The Whippet tank called for particular skill in driving, and a great deal of practice was usually necessary to produce a really efficient driver. “Stalling” of one or both engines was a common occurrence during the earlier stages of training. Steering was effected by varying the speed of either engine, and the radius of movement was proportional to the difference in the speed of the two engines, this difference being controlled by means of a steering wheel connected to the two carburetter throttles, movement of the wheel producing acceleration of one engine and deceleration of the other simultaneously.
The Gun-carrying Tank ([Plate VII]—see [p. 220])
Originally designed for carrying a 60-pounder gun or 6-in. howitzer and ammunition into action, these machines during 1918 were chiefly used for the transport of supplies across country. The engine, a 6-cylinder 105 h.p. Daimler, was placed right at the rear of the machine, and the general lay-out of the transmission corresponded with that of the Mark IV modified to suit the engine position, the primary and secondary gears, etc., being mounted forward of the engine in the case of this G.C. tank. The final drive to the track was at the rear, and exactly followed the Mark IV practice, whilst the track itself was carried on track frames, in this respect somewhat resembling the Medium A machine.
Four men were required to control the G.C. tank, the driver and brakesman being separately housed in two small independent cabs mounted one over each track towards the front of the machine, whilst the secondary gearsmen travelled in the body of the machine.
A system of signalling by signs from driver to other members of the crew was adopted.
Situated between the inner walls of the hull at the front of the tank was a “skid” or platform which could be drawn out, and its front lowered to the ground, forming an inclined runway up which the gun was hauled, by means of a winding gear operated from the engine, to its travelling position on the machine.
Drums for carrying ammunition for the guns were supported on platforms over the tracks immediately in rear of the two control cabs.
The first G.C. tanks were fitted with “tails,” similar to those on the Mark I machines, but these were later on discarded.
The above includes the brief mechanical summary of the various types of British tanks used during the Great War, and though, undoubtedly, the future will bring with it many improvements and may radically change the whole form of the present-day tank, it is doubted if ever, in the whole history of mechanics—let alone warfare, a novel machine has been produced which has proved so efficient on first use and required in the long run of two years of war so few changes.