C7P

C7P (an abbreviation of Ciągnik Siedmiotonowy Polski, "7-tonnes Polish Tractor") was a Polish tracked artillery tractor, used by the Polish Army before and during World War II. The tractor was developed by the design bureau of Witold Jakusz of the PZInż company between 1931 and 1934. In 1931 Poland bought several dozens of British Vickers E tanks and a license to build additional tanks at home. The Polish Army also considered purchase of the Vickers Medium Dragon artillery tractor, based on the Vickers E, but the purchase never happened. As the British tank was considered not suited for service in the Polish climate and needed adaptation, it was decided that a similar Polish tank be built as a modification of the Vickers design. The tank, initially code-named VAU-33, in time became the 7TP. Simultaneously, work started on a new artillery tractor for the Polish Army that was to replace the Citroën-Kegresse tractors built in France in the early 1920s. The main advantage of the new model of artillery tractor, dubbed C6P, C6T and finally C7TP was to be its low price, ease of manufacture and durability. For that purpose, the C7P shared many parts with the 7TP light tank, produced simultaneously. In fact the chassis was almost a direct copy of the tank, while the superstructure was partially borrowed from a license-built Saurer bus. In 1933 the first two prototypes were constructed in the Ursus factory of the PZInż, the C6P and the C6T. The C6P had the engine placed in the front and used front wheel drive, while the C6T had the engine placed behind the crew compartment and used rear wheel drive. After a series of tests the C6T's engine was moved from the rear of the fuselage to the front. These modifications resulted in the C6T/II. The...