PKP class SM42

SM42 is the PKP class for a Polish diesel locomotive for shunting and light freight traffic, built by Fablok in Chrzanów (manufacturer's designation is Ls800E, designer's designation 6D).

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. The production was given over to the Fablok Locomotive Factory in Chrzanów, where it was designated Ls800E (meaning an 800 HP diesel locomotive with electric transmission). The prototype was ready in December 1963. 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] Two improved locomotives were built for the PKP in 1964, and twenty in 1965. In 1967, the locomotive entered serial production and 1,822 were built until production ceased in 1992. During the long production run, some minor improvements were incorporated into the design. The locomotives produced from 1972 onwards (so-called batch 2) had simplified chassis (starting from SM42-521, bu.no. 8499).

The main buyer of Ls800 locomotives, which had priority in orders, were the Polish State Railways, which received 1157 locomotives. They were used for shunting, local freight traffic and local passenger traffic in warm months. 622 were made for the Polish industry, some in Ls800P variant with single steering only (they were designated by their users as Ls800 or SM42, with numbers above 2000).

A variant of type 6D/SM42 locomotive was a type 101D locomotive, with steam heating for passenger trains. Further 268 locomotives of this variant were built and classified as PKP class SP42.