The technical documentation for this locomotive was developed in 1958-1962 by the state Central Construction Bureau of Railway Stock Industry (CBKPTK) in Poznań, as type 6D.

It was lent to the Polish State Railways (PKP), as the SM42-001, the class designation 'SM' meaning a diesel shunter locomotive, and was tested in Warsaw in 1964.

[1] Six similar locomotives, type 6DI, were built in 1982 for Dromex, a Polish building company operating in Iraq.

[1] In the years 1975-1977, 40 locomotives were converted to SU42 ("diesel universal") class, with the addition of 500 V electric train supply for heating of passenger carriages.

Due to the withdrawal of such carriages, in 2000 the electric supply systems were removed and these locomotives were reclassified back to SM42.