Britain Cruiser Mk VIII (Cromwell I/II/III) Ordnance classification - A27M

Tweet The Cruiser Mk VIII was a Cruiser Tank designed in 1943, manufactured by Leyland, it was based on the fully tracked Centaur chassis and was in use from 1944 to 1953. It was commonly called a Cromwell I/II/III. General Details (Cruiser Tank) Specifications Operational Date(s) 1944 - 1953 Ordnance classification A27M Quantity Produced 3066 Weight 27.5 tonne Crew 5 M.G's small 1 M.G's large(>10mm) n/a Length 6.40 mtr Width 2.92 mtr Height 2.49 mtr Engine Details/Performance Max Road Speed 40 mph Max Cross Country Speed 22 mph Range Road 166 miles Range Cross Country 66 miles Fuel Type Petrol Fuel Capacity 110 gal Horse Power 600 hp Power/Weight 21 hp/tonne General Information The Cruiser Mk VIII was a Cruiser Tank designed in 1943, manufactured by Leyland, it was based on the fully tracked Centaur chassis and was in use from 1944 to 1953. It was commonly called a Cromwell I/II/III. The vehicle was powered by Rolls Royce 'Meteor V12' petrol powerplant producing 600 HP which could drive the vehicle on roads at up to 40 mph with a range of about 166 miles before refuelling. Its cross country performance was good providing a max speed of about 22 mph and a range of about 66 miles. It was armed with 1 light machine gun , a BESA Machine Gun 7.92mm. Its main armament consisted of an Ordnance Q.F. 6pdr 7cwt MKI-III which could penetrate 96 mm of flat plate at 200 metres These early models were the upgraded Centaur with the original Leyland 450hp engine replaced by the 600hp Rolls-Royce Merlin engine Armour Details Turret Front 76mm @ 0° (76mm) Side 63mm @ 0° (63mm) Rear 57mm @ 0° (57mm) Top 20mm @ 81° (20mm) Superstructure Front 63mm @ 0° (63mm) Side 32mm @ 0° (32mm) Rear 32mm @ 0° (32mm) Top 20mm @ 90° (20mm) Hull Front 57mm @ 0° (57mm) Side 32mm @ 0° (32mm) Rear 32mm @ 0° (32mm) Top 20mm @ 90° (20mm) Armour (x)mm @ (y)° (Effective mm @ 0°) Effective Armour - Maximum 76 mm - Minimum 20 mm Weapon Details Ordnance Q.F. 6pdr 7cwt MKI-III (Anti Tank Gun) History The 6pdr Mk II—differed from the pre-production Mk I in having a shorter L/43 barrel, because of shortage of suitable lathes. The subsequent Mk IV was fitted with an L/50 barrel, with muzzle brake. Manufactured 1942 - 1945 Calibre 57mm Length L/43 Number of Rounds  64 Ammunition Details Name/Id Calibre Weight MVelocity Explosive Content Shot, AP, Mks 1 to 7 (AP Armor Piercing) 57mm 2.86Kg 853M/Sec Quoted Penetration 68mm@915m Range(Mtr) 100 200 400 800 1200 1600 2000 2400 Flight Time(Secs) 0.12 0.24 0.5 1.09 1.78 2.61 3.61 4.86 Penetration(mm@30°) 90 83 74 63 53 44 35 28 Penetration(mm@0°) 105 96 86 73 62 51 41 33 Hit Probability(%) 98 98 98 98 77 41 22 8 Weapon Details BESA Machine Gun 7.92mm (Machine Gun) History Developed by BSA from the Czechoslovak ZB vz.53 heavy machine gun which used the German 7.92×57mm Mauser ammunition. It was mostly used as the main armament of the Light Tank Mk VIC and Armoured cars such as the Humber Mk I to Mk III. This 7.92mm gun was used in the armoured divisions as their supply lines were separated from the infantry who used .303 bullets. Once the British started capturing German ammunition this could be immediately used in these tank machine guns. Manufactured 1939 - 1966 Calibre 7.92mm Length L/93 Rate of Fire 450 rpm Number of Rounds  2000 Ammunition Details Name/Id Calibre Weight MVelocity Explosive Content Cartridge SA, 7.92 (AP Standard Small Arms) 7.92mm 0.011Kg 785M/Sec Quoted Penetration 11mm @ 1000mtr/0° Range(Mtr) 100 200 400 800 1200 1600 2000 2400 Flight Time(Secs) 0.16 0.37 1.1 Penetration(mm@30°) 10 8 5 Penetration(mm@0°) 12 10 6 Hit Probability(%) 98 98 98 Cartridge SA, 7.92 (BALL Standard Small Arms) 7.92mm 0.012Kg 785M/Sec Range(Mtr) 100 200 400 800 1200 1600 2000 2400 Flight Time(Secs) 0.15 Penetration(mm@30°) 2 Penetration(mm@0°) 3 Hit Probability(%) 98

Hit probability is based on a static 2 x 2.4 metre panel at 0 degrees(vertical) at the range specified.

The data that has been used to create these records has come from Wikipedia, The Lone Sentry, The Bundes Archive and numerous books and websites that have provided the detailed information that has not been available anywhere else. The information we use to calculate the penetration tables, flight times and the hit probability comes from the Gun Calibre, the Shell Mass(Kg) and the muzzle velocity, plus range reductions to allow for gravity and wind resistance. This calculation originally came from a pre-war Krupp calculation which has been modified, and seems to fit the actual test results.

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Page Last Updated: 2025-01-01