Work on the design of a Polish artillery tractor began in 1956 at the
Mechanical Plant in Łabędy, using components of the
T-54A tank, the licensed production of which was implemented there. The tractor was unified by about 75% with the T-54A tank. In 1957, two prototypes were created, initially designated ACS Mazur D-300. In 1958, two improved prototypes were created and in the same year the tractor was put into production, which lasted until 1960 (according to other information, from 1960 to 1961). The assembly of the tractors took place in Łabędy, where the body, drive train and road wheels were manufactured, while the chassis and suspension were manufactured by
Huta Stalowa Wola, and the engines were manufactured by PZL Wola. Despite good performance, the production of the tractor was quickly ended. The reason was the unification of artillery tractors in the
Warsaw Pact forces and the introduction of the Soviet
ATS-59 tractor, produced in Poland under license. Comparative tests were conducted and according to the Soviet side, the ATS-59 proved to be better in most respects. About 1,000 Mazur tractors were produced. In the
Polish People's Army, Mazur D-350 artillery tractors were used until the end of the 1970s. A certain number were sold to Czechoslovakia in the early 1960s (according to Czech information, 218 of them were delivered and were to be colloquially known as Gomulkova pomsta – "Gomułka's revenge"). A small number of these tractors were transferred to the
North Vietnamese army and used by it during the
Vietnam War. Some of the tractors withdrawn from the army were then used, among others, by the railway in rescue trains and in forestry service. The Mazur D-350 was a high-speed tracked tractor used in heavy artillery units for towing artillery equipment – mainly the
1937 (ML-20) howitzer of 152 mm caliber and the
1931/37 (A-19) heavy field guns of 122 mm caliber. Less frequently, it towed
KS-19 100 mm anti-aircraft guns and trailers with radar equipment. The towing force on the
hook was 12.5 T, the maximum trailer weight was 25 t. ==Users==