The Übergangskriegslokomotiven (literally: provisional war locomotives) were austere versions of standard locomotives ('' Einheitslokomotiven'') built by

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

during the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

in order to accelerate their production. They are often just called 'ÜK' locomotives. In the Second World War the requirement for motive power, especially goods train locomotives, rose sharply. To cope with the demand the standard locomotive classes 44, 50 and 86 were built, after 1941, to a simpler, more austere design and given the designation (ÜK) after the class number. Characteristic of ÜK locomotives are e.g. disc wheels on the

carrying axles A carrying wheel on a steam locomotive is a wheel that is not driven; i.e., it is uncoupled and can run freely, unlike a coupled or driving wheel. It is also described as a running wheelWörterbuch der Industriellen Technik, Dr.-Ing. Richard Erns ...

and the omission of the front side windows in the driver's cabs. Even preheaters, feed pumps, ''Frontschürzen'',

smoke deflectors Smoke deflectors, sometimes called "blinkers" in the UK because of their strong resemblance to the blinkers used on horses, and "elephant ears" in US railway slang, are vertical plates attached to each side of the smokebox at the front of a ste ...

and other equipment not essential for the operation of the locomotives were sometimes left out. The ÜK classes proved however to be just an interim step. As early as 1941 the requirement for a further, more radical simplification of locomotive construction became ever more pressing. As a result, genuine war locomotives (the ''

Kriegslokomotive ''Kriegslokomotiven'' (german: for "war locomotives", singular: ''Kriegslokomotive'') or ''Kriegsloks'' were locomotives produced in large numbers during the Second World War under Nazi Germany. Their construction was tailored to the economic circ ...

n'') were developed by the

Deutsche Reichsbahn The ''Deutsche Reichsbahn'', also known as the German National Railway, the German State Railway, German Reich Railway, and the German Imperial Railway, was the German national railway system created after the end of World War I from the regiona ...

. They were sub-divided into wartime steam locomotives (''Kriegs-Dampf-Lokomotiven or KDL'') and wartime electric locomotives ('' Kriegs-Elektrolokomotiven or KEL''). Examples include the steam classes 42 and 52, as well as the Class E 44 and E 94.

See also