Here is another ultra heavy tank, that actually made it into the prototype stage. The Panzerkampfwagen VIII Maus(Mouse). I read it in a book before, but here some info at the site --
http://www.achtungpanzer.com/pz7.htm --
Weight: 188000kg
Crew: 6 men
Engine: Daimler-Benz MB 509 / 12-cylinder / 1080hp (V1)
Daimler-Benz MB 517 Diesel / 12-cylinder / 1200hp (V2)
Fuel Capacity: 2650-2700 liters + 1500 liters in reserve tank
Speed: 13-20km/h
Range: Road: 160-190km
Cross-Country: 62km
Lenght: 10.09m
Width: 3.67m
Height: 3.63m
Armament: 128mm KwK 44 L/55 & 75mm KwK 44 L/36.5
1 x 7.92mm MG34
Ammo: 128mm - 55-68 rounds
75mm - 200 rounds
Armor (mm/angle): Turret Roof: 60/90
Gun Mantlet: 250/round
Front Turret: 220-240/round
Superstructure Roof: 50-100/9
Front Glacis Plate: 200/55
Hull Front: 200/35
Belly Plate Fore: 100/90
Side Turret: 200/30
Hull Side Upper: 180/0
Hull Side Lower: 100+80/0
Rear Turret: 200/15
Hull Rear Upper: 150/37
Hull Rear Lower: 150/30
Belly Plate Aft: 50/90
Penetration of Armor Plate at 30 degrees from Vertical.
Ammunition: 100m 500m 1000m 1500m 2000m 3000m 4000m
Panzergranate 40/43 223mm 212mm 200mm 189mm 178mm 156mm 140mm
Pzgr.40/43 (APCR) - Armor Piercing Composite Rigid (Tungsten Core)