The Centurion – The definitive British tank of the Cold War era (Part I)

After World War II’s end in 1945, the victorious Allies combined an intensive analysis of armoured warfare during the recent conflict with an avid picking over the bones of German technical research into all aspects of tank technology. The Soviets were well content with the tactical and technical performance of their armoured forces in the last two years of the war and continued along the same basic lines, but the Western Allies felt they had cause for considerable revision in their thinking, though there were clearly many good features that could be retained as the basis for new development.

World War II had nearly bankrupted the UK, and the vast demobilisation after the war’s end forced economies on the army at the same time that it further straitened the situation at home. This position was worsened after 1947, when the grant of independence to India signalled the start of a rapid dissolution of the British empire: the departure of India removed the need for many of the imperial ‘way stations’ on the sea and air routes to the old viceroyalty, and in about 15 years the British empires in Africa and in the Near East, Middle East and Far East had gone, further reducing the UK’s need for a large military capability. This capability had never been as large as that which many countries would have used in the same task, but demanded a very capable regular army supported by a territorial force and designed for high levels of strategic mobility so that the eruption of trouble could be met be adequate strength with minimum delay. The dissolution of the empire led to a reassessment of the role of the British army, the inevitable conclusion being that while the dwindling imperial commitment had still to be met, the new role of the army was in Europe as part of the NATO alliance. Like the imperial role, this demanded a modest but high-quality army, though in this instance fielding the best of heavy weapons rather than ordnance designed for easy mobility over strategic distances before use against an unsophisticated enemy. The projected foe was now the USSR, and the vast tank fleet mustered and constantly improved by the Soviets demanded a very high-quality counter.

The light tank concept had fallen out of favour with the British during World War II, and in the period immediately after the war the reconnaissance role was entrusted to wheeled scout cars and wheeled armoured cars. So far as tracked vehicles were concerned, in the short term the British kept in service the best of the cruiser and infantry tanks of World War II while working on replacements. These two types were the A41 Cruiser Tank Centurion and the A45 Infantry Tank Conqueror, both launched on their development careers in 1944. These were seen as complementary vehicles incorporating all the lessons of armoured warfare learned so painfully since 1940 by the Royal Armoured Corps, which had been created in April 1939 to control all mechanised cavalry regiments (with the exception of the Household Cavalry) and the Royal Tank Corps, which thereupon became the Royal Tank Regiment.

Centurion Mk 3 Tank outside the Eastbourne Redoubt Fortress

Several manufacturers
After basic formulation by the Department of Tank Design in 1943, the A41 was entrusted to the AEC company for detail design with the object of producing a high-mobility cruiser tank characterised by improved Horstmann-type suspension, better protection through the adoption of armour that was both thicker and more effectively angled, and heavier firepower through the use of the 17-pdr (76.2-mm/3-in) high-velocity gun in a mounting that would be readily adaptable to larger-calibre weapons as these became available; the secondary armament was also increased in the prototypes to a 20-mm Polsten co-axial cannon, but it was eventually decided to revert to the standard 7.92-mm (0.312-in) Besa machine-gun, which was then replaced by a 0.3-in (7.62-mm) Browning machine-gun. Not included in the original concept were high road speed and anything more than minimal range, and these two factors were to be the Centurion’s main limitations throughout its highly successful and lengthy service career.

Production of the Centurion was entrusted to the Royal Ordnance Factory at Leeds, Vickers-Armstrongs at Elswick and Leyland Motors at Leyland: by the time Centurion production ended in 1962 these companies had built just over 4,400 of the series including about 2,500 for export to countries as diverse as Australia, Austria, Canada, Denmark, Egypt, India, Iraq, Israel, Jordan, Kuwait, Lebanon, Libya, the Netherlands, New Zealand, Singapore, Somaliland, South Africa, Sweden and Switzerland. Such was the worth of the basic design that special-purpose developments are still in service with several of these countries, and until recently the type was still being upgraded to maintain it as a viable weapon with a better fire-control system, modern armament and (in many cases) a diesel powerplant. Though limited in speed to 21.5 mph (34.6 km/h) and in the range of early models to 65 miles (105 km) by its 650-hp (485-kW) Rolls-Royce Meteor Mk IVB petrol engine and miserly 100-Imp gal (458-litre) internal fuel capacity, the Centurion proved a remarkably long-lived weapon because of its capability for up-armouring and upgunning, as indicated below.

Orthodox but nicely conceived design
In overall design the Centurion was unexceptional, with the driver’s compartment at the front behind moderately sloped frontal armour, the fighting compartment in the centre (complete with turret for the commander, gunner and loader), and the engine compartment at the rear. The engine drove rear sprockets, and on each side the running gear comprised three pairs of road wheels each sprung by one set of concentric springs, and six track-return rollers of which the front and rear units support only the inner sides of the track. Provision was made for the installation of skirt plates over the upper halves of the tracks to provide a measure of protection against the hollow-charge warheads that proved so effective in World War II and which have been spectacularly improved since that time. Construction of the hull was welded, while the electrically/manually traversed turret was a cast unit with a welded roof plate.

Six prototypes were completed before the end of World War II, but though these were shipped to Germany they arrived too late to see combat. An extended period of development followed World War II as the concept of a battlefield team of cruiser and infantry tanks faded in face of the notion of the single battle tank that could undertake both halves of what was becoming a unified role, and the initial Centurion Mk 1 entered service only in 1949 with the 17-pdr (76.2-mm/3-in) Mk 3 gun as its main armament. This was the ultimate development of this World War II weapon, and a formidable weapon by the standards of the time: though the L/55.15 bore length remained unaltered, at 2,032 lb (972 kg) and 184.05 in (4.675 m) the gun was both heavier and longer than its predecessors, and could fire the new APDS (armour-piercing discarding sabot) round whose 8.15-lb (3.7-kg) projectile left the muzzle with a velocity of 3,950 ft (1204 m) per second for a penetration of 186 mm (7.32 in) of armour at an angle of 30° at a range of 500 yards (455 m). Compared with the 17-pdr Mk 2 used in the Sherman ‘Firefly’ this represented a 55% improvement in penetrative capability, while the equivalent improvement over the slightly shorter 77-mm Mk 2 used in the Comet was no less than 73.4%.

Steady development
Further development of the baseline model produced the Centurion Mk 2 with improved armour, but a major change came with the Centurion Mk 3 armed with the 20-pdr (83.4-mm/3.28-in) Tank Gun Mk 1. This offered still greater armour-penetration capability and, at a weight of 2,885 lb (1309 kg) and overall length of 220 in (5.59 m), used its L/64.1 barrel to fire a 20-lb (9.07-kg) APCBC (armour-piercing capped ballistic cap) shot with a muzzle velocity of 3,300 ft (1006 m) per second. The Centurion Mk 4 was to have been the close-support counterpart of the Mk 3 with a 94-mm (3.7-in) Tank Howitzer Mk 1, but was not built so the next production variant was in fact the Centurion Mk 5, which was the first definitive version. It was a Vickers-designed counterpart to the Mk 3, which were all brought up to this operationally improved standard. Further development produced the up-armoured Centurion Mk 5/1, and the Centurion Mk 5/2 which entered service in 1959 and was armed with the excellent 105-mm (4.13-in) Tank Gun L7, a product of the Royal Ordnance Factories fitted in a mounting that provided full stabilisation in elevation to complement the turret’s stabilisation in azimuth. The basic details of the L7 included a weight of 2,826 lb (1282 kg) and an overall length of 231.9 in (5.89 m). The L7 was notable for its high degree of accuracy and consistency, and is the standard weapon that entered widespread service in the Western world as the British L7, US Watervliet Arsenal M68 and West German Rheinmetall Rh-105-60 series. The development of improved weapons continued steadily, as did that of upgraded ammunition types. The success of the L7 series helped to standardise the 105-mm (4.13-in) calibre as the norm for Western tanks in the 1960s and 1970s, and thus prompted development of the GIAT CN105 series in France, an OTO Melara weapon of the same calibre in Italy, and a number of modification programmes in countries such as Austria.

Simple yet effective fire control
Even with the comparatively long recoil of the L7, it was possible to install the weapon with an elevation arc that ran from a maximum of +20° to a minimum of -10°, and this latter proved invaluable in combat. The Centurion was used in anger in many wars (most notably the Korean, various Middle Eastern, Indo-Pakistani and Vietnam conflicts), and the main gun’s large depression angle has allowed the tank to adopt a hull-down tactical position for maximum concealment and protection. This proved very useful in operations against Soviet tanks, which had a main gun depression limit of about -3°, meaning that they could not readily hide themselves even in shallow dips. The 105-mm (4.13-in) gun in the Centurion is provided with 64 rounds of ammunition, and was aimed in these initial models with the aid of a 0.5-in (12.7-mm) spotting machine-gun with 600 rounds: this co-axial machine-gun was ballistically matched to the 105-mm (4.13-in) weapon, and after machine-gun rounds had been seen to hit the target the main gun could be fired with a high probability of scoring a decisive first-round hit even when the tank was moving, thanks to the provision of two-axis stabilisation. The standard 0.3-in (7.62-mm) co-axial machine-gun was retained, as was a similar weapon in the 360° vision commander’s cupola, and 4,750 rounds of ammunition were carried for these weapons. Extra tactical capability was offered by the provision of six dischargers for smoke grenades on each side of the turret. The Mk 5 could also tow a 200-Imp gal (909-litre) mono-wheel fuel trailer as an expedient to boost range.

The Centurion was probably produced in more variants than any other tank of the period after World War II, and after the Mk 5 variants the sequence continued with the Centurion Mk 6, which was the Mk 5/2 up-armoured and fitted with additional fuel tankage increasing overall capacity to 228 Imp gal (1037 litres) and range to 118 miles (190 km); variants of the Mk 6 were the Centurion Mk 6/1 with a stowage basket on the turret rear and infra-red equipment to provide a limited night-driving and night-fighting capability, and the Centurion Mk 6/2 which introduced the ranging machine-gun for the main armament. The Centurion Mk 7 was a Leyland model with the 20-pdr (83.4-mm/3.28-in) gun fitted with a fume extractor and provided with 61 rounds, and was subsequently designed FV4007 in the Fighting Vehicle designation system. Variants of the Mk 7 were the Centurion Mk 7/1 (FV4012) with improved armour, and the Centurion Mk 7/2 with the L7 gun. The Centurion Mk 8 was essentially the Mk 7 with a revised gun mounting, contra-rotating commander’s cupola and provision for the commander’s twin hatch covers to be raised for overhead protection with the commander’s torso out of the turret. Standard variants of the Mk 8 were the Centurion Mk 8/1 with improved armour, and the Centurion Mk 8/2 with the L7 gun. The Centurion Mk 9 (FV4015) was the Mk 7 with thicker armour and the L7 gun. Variants of the Mk 9 were the Centurion Mk 9/1 with the stowage basket and infra-red vision devices, and the Centurion Mk 9/2 had the ranging machine-gun. Next came the Centurion Mk 10 (FV4017), essentially the Mk 8 with improved armour and the L7 gun plus 70 rounds. Standard variants of the Mk 10 were the Centurion Mk 10/1 with stowage basket and infra-red vision devices, and the Centurion Mk 10/2 with the ranging machine-gun. The Centurion Mk 11 was the Mk 6 with stowage basket, infra-red vision devices and ranging machine-gun, while the Centurion Mk 12 was the Mk 9 with the same improvements, and the final Centurion Mk 13 was the Mk 10 with infra-red vision devices and the ranging machine-gun.

Specialised developments
The Centurion was also used as the basis of several specialised vehicles such as two armoured vehicle-launched bridges, an armoured recovery vehicle, an assault engineer vehicle and a beach armoured recovery vehicle. There were also a number of projected models such as two types of self-propelled gun, and also two types of tank destroyer with 120- or 180-mm (4.72- or 7.09-in) guns. As the basic gun tank remained in service for several decades, Vickers and a number of overseas companies were able to offer retrofit programmes or kits ranging from a completely new diesel powerpack to modern fire-control systems (laser rangefinder and ballistic computer) for the main armament.

The Centurion was one of the classic tanks of all time, and finally proved that the UK could produce a tank matching the best anywhere in the world. The same cannot be said of the A45, which was conceived as the Centurion’s heavy companion and then planned as the baseline model in the Universal Tank series, which would have used the same hull as the basis of flamethrowing, dozing and amphibious variants. The first FV201 prototype of the A45 was delivered in 1948, and was a massive machine on running gear fitted with Horstmann-type suspension (four twin units each with three concentric springs on each side), the turret of the Centurion with its 17-pdr (76.2-mm/3-in) gun, and a remotely-controlled machine-gun barbette on the left-hand track guard. It became clear during the A45’s prototype trials that this unwieldy tank’s role could be fulfilled without difficulty by the Centurion, and in 1949 the A45 was cancelled. However, its chassis became the core of a new heavy tank planned to tackle the IS-3 and its successors in soviet service. This was developed as theConqueror (FV214), initial proof of concept being undertaken in a model called the Caernarvon (FV221), which was the hull of the Conqueror and the turret of the Centurion. The definitive Conqueror appeared in 1950, and the obsolescence of the concept that led to its development is indicated by the fact that production of only 180 vehicles was undertaken in the period between 1956 and 1959. At a weight of 145,600 lb (66044 kg) attributable mostly to armour of 178-mm (7-in) maximum thickness, the Conqueror attained a speed of 21 mph (33.8 km/h) on its 810-hp (604-kW) Meteor 120 No. 2 Mk 1A petrol engine. The crew was four, and the massive cast turret accommodated a 120-mm (4.72-in) Tank Gun L11 with 35 rounds, one 0.3-in (7.62-mm) co-axial machine-gun and one 0.3-in (7.62-mm) machine-gun on the commander’s cupola. The L11 weighed 3,926 lb (1781 kg) and was 270.2 in (6.86 m) long with an L/55.3 bore. The Conqueror was allocated at the rate of nine vehicles to each of the British armoured regiments in West Germany, and was designed to provide Centurion units with long-range fire and anti-tank support. But in addition to its conceptual obsolescence the Conqueror was unreliable, and was phased out of service in 1966.


Leeds/ROF Woolwich/Vickers Centurion Mk 5/2

Type: main battle tank

Crew: 4

Combat weight: 111,835 lb (50728 kg)

Dimensions: length, gun forward 32 ft 3 in (9.829 m) and hull 24 ft 9.5 in (7.556 m); width 11 ft 1.5 in (3.39 m) over skirts; height 9 ft 8 in (2.94 m) to top of cupola

Armament system: one 105-mm (4.13-in) ROF L7 rifled gun with 64 rounds, two 7.62-mm (0.3-in) Browning machine-guns (one co-axial and one AA) with 4,750 rounds, and six smoke-dischargers on each side of the turret; the turret was electrically powered, the main gun was stabilised in elevation (-10º to +20º) and azimuth (360º), and an optical fire-control system was fitted
Armour: cast and welded steel varying in thickness from 0.66 to 6 in (17 to 152 mm)

Powerplant: one 650-hp (485-kW) Rolls-Royce Meteor Mk IVB petrol engine with 101 Imp gal (458 litres) of internal fuel

Performance: speed, road 21.5 mph (34.6 km/h); range, road 64 miles (102 km); fording 4.75 ft (1.45 m) without preparation and 9.0 ft (2.74 m) with preparation; gradient 60%; side slope 30%; vertical obstacle 3 ft (0.91 m); trench 11 ft (3.35 m); ground clearance 18 in (0.46 m)

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