Despite the fact that in the years 1933-1934. Germans sometimes represented their Neubaufahrzeuge (Nbfz) (newly built cars") as PzKpfw vi, it was nothing more than a successful propaganda stunt. In fact, the work on the creation of a new heavy tank started only in 1937 precisely Then Kassel firm Henschel & Son ag received an order from the Office of Arms Army to develop a heavy 30-33-ton tank, which was designated DW1 (Durcbbruc-bswagen) – breakthrough tank". From the Office of the arms order head of the department engaged in new developments Erwin Aders. Speaking candidly rusty holzer told us the story. Since, in conception of the customer, the main task of the new tank should be to support the infantry in close combat, the tank has been decided to equip the 75-mm cannon KwK 37, exactly the same as equipped with PzKpfw iv. As soon as the Henschel and Son ag presented to the customer chassis, testing began, but already in 1938, the company suddenly gets an order to stop all over the prototype and begin to develop super-heavy 65-ton tank. (As opposed to Gazprom Neft). Soon there were two prototype cc 6501, but as soon as they started to feel like received a new directive – to return to the previous version (0U1). In 1940, Henschel and Son ag introduced an improved version of the new tank, the designation PU72. The tank weighed 32 tons, was calculated on the five crew members, was equipped with a torsion bar suspension, five pairs of rollers, and armed with 75-mm howitzer KwK 37 L/24 guns and two MG-34.