Excelsior tank

The Tank, Heavy Assault, A33 (Excelsior) was a British experimental heavy tank based on the Cromwell (A27) design developed in the Second World War. It was developed when there were concerns as to performance of the Churchill tank.

Tank, Heavy Assault, A33 (Excelsior)
Type	Assault tank/infantry tank
Place of origin	United Kingdom
Production history
Manufacturer	English Electric
No. built	2
Specifications (Second pilot)
Mass	40 tons
Length	22 ft 8 in (6.91 m)
Width	11 ft 2 in (3.40 m)
Height	7 ft 11 in (2.41 m)
Crew	5 (Commander, gunner, loader, driver, co-driver)
Armour	20 to 114 mm (0.79 to 4.49 in)
Main armament	Ordnance QF 75 mm 64 rounds
Secondary armament	2 x 7.92 mm Besa machine gun
Engine	Rolls-Royce Meteor V12 petrol 620 bhp (460 kW)
Suspension	Improved Christie
Operational range	99 mi (160 km)
Maximum speed	24 mph (39 km/h) off-road: 12 mph (19 km/h)

Development

After the Dieppe Raid in August 1942, there was concern that the Churchill infantry tank was slow and too unreliable and it was suggested that production of the Churchill stop in 1943 in order to manufacture more of the A27 (Cromwell) design, which was performing well in trials. While two lines of tanks were still policy, there was interest in a "universal tank chassis" from which infantry tanks, cruiser tanks, and other vehicles could be built. Until then an interim design based on the A27 to replace the Churchill as an infantry tank was considered.^[1]

Rolls-Royce proposed an up-armoured A27M (Cromwell): A31 was a Cromwell with more armour and A32 was a more thorough redesign of the A27 with stronger suspension and armour equivalent to the Churchill. English Electric, contracted to build Cromwells, proposed using the A27 hull and turret with extra armour^{[note 1]} and the track and suspension of the 50-ton US M6 Heavy Tank which had been developed for both US and British use.^[1] This scheme received the General Staff number A33.

English Electric built two prototypes on a Cromwell tank hull, the first with the suspension and T1 track of the M6 tank in 1943 but with a 6-pounder gun. The second was built with a widened Cromwell track and suspension by LMS and different armoured skirts. The design included extra armour and an Ordnance QF 75 mm gun. When the problems of the early Churchill models were worked out, the A33 was no longer required and the project was dropped.^[2]

Survivors

The second pilot vehicle is in the collection of The Tank Museum in Bovington, UK.

See also

• A38 Valiant – a heavily armoured lightweight assault tank
• Comet – a fast cruiser tank also developed from the Cromwell

Tanks of comparable role, performance, and era

• British Churchill – heavy tank, entered service in 1941
• American-British T14 – another prototype heavy assault tank with similar specifications to Excelsior
• American M6 – heavy tank, saw trials but never entered service
• Soviet KV-1 – heavy tank, entered service in 1939

Notes

1. The armour on the Cromwell was bolted to the outside of the turret