The Light Tank Mark VI was the most numerically important light tank to see service with the British Army, with 1,682 produced in four versions between 1935 and 1940. The basic Mark VI was very similar to the Mark V, but with extra space in the turret to hold the No.7 Wireless Set, which had a range of about ten miles and was a great improvement on the No.1 Wireless. A circulating pump was added to the header tank for the water cooling system for the two machine guns. A new clutch was installed, but otherwise the engine, transmission and general layout remained the same. The maximum thickness of armour was increased to 15mm from 12mm. The increase in weight meant that the Mark VI had a better ride than any earlier entry in the light tank series.
Light Tank Mark VIA
Three main changes were introduced on the Light Tank Mark VIA. On the Mark V and Mark VI the single return roller had been attached to the front bogie, and the rear part of the track had rested on the rear bogie. On the Mark VIA the return roller was mounted on the hull, between and above the two bogies, lifting the rear part of the track off the back wheels. This helped to solve a problem that had seen the rear part of the track pick up vibrations from the ground and sometimes come off the wheels. The circular commander's cupola on the Mark VI was replaced with a octagonal model with two lookout slots in the front. The Meadows ESTL engine of the Mark VI was replaced by a Meadows ESTB.
Light Tank Mark VIB
The Mark VIB was produced in larger numbers than any other version of the tank, and was the version that saw most combat during the Second World War. It was very similar to the Mark VIA, but reverted to the circular cupola of the Mark VI, although with the two glass block lookouts of the Mark VIA. The number of armoured cooling louvres over the radiator was reduced from two to one. During 1940 six Mark VIBs were given rear idler wheels, as used on the earlier Mark II and Mark III. Tests with the 1st Armoured Division in France showed that this greatly improved the cross-country performance and smoothness of the ride, but a few months later the German campaign in the west proved that the light tank was no longer of any real use, and this modification was never adopted. The Mark VIB was also produced in an India pattern, without the cupola but with a periscope for the commander.
Light Tank Mark VIC
The Light Tank Mark VIC resembled the India pattern Mark VIB, with no cupola and a periscope mounted on the roof. The Vickers machine guns used on all earlier British light tanks were replaced with two Besa air cooled machine guns, one 7.92mm and one 15mm, adopted by a Czech design. These were the first guns in the British Army to use rimless cases instead of rimmed cartridges, and were adopted as the standard gun for the Royal Armoured Corps. The 7.92mm gun was a success, and remained in service on British tanks until 1958, but the 15mm gun was less reliable and less accurate than the Vickers gun, and was soon replaced. The Mk VIC had a wider track and suspension wheels, reducing the ground pressure.
The Light Tank Mk VI made up a large proportion of the British tank force in France in 1940, equipping four regular and three Territorial divisional cavalry regiments and accounting for 108 of the 321 tanks in the 1st Armoured Division. When the light tank had originally been introduced into the British Army, the War Office believed that tanks would rarely fight other tanks, and at worst British light tanks would have to deal with enemy light tanks, both acting as scouts ahead of the main tank forces. This was quickly proved to be false in France in 1940, where the under-armed and under-armoured light tanks soon found themselves coming up against the main German tank forces.
The most common German tank in 1940 was actually the Panzer II, which had similar armour to the Mark VI, and didn't outgun it by much, carrying a 20mm gun, and was the sort of enemy light tank that the Mark VI was expected to face. Unfortunately it also had to cope with the Panzer III, with either a 3.7cm or 5cm gun, and captured Czech Panzer 38(t)s, and these more heavily armed tanks inflicted heavy losses on the thin skinned British tanks.
The Light Tank Mark VI was also used by the Heavy Brigade of the Mobile Division in Egypt (later to become the 7th Armoured Division, or Desert Rats), arriving in 1939. By September 1940 there were two armoured brigades, each with three regiments, all of which were equipped with some Mark VIs during the fighting in 1940. Once again the light tanks were overwhelmed by their more heavily armed German and Italian opponents, and suffered heavy losses. Much to the relief of their crews the Mark VI was replaced by the American Stuart Tank during 1941.
Light Tank Mk VI
VI: 51 (1935)
VIA: 210 (1936)
VIB: 914 (1936-38)
Plus another 173 of Mk VI to Mk VIB from September to December 1939
VIC: 334 (1939-40)
Hull Length: 13ft 2in
Hull Width: 6ft 10in
Height: 7ft 5in
Weight: 4.8 tons (VI and VIA), 5.2 tons (VIB and VIC)
Engine: Meadows six cylinder 88bhp
Max Speed: 35mph
Max Range: 125 miles operational radius
Armament: One .303 and one .5 Vickers Machine Gun (VI, VIA and VIB); One 7.92mm and one 15mm Besa machine gun (VIC)