Model of caterpillar tractor or tank and transmission gear, built by the Daimler Co. for the War Office, model (scale 1:8). No mention of a case

This model represents an armoured tank of the First World War and illustrates the design used about midway through the development of tanks during the war.

It became the standard tank for use at the front in 1917, but it was noisy and slow with inadequate power. With a crew of seven, the officer had to attend to the brakes, and the secondary gears used for steering required the attention of two men as well as the driver. It gave hard riding since it had only rollers without springs on the tracks. It carried four, or six, Lewis machine guns and two short six-pounders.

It is caterpillar driven; completely enclosed with armour plate, has two swivelling gun turrets for the six-pounders at the sides and a manhole on the roof for entrance to the interior. The drive, supplied by a 105 h.p. Daimler Sleeve-Valve Six Cylinder Engine, is transmitted through a cone clutch, flexible coupling and a gearbox containing a two-speed gear and a worm reduction which carries the drive through two half shafts to secondary gears on each side of the hull from which it is taken by chains to the driving sprockets rack-geared to the tracks. The wormwheel drives the half-shafts through a differential gear. Steering is done by putting either secondary gear in neutral and braking the track on the other side.

Engine cooling is by fans and radiator carried in the interior at the back. Speed of travel is 3.7 m.p.h. max, and the petrol consumption is 2 gals. per pile. A band brake operates on the worm shaft.