The Landkreuzer P. 1000 Ratte (“Rat”) was a WWII-era design for a Nazi German super-heavy tank with a weight of 1000 tonnes, or 1,000,000 kg. By comparison, an Abrams tank weighs 61.4 tonnes and costs $4.35 million US Dollars (USD) to build. Bruhathkayosaurus, a sauropod which may be the heaviest animal that ever lived, had a weight between 175 and 220 tonnes, several times smaller than the Landkreuzer P. 1000 Ratte. The Landkreuzer P. 1000 Ratte was designed by Albert Speer, who had more experience as an architect than an engineer.
The Landkreuzer P. 1000 Ratte was never actually built, in part due to the poor performance of another German super-heavy tank, the largest tank ever actually built, the Panzer VIII Maus (“Mouse”), with a weight of 175 tonnes. The names “Maus” and “Ratte” were likely meant to be ironic – these tanks were anything but small. Even the Maus was too heavy to cross all but the sturdiest bridges, needing to cross rivers underwater instead. It would have been entirely immune to all but the largest air-dropped bombs. The Landkreuzer P. 1000 Ratte could not have been used on roads, as it would chew through concrete like a plow through sod.
The Landkreuzer P. 1000 Ratte was to have a length of 35 m (115 ft), height of 11 m (36 ft), and a width of 14 m (46 ft). Its speed was to be 40 km/h (24 mph), though this estimate was probably too optimistic. The Landkreuzer P. 1000 Ratte had dimensions closer to those of a naval vessel than a tank. Indeed, its assembly would have cost more than $100 million USD (in 2007 currency) and required assembly tools usually relegated to a shipyard.
For armaments, the Landkreuzer P. 1000 Ratte was to be equipped with two 280 mm guns, mounted in a turret usually employed for Gneisenau class warships. It is even said that one of these turrets were built, but if so, it went missing after the war. Other guns included a 128 mm gun, eight 20 mm Flak guns for anti-aircraft, and two 15 mm Mauser machine guns.
The Landkreuzer P. 1000 Ratte would have used six 1.2 meter tracks, two per side, for its movement. This would have devastated the ground so badly that a trail of squashed grass and rocks would have extended for tens of miles along its path. Moving the tank at the speed set by its specifications would have required engines totaling 16000 horsepower, supplied by eight Daimler-Benz 20 cylinder diesel marine engines at 2000 hp each.
Today, with the advent of rockets, smart bombs, and explosively formed penetrators, the Landkreuzer P. 1000 Ratte and similar super-heavy tanks would be worse than obsolete. Even at the time, super-heavy tanks were considered a liability on the battlefield, requiring a large regiment just to protect them at close range. The Landkreuzer P. 1000 Ratte is a perfect example of the sort of overambitious planning that lost the Nazis the war. The obsession with hardware size was carried over into the Soviet Union in later years.