was the engine, which caused many failures due to vibration, a result of the flawed multi-fuel concept. Trials were delayed due to lack of parts to fix broken pieces and redesigns were requested to fix problems. After a lengthy trial period in 1962, the FV4201, now named the Chieftain, was sent to the operational unit in Germany for service and combat trials. The Chieftain was finally accepted for service in 1st May 1963, despite the many faults in the design. The first deliveries of the improved and redesigned Chieftains began in mid-1965. These were the Chieftain Mk 1's, which further revealed problems with the horsepower that the Mk 2 was designed and sent in April 1966. The Chieftain Mk 3 rolled out of the production lines in September 1969, it now weighed 53 tons and the L60 engine was producing 650 hp, still underpowered for the weight. Engine failures were still frequent and left the Chieftain with a sour note until the Mk 5 variant fixed these pressing issues with a new engine and NBC protection. The Mk 5 would be the main variant of the Chieftain in British service. During its production life from 1965 to 1985, a total of 2,265 Chieftains would be built by Britain, with about 1,000 used by the British Army.

Service

The first British units to receive the Chieftains was the 1st and 5th Royal Tank Regiments back during the trials. The Chieftain, despite its initial engine flaws, proved to be combat-proof and could be upgraded to fit new requirements. Some of these upgrades were the addition of composite add-on armour to fight off new anti-tank technology such as the HEAT rounds. The Chieftain earned the title "most formidable tank in the world" during the 1960's Cold War period and also redefined the specifications of a "main battle tank". Its success is due to its novel main gun and heavily sloped armour, as well as satisfactory mobility and speeds able to compete with the Leopard 1. The Chieftain stayed in use by the British Army On the Rhine on the German border with the Warsaw Pact, which caused the Soviets to in turn station their best tanks such as their T-64's against the Chieftains. The British retained the Chieftains all the way until 1997, when it was replaced by the Challenger II, initially being used in addition to Challenger I.

The Chieftain was also successful in the export market, primarily in the Middle East to the hands of Iran, Jordan, Kuwait, and Oman. Another user of the Chieftain was Israel, with Britain initially agreeing to help set up production for locally produced Chieftains. Two Chieftains were sent for trials among the Israeli Defense Force in 1967. After two years of trials and deliberation for the acquirement of the Chieftains, Britain ultimately refused to offer the Israelis the Chieftain for political reasons. The Israeli trials benefit Britain with data on desert combat with the Chieftain, however, and the refusal did jump start Israel's tank program that would become the Merkava.

Despite that, sales to the Middle East soared, with Iran being the major buyer of the Chieftains with at least 887 of mostly the MK3 and MK5 variants sent to them before their revolution in 1979. The Chieftain saw prolonged combat in the Middle East in the Iran-Iraq War, including Operation Nasr which was the largest tank vs. tank battle of the war where the Iranian Chieftains and M60A1 Pattons fought against the Iraqi T-62s. After that war, the Chieftain in Kuwait then saw combat fighting the Iraqis during their invasion in 1990. Kuwait eventually replaced their Chieftains with the Yugoslavian M-84 tanks, which are a variant of the Soviet T-72s.

The Chieftain is still in service Iran, Jordan, and Oman in varying numbers, about 100 in Iran, 350 in Jordan, and 27 in Oman. The Chieftains underwent local upgrades to keep them up to date against a modern threat, which resulted in the Iran Mobarez Chieftain upgrade.

Legacy

The Chieftain helped revolutionize tank design with its innovative features. The most important was the reclining driver seat, which allowed the tank to have a lower profile as the driver was now that highest part of the hull in tank design. It also had the most powerful NATO tank armament in service until the advent of the German Rheinmetall 120 mm, which came about two decades later. Chieftain can be considered the definitive main battle tank of the 1960s and help transition the path between second-generation main battle tanks and the third.

Media

Excellent additions to the article would be video guides, screenshots from the game, and photos.

See also

Links to the articles on the War Thunder Wiki that you think will be useful for the reader, for example:

• reference to the series of the vehicles;
• links to approximate analogues of other nations and research trees.

External links

• [Devblog] Chieftain Mk.10: Dressing Up for War