C4P

Samochód półgąsienicowy wz. 34 (literally "Half-track car, year 1934 model") was a Polish halftrack lorry. It was produced in a variety of variants, the best-known of them being the C4P artillery tractor used by the Polish Army in the period before World War II. The vehicle was based on a 2.5 tonne Fiat 621 truck, licence-built by Polski Fiat in Poland at the time. In 1934 Edward Habich of the Bureau for Technical Studies of the Armoured Arms (BBT BP) designed a half-track version of the Fiat 621 lorry, initially dubbed the Mark 1934 halftrack cargo lorry (Polish: Półgąsienicowy samochód ciężarowy wz. 34). Both Fiat 621 and wz. 34 shared the majority of parts, notably the slightly modified frame, the engine and the crew compartment. There were many notable differences as well though. The front axle was reinforced, a reduction drive was added and the gearbox was modified to better suit the new vehicle. Most notably, the rear axles were replaced with a continuous track system modelled after the Vickers E tank and French Citroën-Kégresse tracks. Heaviest towed pieces were 3143 kg 120 mm wz.1878/09/31 guns. The vehicle entered production at the PZInż Czechowice factory in 1935 and the production run lasted until 1938. Altogether some 400 were built in all variants, including roughly 80 artillery tractors.