Category: Cold War British Other Tanks

United Kingdom (1953)
Medium Gun Tank – 11 Built

In 1949, the British Armed Forces were subjected to a ‘financial blizzard’ that swept through the military procurement. As usual, it was driven by the Treasury in an effort to save money. One of the casualties of this storm of cuts was the Army’s newest tank, the FV201, which was already behind schedule, having originally been planned to have been in service two years earlier.

Under fire from the other services over the cost of the program, the Army saw a chance to save some of the development work, and get the new vehicle into service a lot quicker than normal. To achieve this, they needed an intermediary tank to bridge the development gap, this tank was the FV221 Caernarvon.

Born Again Tank

The FV200 series, the British Army’s new universal tank chassis, had been under development since 1944. Nearly all the development work had been done on the hull, and was quite advanced. The turret was less well evolved. Since 1948, there had been a constant desire to improve the anti-tank performance of the FV201. With the cancelation of the FV201 in July of 1949, the Army saw a chance to achieve their aim.

By fitting the L1 120 mm gun in a new turret on the old FV201 hull, they could push the maximum range that the tank could knock out an IS-3 out to 1,000 yards (900 m) when using Armour Piercing Discarding Sabot (APDS). Beyond that range, the L1 120 mm gun could use High Explosive Squash-Head (HESH) warheads. These were judged capable of knocking out the IS-3 and, as they were chemical energy warheads, they could work at any range the new tank could score a hit at. It might seem odd to use the IS-3, a Second World war tank, as a target to measure against. However, this Soviet heavy tank was considered the hardest target in the Soviet arsenal in the post-war period. This was then used as the requirement to beat for most British anti-tank weapons of the time.

The new tank was called the FV214 Conqueror or, officially, the ‘Tank, Heavy No. 1, 120 mm Gun, FV214, Conqueror‘. The chassis was a simplified variant of the FV201 series. The main simplification was in the engine bay, where the power take-off for the additional devices that the FV200 series was to have been fitted with was removed. This simplification meant the tank was slightly shorter. Both of these factors reduced the weight. These savings in weight were reinvested in the tank’s frontal protection, with the glacis being thickened and sloped back slightly more.

There was a problem. Whilst some elements of the hull design were complete and had been tested as part of the development process, troop trials had not been carried out. Troop trials are where the front line soldiers are given some of the pre-production models and asked to test them out in the field. It is a vital step to any tank development and will usually show up a host of problems that need fixing.

In 1949, the chassis was at the stage it could be used for troop trials, after the extensive work having been done on the FV201. However, the turret of the FV214 had not yet been looked at. As it turned out, the design work on the Conqueror’s turret would not start until 1950. Development work on the turret, followed by the troop trials of the complete tank would push the in-service date ever further back until the late 1950s.

During the development of the FV200 series, a couple of the prototypes had been fitted with A.41 Centurion turrets. It was proposed to use the new chassis, fitted with a new roof plate and complete Centurion Mk.III turrets, armed with the standard 20-pounder gun. This new vehicle was to be called the FV221 Caernarvon. The name Caernarvon is the Anglicised name for the town of Caernarfon and its attendant castle in North Wales

Design

The FV221 is a bridging step in the design of British Cold War tanks. On the FV201, there was to be a five man crew, like most Second World War tanks, consisting of a commander, gunner, loader, driver and hull gunner. The last crew member, meant to operate the hull-mounted weapons, usually a machine gun, was deleted from the FV214 design. On the FV221, as it was using the FV201 hull, the hull gunner’s hatch was maintained. However, it lacked the guns and optics such a position would usually entail.

Other than this oddity, the design was entirely standard and followed the now common design of an engine in the back, three crew in the turret and the driver at the front of the hull. The tank itself was largely analogous to the Centurion Mk.III in regards to its performance. Even armed with the same 20-pounder gun that the Centurion had, and was armored the same on the turret.

The hull armor is a lot harder to pin down. On one hand, the FV201 had 76 mm to 89 mm on the front of the hull. However, the requirement was for 130 mm, sloped at least 60 degrees. From documentation, it is not entirely clear what the armor values were, as even official documents give blatantly wrong information, and some contradict each other. This applies even to plans.

Because the tank was conceived in such a haphazard way and outside the normal way tanks were designed, there is limited data on the automotive components. However, from the designated role of that tank, that of providing troop trials for the Conqueror chassis, it can be reasonably speculated that most of the components are the same as the service FV214. According to the website of the Bovington Tank Museum, the FV214 Conqueror had a Rolls Royce Meteor M120 engine giving 860 bhp connected to a Merritt-Brown transmission with 5 forward and two reverse gears. Caution should be taken in translating these characteristics to the Caernarvon, as later events resulted in a re-work to the Conqueror’s engine, so some of these details may have been different for the FV221.

The suspension on the FV221 Caernarvon was of the Horstmann type, coupled in pairs to the Horstmann suspension bogeys. The bogeys were not evenly spaced, with a larger gap being present between the middle two bogeys. The idler wheel was at the front, while the drive sprocket was at the back. The track return was supported by four return rollers hidden behind the upper part of the side skirts.

The Old Foe

The British Army has a long history of being defeated by the Treasury. The FV221 was to fall victim to this department.

Originally, about 160 Caernarvons were planned, but that meant producing 160 chassis that had no fighting potential if a war was to break out. These chassis would be awaiting turrets taken from the normal Conqueror production line, and such a process would take as long as three years. The other option was to purchase a special batch of Centurion turrets, only to throw them away after the troop trials. This was because the tanks used in the troop trials would be converted to Conquerors at a later date. All they needed was their roof plate changed and they could accept a FV214 turret. The purchase of a special batch of Centurion turrets was the preferred option.

Equally, in an effort to begin troop trials, there would be no pre-production version. The first two prototypes would be hand-built and used for component testing only.

Then the Treasury stepped in, aghast at the £70,000 projected unit cost. In comparison, a fully equipped Centurion would cost just £45,000 (£1,404,387.00 today). The Treasury was under pressure from other departments over the Army’s tank project and its costs. A wide-sweeping cull of Army tank development was carried out and numerous tanks, such as the FV4004 Conway and FV217 tank destroyer, were canceled. The reaper also struck at the FV221 project, claiming one of the prototypes and reducing the number of tanks built to about seventy. Even this was not enough and, later, the number was reduced even further to just ten vehicles.

The decision to skip both pre-production tanks did pay off, with the first troop trials starting in 1953. If the usual pre-production step had been carried out, the troop trials would not have started until 1955 at the earliest.

Service

Six FV221s were sent out for the troop trials. One went to British Army of the Rhine, one to Bovington and one to the 4/7th Dragoon Guards. A further two were sent to the Middle East Land Forces (MELF). The last, the prototype, was sent to Bovington. At least two of the tanks were fitted with a strange barrel extension on the end of the 20-pounder gun. It is possible that this was included to simulate the length of the L1 120 mm gun of the Conqueror during the trials process. The tanks, as issued, used FV201 top plates, which retained the hull machine gunner’s position, although no such weapon was fitted. This meant that there was an extra seat, although any crewman sited there would have no actual job to do.

The troop trials very quickly had an effect. It was found that the three episcope arrangement was extremely difficult for the driver to use while driving unbuttoned. This was later changed to a single unit. There was a workshop bulletin posted requiring that the two side episcopes be removed and the holes blocked off with wood. Other changes included work being done on the driver’s hatch locking system and the engine cooling system. The latter was a critical point, as just running the auxiliary generator on the tank could, under the worst-case scenario, cause the cooling system to boil in just 45 minutes.

By 1954, the FV221s owned by MELF had completed over 2,000 miles (3,200 km) running each. The only issues that had been discovered were the aforementioned problems relating to the cooling of the power plant. The troop trials did confirm one series of tests carried out at Bovington, namely that it was impossible to throw a track on this chassis.

In 1955, the Conqueror began to enter service, and the FV221’s were all converted to that type. The only Caernarvon left in existence was the prototype. It soon lost its turret and was used for testing a gas turbine for a period. Then it was used as a dynamo vehicle at Bovington for many years, before finally being converted into the commentary box for the Bovington museum arena. Its final fate in the late 1990s, was to be scrapped when Bovington redeveloped the arena, and this irreplaceable one of a kind tank was handed to the scrap merchants and disappeared from history.

Conclusion

It is estimated that the FV221 managed to cut a year or two off the Conqueror’s service time, and could then claim to have achieved its goal. However, in 1958, shortly after the Conquerors introduction, the entire fleet of the new tank had to be taken off-road due to dust build-up in the engine. This was down to the positioning of the air intake, and should have been caught by the FV221. It may be that this dust problem was exacerbated by a similar, but unrelated problem due to metal build-up caused by unclean standards at the factory, in which case, the carefully constructed FV221 would not have shown the problems up.

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Illustration of the ‘Tank, Medium Gun, FV221 Caernarvon’ produced by Tank Enyclopedia’s own David Bocquelet with additions from Brian S. Gaydos.

Specifications
Dimensions (L-W)	13 feet 1 inch* x 25 feet 4 inches* (3.99* x 7.72 meters*)
Step	3 ft (0.9144 m)*
Trench	11 ft (3.3528 m)
Total weight, battle ready	55 tons*
Crew	4 (Driver, commander, gunner, loader)
Propulsion	Rolls-Royce Meteor M120 810 hp (604 kW)
Suspension	Hortsmann
Speed (road)	22 mph (35 kph)
Armament	20-pounder gun .30 cal Browning.
Armor	Up to 6in (152 mm)**
Total production	11

*Approximate, taken from A.45, which is almost identical.
**Taken from the Centurion Mk.III gun mantle, which is identical.

Sources

WO 185/292: Tanks: TV 200 Series: Policy and Design, 1946-1951, The National Archives, Kew
E2014.747 FV221, Bovington Tank Museum
E2014.627 FV221, Bovington Tank Museum
E2014.1372, Bovington Tank Museum
FV221 Caernarvon – Instructions for User Trials – REME aspect, September 1953, The Tank Museum, Bovington
Maj. Michael Norman, RTR, Conqueror Heavy Gun Tank, AFV/Weapons #38, Profile Publications Ltd.
Carl Schulze, Conqueror Heavy Gun Tank, Britain’s Cold War Heavy Tank, Tankograd Publishing

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United Kingdom (1953)
Heavy Gun Tank – Approximately 180 Built

On September 7th, 1945, military heads of the Western Powers were horrified by what they saw rumbling towards them along the Charlottenburger Chaussee in central Berlin during the 1945 Victory Parade celebrating the end of the Second World War. During that parade, the increasingly threatening Soviet Union unveiled its latest tank to the world: the IS-3 heavy tank. As these machines clattered down the parade route, a sense of fear enveloped the representatives of the British, US, and French Armies. What they saw was a tank with well-sloped and – apparently – heavy armor, a piked nose, wide tracks, and a gun at least 120 mm in caliber.

The race was on. France, Britain, and the US immediately began the design and development of their own heavy or heavily armed tanks. The Americans would create the 120 mm Gun Tank M103 while the French experimented with the AMX-50. Both of these tanks had 120 mm guns that would – it was hoped – be able to combat the IS-3 threat. The British, on the other hand, would pursue the development of the ‘Universal Tank’, what we know today as a ‘Main Battle Tank’ or ‘MBT’. The FV4007 Centurion was also in development well before the IS-3 appeared. At this time, however, it was only armed with the 17-Pounder gun. It was projected that it would be equipped with the 20-Pounder (84mm) in the future, but a more powerful gun was desired.

This is where the FV200 series of vehicles come in. The FV200s were a projected series of vehicles based on one common chassis, hence ‘Universal Tank’. The FV214 was one of the vehicles in this series, and was a design for a ‘Heavy Gun Tank’. It would become known as the Conqueror. The Conqueror or – to give its officially long-winded title – the ‘Tank, Heavy No. 1, 120 mm Gun, FV214 Conqueror’, was an impressive vehicle. Weighing in at 63 long tons* (64 tonnes), armed with a powerful 120 mm gun, and protected by thick steel armor. The Conqueror – as mighty as it was – had an extremely short service life, in operation between 1955 and 1966. Conqueror was one of the heaviest and largest tanks Great Britain ever produced that made it to active service.

*As this is a British vehicle, mass will be measured in ‘Long Ton’ otherwise known as the ‘Imperial ton’. It will be shortened to ‘ton’ for ease with a metric conversion alongside.

The FV200 Series

In the aftermath of the Second World War, the War Office (WO) reviewed the future of the British Army’s tank arm. In 1946, they did away with the ‘A’ designator used on tanks such as the Churchill (A22) and Comet (A34). The ‘A’ number was replaced by the ‘Fighting Vehicle’ or ‘FV’ number. In an attempt to streamline the tank force and cover all the bases, it was decided that the military needed three main families of vehicles: the FV100, the FV200, and FV300 series. The FV100s would be the heaviest, the FV200s would be slightly lighter, and the FV300s would be lightest. All three projects were almost canceled due to the complexity that would’ve been involved in producing the respective series. In the end, both the FV100 and FV300 series were canceled. The FV200 hung on in its development, however, as it was projected that it would eventually replace the Centurion.

The FV200 series included designs for vehicles that would fill various roles ranging from a gun tank to an engineering vehicle and Self-Propelled Guns (SPGs). It wasn’t until later years that the other uses of the FV200 chassis were explored, such as with the F219 and FV222 Armoured Recovery Vehicles (ARVs). The first of the FV200 series was the FV201, a gun tank that started development in 1944 as the ‘A45’. This tank weighed around 55 tons (49 tonnes). At least two or three FV201s were built for testing, but the project went no further than that. Work on the project ceased in 1949.

Need vs Availability

In June 1949, an official requirement was made for a new Heavy Gun Tank with enough firepower to defeat the toughest armor of the time from a long-range. The term ‘Heavy Gun Tank’ is a uniquely British designation. It refers to the size and power of the gun, not the size and weight of the tank. Heavy Gun Tanks are specifically designed to destroy enemy tanks and/or fortified positions. Work on the new tank began that July, when the FV201 project transitioned into the FV214 project. Designers working on the new specifications soon realized they had a few problems, not the least of which was that they did not have a gun, a turret, or a hull.

The requirement for the new heavily armed tank called for the vehicle to be armed with a large caliber gun. A 4.5 in (114 mm) gun that was first considered for the FV205 in 1946 was explored first, before moving on to a 120 mm gun. The problem was there was no such gun in existence or development in the United Kingdom at that time. On the other side of the Atlantic, the Americans were developing a 120 mm gun for their T43/M103 heavy tank project. This gun had a chamber pressure of 17 long tons (17.2 tonnes), but they were planning to increase this value to 22 long tons (22.3 tonnes). The higher the chamber pressure, the higher the velocity, meaning longer range, and increased penetration. With the US and UK working closely, the UK also designed a gun with a 22-ton (22.3 tonne) chamber pressure. Efforts were even made to standardize the guns between each other. On the British side, Royal Ordnance took charge of the development of the gun, resulting in the Ordnance Quick-Firing (QF) 120 mm Tank, L1A1 Gun.

Weighing in at 2.9 tons (3 tonnes) with a length of 24.3 feet (7.4 meters), the 120 mm L1 gun was monstrous. A new turret would be needed to carry it, but this would have to be designed from the ground up. Work started in 1949, with the turret set to be constructed at Royal Ordnance Factory (ROF) Barnbow. It was clear from the outset that a turret would not be ready for a considerable amount of time.

Another issue was developing a suitable chassis that would be strong enough to carry the immense gun and – what would probably be – a proportionately large and heavy turret that was set to be constructed from cast steel. Instead of going back to the drawing board, the designers decided to use the chassis of the nearly complete FV201.

FV221 Caernarvon, an Interim Development

By 1950, with the gun and turret still in the development phase, it was clear that prototype production and troop trials of the FV214, now known as ‘Conqueror’, were a long way off. The hull and chassis, however, were already in the final stages of development. The chassis was a simplified variant of the FV201 series. The main simplification was in the engine bay, where the power take-off for the additional devices that the FV200 series was to have been fitted with was removed. This simplification meant the tank was slightly shorter. Both of these factors reduced the weight. These savings in weight were reinvested in the tank’s frontal protection, with the glacis being thickened and sloped back slightly more.

With this part of the FV214 complete, the Tank, Medium Gun, FV221 Caernarvon project was launched. The aim of this project was to speed up the development of the Conqueror, while giving crews experience in the operation of the vehicle. The FV221 consisted of an FV214 hull mated with a Centurion Mk.III turret armed with a 20-Pounder gun. With an initial prototype built in April 1952, just 10 of these vehicles were built, the last one in 1953. These had a brief career, nonetheless, they saw extensive trial service in the British Army of the Rhine (BAOR) and the Middle East Land Forces (MELF).

Finalizing the Conqueror’s Design

Come 1951, work on the FV214 had progressed and, by the end of the year, firing trials of the new Ordnance L1 120 mm gun had concluded with the weapon being accepted for service. A program to create a stop-gap carriage for this gun resulted in the Centurion-based FV4004 Conway, although this project was halted after prototype trials. There was also an idea to mount the gun in a casemate style tank destroyer built on the FV200 chassis and designated the FV217 – nothing came of this project either. The design of the turret had also been finalized and it was set to include a number of innovative features, such as an automatic rammer for assisting the loader, a shell ejection system, and a ‘Fire Control Turret’ for the Commander.

By 1952, four pre-production turrets and 3 guns were available to start trials. These were mated with existing FV221 hulls. At least four prototypes were constructed in this manner. Several other hulls were tested with the ‘Windsor’ ballast turret – named after Windsor Castle. It consisted of a large cast steel ring with interchangeable plates and simulated the weight of a fully equipped Conqueror turret.

These vehicles took part in mobility and endurance trials conducted by the Fighting Vehicles Research and Development Establishment (F.V.R.D.E.) between September 1952 and July 1953. Together, the vehicles covered around 7,911 miles (12,732 km, divided between test locations) – just cross country – at speeds of up to 15 mph (23 km/h). Road trials covering 99 miles (160 km) were also conducted. As it performed well in these trials, 5 more pre-production vehicles were ordered for further F.V.R.D.E. tests. For troop trials, 20 vehicles were ordered in 1953, all to be built at the Royal Ordnance Factory in Dalimur, Scotland. Construction of these vehicles was completed in summer 1955.

Mk.1 and Mk.2

While the trial versions were in production, certain details of the vehicle were adapted based on the test results of the first batch of vehicles. This resulted in two types of FV214. Vehicles produced before the alterations were implemented became the Conqueror Mk.1, while vehicles built with the modifications became the Conqueror Mk.2.

The most noticeable differences between the Mk.1 and 2 are the exhausts, fume extractor, and driver’s periscopes. On the Mk.1, the exhausts were equipped with mufflers whereas the Mk.2 featured straight-through exhausts. The Mk.2 is also distinguishable from the Mk.1 as it featured a much larger fume extractor on the 120 mm gun. As a carryover from the FV221 Caernarvon, the Conqueror Mk.1 had three No. 16 Mk.1 periscopes installed in a crescent in front of the driver’s hatch. This was seen as a weak point in the armor and, as such, just the center periscope was retained in the Mk.2. The profile of the upper glacis plate was also changed and the plate made larger. It was also far more common for the Mk.1 to not be equipped with the turret bustle stowage basket, a feature present on most Mk.2s.

The other differences between the two are relatively minor. On the Mk.1 engine deck, fluid filler caps were left exposed, while on the Mk.2 they were concealed by the engine bay cover plates. On the Mk.1, there was a crank to turn over the engine by hand, this was deleted on the Mk.2. Other changes included an improved switch-box in the driver’s compartment and improved hatches for the commander and driver.

The Conqueror in Detail

Overview

Weighing in at 65 tons (66 tonnes), the Conqueror is worthy of its name. Measuring 25 feet (7.62 meters) long – not including the gun, 13.1 feet (3.99 meters) wide and 11 feet (3.35 meters) tall, the FV214 cuts an imposing figure. A four-man crew operates the vehicle, consisting of the Commander (turret rear), Gunner (turret right), Loader (turret left) and Driver (hull right). All crew members had access to their own hatches which popped up and swung open, instead of the two-part doors that had been present since before WW2. The Conqueror was one of the first British tanks to have this style of hatch. The older two-piece type persisted on the Centurion for the entirety of its service.

Hull

The hull was of an all-welded construction, formed from plates of rolled homogeneous steel armor. At the front of the hull, the upper glacis was between 4.7 and 5.1 inches (120 – 130 mm) thick, sloped at 61.5 degrees from vertical. This would give an effective thickness of either 11.3 or 12.3 inches (289 – 313 mm)*. The lower glacis was 3 inches (77 mm) thick, angled at 45 degrees from vertical. This gave an effective thickness of 4.2 inches (109 mm). The armor profile changed between the Mk.1 and Mk.2 due to the deletion of the left and right No. 16 Mk.1 periscopes. On the Mk.1, the hull roof that the hatch was installed in was slightly sloped. On the Mk.2, this part of the roof is flat.

The rear plate and hull floor are 0.7 inches (20 mm) thick, while the hull roof and sides are 2 inches (51 mm) thick. There was also an extra 0.3 inch (10 mm) ‘mine plate’ under the driver’s position. Protection on the sides of the hull was increased by the installation of two sets of armored side skirts or ‘bazooka plates’. These were approximately 0.2 inches (6 mm) thick and detachable, allowing easy maintenance and replacement. The upper set was attached to the track guards, while the lower set was attached to struts in between the suspension bogies and was fixed directly to the hull side, covering the suspension. These plates were designed to counter shaped-charge warheads by detonating them away from the hull sides and reducing the power of the jet from the shell. Tests of skirting plates had also established a high level of effectiveness for relatively little additional weight against other types of shells too, including Armor-Piercing (AP) and HESH (High Explosive Squash Head).

*There is a lot of confusion over the upper plate thickness, so that is why both possible thicknesses are given. Until a tangible measurement becomes available, it cannot be known for sure.

Designers believed that the 2 inches of side armor, together with the added plates, would be enough to counter the IS-3’s 122 mm gun. This, of course, was never tested in combat. By way of illustration, trials in 1959 proved that even a relatively thin single skirting plate just 10 mm thick helped provide significant protection against Soviet 100 mm UBR-412B Armor Piercing High Explosive (APHE) shells fired at a Centurion, justifying the conclusions of the designers of the time.

On the left of the rear hull plate there was an infantry telephone which allowed friendly troops to communicate with the vehicle’s commander. On the upper right corner could be found the gun crutch (travel lock). Three large stowage boxes were placed on the left and right fenders. Behind these were mountings for pioneer tools (shovel, axe, pick etc.), spare track links, and other sundries.

The driver was located at the front of the hull, on the right. Two traditional tiller bars were used to operate the vehicle, with the gear stick situated between the driver’s legs. At his feet were the clutch (left), brake (center), and accelerator (right) pedals. Other instruments included a hand throttle, claxon (horn), battery and generator switches, fuel/temperature/speed gauges, and a gun position indicator. The driver’s seat could be placed at various heights and positions, allowing the driver to operate head-out or under the protection of a closed hatch. Extensions atop the tiller bars allowed easy operation when driving head out. The compartment to the left of the driver was used for ammunition storage. A semicircular hatch that pivoted open to the right provided the main route of access to the compartment. At least one prototype hull (used for testing a turbine engine) was also fitted with a second hatch but this feature was not carried over onto production vehicles. An additional means of escape for the driver was via a passageway into the turret basket so he could enter or exit the vehicle through the turret hatches. Behind the driver was the fighting compartment and turret. The engine bay was separated from the fighting compartment by a bulkhead.

Mobility

The beating heart of the FV214 was the Rolls-Royce Meteor M120 No. 2 Mk.1A engine. This water-cooled, petrol-injection engine developed 810 horsepower at 2,800 rpm and was a derivative of the Rolls-Royce Merlin engine, famous for powering the British Spitfire and American Mustang fighter aircraft of World War 2. The transmission consisted of the 7-speed (5 forward, 2 reverse) Z52, and various models from Mk.A to Mk.C were used. Combined, this powerpack gave the FV214 a top speed of 21 mph (34 km/h) on the road. Maximum fuel capacity was 212 UK-gallons (964 litres). This capacity was split between 3 fuel tanks of 115, 85, and 20 gallons (523, 386, 91 litres) capacity respectively. In all, the vehicle would consume 144 gallons (655 litres) per 62 miles (100 km) when traveling on roads, or 188 gallons (855 litres) per 62 miles (100) km cross-country.

Like the FV201 and Centurion before it, the Conqueror utilized the Horstmann suspension system with 2 wheels per-bogie unit. The wheels were made of steel, measuring approximately 20 inches (50 cm) in diameter, and constructed from 3 separate parts. These consisted of an outer and inner half, with a steel rim in contact with the track. Between each layer was a rubber ring. The idea behind this was that it would be more efficient on the rubber and would not need to be replaced as often. The Horstmann system consisted of three horizontal springs mounted concentrically, guided by an internal rod and tube. This allowed each wheel to rise and fall independently, although the system did struggle if both wheels rose at the same time. Four bogies lined each side of the hull of the Conqueror, giving it 8 road-wheels per side. There were also 4 return rollers, 1 per bogie. The advantage of using bogies lies in maintenance and crew comfort. Having externally mounted bogies means there is more room inside the tank and also, should the unit become damaged, it is relatively easy to remove it and replace it with a new unit.

The drive sprocket was at the rear of the running gear, with the idler wheel at the front. The track – made of cast manganese steel – was 31 inches (78.7 cm) wide and had 102 links per side when new. When the track was close to wearing out, it could use as little as 97 per side. Suspension gave the vehicle a ground clearance of 20 inches (51 cm), and the ability to climb a 35 inch (91 cm) vertical object. It allowed the tank to cross trenches up to 11 feet (3.3 m) wide, negotiate gradients up to 35 degrees, and ford water obstacles up to 4.5 feet (1.4 m) deep without preparation. The vehicle had a turning circle of 15 – 140 feet (4.8 – 42.7 m) depending on gear selection. It could also pivot or ‘neutral’ steer on the spot with each track turning in opposite directions.

Turret

The turret of the Conqueror was a single steel casting. It was an odd shape, with a wide, curved face and a long, bulbous bustle. The turret face was between 9.4 to 13.3 inches (240 – 340 mm) thick, angled at around 60 degrees. This would make the effective thickness either 18.8 inches or 26.7 inches (480 – 680 mm). The mantlet is also estimated to be at least 9.4 inches thick. Armor on the turret sides was around 3.5 inches (89 mm) thick, while the roof and rear were around 2 inches (51 mm) thick.* The roof over the gun was formed by a large rectangular steel plate that was bolted in place. When removed, this allows access to the gun for maintenance. The roof on the right was also slightly stepped to accommodate the gunner’s periscope. The turret was divided into three crew positions with the gunner on the right, loader on the left, and the commander at the rear in his own dedicated position known as the ‘Fire Control Turret’. Both the gunner and loader had their own hatches.

External features of the turret included two ‘Discharger, Smoke Grenade, No. 1 Mk.1’ launchers. One of these was placed on each side of the turret, roughly centrally along its length. Each launcher featured 2 banks of 3 tubes and were fired electrically from inside the tank. Other notable features include the large rack on the rear of the bustle – used to carry tarpaulins, crew sundries, and other stowage – and the circular wire reel mounted on the left side of the bustle. This was a spool of telephone wire – known as the ‘Cable, Reel, Continuous Connection’ – that was carried by most British tanks of the time. It would be used in bivouac areas when the tanks were in their defensive positions. The wire was hooked up to each tank and allowed them to discreetly communicate without broadcasting their positions via radio.

*Much like the hull armor thicknesses, there is much disparity between turret thicknesses depending on the source.

Fire Control Turret

One very important title is held by the Conqueror. It was the first tank in the world to feature what we now call a ‘Hunter-Killer’ system. These systems provide the vehicle’s commander with the ability to spot targets for himself and take manual control of the turret and armament. This allows them to either lay their gunner on to target or take the shot themselves. In Conqueror, this system took the form of the ‘Fire Control Turret (FCT)’, a separate unit manned by the commander at the very rear of the main turret. It was capable of full 360 degree powered traverse (there was no manual override, a sore point among Conqueror commanders) independent of the main turret’s traverse. The FCT features its own defensive armament, consisting of an L3A1 .30 Cal (7.62 mm) machine gun – the British designation of the US Browning M1919A4. This gun was operated internally by the commander via mechanical linkages and, unlike the main gun, could be fired on the move. Although fired from the safety of the turret, the gun was fed by standard 200 to 250-round boxes – 3 of which were carried in the FCT. The commander would have to leave the safety of the FCT to reload and cock the weapon.

The FCT featured a number of optics. In front of the commander’s hatch were his three main viewing devices. The sight for the machine gun – the ‘Sight, Periscope, AFV, No. 6 Mk.1’ – was mounted centrally, with an ‘Episcope, Tank, No. 7 Mk.1’ on either side. Rangefinding for the main gun was done via the ‘Rangefinder, AFV, No. 1 Mk.1’. This was placed laterally at the front of the FCT and had a 47-inch (1.19 meters) sight base, with the apertures appearing on each cheek of the FCT. The rangefinder used the ‘coincidence’ method of ranging. the system laid to images on top of each other. When the two images completly overlap, the range measurement is taken. The system could gauge ranges from 400 to 5000 yards (366 – 4572 meters). Initially, the designers of the Conqueror turned to the Royal Navy for the development of the rangefinder. However, the Navy had trouble downsizing, and as such, the designers turned to the Glasgow based company of Barr & Stroud Ltd. The ‘Sight, Periscope, AFV, No. 8 Mk.1’ – was placed below the rangefinder in the face of the FCT. This had x7 magnification and was the commander’s primary sight for the main gun.

The ‘FCT’ system allowed the commander to set up the next attack while the gunner was finishing his current one. This would work in the following method; the commander spotted the target, measured the range, lay gunner on to it, who began targeting. He then hands off to the gunner who makes the fine adjustments and takes the shot. This allowed the commander to move onto the next target, starting the process over again. Alternatively, the commander could do it all by himself, including firing the main gun or coaxial machine gun with his own controls. The Conqueror was the first British tank to incorporate a range finder.

Armament

Both the 120 mm L1A1 and L1A2 guns were used on the Conqueror. The A1 and A2 were basically identical, other than the A2 being threaded at the muzzle end. The weapon system consisted of 4 major components: the gun, the mount, sighting systems, and ejection gear. The 120 mm barrel was forged and rifled with an overall length from muzzle to breech block of 24.3 feet (7.4 meters). A bore evacuator (fume extractor) was placed roughly halfway down the barrel’s length. The gun was mounted on trunnions placed at the front of the turret. The aperture in the turret was protected by a large, flat-sided frustoconical cast mantlet wrapped around the base of the barrel. The gap between the mantlet and the turret face was sealed by a material baffle. On the left and right of the gun were the large buffers of the hydraulic recoil system. The gun mount also carried an L3A1/Browning M1919 coaxial machine gun, which was located on the left of the main gun.

As well as the 360-degree power traverse of the turret, the gun was also equipped with power elevation with a range of -7 to + 15 degrees. Despite the maximum 7 degrees, a limiter prevented the gun from depressing past -5 degrees. The turret was traversed via the ‘Controller, Traverse, No. 1 Mk.1’ spade grip found in front of and to the right of the gunner. A full rotation using powered traverse took 24 seconds. Elevation for the gun was achieved via the ‘Controller, Elevation, No. 2 Mk.1’. This controller was on the gunner’s left, and also incorporated the electrical trigger for the main gun. Both elevation and traverse had manual overrides. As a safety feature, once the tank passed 1.5 mph (2.4 km/h), a micro switch engaged a system that disconnected the gun from the elevation system. The idea behind this ‘carry mode’ was that it put less stress on the gun cradle if the 2.9 ton gun was not locked into the system as the tank negotiated terrain. This effectively meant that the gunner was just along for the ride, having no control over the free-floating gun. A ‘trimming’ dial at the gunner’s station was used to stop the gun drifting too far up and down. As the tank was never designed to fire on the move, this was not seen as an issue. Still, it took several seconds after the tank had stopped before the gunner could operate the weapon once more. The gunner aimed the main gun via the ‘Sight, No. 10 Mk.1’ which utilized two views with two eyepieces. One of these was a unity sight which granted an unmagnified field of vision. Integral in this view is a marked circle, this circle would show the view available to the eyepiece of the primary sight. The primary sight eyepiece was installed bellow the eyepiece for the unity. The sight had x6 magnification.

Just two types of ammunition were carried by the Conqueror in a combat loadout, these being Armor Piercing Discarding Sabot (APDS) and High-Explosive Squash Head (HESH). Both ammunition types were ‘two-stage’, meaning the shell was loaded separately of the propellent. The gun was loaded manually by the loader. It was not the easiest of tasks as the projectiles were heavy and cumbersome. The APDS projectile weighed in at 21.4 pounds (9.7 kg) while the HESH shell weighed in at 35.3 pounds (16 kg). The gargantuan brass propellent cases were equally hefty, with the APDS’ case weighing in at 60.9 pounds (27.6 kg), and the HESH’s weighing in at 41.5 pounds (18.8 kg). The APDS round had a muzzle velocity of approximately 4,700 fps (1,433 m/s) and could penetrate up to 15.3 inches (390 mm) of flat steel armor – or 120 mm (4.7 in) of 55-degree angled steel armor – at 1,000 yards (914 meters). The HESH projectiles had the advantage of consistent effectiveness regardless of the target range. The shell, which had a velocity of 2,500 fps (762 m/s), created effective spalling on armour of up to 4.7 inches (120 mm) thick, angled at 60 degrees. It also served as a dual-use round just as capable of engaging enemy armor as for use as a high-explosive round against buildings, enemy defensive positions, or soft-skinned targets. Between 35 and 37 rounds were carried, divided between the ammunition types.

Loathing Loading

The Conqueror’s loader had one of the hardest tasks. He had to load the 20-pound projectile and up to 50-pound propellant case by hand. This arduous task was made worse by an initial War Office (WO) requirement that the loader be able to load 4 rounds in 1 minute, 16 rounds in 5 minutes, and be able to expel all rounds in 55 minutes. Tests performed at the Lulworth Ranges in Dorset soon confirmed that this was an unreasonable demand. The story goes that a special training course aimed at maximising loading speed was arranged for personnel set to become Conqueror loaders. This cannot be confirmed, however.

The War Office also looked into mechanical methods of assisting the loader in his tasks. The Army contracted Mullins Ltd., a company that specialised in the design and manufacture of cigarette dispensers. They developed two devices. One was a hydraulic rammer that would ram all of the ammunition components into the breech once the loader had placed them onto a tray behind it. The other was an automatic ejection system. The idea behind this was that it would stop the turret from being overtaken by the large propellent cases when they were ejected. It would also save the gunner from having to dispose of them manually by throwing them out of a turret hatch. The War Office opted to serialise the ‘Ejection Gear’ over the rammer, installing it on all Conquerors. The rammer was rejected as it was found that a well-trained loader could outrun the rammer by 1 second.

As it turned out, the ejection gear was fraught with problems that were never fully resolved during the Conqueror’s time in service. The system came into action after the gun was fired. When the spent propellant case was ejected, it fell down a channel until it was stood vertically on a platform, engaging a micro switch. The platform would then carry the shell up a long chute and out of the tank via an armored door towards the rear of the right side of the turret. The system would then reset in time to receive the next casing, with the whole process taking around 5 seconds. This was when the gear worked as intended, something of a rarity as the following quote describes:

“I hated the ejection gear, it had a mind of its own. The ejected case should have gone up a track and out of a hatch at the back of the turret but, occasionally, it came loose and ended up on top of the breach. Once there it caused havoc and the unlucky loader – me – would have to retrieve it risking being trapped between the breach and the turret roof!”

– ex-Conqueror Loader Allen Whittaker, 17th/21st Lancers, 1965 – 1987.

There was a manual override however, consisting of a hand crank that was operated by the commander. This was not an enjoyable task for the commander as – even empty – the shell lift was heavy. Manually, the process could take over 5 minutes.

Other Systems

A separate smaller engine in the engine bay was used to operate a generator that provided the tank with electrical power – necessary for the turret’s power traverse, radio, and, most importantly, the tea maker (aka the ‘Boiling Vessel’ or ‘BV’) – whether the main engine was on or off. The 29 hp, 4 cylinder, water-cooled petrol engine produced 350 amps at 28.5 volts.

Various radio sets were equipped on the Conqueror. These included the ‘Wireless Set No. 19 Mk.3’, ‘Wireless Set No. C12’, ‘Wireless Set No. 88 Type A AFV (VHF)’, or ‘Wireless Set No. 31 AFV (VHF). On vehicles built later in the production run, a number of these were replaced by such units as the ‘Wireless Set No. A41’, ‘Wireless Set No. C42’, or ‘Wireless Set No. B47’. The radio was installed on the turret wall behind the loader’s station.

The Loader was also responsible for the most important feature of a British tank, the ‘tea maker’. Otherwise known as the ‘Boiling Vessel’ or ‘BV’, this was a hot water boiler that was used not only to make tea, but also to heat rations. This is a feature that continues to be present on most tanks today. In the Conqueror, it was located on the right of the hull, behind the driver.

Service

Conqueror finally entered service in 1955, with the last vehicles being produced in 1958. Its role on the battlefield was to support its allies, rather than strike out on its own. It was designed to destroy enemy tanks from afar, covering the advance of the lighter FV4007 Centurion. In offensive operations, Conquerors would be placed in overwatch positions and fire over the heads of the main force as it advanced. In defensive operations, Conquerors would again take an overwatch role, but this time from key strategic positions to meet an advancing enemy.

The majority of FV214s went straight to the West Germany (Federal Republic of Germany – FRG) based units of the British Army Of the Rhine (BAOR). A small number of vehicles were retained in the UK for training and development, and to keep as donor vehicles for spare parts. Right from the start of its operational life, it was clear that the sheer size of the Conqueror was going to cause problems. The initial delivery of tanks – consisting of 4 Conquerors – landed at Hamburg Docks in mid-1955. From there, they were to be taken to Hohne on the back of Antar tank transporters. What should have been an approximately 2-hour, 90 mile (146 km) trip instead took 12 ½-hours. This was largely due to the combined mass of the tank and the Antar, a combined weight of 120 tons (122 tonnes). No bridge would take this weight, so every time the convoy came to one, the Conqueror’s had to be dismounted. Each vehicle would then be driven across separately.

At this time of the FV214s adoption, armored regiments were equipped with various marks of the Centurion. Generally, 9 Conquerors were issued to each regiment, although this did occasionally differ. Regiments would deploy their Conquerors in different manners, the majority placing them in troops of 3, with one ‘heavy troop’ to one armored squadron. Others placed them into single ‘heavy squadrons’, while some integrated them into mixed squadrons of 3 Centurions to 1 Conqueror.

1958 almost saw the premature end of the Conqueror. That year, 5 tanks succame to engine failure in quick succession. Two failed due to metal filings found in the oil system which had ground against bearings and other moving parts. Two others failed due to dust contamination, while one failed due to poor engine construction. Thankfully, the issues were fixed. The metal filings originated at the factory where engines were not being kept clean during construction. The solution was changing oil filters every 100 miles. The dust issue came from the fact that the air intakes on Conqueor were near the tracks, so debris shaken off them would sucked into the system. Following this, air filters were cleaned far more regularly.

Mobility-wise, and contrary to a popular perception of heavy tanks as being slow and somewhat hapless, the Conqueror performed better than most at the time had expected. On road marches, the tank was able to keep up with the smaller Centurion, despite being around 15 tons heavier. On rough ground, it was found that the Conqueror was less likely to become bogged down, largely due to its wider tracks. Thanks to its metal-on-metal running gear, it was also very rare for the Conqueror to throw its tracks of boggy ground – a much more common occurrence on the Centurion due to the rubber on the wheels flexing away from the track’s guide horns. The Centurion did have the advantage on softer ground as it was lighter, but if it was driven to the limit, the Conqueror was able to keep up.

Conqueror’s were operated by the following units in the BAOR: The 1st, 2nd, 3rd, 4th, 5th, 7th (The Desert Rats), and 8th Royal Tank Regiment (RTR), 9th Queen’s Royal Lancers, 16/5th Queen’s Royal Lancers, 17/21st Lancers, 9th/12th Royal Lancers (Prince of Wales’), 3rd Kings Own Hussars, The Queen’s Own Hussars, 8th King’s Royal Irish Hussars, 10th Royal Hussars (Prince of Wales’ Own), 11th Hussars (Prince Albert’s Own), The Queen’s Royal Irish Hussars, 14/20th King’s Hussars, 13/18th Royal Hussars (Queen Mary’s Own), 4/7th Royal Dragoon Guards, 5th Royal Inniskilling Dragoon Guards, 3rd Carabiniers (Prince of Wales’ Dragoon Guards), and the Royal Scots Greys (2nd Dragoons).

One of the first units to receive the Conqueror was the 4/7th Royal Dragoon Guards based at Fallingbostel, West Germany. This unit had to adapt to the size of the Conqueror. The 4/7th was based in a Second World War-era ex-German Army base, complete with tank hangars. The problem was the hangars were built for smaller tanks – such as the Panzer IV – not something the size of the FV214. At a squeeze, the tanks would fit in the pens, but the 24-foot (7.3 meter) long gun would be left protruding out of the doors. Unable to close them, the crews cut squares out of the doors so they would shut (this led to the rather comical image below). The gun’s length also effected how the tank crossed rough terrain. If the tank descended a steep incline, there was a danger that the muzzle could get driven into the ground – filling it with mud or causing damage in the process. To overcome this, the turret had to be traversed to the rear.

Unfortunately, mechanical faults plagued the Conqueror throughout its service life. Constant engine breakdowns and recurring fuel leaks would often keep tanks off the front line. Continuous malfunctions of the ejection gear also brought combat effectiveness of the tank into question as it greatly reduced the vehicle’s rate-of-fire.

The sheer size of the vehicle also caused numerous logistical and tactical problems. Small country roads were all but destroyed due to the weight of the vehicle, coupled with its bare manganese-steel tracks. Country bridges were also unable to accommodate the vehicle, causing delays in deployment. The tank’s long gun also caused problems if the tank had to operate in constricted locations such as small villages or heavily wooded areas. Its size also caused problems when it came to placing the vehicles under shelter when bivouacking or for maintenance.

In 1959, the Conqueror’s fate was sealed. That year, Royal Ordnance had begun the final tests of the famous 105 mm L7 tank gun. It was found that, ballistically, the performance of the smaller 105mm almost matched that of the larger L1 120 mm gun of the Conqueror. This new 105 mm was set to be mounted in all future models of the Centurion. This simple act made Conqueror obsolete almost overnight. The vehicle, however, remained in service until 1966, when the final nail in the coffin was hammered home; the arrival of the Chieftain. The FV4201 Chieftain was leaps and bounds ahead of the Conqueror technologically and also featured a new, even more powerful L11 120 mm gun. So, after just 11 years of service, the Conqueror was retired, just 8 years after the last Conqueror rolled off the assembly line.

Variants

FV219 & FV222, Conqueror ARV Mk.1 & 2

The Conqueror Armoured Recovery Vehicle (ARV) was the only variant of the FV214 gun tank to reach production and service. Weighing in at 65 tons (66 tonnes), the Conqueror outweighed the British Army’s existing recovery vehicles. As such, in 1959, a recovery vehicle based on the Conqueror itself was developed. This would be designated as the FV219 Conqueror ARV Mk.1. In 1960, the second incarnation followed as the FV222 Conqueror ARV Mk.2. Just 8 Mk.1s were built before production shifted to the FV222. Twenty of these were built.

The two ARVs differ in appearance (the Mk.1 featured a small superstructure in place of the turret whereas the Mk.2 featured a larger structure and sloping glacis plate at the front) but their equipment was identical. Both vehicles carried 2 x tie-bars, a wooden bumper/buffer bar, 2 x heavy-duty single-sheave snatch blocks, and 3 x steel cables – 1 x 98 foot (30-meter), 2 x 15 foot (4.5 meter).

While the FV214 gun tank was retired in 1966, the ARV continued to serve after this. Although it was officially replaced in service by the FV4006 Centurion ARV (a similar vehicle, just built on the Centurion hull) which entered service in the early 1960s, a few were retained in operation in various locations. Records show that at least one Conqueror ARV was still in operation in Germany in the 1990s. One is also reported to have been in operation at the Amphibious Experimental Establishment (also known as ‘AXE’) at Instow in North Devon. It was used for beach tank recovery practice.

Turbine Test Vehicle

Between 1954 and 1956, a petrol-operated turbine engine was tested in the turretless hull of a Conqueror. When it was publicly unveiled in September 1954, the vehicle made history as it was the first armored vehicle in the world to be propelled by a turbine engine. It was not until much later in the 20th Century, with the appearance of the Swedish Strv 103, American M1 Abrams and Soviet T-80, that this engine type would be seen in a production vehicle.

The engine was designed and built by the firm of C. A. Parsons Ltd., based in Newcastle upon Tyne, and was tested by the Fighting Vehicles Research and Development Establishment (FVRDE). Turbine engines were investigated as a means of providing an armored vehicle with a more powerful engine without increasing the vehicle’s weight. Turbine engines are generally made of lighter materials than traditional combustion engines. A turbine engine operates thusly: In an open cycle, a rotary compressor mixes air with combusting fuel. The expanding air is forced over power output, in this case, a turbine, which provides rotation to the drive shaft.

In FVRDE tests, it was found the engine could develop 1,000 hp at 6,500 rpm. Although a general success, the project ended in 1956, with the last official report on it being filed in 1955.

However, the vehicle was not scrapped. Later, it found use as a Dynamometer Vehicle, used to measure engine power. A welded superstructure was placed atop the hull, with a large cab placed at the front and was painted bright yellow. Later still, it found use at The Tank Museum, Bovington as a commentary box in their arena. For this, an additional cab was fitted atop the Dynamometer cab. Sadly, despite the vehicle being one of a kind and a unique piece of tank history, the vehicle was later sent to the scrapper by the Museum.

Shaped Charge Trial Vehicle

In recent years, a number of myths have been propagated over this variant, with two large games companies (Wargaming and Gaijin, makers of World of Tanks and War Thunder, respectively) labeling it as a ‘Super Conqueror’. No such name was ever used. The tank was, in fact, a mere static test vehicle, a guinea pig that was pummeled by High-Explosive Anti-Tank (HEAT) and High-Explosive Squash Head (HESH) ammunition to test their effects on armored vehicles. For this, the vehicle was covered with additional 0.5 – 1.1 inch (14 – 30 mm) armor plates over its bow and turret cheeks.

The vehicle was constructed from spare parts. The tests started in 1957, with prototype versions of the American T42 ‘Dart’ HEAT shell and a single Malkara warhead tested against the armor. Internally, the vehicle was fully stocked with a standard APDS and HESH ammunition loadout. The crew positions were filled with life-size dummies or a more grisly alternative; live rabbits.

Conclusion

For the British Army, the Conqueror was the last of its kind. Just a couple of years after it entered service, most of the world’s major powers realized that the day of the heavy tank had passed and that the Main Battle Tank (MBT) would dominate the battlefields of the future. With the British Army investing in the Conqueror’s replacement – the FV4201 Chieftain – the Conqueror was retired, never having got the chance to combat its rival, the IS-3. By this time, the IS-3 had been replaced in Soviet front line units. It would later see combat in the Middle East where the fear placed in it by the Allies in 1945 was shown to be overblown.

Upon retirement, the majority of Conqueror’s went straight to gunnery ranges across the United Kingdom and West Germany. A number of gutted, rusted hulks still remain on ranges such as Kirkcudbright and Stanford (UK) and Haltern (Germany).

Unfortunately – of the approximately 180 vehicles built – only a handful remain intact. In the UK, examples can be found at The Tank Museum, Bovington, and the Wight Military & Heritage Museum, Isle of Wight. An example can also be found at Musée des blindés, Saumur, and at Patriot Park, Moscow. Other examples of varying conditions can be found dotted across the world.

An article by Mark Nash, assisted by David Lister & Andrew Hills.

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FV214 Conqueror Mk.2. Weighing in at 65 tons (66 tonnes), the Conqueror is worthy of its name. Measuring 25 feet (7.62 meters) long – not including the gun, 13.1 feet (3.99 meters) wide and 11 feet (3.35 meters) tall, the FV214 cut an imposing figure. It was one of the largest and heaviest tanks ever to serve with the British Army.

FV214 Conqueror Mk.2 with turret fully traversed. The powerful, 2.9 ton (3 tonne), 24.3 foot (7.4 meter) long Ordnance QF 120 mm Tank L1A2 Gun is resting in the travel lock. Note the hatch in the turret bustle. This was where shells ejected by the troublesome Mollins gear were jettisoned from the tank.

These illustrations were produced by Ardhya Anargha, funded by our Patreon Campaign

Specifications (Conqueror Mk.2)
Dimensions (L-W-H)	25 feet (without gun) x 13.1 feet x 11 feet (7.62 x 3.99 x 3.35 meters)
Total weight, battle ready	65 tons (66 tonnes)
Crew	4 (Driver, commander, gunner, loader)
Propulsion	Rolls-Royce Meteor M120 810 hp (604 kW)
Suspension	Hortsmann
Speed (road)	22 mph (35 kph)
Range	100 mi (164 km)
Armament	Ordnance Quick-Firing (QF) 120 mm Tank L1A2 Gun Sec. 2x L3A1/Browning M1919A4 .30 Cal (7.62mm) Machine Guns
Armor	Hull Front (Upper Glacis): 4.7 – 5.1 in (120 – 130 mm) @ 61.5 degrees Front (Lower Glacis): 3 in (77 mm) @ 45 degrees Sides & Roof: 2 in (51 mm) + 0.2 in (6 mm) ‘Bazooka Plates’ Floor: 0.7 in (20 mm) + 0.3 in (10 mm) ‘Mine Plate’ Turret Face: 9.4 – 13.3 in (240 – 340 mm) @ 60 degrees. Mantlet: 9.4 in (239 mm) Sides: 3.5 inches (89 mm) Roof & Rear: 2 inches (51 mm)
Total production	Aprx. 180

Sources

WO 185/292: Tanks: TV 200 Series: Policy and Design, 1946-1951, The National Archives, Kew
E2004.3658: RAC Conference Notes, 1949, The Tank Museum, Bovington
E2011.1890: Development report,1951, The Tank Museum, Bovington
Letter from Captain R. A. McClure, MELF, to the Ministry of Supply, December 1954, The Tank Museum, Bovington
FVRDE Report No. Tr. 7, Firing Trials of the 120mm Gun, February 1957.
FV221 Caernarvon – Instructions for User Trials – REME aspect, September 1953, The Tank Museum, Bovington
User Handbook for Tank, Heavy Gun, Conqueror Mk.1 & 2 – 1958, WO Code No. 12065
Rob Griffin, Conqueror, Crowood Press
Maj. Michael Norman, RTR, Conqueror Heavy Gun Tank, AFV/Weapons #38, Profile Publications Ltd.
Carl Schulze, Conqueror Heavy Gun Tank, Britain’s Cold War Heavy Tank, Tankograd Publishing
David Lister, The Dark Age of Tanks: Britain’s Lost Armour, 1945–1970, Pen & Sword Publishing
Inside the Chieftain’s Hatch: Conqueror, Part 1 – 4.
overlord-wot.blogspot.com

Videos

Video of the Ejection Gear
FCT instructional video
Video of the Turbine Test Vehicle

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United Kingdom (1958)
Self-Propelled Gun – 234 Built

In the late 1950s, the United Kingdom was looking for a new Self-Propelled Gun (SPG). It was envisioned that this would replace the Ram-based Sexton, a Second World War-era 25-Pounder gun-armed SPG that was still in service with the Royal Artillery. It was also planned that it would somewhat replace the 25-Pounder gun in general, as the towed version was also still in service. Even so, there were some developments with 25-pounder armed SPGs, such as the Centurion-based FV3805. This was unsuccessful, however.

A 105 mm gun would be developed to replace the 25-Pounder. For ease of production, it was decided that this new SPG would be based on the FV432 ‘Trojan’ Armoured Personnel Carrier, then coming into service. The SPG would receive the designation ‘FV433’ and would be designed and constructed by Vickers. They would go on and build a total of 234 vehicles, the majority of which would see service with the British Army, though a few simpler, ‘Value Engineered’ versions would also be designed and sold to the Indian Army.

The FV433 would be the last Self-Propelled Gun to be named – in British tradition – after a religious title. In this case, ‘Abbot’. An Abbot is a man in charge of an abbey of monks. As well as the above mentioned Sexton, there were others named in this way, such as the Deacon, Bishop, and M7 ‘Priest’.

Foundation, The FV432

The FV432 Armoured Personnel Carrier (APC) was a small vehicle at 17 feet 2 inches (5.25 m) long, 9 feet 2 inches (2.8 m) wide and 7 feet 5 inches (2.28 m) tall. It had a two-man crew (Commander & Driver) and had the ability to carry up to ten troops.
The FV432 weighed 15 tons (15.3 tonnes) and was powered by the 240 hp Rolls-Royce K60 multi-fuel engine. This gave it a top speed of 44 mph (70 km/h). A torsion-bar suspension gave the vehicle a smooth and comfortable ride. It had five road-wheels per-side, with the drive sprocket at the front and the idler at the rear.

The Abbot would utilize the exact same powertrain and suspension as the FV432 APC. This SPG was one of many variants that would be born from the FV432, or ‘Battle Taxi’, as it would come to be known throughout its service life.

Development

Development of the FV433 took place between 1958 and 1960 at the Fighting Vehicle Research and Development Establishment (FVRDE) located in Chertsey, Surrey. Basing a vehicle on an existing model has a number of benefits: It allows for a commonality of parts making maintenance easier, but also allows possible operators to familiarize themselves with the particulars of the vehicle when it comes to driving, for example. It also lowers costs and simplifies the logistical train required.

Vickers came up with a design for this new Self-Propelled Gun. The aim was to create a small, mobile SPG that was flexible and could be deployed quickly. It would be armed with a large caliber, quick-firing gun to enable saturation of a target in a short time.

They would utilize as many components from the FV432 APC as possible for the hull. For the gun, the new 105 mm L13A1 gun was chosen although at the time there were several contenders to be the new standard artillery caliber. This was placed in a turret towards the rear of the vehicle. As in the FV432, the engine and transmission were located at the front of the vehicle. A unique feature to the ‘Abbot’ compared to other SPG’s of the time was the fact that it was amphibious. This was possible via a flotation screen, like those used on the famous Sherman DD tanks of D-Day. The SPG would also have Nuclear, Biological & Chemical (NBC) protection.

By 1961, Vickers had produced 12 prototypes of the FV433. Six of these were fitted with the Rolls-Royce B81 petrol engine before the multi-fuel K60 of the FV432 was chosen as the production standard. This was a 6-cylinder horizontally opposed engine. These engines consist of two pistons per cylinder, working against each other in opposite directions. The idea behind multi-fuel engines was that in an emergency, the engine could run on either petrol (gasoline), diesel, or other fuel types. A similar, although less successful and more troublesome, engine was installed on the FV4201 Chieftain.
Vickers began full-scale production of the FV433 Abbot at their Elswick facility in Newcastle-upon-Tyne in 1964.

Design

Hull

Sharing the same hull as the FV432 APC, the Abbot gained similar dimensions at 19 feet 2 inches (5.8 m) long, 8 feet 8 inches (2.6 m) wide, and 8 feet 9 inches (2.7 m) high. The vehicle would weigh around 16 tons (16.2 tonnes). It utilized the same running gear and track.

The general shape of the hull was also similar, small and boxy, but sloped down towards the front. This sloping front housed the engine, gearbox, transmission, and fuel tanks. The driver was also located at the front, to the right. On the front of the hull, there were four large headlights mounted in two double-light units (the prototype only had two lights).

On the rear of the hull, there was a large hatch that opened out to the right. This hatch was used while the gun was in operation. It allowed the crew easy access to the fighting compartment and provided ventilation. It would also provide an opening to discard spent cartridges, instead of letting them pile up in the confined space of the turret. Obviously, this door would not be used in hazardous situations. There was stowage above the door for some pioneer tools.

The exhaust was located on the left of the hull. On the prototypes, this was placed above the flotation screen. On the production model, this was moved to between the flotation screen and top of the fender.

As mentioned above, the ‘Abbot’ was equipped with a flotation screen. This allowed the SPG to negotiate through calm waterways. Propulsion was provided by the revolution of the tracks, as was steering. When not in use, the screen collapsed onto the hull. On the prototypes, this sloped from the back to the front of the hull as one piece. On production models, this was adapted so it followed the shape of the hull. In later years of its use in service, however, this screen was removed.

Turret

The turret was capable of 360-degree horizontal rotation, allowing for great flexibility in fire-missions. It was rather small and took the shape of a non-equal octagon. It was also slightly frustoconical, narrow down towards the roof, meaning all panels sloped back a few degrees. The right turret cheek had a triangular bulge incorporated to make way for the gunnery equipment inside the turret. The turret face had a bolted-on reinforcing plate around the gun slot. At the top of this, there was a semi-circular cut-out that allowed the gun to reach maximum elevation. There were hatches at the left and right rear for the commander (right) and loader (left). There was also a small ‘ammunition supply’ hatch on the rear of the turret. When open, it revealed a tray with grooves for two 105 mm rounds.

The outer circumference of the turret was covered in stowage. On the left and right turret sides, there were fastening points that would allow the attachment of large ‘soft’ bins. Smaller boxes were scattered around, with a shovel being stored on the right turret cheek. On the right rear corner, the large ventilation unit for the NBC system was installed. On the left rear corner, a wire reel was hung. This was a spool of telephone wire that was carried by most British tanks at the time. It would be used in bivouac areas when the tanks were in their defensive positions. The wire was hooked up to each tank and allowed them to discreetly communicate without broadcasting their positions via radio comms.

Crew

The driver was located at the front right corner of the hull. He was provided with a two-part hatch cover which opened to the left and right. For closed-down driving, he was provided with a single wide-angle periscope built into the hull roof just in front of the driver’s hatch. This periscope was even equipped with twin wipers.

Three crew members were stationed in the turret. These were the Commander, Gunner – also known as the Gun Layer, and Loader. The Gunner was located at the right front of the turret and was without a hatch. The Commander was positioned directly behind him. He had override controls for the rotation of the turret. This allowed him to quickly lay the gun onto a target in an emergency. The commander sat under a rotating vision cupola with a hatch that opened up and rear and three vision periscopes. The Loader was positioned in the left rear corner of the turret, had a basic one-piece hatch over his head and also performed radio operator duties.

Although the vehicle technically had a six-man crew, only four were present on the tank at all times. There was not enough room for all six. The Driver, Commander, Gunner, and the Radio-Operator/Loader would travel with the SPG. The other two men were the Ammunition Handler and the Second in Command, who was responsible for correct ammunition preparation (setting charges and fuses correctly). These men would travel in an accompanying support vehicle and would join the rest of the crew upon reaching the designated firing position.

Armor

The ‘Abbot’ was only lightly armored, as it was not intended to combat enemies head-on. Armor on the hull consisted of 12 mm (0.47 inches) on the front and sides, 10 mm (0.39 inches) at the rear and 6 mm (0.23 inches) on the floor. Armor on the turret was 10 mm around the sides and 12 mm on the roof. This armor was simply intended to protect the vehicle’s occupants from shrapnel and small arms fire.

Armament

The 105 mm L13A1 was a brand new design built by the Royal Ordnance Factory (ROF). It was not only intended as the weapon of choice for Self-Propelled Guns but also as the main-stay towed piece of British artillery units. The 105 mm (4.1-inch) caliber was chosen after detailed examination showed it had an effective blend of weight, lethality and range.

The gun was 37 calibers (3.8 meters) long with a double-baffle muzzle break at the end and a fume extractor halfway down the length. The gun uses a semi-automatic, vertically sliding breech (a semi-automatic breach means the spent rounds are not ejected automatically after firing, but the breech closes automatically when loading) and is mounted in a ring-type cradle with twin hydraulic buffers. It was also equipped with a single hydro-pneumatic recuperator. The gun was mounted in the 360-degree-capable turret and had an elevation range of +70 to -5 degrees. Elevation was tended by hand wheels, although the rotation of the turret was powered. There was a travel lock located on the front of the hull, just off to the left of the centerline.

For indirect-fire, the gun was laid via a periscope that protrudes from the turret roof and was protected by a small armored cupola. Thanks to its fully rotatable turret and wide elevation range, the ‘Abbot’ was also capable of direct-fire at enemy vehicles. This was an ability requested by Gunners themselves. For this, a telescopic sight was provided. It should be noted, however, that the ‘Abbot’s’ primary role was to provide fire-support. It was not designed to be in the front line or engage in combat with tanks. They were designed to fire shells over the heads of friendly troops from long range.

Because of the amount of ammunition carried and the compact nature of the turret, the FV433 did not have calibrating sights. To overcome this, the gun mount had both Tangent Elevation (TE) and Angle of Sight (AOS) scales with a separate gun rule to convert the range into TE in mils, with corrections made for the ammunition type in use. The single eye-piece sight used internal, illuminated scales.

Secondary armament consisted of a light machine gun installed on the Commander’s cupola. In the early years of the ‘Abbot’s’ service, this would have been the L4 7.62 Light Machine Gun – an upgraded version of the faithful Bren Gun of WW2. In later years, this was replaced by the General-Purpose Machine Gun, or ‘GPMG’, also chambered in 7.62 mm (.30 Cal). The FV433 was also equipped with smoke grenade launchers, three-per turret cheek.

Ammunition

A wide range of ammunition was available to the ‘Abbot’. For indirect-fire, this consisted of L31 High Explosive (HE), L37, L38 & L45 Smoke, and L43 Illumination. For direct fire, the Abbot was equipped with L42 High-Explosive Squash Head (HESH) shells and the L31 HE shell could also be used in the direct-fire role. The ammunition was two-part, meaning the projectile was separate from the propellant case, and that they were loaded separately. In this case, the projectile was loaded with the assistance of an electrically powered rammer, while the propellant was inserted by hand. The propellant for the 105mm gun was placed in brass cartridge cases. The primers were electrically triggered, rather than mechanically via a firing-pin. The propellant in the cases was contained in specific amounts in marked bags. A total of eight could be used in a cartridge; the more bags, the greater the range. There were, however, two cartridge types – supercharged and standard. The supercharged cartridge produced the greatest range and was filled with a much more potent charge. The standard cartridge contained 1-5 charge bags of equal size. There were also two lower-power charges known as ‘Sub zone A & B’. These were used in standard cartridge cases emptied of the standard charges. A maximum of 42 rounds were carried aboard the ‘Abbot’ (36 HE and 6 HESH). In normal operations, however, only 40 rounds were usually carried (32 HE and 6 HESH). The rounds were stored around the inside of the turret and the hull.

Gun Performance

The ‘Abbot’ had an extremely high rate of fire, so much so that three ‘Abbots’ could saturate a target with about half a tonne (453 kgs, 6-8 rounds) of shells per minute. This rate of fire was achieved thanks to the rotating turret and the semi-automatic breech with a powered rammer. At the time of its introduction, the ‘Abbot’ was unrivaled when it came to its blend of firepower, accuracy, and range covered. Its rotating turret gave it the ability to engage any target, in any direction without the need to reposition the hull. The high elevation angle of the gun also gave the ability to engage targets behind the steepest covers. It was able to engage targets accurately up to its maximum firing range of 19,000 yards (11 mi, 17.3 km). The 105 mm gun had a service life of 10,000 rounds.

Variants

The ‘Value Engineered’ ‘Abbot’ (VEA)

In 1965, Vickers presented the ‘Abbot’ to the Indian military. The Indians were impressed with everything about the SPG, apart from its price tag. This resulted in a full-scale investigation by the ‘Value Engineering’ Department of the Vickers Armament Division. Simply put, the Value Engineering process produces a cheaper vehicle, without impact to its tactical capability. The first ‘Value Engineered’ ‘Abbot’ was produced in 1967 and was taken to India for demonstration the same year.

The VEA was different from the standard Abbot in the following ways:

• The flotation screen was removed
• The engine was exchanged for the Rolls-Royce K60 Mark G/1, a variant of the standard engine that only ran on diesel
• No rubber pads on the tracks
• No power traverse – turret traverse and gun elevation/depression were manual
• No electric rammer
• The armored cover of the roof-mounted gun sight was replaced by a canvas one, sights were replaced with a German model
• The Commander’s cupola did not rotate and was only equipped with one periscope.
• No smoke launchers or roof-mounted machine gun
• Reduced external stowage

The Indian Army was happier with this cheaper ‘Abbot’, so much so that they accepted the vehicle for service. From 1967 onwards, a total of 88 VEAs were built. Twenty of these went to the British Army, specifically to the British Army Training Unit Suffield (BATUS) in Canada, as training vehicles. The remaining 68 SPG’s were sent to the Indian Army, where they were operated well into the late-1990’s.

The VEA was not the only vehicle that Vickers sold to the Indian Army. In the mid-1960’s, Vickers developed a main battle tank (MBT) which they called the ‘Vickers Main Battle Tank’. While it never entered service in the UK, the Indian Military were extremely happy with it, becoming India’s first MBT, and was named the ‘Vijayanta’.

The ‘Falcon’

Developed in the late-1960s, the ‘Falcon’ was a Self-Propelled Anti-Aircraft Gun (SPAAG) system based on the ‘Abbot. It utilized the VEA’s hull, but could easily be upgraded to standard ‘Abbot’ configuration (re-application of flotation screen, headlights, etcetera). A new turret was designed for the ‘Falcon’, which was armed with two Hispano Suiza HSS 831L 30 mm auto-cannons. These cannons utilized the same ammunition as the British-made 30 mm Rarden cannon, as used on the Scimitar and Fox light vehicles. The vehicle was operated by a crew of three, consisting of a Commander, Gunner, and Driver. Though designed to combat aircraft, it was also capable of combating lightly armored vehicles.

Despite extremely successful tests in the early-1970’s and favorable opinions from military officials, the ‘Falcon’ never entered service. This was largely due to a rather small ammunition capacity, caused by the small and cramped nature of the FV430-type hull.

Service

The ‘Abbot’ entered service in 1965, alongside around 140 M109 Howitzers purchased from the United States. The 3rd Battalion Royal Horse Artillery (3 RHA) became the first regiment to be equipped with it. The ‘Abbot’ spent almost all of its service life with British forces stationed in Germany. Its small size and good mobility allowed it to be deployed anywhere in a very short time, should the Cold War have turned hot. The ‘Abbots’ were placed in Field Regiments supporting Armoured Brigades, this would have been about 8 Regiments (142+) guns in the British Army of the Rhine (BAOR).

The ‘Abbot’ was an extremely reliable vehicle and was easy to maintain. As a result, the ‘Abbot’ became loved by its crews, despite it being very cramped internally. To describe how cramped it was inside, fellow amateur tank researcher and enthusiast, Rita Cardoso Sobral, has said “I am only 5′ 3” and it was nearly impossible for me to get in/out.”

The ‘Abbot’ served the British Army for 28 years before it began to be replaced by the 155 mm gun-armed AS-90 in 1993.

Surviving Vehicles

Thanks to its reliability, many ‘Abbots’ still survive and are operated by private owners and/or companies. They are relatively easy to come by for private purchase at a relatively good price, and many can be found in museums across the world. These include the Wight Military and Heritage Museum, Isle of Wight (UK) and the Australian Armour and Artillery Museum (AAAM), Queensland, Australia, among many others. Many tank-driving attractions also feature ‘Abbots’ as part of their fleet. Such places include ‘Tanks-Alot’, based in Brackley, England, and ‘Drive A Tank’ based in Minnesota, USA.

One of the best examples of a private company using the ‘Abbot’ is the ‘Grenade’ sports nutrition company. In the UK, they use an ‘Abbot’ covered in their brand logo as an advertisement. As of 2019, they have also started selling authentic ‘Abbot’s’, done up in ‘Grenade’ colors on their website for the price of £75,000 ($94,000). See HERE.

Conclusion

The ‘Abbot’ was an attempt by the British Military to create an effective SPG on a common platform. In doing so, it became one of the most successful Self-Propelled Gun platforms used by the UK, largely due to its firepower, flexibility, and ease of maintenance. It was also one of the first British SPGs to adopt the post-war move to turreted self-propelled artillery pieces. In its almost 30-year service life with the British Army, it never fired a shot in anger.

The Abbot is one of the best examples in the world of a military vehicle that has been successful in both military and private sector service. It was loved by its military crews, and continues to be loved by civilian crews.

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The FV433 Abbot Self-Propelled Gun (SPG). Based on the FV432 APC, it had a 105mm gun in a fully rotating turret.

The ‘Value Engineered Abbot’ or ‘VEA’, a cheaper, simplified version of the Abbot developed for the Indian Army.

The ‘Falcon’ Self-Propelled Anti-Aircraft Gun (SPAAG), based on the Abbot chassis.

These illustrations were produced by Tank Encyclopedia’s own David Bocquelet.

Specifications
Dimensions	19ft 2in x 8ft 8in x 8ft 9in (5.8 x 2.6 x 2.7 meters)
Total weight, battle-ready	16 tons (16.2 tonnes)
Crew	6 (Commander, Loader/radio operator, Gunner/Layer, Driver/Ammunition Handler, Ammunition Handler, Second in Command/Ammunition Prepper)
Propulsion	240 hp Rolls-Royce K60 multi-fuel engine
Suspension	Torsion Bar
Speed (road)	29 mph (47 kph)
Armament	105mm L13A1 Gun L4 7.62mm Light Machine Gun/GPMG 7.62mm Machine Gun
Armor	12 – 10mm (0.39 – 0.47in)
Total Production	234 (176 FV433s, 88 VEAs)

Sources

Rob Griffin, FV432 Variants, Tankograd Publishing
Profile Publications Ltd. AFV/Weapons #51: Abbot FV433 Self-Propelled Gun, Christopher F. Foss
www.forecastinternational.com
www.driveatank.com
Wight Military and Heritage Museum
Australian Armour and Artillery Museum (AAAM)