The Light Tank AA Mark I was an attempt to produce an anti-aircraft tank on the chassis of the obsolete Light Tank Mk VI, but it wasn't a terribly effective design, and only a handful were produced.
Work on developing an anti-aircraft tank began in 1940, in response to the German use of powerful close air support during the blitzkrieg of May 1940. Two prototypes were produced on Light Tank Mk V chassis, one armed with two 15mm Besa machine guns (with the ammo boxes jutting out to the side of the turret) and one with a Boulton & Paul quadruple Browning power-operated aircraft turret. At first this retained the Perspex canopy, but this was later removed. This version also had light armoured flaps to protect the exposed gunner.
The first production version, the Light Tank AA Mark I, used a new turret design. This was armed with four 7.92mm Besa machine guns mounted in a horizontal row. The turret was mounted on top of a low rectangular box that was installed on top of the existing superstructure. The turret had level sides and a flat open top. The Light Tank AA Mark I was built on the chassis of the Light Tank Mk VIA, which had the return roller moved from the top of the leading bogie to the hull sides). Around fifty Light Tank Mk VIs were converted into AA tanks, probably a mix of the Mark I and the improved Mark II, which had a larger turret and improved gun sights.
Hull Length: 13ft 2in
Hull Width: 6ft 10in
Engine: Meadows six cylinder 88bhp
Max Speed: 35mph
Armament: Four 7.62mm Besa machine guns