SM02 was designed at the beginning of the 1950s and the production started in 1952 in Fablok, Chrzanów. Before 1960 those locomotives were named Lo1xx in PKP, where xx stands for numbers. Those machines were lightly used in PKP mainly due to poor performance. The class was nonetheless widely used in industrialservice. Early on the S64L enginesproved to be insufficient for the locomotives' duties, so later examples were fitted with more powerful S324HL motors. Likewise, several older locomotives had their engines replaced during servicing.
Preservation
Several Ls40 locomotives remain in industrial use, but are being withdrawn systematically. Ls40-5438 is an exhibit at the Skansen Parowozownia Kościerzyna museum and Ls40-4572 was bought by Polskie Stowarzyszenie Miłośników Kolei from Grodziskie Zakłady Farmaceutyczne "Polfa" in Grodzisk Mazowiecki on 30 June 31995.