The T28 was an American tank destroyer / heavy tank originally designed to be used to break through defenses at the Siegfried Line, and was later considered as a possible participant in the planned land invasion of the Imperial Japanese mainland.
Initially known as Heavy Tank, T28 when construction was authorized in 1944, the design did not fit in the usual categories of vehicles, and due to it not having a revolving turret, it lead to reclassification as the 105mm Gun Motor Carriage, T95, this change became official in March 1945. However, due to its heavy armour and armament (while self-propelled guns in US service were lightly armoured) it was renamed Super Heavy Tank, T28 in June 1946 by OCM 37058.
The outer tracks for the T28/T95 were removable, so the tank could be transported by rail, this took 2 hours to complete. The outer tracks - once removed - could be attached to each other, which could then be towed behind the T28.
Due to the extreme weight of the T28, it could not cross any of the portable bridges of the time, it also had extremely limited obstacle-crossing ability. The engine was fairly underpowered, leading to a top speed of about 13km/h. The tank was considered impractical, and other designs mounting 105mm or higher guns, that were more maneuverable, were being designed.