Ratte tank
The Krupp Landkreuzer P-1000 Ratte was a proposed German main battle tank in 1942 which, if actually built, would have been the largest tank ever placed in the field. Its extreme size and the estimated cost of production during World War II led to the project's cancellation in 1943.
Description
The Ratte was planned to have been 115 feet long, 36 feet high, and 46 feet wide. Three tracks were on either side, each track nearly 4 feet wide and riding on 11 large wheels. The hull was conventional like other tanks, with straight skirted sides and sloping front and rear; its armor was up to 9 inches thick. Its operational weight was estimated at 1,000 metric tons.
Primary armament were two 280mm 54.5 SK C/34 naval guns mounted in a single turret with full 360-degree rotation, and possibly based on a modified design from the Gneisenau-class battleship. Smaller guns would have been fitted to the main turret and the rear of the hull.
Marine diesel engines were planned to move the Ratte: either 4 MAN V127Z32/44 engines used in U-boats or 8 Daimler-Benz MB501 engines from coastal patrol E-boats; each would have produced 17,000 and 16,000 shaft horsepower respectively, with a top estimated speed of 40 miles per hour. Its operational range was unknown.
Limitations
Although a major threat on paper, it operational limitations on the battlefield were realized on the drawing board. It was an "open-field" tank only, incapable of crossing even the sturdiest of bridges or the best-laid roads due to its immense weight; fording rivers would have been impossible, and if engaged in battle it would have been picked off by aircraft like any other tank. More than five times the crew of a standard Panzer tank was needed to man the tank or maintain it on a daily basis.
By late 1942 German resources and production during the war were beginning to show a decline, and the Ratte represented an exotic, impossible system that could bring nothing decisive to the war in time. Albert Speer, German Minister of Armaments and War Production, saw the project as fruitless and cancelled it early in 1943.