Cromwell I

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Tank, Cruiser, Mk VIII, Cromwell I (A27M)
General characteristics
5 peopleCrew
85 %Visibility
front / side / backArmour
64 / 46 / 32Hull
64 / 51 / 44Turret
27.0 tWeight
1 145 hp600 hpEngine power
42 hp/t22 hp/tPower-to-weight ratio
71 km/h forward
4 km/h back
64 km/h forward
3 km/h back
57 mm 6pdr OQF Mk.III cannonMain weapon
75 roundsAmmunition
4.0 / 5.2 sReload
-12° / 20°Vertical guidance
7.92 mm BESA machine gunCoaxial weapon
4 950 roundsAmmunition
8.0 / 10.4 sReload
225 roundsBelt capacity
600 shots/minFire rate
11 000 Rp icon.pngResearch
38 000 Sl icon.pngPurchase
Sl icon.png1 490 / 2 015/1 210 / 1 637/790 / 1 068Repair
11 000 Sl icon.pngCrew training
38 000 Sl icon.pngExperts
210 Ge icon.pngAces
124 % Rp icon.pngReward for battle
80 % Sl icon.png80 % Sl icon.png60 % Sl icon.png
This page is about the British medium tank Cromwell I. For other versions, see Cromwell (Family).


GarageImage Cromwell I.jpg

The Tank, Cruiser, Mk VIII, Cromwell I (A27M) (or just Cromwell I) is a rank II British medium tank with a battle rating of 3.7 (AB/RB/SB). It was released along with the initial British ground tree in Update 1.55 "Royal Armour".

The Cromwell Mk I uses the 6-pdr, which provides higher penetration than the 75 mm on the Mk V. It is also slightly faster and more manoeuvrable, thanks to the addition of an engine governor on the Mk. V that lowered its maximum output. However, these advantages are offset by the higher BR which means the Cromwell will be facing some tanks that are a good match for the Cromwell in terms of speed, like the M18, and some tanks that are largely invulnerable, like the KV-2.

The Cromwell I is one of the fastest tanks in the game, due to its Meteor engine derived from the famous Rolls-Royce Merlin of Spitfire fame. It can outrun almost every other tank, including most low-rank light tanks like the BT series or M3, but has adequate armour for a medium tank and a reasonable gun. Generally speaking, it can easily outfight most tanks that can keep up with it, and outrun anything that is a serious threat. Just don't sit still; anyone can snipe if given the chance, and the Cromwell's armour makes it a one-hit-wonder.

General info

Survivability and armour

Armour type:

  • Rolled homogeneous armour
  • Cast homogeneous armour (Gun mantlet, Driver's port, Side armour, Compartment hull roof)
Armour Front Sides Rear Roof
Hull 63.5 mm Front plate
25.4 mm (74°) Front glacis
57 mm (13°) Joint plate
25.4 mm (68°) Lower glacis
Front compartment:
44 mm Upper side
32 + 14 mm Lower side

Engine compartment:
38 (0°) + 32 mm (34°) Upper side
25.4 + 14 mm Lower side

32 mm (0-7°) Top
20 mm (47°) Bottom
20 mm Compartment
14 mm Engine
Turret 64 mm Turret front
63.5 mm Gun mantlet
51 mm 44 mm 20 mm


  • Suspension wheels and tracks are 20 mm thick.


Game Mode Max Speed (km/h) Weight (tons) Engine power (horsepower) Power-to-weight ratio (hp/ton)
Forward Reverse Stock Upgraded Stock Upgraded
Arcade 71 4 27 930 1,145 34.44 42.41
Realistic 64 3 531 600 19.67 22.22


Main armament

57 mm 6pdr OQF Mk.III Turret rotation speed (°/s) Reloading rate (seconds)
Mode Capacity Vertical Horizontal Stabilizer Stock Upgraded Full Expert Aced Stock Full Expert Aced
Arcade 75 -12°/+20° ±180° Vertical 24.5 32.94 40.00 43.15 47.06 5.20 4.60 4.24 4.00
Realistic 14.88 17.50 21.25 23.50 25.00


Penetration statistics
Ammunition Type of
Penetration @ 0° Angle of Attack (mm)
10 m 100 m 500 m 1,000 m 1,500 m 2,000 m
Shot Mk.5 AP 101 97 82 66 53 43
Shot Mk.5 HV AP 108 104 87 70 57 46
Shot Mk.8 APC 110 106 89 72 59 48
Shot Mk.9 APCBC 122 118 101 84 70 58
Shell Mk.10 HE 9 9 9 9 9 9
Shell details
Ammunition Type of
Mass (kg)
Fuse delay
Fuse sensitivity
Explosive Mass
(TNT equivalent) (g)
0% 50% 100%
Shot Mk.5 AP 815 2.8 N/A N/A N/A 47° 60° 65°
Shot Mk.5 HV AP 853 2.8 N/A N/A N/A 47° 60° 65°
Shot Mk.8 APC 853 2.87 N/A N/A N/A 48° 63° 71°
Shot Mk.9 APCBC 801 3.23 N/A N/A N/A 48° 63° 71°
Shell Mk.10 HE 655 2.72 0.1 0.1 590 79° 80° 81°

Ammo racks

Ammo racks of the Cromwell V (identical).
rack empty
rack empty
rack empty
rack empty
rack empty
rack empty
rack empty
rack empty
75 66 (+9) 56 (+19) 46 (+29) 37 (+38) 28 (+47) 19 (+56) 10 (+65) (+74) No


Cromwell I Optics
Which ones Default magnification Maximum magnification
Main Gun optics x1.8 x3.5
Comparable optics M10 GMC

Machine guns

Main article: BESA (7.92 mm)
7.92 mm BESA
Mount Capacity
(Belt capacity)
Rate of fire
Coaxial 4,950 (225) 600 N/A N/A

Usage in battles


The Cromwell I is a fast tank with a good cannon and acceptable armor protection. Commanders should play it like a light tank, but be careful of the slow reverse gear. It excels in close quarters combat due to the excellent gun and hull handling characteristics, as well as the fast reload rate. Commanders should avoid long range fights due to the slow reverse gear. This lack of a reverse gear makes it difficult to return to cover after exposing your tank to fire on the enemy. The best strategy in the Cromwell I is to hug the map corners and try to flank, outmaneuvering enemy forces. The tank is very rewarding to players who have experience with the map that is being played, and are able to predict enemy movements. It is a true Cruiser tank, able to exploit gaps in the enemy defenses by disrupting the enemy back line.


The best shell to use is the Shot Mk.9 APCBC due to its penetration characteristics. Generally this is a great round due to the fast reload and shell velocity. However this round struggles against angled armor, most notably against Russian T-34 tanks. Against this enemy Cromwell gunners will have to aim for the turret or machine gun port, as the upper front plate will bounce the Shot Mk.9 easily.

Staying Alive:

In terms of armor, the Cromwell I is in a better situation than many players would assume. While the front armor is not particularly impressive, the design is very square and the side armor is acceptable. This means that the Cromwell I is an excellent tank to angle your hull and turret armor in. When the enemy fires, a quick turn using the impressive handling and acceleration can cause a bounce. Generally Cromwell I commanders should seek to move unpredictably when under fire and create angles that are difficult to penetrate.

One somewhat unconventional tool that the Cromwell has access to is an abundance of smoke grenades. Commanders can use these grenades to shut down enemy firing angles and protect themselves from being shot in the side. However, be careful not to spam these too much as they may get in the way of your teammates as well.


Tier Mobility Protection Firepower
I Tracks Parts Horizontal Drive Shot Mk.5 HV
II Suspension Brake System FPE Shot Mk.8 Adjustment of Fire
III Filters Crew Replenishment Shot Mk.9 Elevation Mechanism
IV Transmission Engine Artillery Support Smoke grenade

Pros and cons


  • Very fast for a medium tank
  • 57 mm is a good gun in dealing with many vehicles that it may face
  • Above 2 combined make it excellent for seizing zones and destroying the lighter tanks from other nations that are usually the first there
  • Great gun handling
  • With judicious use, the tank can often end up with the most formidable tank in a lower rank game
  • Can easily hide behind obstacles and surprise passing enemies with a flanking manoeuvre
  • If played correctly, it can outflank and destroy even higher ranking tanks
  • Has a speed of 64 km/h on flat terrain


  • Terrible reverse speed
  • Neutral turning does not like any terrain sloping
  • Poor at peeking shots
  • Not well armoured when up-tiered and the 57 mm gun is marginal
  • Sensitive steering in forward travelling gears
  • Boxy, vertical armour on hull and turret makes angling critical
  • 57 mm struggles to penetrate sloped or angled (or both) armour. T-34s and KV-1s are an issue at this rank as they are very difficult to penetrate at long range
  • Gunner is frequently knocked out from frontal shots



Development for the tank started back in 1940, just around the time the Crusader cruiser tank was being put into service in the British Army. The development of a stronger cruiser tank was initiated due to the belief that that the Crusader would become obsolete in the face of more advanced German tanks as the time pass. The initial plans was for the tank to mount the OQF 6-pounder gun and was to be completed in 1942. The project was taken up by three companies who submitted their designs. Vauxhall developed the A23, a scaled down Churchill tank with 75 mm of armour and a 12-cylinder Bedford engine. Nuffield developed the A24 based off the Crusader that was powered by the Liberty engine and had an advantage of being put into production quickly. Leyland and Birmingham Railway Carriage & Wagon developed a design that was similar to Nuffield's, but with different suspension and track designs. All these designs were examined in January 1941 and it was decided that Nuffield's A24 would become the vehicle of choice for the project. Six prototypes of the vehicle, now called Cromwell I were ordered for delivery in the Spring of 1942, but arrived four months late, with current events making the tank designs outdated. Despite that, the tank was put into production and experienced an unsatisfactory performance history as being an under-powered tank. The lack of available tanks led to the demands for more 6-pounders on the battlefield, which were used to be mounted on the older tank designs.

When Britain entered the war, Rolls-Royce stopped producing cars and set up a team to find ways to use their production lines. The team was made under Roy Robotham at Clan Foundry near the city of Belper. Meeting with Henry Spurrier of Leyland, they talked tank designs and a project began of fitting a Rolls-Royce Merlin engine onto a tank. A Leyland-built Crusader was used for the test, removing the supercharger from the engine before installing it in the tank. The result was an absurdly fast tank, able to reach a speed of 80 km/h, estimated since timing the speed runs was difficult. The impressive performance had Leyland organize a production for 1,000 units of the engine, renamed as the Meteor. This plan was changed after concerns of the engine's cooling was raised, Leyland decides to produce their own version of Meteor which was weaker (350 hp) compared to the Rolls design (500 hp). Thus, the Tank Board decided to just order the engine straight from Rolls-Royce for the Meteor engine. The A24 tank design with the Meteor engine was redesignated as the A27. During the development, Leyland suggested that the tank should be made to fit both the Meteor and the American-designed Liberty engine, thus the designation expanded to A27M (Meteor) and the A27L (Liberty) and were called Cromwell III and Cromwell II respectively. Leyland's attempt at building their own engine was abandoned. The A27M tank was made into a prototype and delivered on January 1942, it proved extremely mobile with its 600 hp engine and orders were placed for both engine versions. This proved difficult due to production difficulties with the Meteor and soon Leyland took over production of both versions. Production lines for the Meteor engine continued to be strained until late 1942, where Ernest Hives of Rolls met with Spencer Wilks of the company Rover made a deal in January 1943 to exchange factories, with Rolls establishing a Meteor engine factory at Barnoldswick, Lancashire.

Production of the tank began in November 1942 with new names given out the tanks. The original A24 Cromwell I from Nuffield was renamed the Cavalier, the Liberty powered Cromwell II became the Centaur, and the Meteor powered Cromwell III retained the name as the Cromwell. The actual Cromwell tank production was delayed until January 1943 due to low supply of Meteor engines until the Rover factory began producing it. With more Meteor engines being produced, the Centaur tanks were often converted to use the Meteor engine, turning them into Cromwells. Field tests with the tanks took place in August to September in 1943 alongside the M4A2 and M4A4 Shermans. The tests proved the Shermans to be more reliable than the Cromwell and Centaurs, needing only about 0.03 hours of mechanical attention every mile compared to the Cromwell's 0.07 hours per mile and the Centaur's 0.08 hours per mile. The two tanks were thus given time to iron out these deficiencies, the Cromwell suffered from oil leaks along with brake and clutch failures. While the tank suffered from these defects, the crews expressed their satisfaction with the designs for their speed and handling, but the Centaur was not given the same attention as the Cromwell. The second test in November had the Cromwell perform with improved results while the Centaur was still experiencing the same problems. The production model was finalized on February 2, 1944, after a specifications for a "Battle Cromwell" came in from Leyland, which included some design changes, an increase of 6 mm on the bottom of the tank, seam welding the joints, and the standard usage of the Meteor engine and the Merritt Brown transmission. The Centaur was relegated to training roles or modified for specialist roles such as anti-aircraft guns or engineering vehicles. Total production for the A27 tank series is 4,016 tanks, of which 950 are Centaurs and 3,066 are Cromwells.


The Cromwell's frame used a riveted construction in its initial production models, but this later changed to welding. The frame was strengthened with bolted armour plates. Companies involved in the A27 production were LMS Railway, Morris Motors, Metro-Cammell, Birmingham Railway Carriage & Wagon Company, and English Electric. Some of these models were not consistent in construction, such as some variants built with 360 mm wide tracks and some with 393 mm tracks. The suspension was a Christie suspension derived from the earlier cruiser tank designs. Four of the tanks' road wheels have shock absorbers, and no return rollers are available, the tracks are supported on the top of the large road wheels. The gearbox has five forward and one reverse gear, with the first forward gear made for confined areas and sharp turns. While the Meteor engine is capable of going faster, it is restricted to 540 hp output with a governor to avoid straining the engine and suspension. The Cromwell's armaments changed over a few times, it's initial model mounted the 6-pounder gun, but the later models mounted the 75 mm gun. The adaption was easy due to the 75 mm gun being a 6-pounder bored for the larger calibre. A 7.92 mm BESA machine gun was available for coaxial firing on the turret. The armour on the Cromwell started as a 76 mm plate, which increased gradually to 83 mm and 100 mm overtime for additional protection.

The A27M Cromwell I was exactly the same as Centaur I, with the biggest difference being that it was powered with a Meteor engine. It featured a 6-pounder as its main armament, but only a few were produced before the Cromwell changed armament to the 75 mm gun

Combat usage

The British, at the time of Operation Overlord, primarily service the M4 Sherman as the main tank of their armoured units, only the armoured brigades of the 7th Armoured Division were equipped with the Cromwell tanks. Although the Cromwell also saw use as armoured reconnaissance regiments in other British divisions such as the Guards Armoured Division and the 11th Armoured Division. Compared to the Sherman, the Cromwell was much faster, so fast that it earned the title as the fastest British tank in World War II. The Cromwell also presented a smaller profile, making it a lower target, and has a thicker frontal armour plate. However, the Cromwell's armour was not sloping, was not as reliable in comparison to the Sherman, and a slightly smaller crew space inside the tank. Nevertheless, the Cromwell proved very mobile and effective on the battlefield alongside the Sherman, often outflanking German armour with their superior speed to hit the tanks on their sides or rear. Since the Cromwells are not able to mount the larger and more powerful 17-pounder and a derivative, the A30 Challenger, met with production issues, Cromwell units were equipped with Sherman Fireflies in order to supplement the firepower of the 17-pounder. Later in the war, these units began to be succeeded by the Comet tank which had more armour and a more powerful 77 mm gun derived from the 17-pounder.

During the war, the Cromwell chassis was used in various specialized roles on the battlefield. The A30 Challenger is a tank design that attempted to mount the 17-pounder on a lengthened Cromwell chassis, the A30 SP Avenger was another attempt to equip the 17-pounder, but used a lighter turret instead. Some were made into observation posts or command tanks. The Centaur saw a wider conversion with some becoming engineering vehicles, armoured recovery vehicles, and armoured personnel carriers. After the war, the British attempted to up-gun the Cromwell into the Charioteer, which was designed in the 1950s to supplement tank units before the Centurion was mass-issued.

The Cromwells were also given out to Allied units such as the 1st Polish Armoured Division and the 1st Czechoslovak Armoured Brigade. These units served in Northern Europe with the Allies as they breakthrough deeper into Europe. After World War II, some Cromwell stayed in service and saw service in the Korean War with the 7th Royal Tank Regiment and the 8th King's Royal Irish Hussars. The Cromwells also were given to Greece, where it had the distinction of being the first tank put into service by the Greek Army. 52 Centaurs were given to Greece in 1946 to fight in the Greek Civil War, but these were stored due to lack of crews with adequate training. Formal training began in Greece began in 1947 with the return of trained officers from Britain. The Centaur saw limited service in the Greek Armoured Corps, fighting in the Greek mountains. These units kept the Centaurs up until 1963 where it was replaced by the American M47 Pattons.


  • Cromwell I in the desert.

See also

External links

Britain medium tanks
Cromwell  Cromwell I · Cromwell V · Cromwell V (RP-3)
Based on Cromwell  Challenger · Comet I · Comet I "Iron Duke IV"
Centurion  Centurion Mk 1 · Centurion Mk 3 · Centurion Mk.5 AVRE · Centurion Mk 10 · Centurion Action X · FV4202
Chieftain  Chieftain Mk 3 · Chieftain Mk 5 · Chieftain Mk 10
Challenger  Challenger Mk.2 · Challenger Mk.3 · Challenger 2 · Challenger 2 (2F)
Valentine  Valentine I · Valentine IX · Valentine XI
Vickers  Vickers MBT · Vickers Mk.7
Foreign  Grant I (USA) · Sherman IC "Trzyniec" (USA) · Sherman Firefly (USA) · Sherman II (USA)
  A.C.IV (Australia) · Strv 81 (RB 52) (Sweden) · Sho't Kal Dalet (Israel)