The class 50 locomotive came into being shortly before the start of World War II as the last of the so-called "standard design steam locomotives". In April of 1937 the Reich Transportation Ministry (RVM) charged the German State Railroad Central Office (RZA) with the design of a powerful freight locomotive for branch lines, among other things, as a replacement for the class 57.10-40 (Prussian G 10) 0-10-0 freight steam locomotives. It had to be able to pull a medium weight train on flat terrain, negotiate curves with a radius of 140 meters / approximately 460 feet, and be usable with about a 15 metric ton wheel load on branch lines with less than ideal roadbed. A suitable maximum speed appeared to be 80 km/h / 50 mph. Since many end terminals had no turntable or one that was too short, this locomotive had to be able to go at the same speed in both directions. For that reason a protective wall was planned for the tender to protect the locomotive crew when running in reverse. The RZA initially planned a 2-8-0 locomotive (class 46) because no faith was placed in a 2-10-0 design for the required high speed in reverse and the necessary tractive effort. The required wheel loads could not be reached with a 2-8-0 design, so the design remained with a locomotive with 5 driving axles and a pilot truck. From April to July of 1939 Henschel delivered the first twelve locomotives with a steel firebox, alloy steel for the boiler plating, a two-cylinder, super heated steam running gear layout with a Wagner super heater as well as 232 pounds per square inch boiler excess pressure. The class 50 that came out of this was soon destined to become the German State Railroad's most successful design, because this locomotive with its approximately 1,600 horsepower and 80 km/h / 50 mph speed quickly became a general-purpose, sturdy, reliable unit. The outbreak of war on September 1, 1939 caused a leap in the demand for freight locomotives, and the twelve pre-production locomotives were followed by another 3,152 units over the course of the next few years. Almost all of Europe's locomotive builders participated in the construction of these units. Like the class 44, the class 50 was also simplified in steps during the course of World War II, so that starting in 1942 locomotives were delivered as the class 50 ÜK. Over 300 units were so simplified in the end that, although they were planned as the class 50, they were designated as the war class 52. Despite numerous losses to the war, after 1945 there were almost 3,000 locomotives on the two German railroads alone. The East German DR had over 317 after giving up and retiring a quantity, and the DB had more than 2,000 units. The DB units were at home all over the German Federal Republic. They were equipped with Witte smoke deflectors, and the running board skirting was removed on most units. Starting in 1961 the tenders on 730 locomotives were equipped with engineer's cabs as part of a rationalization and updating of service and operations. This did limit the coal capacity to 6.6 metric tons. With the lower weight these locomotives became more multifaceted in their use and replaced tank locomotives on many branch lines. With the introduction of computer numbers starting in 1968 the class 50 became the classes 050-053. They were among the last steam locomotives on the German Federal Railroad and were in use until 1977.