The rhomboid shape of the Mk. VIII's track frames harkened back to the earliest British landship designs. The 6 pounder guns were located in the sponsons, as in earlier designs, and behind each sponson was a door that mounted a .30cal MG. The longitudinal line of rivets that runs under the sponson shows the outline of the hull, which itself is hidden between the tracks. The mechanism for the track tension idler can be seen at the front of this line of rivets. The commander's boxlike cupola can be seen resting atop the nonrotating turret. The structure above the rear tracks was the unditching gear strut, and the aperture behind the side door with the machine gun was a mud deflection chute. (Picture from Development of Armored Vehicles, volume 1: Tanks.)