The Churchill Mk III was the first version of the Churchill tank to be armed with a 6-pounder gun, replacing the 2-pounder turret gun of the Mk I and Mk II. Construction work on the new turret, which had been designed by Babcock and Wilcox, began in July-August 1941. It used flat armoured plates welded together, and a shortage of suitable weldable armour plate limited production of the Mk III. The first sample turret failed its initial firing trials, not an impressive start.
675 Churchill Mk IIIs were produced, most during 1942. The first Churchill Mk IIIs were completed late in 1941 and entered service in March 1942. A number of Mk Is and Mk IIs were upgraded to Mk III standard by giving them the new turret.
Mk IIIs produced before May 1942 were built without track covers and with the air intakes on the sides, as on the Mk I and Mk II. Tanks produced after May 1942 were given track covers which protected the front, rear and top of the tracks.
The Churchill Mk III took part in the disastrous attack on Dieppe of August 1942. They were used by the Canadian Calgary Regiment, 14th Canadian tank battalion. Twenty nine tanks began the attack, about half got across the sea wall, and all of them had to be left behind at the end of the attack.
Six Churchill Mk IIIs took part in the Second Battle of El Alamein, where they formed 'Kingforce', commanded by Major Norris King, MC. The force was attached to HQ, 1st Armoured Division, and performed well in a large tank battle at Tel el Aqqaqir. Their heavy armour made them almost invulnerable, and they didn’t suffer from over-heating problems that had been predicted.
The Mk I, Mk II and Mk III made up the equipment of the 21st Army Tank Brigade and 25th Army Tank Brigade during the fighting in Tunisia early in 1943.
Some Mk IIIs were upgunned to carry the 75mm gun. Those that retained their original armour became the Mk III* while those that got extra appliqué armour became the Mk IX LT (in theory there was also a Mk IX, which also gained the cast/ welded turret of the Mk VII, but it isn't clear if any of these were produced).
Around 700 Churchill Mk IIIs and Mk IVs were converted into Churchill AVREs, an excellent engineer's tank, armed with the short-range but powerful Petard mortar.
Churchill Mk III, A22, Infantry Tank Mk IV
Hull Length: 24ft 5in
Hull Width: 9ft
Height: 10ft 8n
Crew: 5 (commander, gunner, loader, driver, co-driver/ hull gunner)
Engine: 350hp Bedford twin-six
Max Road Speed: 15.5mph
Max Cross-county Speed: 8mph
Road Range: 90 miles radius
Armament: 6-pounder gun and 7.92mm Besa machine gun in turret, 7.92mm Besa machine gun in hull front