The ‘Tank, Medium Gun, FV221’, otherwise known as ‘Caernarvon’, appeared in the early 1950s and was a mating of an FV200 series chassis and the turret of an Mk. III Centurion. It was designed as an interim vehicle to fill the gap while Britain’s first Heavy Gun Tank, the FV214 Conqueror, was in the final stages of development.
Decades later, in 2018, and despite the real FV221 Caernarvon already being present, the popular online game World of Tanks (WoT) – published and developed by Wargaming (WG) – was looking for a new premium tank (a vehicle bought with real money that provides special in-game benefits) to add to the British ‘tech tree’. The result was a ghastly blend of 4 separate parts (engine, turret, armor plates and hull), all to create a fake tank with a double fake name. It is known in-game as the Caernarvon ‘Action X’.
While all of the constituent parts used to make this tank did exist in one form or another, they were never put together in this way.
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The WoT Representation
A small ‘history’ is provided for this vehicle by Wargaming:
“A further development of the vehicles designed by the English Electric company under the “universal tank” concept (FV200). The project was discontinued in favor of the A41 tank (Centurion). No prototypes were built.”
– WoT Wiki extract
The Caernarvon ‘Action X’ is portrayed as a variant of the real FV221 Caernarvon, which is in turn part of the FV200 series of vehicles. Despite not being given its ‘Fighting Vehicle (FV)’ number, this fake is presented as a vehicle of the FV200 series produced in the early 1950s, in the early years of the Cold War.
The FV200 dates back to the final stages of the Second World War, when the British War Office (WO) was looking for a ‘Universal Tank’. The ancestor of today’s Main Battle Tanks (MBTs), the idea of the Universal Tank was that one chassis would spawn many variants, thus reducing costs, development and making maintenance and supply far easier. The first in the series was the FV201.
Despite a long development period, the FV201 project was canceled in 1949, with development moving onto the FV214 Conqueror, and in turn, the FV221 Caernarvon. As such, only four vehicles of the FV200 series were ever produced and entered into service. These were the FV214, and FV221 gun tanks, and the FV219/FV222 Conqueror Armoured Recovery Vehicles (ARVs).
Reality: FV221 Caernarvon
In 1950, the gun and turret of the FV214 Conqueror was still in the development phase. 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 and 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, seeing extensive trial service in the British Army of the Rhine (BAOR) and the Middle East Land Forces (MELF).
In-Game Design of the Caernarvon ‘AX’
This fake tank is simply a fictional ‘upgrade’ to the FV221 Caernarvon ‘Medium Gun Tank’. As this vehicle is also equipped with a 20-pounder (84 mm) gun, it also fits the ‘medium gun tank’ designation. The term ‘Medium 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. The role of a ‘Medium Gun Tank’ was to provide support for assaulting infantry by the sheer volume of fire and engaging lighter enemy armored vehicles. The role of engaging heavily armored vehicles and defensive positions fell to the ‘Heavy Gun Tank’, such as the Conqueror.
The hull armor for this vehicle is listed by WG as 130 mm on the hull front, 50.8 mm on the sides, and 38.1 mm on the rear. This is not too far off reality, however, it is still unclear as to just how thick the upper glacis of the tank was due to conflicting sources. That said, it is believed that the upper glacis is between 4.7 and 5.1 inches (120 – 130 mm) thick. The side armor is accurate, at about 2 inches (50 mm) thick, while the rear plate is actually around 0.7 inches (20 mm).
Despite the countless falsehoods present on this vehicle, the Caernarvon ‘AX’ does share some accurate parts of its design with the real FV221. These include the 4-man crew (commander, gunner, loader, driver), Horstmann suspension system, and the layout of the hull.
The ‘Action X’ Turret
The ‘Action X’ turret is where this mutated tank gets its name. In its own right, the ‘history’ of this turret is a comedy of errors but, nonetheless, it must be clearly stated that the turret, by itself, WAS a real project. Unfortunately, the history of this turret is long lost, leading historians to piece together its history from fragments of files. The following information has been compiled by amateur military historians and TE members, Ed Francis and Adam Pawley.
The first falsehood to tackle is the name ‘Action X’. The official name for this turret was the ‘Centurion Mantletless Turret’, so called because it was a design for a new turret for the Centurion. The name ‘Action X’ appeared in a book published in the early 2000s, after the author cited seeing the name written on the back of a photo of the turret. What he fails to mention is that this was written in the 1980s, and does not appear in any official material.
Evidence suggests that the turret was developed alongside the Centurion and Chieftain, as a means of creating a method for poorer countries to upgrade their Centurion fleets if they could not afford to invest in the Chieftain. Despite popular belief, its development had nothing to do with the FV4202 project. The design was quite different from the standard Centurion design.
Where the standard Centurion turret had a large mantlet that covered the majority of the turret face, this design was mantletless. A large sloped ‘forehead’ replaced the mantlet, with the coaxial machine gun being moved to the top left corner. The rest of the turret remained rather similar to the standard turret. The bustle stayed the same basic shape, the commander’s cupola remained at the back right, with the loader’s hatch on the back left. Unfortunately, the real armor values are currently unknown. In-game, they are listed as 254 mm (10 inches) on the front, 152.4 mm (6 inches) on the sides, and 95.3 mm (3 ¼ inches) on the rear.
Other than the fact that just 3 of these turrets were made, with 2 of them fitted and tested on Centurion chassis and 1 destroyed in a firing trial, little more official information remains on the project. One of these three originals still survives, and currently sits in the car park of The Tank Museum, Bovington, England.
Second to the name, the next error is the fact that this turret was never intended to be installed on any member of the FV200 series of vehicles. For one thing, this turret was developed almost a full decade after the FV221 Caernarvon. Another issue is the addition of the additional armor on the turret cheeks. The design of these has been taken straight from another WoT fake, the ‘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. There was never any intention – or even a need – to place these plates on the ‘Mantletless Turret’. In the World of Tanks game, a single Browning M1919A4 .30 caliber (7.62 mm) machine gun was also added to the commander’s cupola on the turret roof. This was known as the L3A1 in British service.
The Caernarvon ‘Action X’ is not the only vehicle in WoT to use the false name. The other vehicle is the Centurion ‘Action X’, which is based on the Centurions which were tested with the ‘Mantletless Turret’.
The armament installed on this spurious vehicle is the Ordnance Quick-Firing (QF) 20-pounder Gun with ‘Type B’ barrel. There were two types of 20-pounder: the ‘Type A’ without a fume extractor, and the ‘Type B’ with a fume extractor. The gun is, at least, an accurate choice, as the ‘Mantletless Turret’ was tested with both the 20-pounder and L7 105 mm gun. The 20-pounder was the successor to the 17-pounder gun of the Second World War and had a 3.3 inch (84 mm) bore. A range of ammunition was available to it. When firing an Armor Piercing Discarding Sabot (A.P.D.S.) round at a muzzle velocity of 4,810 ft/s (1,465 m/s), the gun could penetrate up to 13 inches (330 mm) of armor at 1,000 yards (914 m). In-game, maximum penetration is listed as just 10 inches (258 mm).
Despite the accurate selection of a gun, there remains an error in the presentation of it in that there is a thermal sleeve around the barrel. Thermal sleeves are used to provide consistent temperature to the barrel, in turn preventing distortions due to thermal expansion caused by the temperature fluctuations around the tube. There were no such sleeves added to the barrels of the 20-pounder gun (either A or B) or the 105 mm until the 1960s.
The 20-pounder gun – both ‘A’ & ‘B’ types – was installed on multiple vehicles. It served on the Centurion from the Mk. 3 to the Mk. 5/2, after which it was replaced by the 105 mm L7. It was also the main armament of the FV4101 Charioteer Medium Gun Tank and, of course, the real FV221 Caernarvon.
As with the equally fake FV215b, the Caernarvon ‘AX’ is equipped with the Rolls-Royce Griffon. This is, in reality, an aircraft engine. While Rolls-Royce aero engines have been adapted for use in armored vehicles, there is no evidence at all to suggest that there was ever a plan to make an AFV variant of the Griffon. An example of a converted Rolls-Royce aero engine is the Meteor, as used in the real FV221 Caernarvon. This was an adaption of the Merlin, an engine famous for powering the British Spitfire and American Mustang fighter aircraft of World War 2.
The Griffon was a 37-liter, 60-degree V-12, liquid-cooled engine. It was the last V-12 aero engine built by Rolls-Royce, with production ceasing in 1955. It was used on such aircraft as the Fairey Firefly, Supermarine Spitfire, and Hawker Sea Fury. The engine produced over 2,000 hp in its plane configuration, but in-game it is listed as producing just 950 hp. This is not too far fetched, as converted aero-engines were often de-rated for use in armored vehicles. Meteor is an example of this. As the Merlin, it produced up 1,500 hp depending on the model. When de-rated as the Meteor, it produced just 810 horsepower.
On the real FV221, the Rolls-Royce Meteor M120 No. 2 Mk. 1 produced 810 hp and propelled the vehicle to a top speed of 22 mph (35 kph). In this fake tank, the engine is listed as propelling this vehicle to a top speed of 36.3 km/h (22.5 mph).
The Horstmann suspension of the Caernarvon ‘Action X’ is one of the accurate parts of this vehicle. On the FV200s, the suspension system had 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 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 vehicle, giving it 8 road-wheels per side. There would also be 4 return rollers, 1 per bogie. The drive sprockets were relocated at the rear of the running gear, with the idler wheel at the front.
Fake, Pure and Simple
The Caernarvon ‘Action X’ is just one of a litany of convenient or lazy fakes by Wargaming. Not only do they erroneously mate a turret with a hull that was never intended to carry it, they also use a completely false designation for said turret. To cap it all, they then adorn the turret with false additions, such as the armor plate.
Had this tank ‘existed’, it would have been completely redundant. The turret itself was not developed until the 1960s, after the Caernarvons had all been retired or turned into Conquerors. By this time, the FV4201 Chieftain was in development, and the Conqureor was about to leave service, showing just how obsolete the chassis was, not to mention the 20 pounder gun.
Illustration of the fake Caernarvon ‘Action X’ produced by Ardhya Anargha, funded by our Patreon campaign.
WO 194/388: FVRDE, Research Division, Trials Group Memorandum on Defensive Firing Trials of Centurion Mantletless Turret, June 1960, The Tank Museum, Bovington
WO 185/292: Tanks: TV 200 Series: Policy and Design, 1946-1951, The National Archives, Kew
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