The Mark VI Tank was a British design for a tank that would have been lighter and faster than earlier tanks, and with a centrally mounted main gun, but an order for 600 machines was soon cancelled and it only reached the mock-up stage.
A full scale wooden mock-up of the Mark VI was ready by 23 June 1917 when it was photographed outside the Metropolitan Works. It had the same basic design as other British heavy tanks, with the tracks running all around the fuselage on a large rhomboid track frame, but the hull may have been lower and shorter than on earlier tanks, and at the front the upper section of the tracks curved down slightly, presumably to improve the driver’s view.
The biggest difference came with the location of the main 6-pounder gun. Instead of having this carried in sponsons, on the Mark VI the gun was carried in the front of the hull. It had a smaller range of movement, but this meant that the driver and gunner could both see their target, and the entire tank could be aimed at it.
Further back it had a large superstructure carried above the tracks. At the front of this was the driver’s position, with the commander in a small tower behind and above it. Behind them was a fighting structure armed with four machine guns, one at each corner.
Two more machine guns were carried in much smaller sponsons that were carried in the exit doors, one at each side, towards the front of the vehicle.
The Mark VI was to use the new Ricardo tank engine and Wilson epicyclic gearbox, but in a different layout to normal. In most cases the engine was in the centre of the tank, allowing the two epicylic gearboxes to be on either side. In the Mark VI the engine was on one side, in order to free up more room in the centre of the tank (presumably for the men manning the four central machine guns). Both of the epicylic gearboxes were on the same side of the tank, so one drive shaft had to run right across the width of the vehicle.
It would also have had thicker 14mm armour and wider 29.5in tracks than any earlier tank.
After the American entry into the war on 6 April 1917 the United States placed an order for 600 Mark VIs, but this was soon cancelled and attention moved onto the Mark VIII ‘International’.