Debut: July 2015

 




   

.: Dave Garner's Cromwell Mk.IV

Brand:

Tamiya

Scale:

1/35

Modelling Time:

3 weeks

PE/Resin Detail:

none

Comments:

"Normandy Invasion Tank
Covered in sand from amphibious landing. "

Cromwell tank

From Wikipedia, the free encyclopedia
Tank, Cruiser, Mk VIII, Cromwell (A27M)
Cromwell in the Kubinka Museum.jpg
Cromwell Mk VII in the Kubinka Tank Museum
Type Cruiser tank
Place of origin United Kingdom
Service history
In service 1944–1955
Used by British ArmyIsraeli ArmyGreek ArmyPortuguese Army
Wars World War II1948 Arab–Israeli WarKorean War
Production history
Designer Leyland, then Birmingham Railway Carriage and Wagon Company from 1942[1]
Manufacturer Nuffield Mechanisation and Aero
Number built 4,016
Specifications
Weight 27.6 long tons (28 tonnes)
Length 20 ft 10 in (6.35 m)
Width 9 ft 6 1⁄2 in (2.908 m)
Height 8 ft 2 in (2.49 m)
Crew 5 (Commander, gunner, loader/radio operator, driver, front gunner)

Armour 3 inches (76 mm)
Main
armament
Ordnance QF 75 mm
with 64 rounds
Secondary
armament
2 x 7.92 mm Besa machine gun
with 4,950 rounds
Engine Rolls-Royce Meteor V12 petrol
600 horsepower (450 kW)
Power/weight 21.4 hp/tonne
Transmission Merritt-Brown Z.5 gearbox (five forward and one reverse gear) driving rear sprockets
Suspension Improved Christie
Ground clearance 16 inches
Fuel capacity 110 gallons + optional 30 gallon auxiliary
Operational
range
170 miles (270 km) on roads, 80 miles cross country[2]
Speed 40 miles per hour (64 km/h) with 3.7:1 final reduction drive
 

Tank, Cruiser, Mk VIII, Cromwell (A27M),[a] and the related Centaur (A27L) tank, were one of the most successful series of cruiser tanks fielded by Britain in the Second World War. The Cromwell tank, named after the English Civil War leader Oliver Cromwell, was the first tank put into service by the British to combine a dual-purpose gun, high speed from the powerful and reliable Meteor engine, and reasonable armour, in a balanced package. Its design formed the basis of the Comet tank.

The Cromwell and Centaur differed in the engine used. While the Centaur had the Liberty engine of the predecessor cruiser tank, the Crusader (and the interim A24 Cavalier), the Cromwell had the significantly more powerful Meteor. Apart from the engine and associated transmission differences, the two tanks were the same and many Centaurs built were fitted with the Meteor to make them Cromwells.

The Cromwell first saw action in the Battle of Normandy in June 1944. The tank equipped the armoured reconnaissance regiments, of the Royal Armoured Corps, within the 7th, 11th and Guards Armoured Divisions. While the armoured regiments of the latter two divisions were equipped with M4 Shermans, the armoured regiments of the 7th Armoured Division were equipped with Cromwell tanks. The Centaurs were not used in combat except for those fitted with a 95mm howitzer, which were used in support of the Royal Marines during the invasion of Normandy.

Development

Initial designs

Development of the Cromwell and Centaur dates to 1940, as the Crusader tank was being readied for service. The General Staff was aware that the Crusader would become obsolete, and in late 1940 they set out the specifications for the new tank to replace it. The tank was to be fitted with the QF 6 pounder gun and was expected to enter service in 1942.

Vauxhall responded with the A23, a scaled down version of their A22 Churchill infantry tank. This would have had 75 mm of frontal armour, used a 12-cylinder Bedford engine, carried a crew of five and would have the same suspension as the A22.

Nuffield submitted the A24, heavily based on its Crusader design and powered by its version of the Liberty engine, a V-12 design dating the late days of World War I and now thoroughly outdated. Nevertheless, as the design was based on the Crusader, it was expected it could be put into production rapidly.

The final entry was from Leyland and Birmingham Railway Carriage & Wagon (BRC&W). Their design[b] was similar to the Nuffield, but with different suspension and tracks.[3]

The designs were received and examined in January 1941, with Nuffield's A24 being declared the winner on 17 January. Six prototypes of the Cromwell I were ordered for the spring of 1942. These arrived four months late and by this time the design was already outdated. It was put into production anyway, but in service it proved entirely underpowered and only a small number were built.

Delays in the A24 program led to demands to get the QF 6 pounder into service earlier. This led to a series of up-gunned Crusaders mounting the 6-pounder.[4]

A27

With the start of the war, Rolls-Royce ended car production and set up a design team looking for other ways to use their production capacity. The team formed under the direction of Roy Robotham at Clan Foundry near Belper, north of Derby. In October 1940 Robotham met with Henry Spurrier of Leyland Motors to discuss British tank design. They decided to attempt to fit a Rolls-Royce Merlinengine to a Leyland tank for testing. They removed the supercharger from a Merlin Mk. III and fitted it to a Leyland-built Crusader. Delivered to Aldershot on 6 April 1941, the test team had trouble timing its runs because it was so fast, estimating it reached 50 miles per hour (80 km/h).

Everyone was so impressed by this display that Leyland arranged to start production of 1,000 examples of the engine as the Meteor. They planned to fit this to BRC&W-built versions of their original A24 submission. However, in mid-1941 Leyland changed its mind, concerned about cooling problems. They instead suggested using a diesel engine of their own design, although this would produce only 350 horsepower (260 kW) compared to over 500 from the Rolls design. The Tank Board then placed an order directly with Rolls for the Meteor. The resulting design was ordered as the A27. When Leyland suggested that the tank be designed to fit either the Meteor or the Liberty, the two versions were given the General staff numbers A27M and A27L, respectively, and the names Cromwell III and Cromwell II. The diesel concept was abandoned.

The first prototype of a Meteor-powered Cromwell III was delivered in January 1942, several months before the A24 that was supposed to precede it. With nearly 600 hp (450 kW) it proved to be exceptionally mobile when tested. Orders were placed for both versions, as there were concerns about the production rate of the Meteor. Even when assigned reduced production quotas, BRC&W proved unable to meet demand, and Leyland eventually took over production of both versions.

Rover enters

Rolls was at this time having trouble meeting demand for the Merlin, let alone the Meteor. Meanwhile, Rover was having troubles developing Frank Whittle's Power Jets W.2 jet engine design due to increasing animosity between the engineers at Power Jets and Rover. Things became particularly heated when Whittle learned that Rover had set up a secret lab to develop their own versions of the design. Whittle had, during the same period, contacted Rolls for help delivering some of the required parts that Rover proved unable to produce.

A solution to both their problems was offered by Ernest Hives, a Rolls board member, who had met Whittle and was fascinated by the jet engine. Hives called a meeting with his counterpart at Rover, Spencer Wilks, and the two met late in 1942 at the Swan and Royal pub in Clitheroe. Hives offered to trade the Meteor for the W.2, an offer Wilks jumped at. The official handover took place on 1 January 1943. Rover set up production at their Tyseley factory, and an additional line was set up by Morris Motors in Coventry.

Production began in November 1942. That month, new names were given to all three designs; the original A24 Cromwell I became the Cavalier, the Liberty powered A27L Cromwell II became Centaur, and the Meteor powered A27M kept the name Cromwell. It would take considerable time for Rover to make ready production lines for the Meteor, and it was not until a few months later, in January 1943, that sufficient Meteor engines were available and the A27M Cromwell began production. The Centaur production design allowed for the later conversion to the Meteor engine and many Centaurs were converted to Cromwells before use.

Final changes

The first real field test of the design was carried out in August–September 1943, when examples of the Centaur, Cromwell, Sherman M4A2 (diesel engine) and Sherman M4A4 (multi-bank petrol engine) were all tested in Exercise Dracula, a 2,000 mile long trip around Britain. The Shermans proved to be the most reliable, by far, requiring 420 hours of specialist fitter attention over a total distance travelled of 13,986 miles (22,508 km). This corresponds to 0.03 hours per mile. In comparison, the Cromwells drove 11,582 miles (18,639 km) and required 814 hours, or 0.07 hours per mile. The Centaur managed only 8,492 miles (13,667 km) due to constant breakdown, and required 742 hours, or 0.087 hours per mile.[5]

The Cromwell and Centaur were given additional time to work out these problems. The Cromwell's problems were mostly related to oil leaks and brake and clutch failures, an observer noted that these were well known and should have been corrected before this point. The crews, however, expressed their love for the design, and especially its speed and handling. The Centaur was largely dismissed, with one observer expressing his hope that units were being equipped with it only for training purposes. The same reviewers unanimously supported the Sherman.[5] A similar test in November demonstrated the Cromwell was improving, while the underpowered Centaur faired no better than the first test.

The production model design was finalized on 2 February 1944 when Leyland released specifications for what they called the "Battle Cromwell". This included a number of minor changes to the basic design, including 6 millimetres (0.24 in) of extra armor below the crew compartment, seam welding all the joints to waterproof and strengthen the tank, and standardizing on the Meteor engine and Merritt Brown transmission.

Please go to Wikipedia, if you want any further information

Thanks Wikipedia!

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