This is a Köf II, originally a German army design from the wartime. Köf II stands for "Kleinlokomotive, ölgefeuert, II Generation" or small locomotive, (diesel) oil powered, second generation. The original idea was that it was easier to move trains in the vicinity of enemy during war time when there was no cloud of smoke to reveal the engine. Germany, which had invaded Denmark, forced also Danish factories to build several types of German locomotives and the Danes continued making them after the war. This one has been built by Frichs in Denmark 1947, but Köf IIs were built in Denmark all the time until 1969.