Built in 1949, this was one of a number of Soviet locomotive

Locomotive

A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...

 designs that was very successful. The cylinders were placed above the center driving axle. Unlike nearly all steam locomotives, the pistons had rods on both ends which transferred power to the wheels. The idea was to balance the driving forces on the wheels, allowing the counterweights on the wheels to be smaller and reducing "hammer blow

Hammer blow

Hammer blow, in rail terminology, refers to the vertical forces transferred to the track by the driving wheels of a steam locomotive and some diesel locomotives. The largest proportion of this is due to the unbalanced reciprocating motion, although the piston thrusts also contribute a portion to it...

" on the track.

External links

• Russian Reforms - Describes this and other Russian locomotive types