Vickers D3E1 Wheel Track Tank was completed in April 1926. The idea was that it would run on wheels when possible, thus saving on track wear. D3E1 had two turrets. Apparently, no armament was ever actually fitted. The engine was an Armstrong Siddeley V8 giving a top speed of 30 mph on wheels and 13 mph on tracks. A further unturretted vehicle, D3E2 was also built. Both vehicles were delivered in May 1928. The design of these vehicles was very cumbersome and mechanically complex. They were never adopted into service.
They were photographed extensively, mostly running on tracks, and were not disposed of until 1933 suggesting they performed fairly well.