Landkreuzer P. 1000 Ratte

The project gained the approval of Adolf Hitler, who had expressed interest in development of such a tank, but was cancelled by Minister of Armaments Albert Speer in early 1943.

[1] The study led to a suggestion from Krupp's director (Grote), a special officer for submarine construction, who, on 23 June 1942, proposed to Adolf Hitler a 1,000-tonne self-propelled gun which he named "Landkreuzer" ("Land Cruiser").

[3][6] Albert Speer saw no reasonable use of the tank and canceled the project in 1943 before any prototype could be manufactured,[7] although this did lead to the concept of the Landkreuzer P. 1500 Monster self-propelled siege gun, which would have been heavier than the Ratte.

Although it is generally accepted that Hitler asked for a feasibility study into a 1000-ton tank in 1942, there is much doubt around the specifics of the plan to use the 280-millimetre (11 in) guns or spare turrets from the battleship Gneisenau.

[8] The Ratte's proposed size was enormous: it would have weighed at least 1,000 tonnes (1,100 short tons), more than five times the weight of the Panzer VIII Maus, the largest tank ever constructed by Nazi Germany.

The tank was to be provided with a vehicle bay that could hold two BMW R12 motorcycles for scouting, and several smaller storage rooms, a compact infirmary area, and a self-contained lavatory system.

Though its top intended speed was 40 kilometres per hour (25 mph), its huge size and high visibility would have made it extremely vulnerable to aerial bombardment and artillery fire.

Its great size would also have meant that once built the vehicle's strategic, operational, and tactical mobility would be entirely dependent on its own drivetrain, for there were no other realistic means of moving it from one firing position to another.