FV215 Heavy Gun Tank
The design team chose to base the vehicle on the chassis of the FV200. The chassis underwent minimal modifications, the largest change being the repositioning of the turret to the rear of the vehicle. This was to avoid the extremely large main armament hanging over the bow too far. The driver also remained at the front right of the tank.
The large box-like turret mounting the 183 mm (7.2 in) main armament, in theory, had a full 360 Degrees of traverse, but this was not recommended on sloping services. It was commonly believed that the turret could only traverse 90 Degrees left and right. Despite its large size, there was still not enough room inside the turret for a working loading mechanism. As such, the predicted 6 rounds per minute would have been a hopeless fantasy. It is expected that this vehicle would need 2 loaders to service the weapon, but even so, the desired loading time would likely have gone un-reached. The vehicle had a meager load out, also likely due to space constraints, carrying only 20 separately loading rounds. The combined weight of charge and projectile was 104.8 kg. Not an easy task for the two loaders.
Defensive armament consisted of a machine gun of unknown caliber, most likely a .30 cal (7.62 mm) machine-gun. It was mounted in a small structure on the forward right of the turret roof. It was able to aim up and down a few degrees. There was also one .50 cal (12.7 mm) M2HB on an AA mounting above the commander’s hatch, on the right rear of the turret.
The armor thicknesses of the vehicle changed throughout its development. As it was intended as a relatively long range vehicle, its reliance on armor would have been minimal. None the less, it was given similar armor properties to the Conqueror. The upper plate varied from 125 to 152 mm (4.92 – 6 in) thick. The sides plates were 50 mm (1.97 in) thick, with spaced armor in front. The turret had the thickest armor on its front. It was 254 mm (10 inches) thick.
The vehicle was designed to be powered by an 810 hp Meteor Mk.12 engine. This would’ve propelled the 65-ton vehicle to 32 km/h (20 mph).
The QF 183mm L4
In 1950 work started on the QF 183 mm (7.2 in) L4 gun. At the time it was the largest and most powerful tank gun in the world. The cannon was based on the 183 mm BL 7.2 inch howitzer, a WWI era weapon. The gun itself weighed a mighty 4 tons, and when fired produced 87 tons worth of recoil force. A shell of this size would understandably produce a substantial amount of fumes and smoke inside of the fighting compartment. As such, a large fume extractor was added to the barrel, a relatively new feature at the time.
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The L4 was designed to be chambered for only one type of ammunition, HESH (High Explosive Squashed Head).The 183mm was tested in live fire trials against a Centurion and a Conqueror. In 2 shots, the 183 blew the turret clean off the Centurion, and split the mantlet of the Conqueror in half.
Fate
The Morris company was the first to be tasked with building a full-scale model, followed by two prototypes, one to test mobility, and for armor testing. In June 1954, Vickers-Armstrong became the owners of the contract and were given the same task.
January 1957 marked the end of the road for the SPG, even though the requested scale model was finished, and 80% of the blueprints were ready and waiting for further development. The intended role of the vehicle had been over taken by increasing development of ATGMs (Anti-Tank Guided Missiles). These granted the same, if not better, anti-armor capabilities, with the experiments ultimately culminating in the Malkara and Orange William missile systems.
The only 183mm armed vehicles to reach prototype phase were the FV4005 Stage I and Stage II. Both vehicles were based on the Centurion MBT. The Stage I featured an exposed gun with an automatic loading system, on a limited traverse ring. The Stage II featured a fully enclosed turret, with a full 360-degree traverse. As the loading system wouldn’t fit in the turret, it was removed.
Just one vehicle was used for both prototypes. The Stage II now sits outside the Tank Museum in Bovington.
FV215 Heavy Gun Tank
Dimensions
Total weight 65 tons
Crew 5 (driver, gunner, commander, x2 loaders)
Propulsion 810 hp Meteor Mk.12
Speed (road) 31.7 Kph ( mph)
Armament QF 183mm L4 Tank Gun
.30 Cal. machine gun.
.50 M2HB Machine gun.
Armor 125 to 152 mm (0.79-3.07 in) hull front, 50mm (1.9 in) sides, 254 mm (10 inches) thick on the turret face.
Scources:
Tank, Heavy No. 2, 183 mm Gun, FV215 - Tank Encyclopedia
Британский исполин: противотанковая 183-мм САУ FV4005 | Warspot.ru (Russian)
