The Infantry Tank Mk. IV, A.22A, Churchill Mk. I was the first production Churchill. It was built to traverse difficult terrain as the British assumed that the battlefields would break into mud, trenches, and obstacles created from prolonged battle.


See Infantry Tank Mk. IV, Churchill for all variants.


The Churchill I and Churchill II were sold to the Soviet Union, they found the following defects that the British were already aware of:

  1. Engine
    1. In order to reduce the chance of the cast iron clutch socket cover, part Z.V.1/BB/44365, the engine RPM should never rise above 2000rpm. It is possible that some engines are limited below this number, but most are set at 2400rpm.
    2. There were complications when starting the engine in the cold. The symptoms of this are: the engine cannot turn over at any rpm, and doesn't budge at a certain point when a start is attempted. If this happens, the engine must be thawed, and then started. This happens when a small amount of ice forms along the diameter of the cylinders, between the bottom of the piston and cylinder head.Water gathers in the engine from condensation in the exhaust system, and the condensate leaks through the open exhaust valve.
    3. The fact that the engine has started cannot always be heard from the driver's seat. Be wary, and do not use the manual started when the engine has almost started, or is at least turning over. Make long pauses between start attempts in order to avoid damage to the starter gear and the flywheel crown. If the electric starter is faulty, there is no other way to start the engine other than towing the tank.
    4. Since the engine of this tank has hydraulic plungers, it is especially important to drain and refill the oil, replace the filter elements, and clean the mesh filters, every 300mi (482km).
    5. Certain difficulties were had with the cylinder head liners. To replace a damaged liner, the engine must be taken out of the hull. The cylinder head liner can also be replaced by using a special instrument, inserted into the two openings for spark plugs, to raise the cylinder head and replace the liner without removing the engine from the hull. Great care must be taken when replacing the cylinder head bolts, that the bolts are well tightened, and provide even pressure.
  2. Clutch Socket
    1. The cast iron cover, part Z.V.1/BB/44365, is not robust enough, and may crack. Cracks radiate out of the central opening of the cover, to the clutch lever slots. In order to prevent wounding of personnel and damage to the vehicle, the socket covers must be inspected often. If a crack is discovered, the vehicle must be taken off the road until a new socket cover is ready. Also, remember that when the clutch disks or case cover are changed independently, they should be carefully balanced before assembly.
    2. The bolts of the clutch shaft with universal ball joints should be inspected regularly and tightened.
  3. Gearbox and Steering
    1. The 4-speed gearbox causes difficulty due to slipping of the third gear. When driving, be very careful, and fully engage every gear.
    2. Some vehicles may be equipped with a limiter on the selected lever, to prevent engagement of a high gear. Due to the limit placed on the engine speed in section 1.1, the high gear limiter may be removed to compensate for the loss of speed.
  4. Final Drive
    1. The bolts in the clutch between the gearbox and final drives must be regularly inspected and thoroughly tightened.
  5. Tracks
    1. Tracks, consisting of plates, must be calibrated in such a way that the plates engage the idler on both sides.
  6. Suspension
    1. The bolts that attach the bogey carrier to the hull, and the bolts that attach the side armour, must be frequently inspected and tightened.
    2. Rubber shock absorbers on each bogey, attached to the suspension carriers, need to be inspected often. Defective shock absorbers must be replaced immediately. If they are not replaced, then the bogey carrier may be damaged.
    3. Difficulties in lubricating the road wheel axles with grease pumps, installed at the ends of the axles, may arise. The grease pumps consist of a double valve, and great care must be taken to ensure that sufficient amount of lubricant makes it to the axles to sufficiently lubricate the ball bearings.
    4. The bogey carrier axle bolts should be frequently inspected and thoroughly tightened.
  7. Hull
    1. It is especially important to keep the hull under the engine and within the gearbox case clean and not covered in oil, gasoline, or water. This condition influences the performance greatly of the brakes, since the oil, gasoline, or water, may be easily caught into a stream of air from the engine fan, and end up in the right brake drum in the gearbox case.
    2. To avoid having the track catch onto the rear tow loops, the rear loops must always be on the rear top eyes. When tow loops are used in the lower eyes, watch them to ensure that track links are not damaged.
    3. The air that cools the radiators, passes through grilles on each side of the vehicle using a fan on a flywheel. The sucking action of the fan is enough to pull in dust, dirt particles, glass, leaves, etc., when driving off-road or on narrow roads. These foreign materials are deposited on the inner side of the radiator, lowering its effectiveness, and causing overheating or engine damage. The radiator must be inspected frequently, and foreign particles removed.
  8. Turret Traverse Drive
    1. When these tanks travel through a forest, it is important to make sure that the turret gun does not hit trees, or other obstacles while the vehicle moves. This causes serious damage to the turret traverse drive, since the friction clutch in the mechanism does not protect it when the tank travels at a speed of more than 6mph (10km/h)
  9. Steering
    1. When steering with the double differential, it is recommended to do so while the engine is at high rpm, avoiding doing so during contact with an obstacle or crossing of a steep grade, to avoid stalling the engine.
    2. On soft terrain, there is a chance that the track will slip while driving, losing energy due to the action of the double differential, but immediate action of the brakes to the slipping track will allow the driver to prevent complete loss of energy and bogging down.
    3. All of these peculiarities are characteristic of this special type of vehicle, and special attention must be paid to them while driving.
Flag of United Kingdom (1801 to Present) United Kingdom Warflag of the United Kingdom
Land Vehicles
Interwar & World War II
Tracked Vehicles
Light Tanks Standard Light Tanks Carrier, Machine Gun, No. IA.18Light Tank Mk. I (Mk. Ia)Light Tank Mk. II (Mk. IIaIIbIndian Pattern No. 1Indian Pattern No. 2)SceptreTetrarchVickers E (AB)Vickers F
Amphibious Light Tanks A.4E11A.4E12
Medium / Other Tanks Medium Tanks A.8E1Medium Tank Mk. I (CS)Medium Tank Mk. IIMedium Tank Mk. IIIMedium Tank, Grant Mk. I
Cruiser Tanks A.19A.40ChallengerCometCruiser Mk. ICruiser Mk. IICruiser Mk. IIICruiser Mk. IVCruiser Mk. V, CovenanterCruiser Mk. VI, Crusader (Mk. IMk. I CSMk. IIMk. II CSMk. III)Cruiser Mk. VII, CavalierCruiser Mk. VIII, Centaur (Mk. IMk. IIMk. IIIMk. IV)Cruiser Mk. VIII, Cromwell (Mk. IMk. IIMk. IIIMk. IVMk. VMk. VIMk. VIIMk. VIII)Sherman (Mk. IMk. I HybridMk. IbIbyIcMk. IIMk. IIaMk. IIayMk. IIcMk. IIIMk. IIIaMk. IIIayMk. IIIcMk. IVMk. IVaMk. IVbIVbyMk. IVcMk. VMk. VcMk. VIIMk. VIIc)
Infantry Tanks Black PrinceInfantry Tank Mk. IInfantry Tank Mk. II, Matilda (Mk. IMk. IIIIaMk. II CSMk. IIIMk. III CSMk. IVMk. IV CS)Infantry Tank Mk. III, Valentine (Mk. IMk. IIMk. IIIMk. IVMk. VMk. VIMk. VIIMk. VIIaMk. VIIIMk. IXMk. XMk. XI)Infantry Tank Mk. IV, Churchill (Mk. IMk. IIMk. II CSMk. IIIMk. III*Mk. III AVREMk. III NA75Mk. IVMk. IV AVREMk. IV NA75Mk. V CSMk. VIMk. VIIMk. VII AVREMk. VIIIMk. VIII CSMk. IXMk. IX LTMk. XMk. X LTMk. XIMk. XI LT)Valiant
Flamethrowing Tanks Churchill Mk. II OkeChurchill Mk. III OkeChurchill Mk. VII CrocodileSherman Mk. III AdderSherman Mk. V Adder
Heavy Tanks Standard Heavy Tanks A.7E1A.7E2A.7E3Heavy Tank, TOG 1Heavy Tank, TOG 2Heavy Tank, TOG 2*Heavy Tank, Vickers Independent
Heavy Cruiser Tanks A.14E1A.14E2A.16E1
Assault Tanks A.37A.T.1A.T.2A.T.3A.T.4A.T.5A.T.6A.T.7A.T.7AA.T.8A.T.9A.T.10A.T.13A.T.14A.T.15A.T.15AA.T.16A.T.17A.T.18CommodoreTortoise
Self-Propelled Guns Self-Propelled Anti-Aircraft Gun Crusader AA Mk. 1Crusader AA Mk. IICrusader AA Mk. IIICruiser Tank, Mk. VIII, Centaur Mk. III, AA, Mk. ICruiser Tank, Mk. VIII, Centaur Mk. III, AA, Mk. IVickers Light Tank Mk. VIa, AA, Mk. I
Self-Propelled Anti-Tank Gun 6-pdr, SP, Molins6-pdr, SP3, Alecto Mk. II17-pdr, SP, M10, Achilles Mk. Ic17-pdr, SP, M10, Achilles Mk. IIc17-pdr, SP1, Valentine, Mk. I, Archer17-pdr, SP2, Avenger
Self-Propelled Gun 3.75-inch, SP, Alecto Mk. I25-pdr, SP, Alecto Mk. III32-pdr, SP, Alecto Mk. IVGun Carrier, 3-inch, Mk. I, Churchill
Self-Propelled Howitzer 25-pdr, SP, Archer25-pdr, SP, BishopSP 25pdr, Loyd
Self-Propelled Mortar 9.75-inch Flame Mortar, SP, Valentine, Mk. I
Utility APC Churchill Kangaroo
ARV Churchill Mk. I ARVChurchill Mk. II ARVChurchill Mk. III ARVChurchill Mk. IV ARV
Bridge Laying Churchill Mk. III ARKChurchill Mk. IV ARKShermon Octopus
CP Covenanter Mk. II CommandCrusader Mk. III Command
Mine Clearing Churchill SnakeValentine Snake
OP Covenanter Mk. II OPCovenanter Mk. IV OPCrusader Mk. III OP
Spot. A.41, CDLChurchill Mk. II, CDLMedium Tank, Grant Mk. I, CDLInfantry Tank Mk. III, Valentine, CDL
Half-Tracked Vehicles
Tankettes Crossley-Martel TanketteMorris-Martel Tankette
Transport & Towing Crossley BGVM2 HalftrackM5 Halftrack (A1A2)M9 Halftrack (M9A1 Halftrack)
Self-Propelled Anti-Aircraft Gun Burford Halftrack12.7mm M13 MGMC12.7mm M14 MGMC12.7mm M16 MGMC12.7mm M17 MGMC
Self-Propelled Anti-Tank Gun 57mm T48 GMC75mm M3 GMC
Wheeled Vehicles
Armoured Cars ACV-IP Mk. I (Mk. IIMk. IIaMk. IIbMk. IIcMk. IIIMk. IV)AEC Mk. I (Mk. IIMk. III)BoarhoundCoventry Mk. I (Mk. II)Daimler Mk. I (Mk. II)Dingo Mk. I (Mk. IaMk. IbMk. IIMk. III)GreyhoundGuy Mk. I (Mk. Ia)Humber Armoured Car Mk. I (Mk. IIMk. IIIMk. IV)Humber Light Reconnaissance Car Mk. I (Mk. IIMk. IIIMk. IIIa)Lanchester Armoured Car Mk. I (Mk. II)Marmon-Herrington Armoured Car Mk. I (Mk. IIMk. IIIMk. IIIaMk. IVMk. IV FMk. VMk. VIMk. VIIMk. VIII)Morris CS9Morris Experimental TankMorris Glanville Fighter CarMorris LRC Mk. I (Mk. II)Morris SalamanderRolls-Royce Armoured Car 1914 Pattern FordsonRolls-Royce Armoured Car 1920 Pattern Mk. IRolls-Royce Armoured Car 1920 Pattern Mk. IaRolls-Royce Armoured Car 1921 Indian PatternRolls-Royce Armoured Car 1924 PatternRover Light Armoured Car Mk. I (Mk. II)Staghound Mk. I (MK. IIMk. III)Standard Car Mk. I (Mk. IIMk. IIIMk. IV)
Self-Propelled Anti-Aircraft Gun AEC Armoured Car Mk. II, AAHumber Mk. I, AALeyland Beaver-EelStaghound Armoured Car, AA, Mk. I
Self-Propelled Gun AEC Deacon Mk. IMorris Firefly
Command AEC ACVGuy Lizard ACVLanchester Armoured Car Mk. IaLanchester Armoured Car Mk. IIa
Observation Humber Mk. II, OPMorris LRC Mk. I, OP
Unarmed Reconnaissance Lynx Scout Car Mk. ILynx Scout Car Mk. II
Transport & Towing AEC Matador 0853Albion BY3NAustin 10Austin K2/YAustin K3/YFAustin K30Chevrolet 1.5 tonChevrolet 1311X3 15cwtChevrolet 1533X2 30cwtChevrolet C8Chevrolet Standard 40CMP Ford 8cwtFord 15cwtFord C8AFord F30Ford WOA2Humber FFWHumber FWDHumber Staff SaloonHumber Super SnipeWillys MB
Amphibious Transport & Towing Terrapin
Motorcycles Ariel W/NGBSA (W)M20Triumph-3HWTriumph-3SW
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