On June 23rd of 1942, Dir. Dip. Ing. Grote (along with Dr.Hacker) from the Ministry of Armament, who was responsible for the production of U-Boats suggested the development of a tank with a weight of 1000 tons. Adolf Hitler himself expressed interest in this project and allowed Krupp to go ahead with it. Project was designated as Krupp P 1000 (Ratte – Rat). This "land cruiser" would be 35 meters long, 14 meters wide and 11 meters high. P 1000 would be equipped with 3.6 meters wide tracks per side made of three 1.2 meters tracks, similar to those used in excavators working in coalmines.It was planned to power P 1000 with two MAN V12Z32/44 24 cylinder Diesel marine engines with total power of 17000hp (2 x 8500hp) or with eight Daimler-Benz MB501 20 cylinder Diesel marine engines with total power of 16000hp (8 x 2000hp).According to the calculations it would allow P 1000 to travel at maximum speed of 40km/h. P 1000 would be armed with a variety of weapons such as: two 280mm gun (naval gun used in Scharnhorst and Gneisenau warships), single 128mm gun, eight 20mm Flak 38 anti-aircraft guns and two 15mm Mauser MG 151/15 gun.
In December of 1942, Krupp created new design of 1500 ton tank – P 1500. It frontal armor would be 250mm thick and it would be armed with 800mm super heavy mortar "Dora" type and possibly two 150mm artillery pieces. P 1500 would be powered by two or four submarine diesel engines. In early 1943, Albert Speer cancelled both projects. P 1000 turret ended up at coastal defence battery (Batterie Oerlander) near Trondheim, Norway.
Even before P 1000 and P 1500, in 1939, Krupp began working on other similar projects for projected series of self-propelled coastal guns for the German Navy – Kriegsmarine.Series was to include 14 different platforms designated from R1 to R14. Armament was to range from 150mm to 380mm and it was to be mounted on fully traversible turntables on tracked carriages. One of the designs was R2 coastal gun armed with 280mm gun. The series never left drawing boards.
Specifications for P 1000
2 x MAN V12Z32/44 Diesel / 24-cylinder / 2 x 8500hp
8 x Daimler-Benz MB501 Diesel / 20-cylinder / 8 x 2000hp
2 x 280mm SK.C/34 L/54.4
1 x 128mm Kanone
8 x 20mm Flak 38
2 x 15mm Mauser MG 151/15
Panzer IX and Panzer X never existed as projects on drawing boards and were only drawings made by an artist.
The two modern looking tanks were not even considered by the designers, but instead were propaganda sketches published in the German "Signal" magazine in 1944 (issue 3/44), to build up the German morale at home and misinform the Allies about the German tank development. In 1944, the German war industry was not in a position to develop and produce such advanced designs at the time when it was not able to fully supply replacements for lost armored vehicles.
Although, there are no real blueprints showing the realistic look of both vehicles. Based on the drawings, PzKpfw X was to be wider but lower than Maus and was to be surely armed with 88mm or even 128mm gun. Both drawings represented very advanced and modern looking designs including many features (such as hidden road wheels and tracks along with rounded armour) which can be found in modern main battle tanks.