The SM15 (factory designation 12D) is a Polish diesel

shunter A switcher locomotive (American English), shunter locomotive (British English), station pilot (British English), or shifter locomotive ( Pennsylvania Railroad terminology) is a locomotive used for maneuvering railway vehicles over short distan ...

used by PKP and industry — where it carried the designation Ls750H. It is based on the Soviet ТГМ3 (TGM3) locomotive.

History

Between the years 1963–1966, a total of 56 locomotives had been produced — 27 of which were used by PKP. Of the latter 27, the first two units (SM15-01 and SM15-02) were built at the Людиновский тепловозостроительный завод (en:

Lyudinovo Lyudinovo () is a types of inhabited localities in Russia, town and the administrative center of Lyudinovsky District in Kaluga Oblast, Russia, located on the shores of Lake Lompad formed by a dam on the Nepolot River, southwest of Kaluga, the ...

Diesel Locomotive Factory) and exported to Poland. Production then resumed at the

Fablok Fablok is a Polish manufacturer of locomotives, based in Chrzanów. Until 1947 the official name was ''First Factory of Locomotives in Poland Ltd.'' (), Fablok being a widely used syllabic abbreviation of ''Fabryka Lokomotyw'', among others as th ...

factory in

Chrzanów Chrzanów () is a town in southern Poland with 35,651 inhabitants as of December 2021. It is situated in the Lesser Poland Voivodeship (since 1999) and is the seat of Chrzanów County. History History to 1809 It is impossible to establish ...

where the remaining 25 units, earmarked for PKP, were built. The newly built SM15s were assigned to the depot in Kraków Płaszów, before being withdrawn from service in the late 1960s and early 1970s, when the SM42 series replaced them. Despite their relatively short operational history, the

engineers Engineers, as practitioners of engineering, are professionals who invent, design, build, maintain and test machines, complex systems, structures, gadgets and materials. They aim to fulfill functional objectives and requirements while consider ...

who drove the locomotives remember them as being very powerful machines.

Technical data

The SM15 is equipped with a

Soviet The Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

550 kW

diesel engine The diesel engine, named after the German engineer Rudolf Diesel, is an internal combustion engine in which Combustion, ignition of diesel fuel is caused by the elevated temperature of the air in the cylinder due to Mechanics, mechanical Compr ...

(a number of SM15s had Polish V12CD9 engines installed, rather than the Soviet variant) with hydromechanical

transmission Transmission or transmit may refer to: Science and technology * Power transmission ** Electric power transmission ** Transmission (mechanical device), technology that allows controlled application of power *** Automatic transmission *** Manual tra ...

. Certain models destined for use in industry had

hydraulic Hydraulics () is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concer ...

transmission, and these carried the designation Ls750Hu. The SM15 is a

B′B′ B-B and Bo-Bo are the Association of American Railroads (AAR) and British classifications of wheel arrangement for railway locomotives with four axles in two individual bogies. They are equivalent to the B′B′ and Bo′Bo′ classifications i ...

locomotive, which means that the unit runs on two

bogie A bogie ( ) (or truck in North American English) comprises two or more Wheelset (rail transport), wheelsets (two Railroad wheel, wheels on an axle), in a frame, attached under a vehicle by a pivot. Bogies take various forms in various modes ...

s, with all axles powered. The main reason behind the SM15's short operational lifespan was the unreliability of its transmission and power units.

Preserved Units

Currently, there are three known examples of the SM15 in preservation: *SM15-17 is an exhibit at the

Warsaw Railway Museum The ''Stacja Muzeum'' is located at the former Warsaw Główna PKP railway terminus and is very close to the Warszawa Ochota railway station. The museum's exhibits are divided into permanent and temporary collections — the latter being di ...

*SM15-22 has been kept back as a

monument A monument is a type of structure that was explicitly created to commemorate a person or event, or which has become relevant to a social group as a part of their remembrance of historic times or cultural heritage, due to its artistic, historical ...

at the Technical Rail College in

Tarnowskie Góry Tarnowskie Góry (; ; ) is a city in Silesia, southern Poland, located in the Silesian Highlands near Katowice and seat city of Tarnowskie Góry County Located in the north of the Metropolis GZM, a megalopolis (city type), megalopolis, the great ...

References

Railway locomotives introduced in 1963 Diesel–hydraulic locomotives of Poland B′B′ locomotives Standard-gauge locomotives of Poland Fablok locomotives Shunting locomotives {{poland-rail-transport-stub