I've seen this before, and stumbled upon it again yesterday. It was designed to smash through the Siegfried line and take direct fire from any land based artillery.
T-28 Super Heavy Tank
Armament: 105mm Main Gun & 1 M2 .50 cal
Armor: 12 inches
Engine: Ford V8 gasoline producing 500 horsepower
Top Speed: 8mph / 13kph
Weight: 95 Tons
http://www.youtube.com/watch?v=-kO5IsVHlTo