PKP ST44 (M62)

Updated: August 2026 – Six axles, a long bonnet between two cabs, no pantograph, and an engine sound you could identify with your eyes closed: the ST44 is Poland’s version of the Soviet M62 design and one of the best-known diesel locomotives in Central Europe. This page shows you how to identify it confidently, what its code means, and what matters when photographing it.

What is the PKP ST44?

The ST44 is a six-axle diesel-electric line locomotive for freight traffic, based on the Soviet M62 design from the Luhansk locomotive works. It has two cabs at the vehicle ends and a continuous machine bonnet in between – a design rarely found in Western Europe, but very common in Central and Eastern Europe.

The M62 was supplied in large numbers to the countries of the former Eastern Bloc; at Lietuvos geležinkeliai it still shapes the diesel fleet today. In Poland it runs as the ST44 with the nickname “Gagarin”, while the same basic design ran for the Deutsche Reichsbahn as Class 120 – better known there as the “Taigatrommel”. Once you have learned the silhouette, you will recognise it across several railway administrations – at the Hungarian MÁV, the same basic design runs under the nickname Szergej.

Reading the PKP code: why ST44 is no coincidence

Poland does not name locomotives with a plain number like Germany, but with two letters plus a design number. That is the biggest advantage for spotters: you can read what a vehicle is from its code before you even know it.

Position	Meaning	Examples
First letter	Traction type	E = electric, S = combustion engine
Second letter	Purpose	U = universal, T = freight train, P = passenger train, M = shunting duty, N = railcar
Number	Design number	44 for the ST44, 42 for the SM42, 07 for the EU07

That makes ST44 a diesel locomotive for freight duty, SM42 a diesel shunting locomotive, EU07 an electric universal locomotive and EN57 an electric multiple unit. This system carries you through practically every Polish vehicle – an enormous advantage over countries where the number carries no meaning. How you also decode the twelve-digit international vehicle number, in which 51 stands for Poland, is explained in the guide to reading the UIC number and its check digit.

Identifying the ST44 in the field

The third step is the most important distinction: the also six-axle PKP ST43 is a different design with its own visual language, and the common SM42 or SU42 is a smaller, four-axle shunting locomotive. If you want to identify systematically rather than by gut feeling, the general guide to identifying classes helps – it describes the order in which to work through features so you don’t get lost in details.

Where the ST44 fits operationally

As a freight locomotive without a pantograph, the ST44 follows a clear logic: it runs where there is no overhead wire or where electric traction is impractical – in Poland mostly in the fleet of PKP Cargo. For your search, that means something quite different from a passenger locomotive.

Environment	Chance of a sighting	Why
Marshalling yards and freight hubs	high	Train formation, staging and long dwell times
Non-electrified freight lines	high	Core territory of diesel traction
Sidings serving industry and mining	medium	Often private keepers with their own machines, access often not public
Engineering and works trains	medium	Deployed at short notice and hard to plan for
Electrified main lines with passenger traffic	low	Electric locomotives and multiple units dominate there

On electrified main lines, heavy freight traffic is traditionally handled by the PKP ET22 – under the same letter system an electric locomotive for transport duty. That contrast is exactly what makes the system so practical: ET and ST differ only in traction, not in purpose.

Spotting and photo tips for the ST44

The ST44 is a rewarding photographic subject because it is angular, loud and full of character. At the same time it often stands where you can’t easily get to.

Marshalling yards are the natural territory of this design but demand especially careful conduct: the guide to spotting at marshalling yards explains which areas are public and which are not. The basic rules on safe distance from the track apply regardless and cannot be argued away. And because for this design the individual machine matters more than the type, a well-kept sighting log pays off.

Common mix-ups

Verdict

The ST44 is one of the vehicles that best teaches you the Polish designation system: two letters tell you traction and purpose, the number the type. Add to that a silhouette you won’t forget after seeing it once. Anyone who recognises the design in Poland will also recognise it as the Reichsbahn Class 120 in German museum collections.