Originating out of the need to build military hardware from available materials, the tank was built from corrugated iron on a tractor base.

The use of the American Disston "Six Ton Tractor Tank", a 1937 vehicle constructed of an armoured box on a Caterpillar Model 35 chassis[4] which had been sold to Afghanistan, was suggested.

[2] A lack of weapons meant that it was equipped with six Bren light machine guns — one in each side, two facing the front, one in the turret and one at the rear.

[8] The intention was to disperse the hulls at locations ready in case of a Japanese invasion at which point they would be mounted on tractors for use.

By using a large tractor as a base, and bolting on a hastily designed and poorly constructed tank superstructure, the resultant tanks were inadequately armored, extremely heavy (20–25 ton), unstable, restricted by tractor gearing to slow speeds, and had to stop to change gears.

Furthermore, due to the shape of the underlying tractor and undue vibrations, shooting from the tank was both difficult and inevitably inaccurate.