P 1000 Ratte
The development history of the Ratte originates with a 1941 strategic study of Soviet heavy tanks conducted by Krupp. This study also gave birth to the Ratte’s smaller and more practical relative: the Maus. From the start the Maus was envisioned as an even larger and more formidable version of a heavy tank, while the Ratte was to be a class of vehicle unto itself.
The Landkreuzer P.1000 "Ratte" ("Rat") was a super-heavy tank design proposed by Krupp in 1942. Hitler gave the project his blessing to the program to create the the largest and most powerful tank ever devised. Albert Speer, the Minister of Armaments and War Production for the Third Reich, saw the fruitlessness of such an endeavor and cancelled the P.1000 in early 1943, and, the Ratte never made it off of the drawing boards. Externally, the P.1000 would have dwarfed every other tank in production. With as many as 11 large road wheels affixed to either track side, the tracks measured a near-four feet in width. The hull was conventional by 1942 standards, with straight faced skirted sides and an angled front and rear hull. Armor would have been between 150mm and 360mm. The P.1000 had a height of 11 meters, a width of 14 meters and a length of 35 meters. The overall operational weight was expected to reach 1,000 tons (2,000,000 lbs).
The massive turret was positioned well forward in the hull, with a primary armament envisioned as a pair of 280mm 54.5 SK C/34 naval guns. The turret would be a modified heavy cruiser emplacement (possibly from the Gneisenau-class) with full 360-degree traverse. Secondary armament included a 128mm KwK 44 L/55 anti-tank gun, and 8 x 20mm Flak 38 anti-tank cannon systems. The 128mm system would have been mounted in the main turret in a smaller turret fitted to the rear of the hull. A pair of 15mm MG 151/15 autocannons would have also been part of the armaments package. A crew of 20 men was required to man the various onboard systems.
Krupp suggested the use of either 8 x Daimler-Benz MB501 20-cylinder marine diesel engines, developing an estimated 16,000 horsepower or 4 x MAN V127Z32/44 24-cylinder marine diesel engines of 17,000 horsepower output. The former engine type was utilized in German E-Boat systems while the latter was prominent in U-Boat submarine designs. Though a top speed of 40 kilometers-per-hour was estimated, its durable operational range was not, and it may be assumed that the P.1000 would have been extremely limited in this area.
On paper, the P.1000 had the armament and armor to destroy anything on the modern battlefield. But in reality, it is doubtful the system would have added much to German fortunes. The sheer size of the P.1000 would have limited its use and effectiveness. Weight alone would have forced roads to crumble, while passing over the bridges would have been simply impossible. Additionally, the use of multiple complex engines in one hull would prove a maintenance nightmare. If used at all, the P.1000's reach would have been severely limited by the design's inherent restrictions.
While the P.1000 project eventually foundered, the Panzerkampfwagen VIII Maus ("Mouse") went on to become the largest tank to be built in World War 2, though only reaching prototype form before the end of the war.
