German Reichsbahn class 50⁴⁰

Even before the start of the reconstruction program, the Reichsbahn began procuring new freight locomotives to replace outdated Länderbahn locomotives and worn-out war locomotives. What was required was a locomotive with an axle load of not much more than 15 tonnes that could be used everywhere. Since it was not possible to procure the Czechoslovak class 556.0 due to political problems, a new ome was developed on the basis of the class 50. Care was taken to use as many identical parts as possible with the class 23¹⁰ built at the same time.

In terms of frame dimensions, the class 50⁴⁰ was almost identical to the classes 50 and 52. As with the war locomotives, a plate frame was used, which later showed itself to be too weak for the strains which were posed upon them. The boiler was a new design with a combustion chamber and mixing preheater, which had about 150 hp more than that of the class 50. This was later also used on the classes 50³⁵, 58³⁰ and 52⁸⁰. Trofimoff valves were used for better idling characteristics.

Originally, 350 locomotives were to be ordered. However, production was discontinued in December 1960 after only 88 locomotives had been completed, presumably because of the reconstructed locomotives. 50 4088 was the last standard-gauge steam locomotive to be newly built in Germany. As early as 1968, the class 50⁴⁰ was only in use in the area of the Reichsbahn division in Schwerin. It was not until 1980 that the last one was retired. 50 4073 in Nördlingen is the only one that has survived to this day. It was rebuilt since 2016, has been in the Meiningen steam locomotive works since June 2022 and is operational again since 2024. 50 4088 was also earmarked for preservation, but this had to be abandoned after an accident.