Cromwell II prototype - Vauxhall turret
Design and service history:
The development of the Cromwell tank was to put things lightly a convoluted mess of inter-company and War Office bureaucracy, that would ultimately lead to three separate tanks, now known as the Cavalier, Centaur and Cromwell. The origins of the Cromwell II with Vauxhall turret is an offshoot of this, which had its roots in the initially disappointing performance of the Churchill tank then in production from Vauxhall. This uncertainty at the time for the long time viability of the Churchill tank prompted some in the company to express a desire to drop the Churchill and instead join the Cromwell program. Because of this Vauxhall began to design their own fittings and turrets for the Cromwell, though they would make no modifications to the hulls currently in development with other companies. These turrets were very similar to the cast ones they had developed for the Churchill, though they were not identical as is sometimes reported.
Two of these “new” cast turrets were made, and they were a combination of a cast main body combined with a welded roof. Interestingly this turret was not cast by Vauxhall, and instead, they contracted it out to two other firms. The first firm was English Steel Corporation, who cast the main body of the turret, and would use this experience to later cast parts of the Tortoise. The plates for the top and bottom of the turret on the other hand were fabricated by the Whessoe Foundry, who would also be tasked with welding the turrets together. This turret would then be mated to the Cromwell chassis using a Vauxhall-designed turret ring, resulting in a subsequent prototype produced by 3 firms.
Around this time Vauxhall backtracked on their plans to switch from Churchill production to Cromwell production, as after heavy modification the Churchill was found to be adequate for service after extensive overhauls. This in combination with delays around the Meteor engine, resulted in Vauxhall committing to the Churchill, as the Cromwell was currently riddled by over 2 years of delays. Despite this, the Turret was mounted on the Cromwell chassis for testing on the 9th of September 1943.
During this testing the tank was struck with a mixture of rounds from small arms up to 25-pounder HE, which found that the turret performed well. The only weak point seemed to be the pistol port, which allowed small arms fire to splash through and enter the turret, and this was earmarked for improvement. Another issue was found with the shot trap produced by the turret ring bulge, which tended to deflect rounds down into the upper deck if struck roughly 1 inch above it. With these two issues identified, overall the turret was praised, as it had held up well to test firing and the armour was deemed sound and suitable for service.
The original prototype then crops up again on the 8th of September 1944, when it appeared at Sheoburyness, where it again underwent firing trials to test various fittings for the Cromwell that was now entering service. One of the tests involved fitting a turret ring traverse gearbox bolted to the inner turret wall and how it would hold up after being struck by 25-pounder HE rounds. A this point the tank was unlikely in running condition, but it continued to soldier on, with more pictures of it surfacing in July of 1945, when again at the same range it was tested for damage done to the tillers and drivers, from shot and mine attacks, which left the tank ragged and in a sorry state, with the turret dislodged and the side skirts missing. The name “Jinx” had been scrawled on the turret, and during the testing she was shot multiple times, with measurements taken before they detonated mines under her forward left side, leaving the tank little more than a wreck. At this point the tank disappears from written records, and with no trace of it left, it is likely it was scrapped shortly after these tests.
Mass 28.0 t
Length 6.35 m
Width 2.908 m
Height 2.49 m
Crew 5 (Commander, gunner, loader/radio operator, driver, front gunner)
Armour 76 mm
Main armament Ordnance QF rifled 57mm, 6-pdr Mark III (43 caliber)
Secondary armament 2 x 7.92 mm Besa machine gun with 4,950 rounds
Engine Bedford engine 12 cylinder
Power/weight 21.4 hp (16 kW) / tonne
Transmission Merritt-Brown Z.5 gearbox (five forward and one reverse gear) driving rear sprockets
Suspension Improved Christie
Ground clearance 410 mm
Fuel capacity 500 l
Operational range 270 km on roads -130 km cross country
Speed 37mph (60 km/h)
Additional pictures and images:
- Cromwell tank - Wikipedia (Mentioned in the variants)
- Panzerserra Bunker- Military Scale Models in 1/35 scale: Cromwell II with Vauxhall turret - A23 cruiser tank prototype - case report (History and lots of photos)
- Cromwell II - The Lost Member of the Cromwell Family - (Additional history)