[8] The next day, in a meeting with the French to coordinate allied tank production, the Commander-in-Chief of the British forces Field Marshal Haig ordered the manufacture of two hundred vehicles, the first to be ready on 31 July.

The production model had the turret replaced with a fixed armoured structure and the fuel tank was moved from the rear of the vehicle to the front.

This arrangement had the advantage over that of earlier tanks of being controlled by one man only, but called for great skill on the part of the driver, because one or both of the engines could be stalled if care was not exercised.

[14] Although in theory a simple solution to give gradual steering, in practice it proved impossible to control the speeds of the engines, causing the vehicle to take an unpredictable path.

Crews that believed that treads had to be as long as the hull, as with the heavy tanks, were surprised to see the Whippet, with shorter tracks, successfully exit holes.

Whippets arrived late in the First World War, at a time when the British Expeditionary Force, recovering from the Third Battle of Ypres in Flanders, was quite inactive.

They were so successful that by summer 1918 civilians "seemed to talk in terms of whippets", not knowing of heavy tanks' importance in breaking through fortifications and barbed wire.

For nine hours it roamed at will, destroying an artillery battery, an observation balloon, the camp of an infantry battalion and a transport column of the German 225th Division, inflicting many casualties.

At one point, cans of petrol being carried on Musical Box's roof were ruptured by small-arms fire and fuel leaked into the cabin; the crew had to don gas masks to survive the fumes.

[25] Major Philip Johnson, the unofficial head of Central Tank Corps Workshops in France, as soon as he received them began fitting one of the Whippets with leaf springs.

Later, in 1918, he fitted this vehicle with sprung track rollers, Walter Gordon Wilson's epicyclical transmission from the Mark V and a 360 hp (270 kW) V12 Rolls-Royce Eagle aero-engine.

Other experiments included the fitting of a large trailing wheel taken from an old Mark I tank and attaching a climbing tail, in both cases attempts to increase trench-crossing ability.

The German Leichter Kampfwagen – developed from December 1917 – being also a turret-less tank with the engine in front resembled the Whippet, but was a smaller vehicle with thinner armour.