This is something that I collected about the Polish light tank. I think it might be of some interest to those looking to see what equipment Poland used in 1939 against the German invasion. I wonder what, in my quest of Polish artillery and tanks, was originally designed in Poland. The tanks that I’ve discovered were designed by the enemy countries of Germany and/or Russia.
Some of this is cut and pasted:
In 1928, British Vickers-Armstrong designed the 6ton Tank Mark E and of which in 1931, Poland purchased 50 examples. 6ton Mark E was not accepted by the British Army but Vickers sold it along with a licence (in some cases) to Bolivia, Bulgaria, China, Estonia, Finland, Greece, Japan, Portugal, Romania, Russia (T-26 series) and Thailand (Siam). Two types Mark A and Mark B were purchased along with the licence. 16 Model A and 22 B were delived in 1932 and 1933, while the rest remained as payment for the licence or were delivered as spare parts. The twin turret Mark A was armed with two 7.92mm Hotchkiss wz.25 and in late 1930s rearmed with 7.92mm Browning wz.30 machine guns. Single turret Mark B was armed with 47mm Vickers-Armstrong gun and 7.92mm wz.30 machine gun. The main problem with 6ton Vickers was its Siddeley engine, which easily overheated. After examination in Poland, it was decided to modify Mark E and start the development of their own light tank by improving Mark E. New tank development program was designated as VAU-33 (Vickers-Armstrong-Ursus 33), either jw (single turret) or dw (twin turret).
Polish designers attempted to modify original Vickers tanks as late as 1936, including various armament configurations in twin turret models. Polish designers also worked on replacing original Armstrong-Siddeley engine with licensed built Swiss Sauer diesel engine as well as on improving its armor protection. Experience gained during the work was used in the development of new Polish tank and Vickers tanks remained in service to the outbreak of war without major modifications(e.g. cooling system was improved). In 1934, the development of domestic light tank designated 7TP (PZInz.220) based on Vickers Mark E started. In Spring of 1935, it was accepted for production and production of first 7TPdw with two small turrets, each armed with 7.92mm Browning wz.30 machine gun started. Other alternate armament was 13.2mm Browning wz.30 heavy machine gun mounted in one turret and 7.92mm Browning wz.30 machine gun in the other. Also considered wasconfiguration with 37mm Puteaux SA 1918 gun in one of the turrets. 7TPdw was considered to be the temporary solution and only some 24 were produced, while the rest was finished as 7TPjw tanks. Early 7TPdw were mounted with turrets removed from 22 Vickers tanks in 1934, which were converted to single turret model.
http://www.achtungpanzer.com/polish-armor-1939-7tp-7-tonowy-polski-light-tank.htm