Mark IX

Mark IX or Mark 9 often refers to the ninth version of a product, frequently military hardware. "Mark", meaning "model" or "variant", can be abbreviated "Mk."

Mark IX or Mark 9 can specifically refer to:

In technology

In military and weaponry

Other vehicles

Other uses

Mark IX tank

A British armoured fighting vehicle from the First World War, the Mark IX was the world's first specialised armoured personnel carrier (APC).

Development

During the first actions with tanks, it became clear that infantry often could not keep up with the tanks; not because soldiers were too slow — the early tanks themselves could only move at a walking pace — but because soldiers on foot remained vulnerable to enemy machine gun fire, though tanks had been invented to solve that very problem. On many occasions, positions gained at great cost were immediately lost again for lack of infantry to consolidate. It was thought this problem might be solved by cramming a few infantry soldiers into each tank. But it soon became clear the atmosphere inside was of so poor quality that these soldiers became ill — if they did not lose consciousness outright, they'd be incapacitated for about an hour recovering from the noxious fumes, when exposed to fresh air on leaving the tank.

Therefore, in the summer of 1917, Lieutenant G.R. Rackham was ordered to design an armoured vehicle specifically for troop transport. The early design process was complicated by a demand that the vehicle could also be fitted with sponsons, converting it into a more modern tank than the Mark V, in case the Mark VIII tank design proved a failure. This is why the type was still designated as a tank, a "Mark IX" succeeding the Mark VIII. That requirement was soon dropped, and in September 1917 Armstrong, Whitworth & Co. in Newcastle-upon-Tyne began constructing two prototypes of a pure transport vehicle, which could also serve as a supply tank. The prototypes were approved the following year. At the time it had become clear that a possible alternative, the stretched Mark V* tank, was not really suited for infantry transport. Therefore two hundred vehicles were ordered of the Mark IX, to be built by the tractor manufacturer Marshall, Sons & Co. of Gainsborough, Lincolnshire.