In 1925, the Deutsche Reichsbahn initially bought a few experimental small locomotives. These locomotives had internal combustion engines, which were later to replace steam traction. After the tests had been positive, the Reichsbahn classified further procurement into two performance groups starting in 1931:
– Power group I: Locomotives up to 39 hp and max. 30 km/h speed. They were intended for switching operations in small stations under simple conditions
– Power group II: Locomotives from 40 – 150 hp. They were intended to enable trained personnel to carry out shunting tasks in one-man operation
The letter K was introduced to identify the locomotives, followed by an index for the type of engine used: b (benzene) for gasoline engines and ö (oil) for diesel engines. For locomotives with a liquid gearbox, the letter “f” was added.
On the German Federal Railways they were known as class 311 or 321-324 from 1968 and on the German Reichsbahn as class 100 in 1970.
This locomotive is an example of the so-called standard small locomotives of the Deutsche Reichsbahn. After the testing of a fluid gearbox instead of the original gearbox at the end of 1937, more locomotives were ordered with this gearbox. After the end of the Second World War, only a fraction of the once existing small locomotives were operational. Since the demand for switcher locomotives was high after the war, further examples were procured or replicated.

Our locomotive was delivered to the Deutsche Reichsbahn in 1934 as Kö 4290. In 1943, the locomotive was converted to liquid gas operation and renumbered Kb 4290. After the war, the locomotive was converted to diesel operation again and was renumbered Kö 4290. In 1955, the existing gearbox was replaced by a liquid gearbox (Köf 4290). In 1968, the locomotive was given the designation 321 023-4 and was rebuilt again in the same year (322 143-9). After it was taken out of servicein Koblenz in 1975, it was sold to the company J. B. Weinand, Bad Kreuznach (“Lok 1”). In 1991, the locomotive came to our museum and received its designation Köf 4290 again.