Cromwell tank

The Tank, Cruiser, Mk VIII, Cromwell (A27M), named after the English Civil War leader Oliver Cromwell, was one of the most successful series of cruiser tanks fielded by Britain in World War II. It was the first tank in the British arsenal to combine a dual-purpose gun, high speed, and reasonable armour. Late in the war it was the most common British design in use, replacing the Sherman tank for some units. Its design formed the basis of the superior Comet.

History

The Cromwell was the product of further development of British cruiser tanks, and was designed as the replacement for the Crusader tank, which was fast becoming obsolete. In late 1940, the General Staff set out the specifications for the new tank, and designs were submitted in early 1941.

Due to the typical rushed production and lack of components, the first of these tanks to be accepted, the Cavalier, had far too many problems to see active combat service. One of the key problems was that its Nuffield-built Liberty engine was simply not up to the task.

A new engine, based on the powerful Merlin engine used in aircraft such as the Spitfire, was designed and called the Meteor. Rolls-Royce, the makers of the Merlin, were already fully committed to its manufacture and could not spare the facilities for the Meteor, and manufacture was passed to the Rover Car Company. A modified tank design, the A27 Mk VIII, was then drawn up to take advantage of the new power available, approximately 600 hp (447 kW), double that of the Liberty.

It would take considerable time for Rover to make ready production lines for the Meteor, so the initial A27s were equipped with the antiquated Liberty engine. These became known as A27L Centaurs. It was not until a few months later, in January 1943, that sufficient Meteor engines were available and the A27M Cromwell began production.

The Cromwell still had revisions to make before service, most notably upgunning from the 6-pounder (57 mm) to the ROQF 75 mm gun (an adaptation of the 6 pounder design to fire the ammuntion of the US M3 75 mm gun), and it was not until June 1944 that it first saw action during Operation Overlord, the Allied invasion of Normandy. It had a mixed reception by crews. It was faster and had a lower profile than the Sherman tank. However, while its armour was of equivalent thickness, it was less sloped and therefore less effective than that of the Sherman. The 75 mm gun, though able to fire a useful HE shell, was not as effective against armour as the 6 pdr or the 17 pounder that was fitted to the Firefly variant of the Sherman.

The Centaur was chiefly used for training, only those in specialist roles saw action. The Close Support version of the Centaur saw service as part of the Royal Marine Armoured Support Group on D-Day and a number were used as the basis for engineering vehicles.

The Sherman remained the most common tank in British and commonwealth armoured units. Cromwells were used to fully equip only one division, the 7th Armoured Division. The Cromwell was also used as the main tank in the reconnaissance battalions of British armoured divisions because of their great speed. The Cromwell in turn was succeeded by small numbers of the Comet tank. Although the Comet was similar to the Cromwell, and shared some components, it was a much better tank with the 77 mm gun (an adaption of the QF 17 pounder gun).

Post war the Cromwell remained in British Service and was also used by Finland.

Performance

The Cromwell was the fastest tank to serve in WW2, with a top (un-governed) speed of 40 mph. Unfortunately this speed proved too much for the Christie suspension and the engine was governed to give a top speed of 32 mph which was still fast for its time. Thanks to its Christies parentage the Cromwell was very agile on the battlefield. The dual purpose 75 mm main gun fired the same ammunition as the US 75 mm gun and therefore it around the same HE and armour-piercing capabilities as the 75 mm equipped Sherman tank. The Cromwell's armour ranged from 8 mm to 76 mm thick overall but the maximum thickness was later increased to 102mm with appliqué armour plates which were welded on. This armour compared well with that of the Sherman although the Cromwell did not share the Sherman’s sloped glacis plate. The Cromwell crews in North West Europe succeeded in the Cromwell with superior speed, manoeuvrability and reliability outflanking the heavier and more sluggish German tanks, however the Cromwell was still not at match for the best German armour and British tank design would go through another stage, the Comet tank, before going ahead in the tank development race with the Centurion tank.

Variants

Centaur I
First draft. Armed with the RO QF 6 pounder (2.7 kg) gun (64 Rounds). It was used only for training.

Centaur II
Mark I with wider tracks and no hull machine gun. Experimental only.

Centaur III
Centaur armed with the 75 mm ROQF Mk V gun. In 1943, most Centaur I's were converted to III's, but a few remained as such.

Centaur IV (80)
Centaur armed with a 95mm howitzer (51 Rounds). This is the only version of the Centaur known to have seen combat, in service with the Royal Marines Armoured Support Group. The vehicles were fitted with wading gear to get them ashore. Trunking waterproofed the engine inlets and covers were fitted to the guns.

Centaur AA I
Used a Crusader AA II turret with twin Oerlikon AA guns. Were originally deployed in Normandy, but withdrawn as unnecessary due to Allied air superiority.

Centaur AA II
Same as the AA I, but used twin Polsten AA guns.

Cromwell I (600)
Exactly the same as the Centaur I, but using the Meteor engine. Only a few built due to the switch from the 6 pounder (2.7 kg) (64 Rounds) to the 75 mm gun.

Cromwell II
Increased track width and removal of the hull MG to increase stowage. None produced.

Cromwell III (~200)
Centaur I upgraded with Meteor V12 engine. Few produced due to scarcity of Centaur I's.

Cromwell IV (1935+)
Centaur III upgraded with Meteor engine. The most numerous variant.

Cromwell V
Cromwell built from the start with the 75 mm gun. Used a welded instead of riveted hull.

Cromwell VI
Cromwell armed with 95 mm howitzer.

Cromwell VII (~1500)
Cromwell IV and V upgraded with additional armour, wider tracks, and additional gearbox. These were introduced very late in the war and did not see much in the way of combat.

Cromwell VIII
Cromwell VI with same upgrades as VII.

Vehicles based on chassis

Tank, Cruiser, Challenger (A30)

The design combined lengthened Cromwell chassis and the 17-pounder gun in a new turret.

SP 17pdr, A30 (Avenger)

an open turreted version of the Challenger.

Centaur dozer

A Centaur with the turret removed and given a simple dozer blade operated by a winch. One of Hobart's Funnies.

FV 4101 Charioteer

In the early 1950s, in an attempt to give extra firepower to the units of the Royal Armoured Corps, some Cromwells received a 20 pounder gun (the same as the Centurion) in a new turret. The resulting vehicle was designated FV 4101 Charioteer tank destroyer. About 200 units were converted by Robinson and Kershaw Ltd in Cheshire. In practice the Charioteer was used by British Territorial units only and during mid and late 1950s most of the vehicles were sold to Austria, Finland and Jordan:

Austria purchased some 80 vehicles.

Finland had bought 38 "Charioteer Mk VII Model B" in total by 1960 and they remained in use until 1979.

Jordan equipped two squadrons (24 vehicles) of their 3rd Tank Regiment in 1954. Some of the Jordanian Charioteers were sold to Lebanon. Several of those were used by the PLO against Israeli forces in Southern Lebanon during the Operation Litani (1978).

Surviving vehicles

Bovington Tank Museum, Dorset, England. Well preserved Cromwell IV displayed in interior location accessible to public on payment of entry fee to museum.
Thetford Forest, Norfolk, England. Cromwell IV in outside location freely accessible to public. This tank is located on the A1065 two miles north of Mundford. Between January and May 1944 the area was occupied by armoured regiments of the 7th Armoured Division (Desert Rats) prior to their embarking for Normandy. The tank forms part of a 1998 memorial to the Division. It is in good display condition having been refurbished and painted as a replica of the tank ‘Little Audrey’ of 1st Royal Tank Regiment.

External links

WWII Vehicles
OnWar specifications: Cromwell I, Cromwell IV
LemaireSoft
Henk of Holland
Nase noviny
Photo Gallery of WW2
Shermanic Firefly

Notes

Medium tanks | World War II British tanks

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