Ls75 and 2Ls75
An Ls75, photographed at Fablok premises, date unknown. Factory photo via SS vol. 1/2011.
Another picture from the same source: factory photo of a 2Ls75.
Side drawing of the 2Ls75 by Jacek Wardęcki; source – as above.
In 1952 Pierwsza Fabryka Lokomotyw w Polsce (First Locomotive Factory in Poland) of Chrzanów, commonly known as Fablok, built prototype light diesel switcher, designated Ls40. Its design was based on pre-war Deutz OMZ 122 and it was fitted with the S64L diesel engine. Production lasted until 1961, with 581 examples built. Ls40, which sacrificed everything for simplicity, was far from satisfactory. Maximum speed barely exceeded 11 km/h, mechanical transmission tended to overheat and was prone to failure and driver’s working conditions left much to be desired. With new, more powerful diesel engines being developed by WSW Andrychów, it was decided to design a more modern locomotive, suitable as a replacement of old steam engines used for switching. In 1957 four-cylinder S-324HL power plant, rated at 75 hp (which was also fitted to late production Ls40s), was selected and new locomotive was accordingly designated Ls75. A more powerful Ls150, powered by DSR150 diesel, was developed in parallel and these two types had in fact much in common.
Ls75 utilized certain components from earlier Ls40, including wheelsets, axleboxes and suspension elements. Fully enclosed and heated cab, fitted with thermal insulation, provided much better working conditions for the driver. Prototype (Fablok 3886/1958) was delivered to a petroleum products depot in Wrocław and followed by 3887/1959, sold to a sugar plant. Both these locomotives were fitted with four-speed 1P-154 transmission gear, the same as used in the Ls150 and based on a pre-war Fablok design. In 1960 a small batch of eighteen examples was built (serial numbers 5081 through 5098), which featured several modifications; in particular, 1P-103 three-speed transmission gear with hydraulic control, lighter by some 200 kg, was used. These locomotives were to be powered by 112 hp S-326H six-cylinder diesel engine, but eventually S-324HL was retained; type designation Ls100 was envisaged for them, but they were delivered as type 2Ls75. Externally these two variants could be distinguished by different arrays of cooling louvres in engine cowling. Both were fitted with air brakes, although hand brakes, as in Ls40, were initially planned. Production was discontinued in August 1960, as Ls150 turned out to be much more useful and versatile: this locomotive, classed SM03 with PKP and 409D with industry, was later developed into SM04/409Da and production totaled almost 1800 examples. Thus, Ls75 was outlived in production even by the obsolete Ls40!
Locomotives of this type were designated with their factory numbers, but in parallel were assigned acceptance numbers from 1 to 20. All but one went to various industrial establishments; the sole exception was 2Ls75-5087, sold to Polish Army and about 1975 assigned military designation WP-14. Ls75 was considered untypical and difficult to maintain; in particular, transmission repairs were troublesome. Withdrawals started in 1970s and by mid-1980s most examples had been written off. Probably the last one in use was 2Ls75-5095, which survived until early 1990s. Most probably not a single example has been preserved, which makes Ls75 the sole post-war diesel locomotive distinguished in this dubious manner.
Main technical data*)
*) Note: technical data, apart from production number, refer to type 2Ls75.
References and acknowledgments
- Monographic article by Zbigniew Tucholski (SS vol. 1/2011);