German Reichsbahn Kleinlokomotive class I

These locomotives were developed from 1930 to take on light shunting tasks at small stations. In 1931 it was defined that power group I should consist of small locomotives with an output of less than 40 hp. A few locomotives were initially ordered between 1931 and 1934, which the four manufacturers Jung, Orenstein & Koppel, Windhoff and Gmeinder had developed independently of one another. These could be obtained cheaply and served their purpose, but they were all built differently.

For this reason, a standard design was created in 1934, the vehicles of which were identical except for different diesel engines. The first variant had an operating weight of eight tonnes and, depending on the engine, an output of between 25 and 30 hp. In 1935 and 1936, a reinforced standard design with 35 to 40 hp was created. The power was transmitted in a very simple way via chains from the gearbox to both axles. Its designation was Kö I, which stood for “Kleinlokomotive mit Ölmotor” (Light locomotive with oil engine). During the war some were converted to run on LPG and then designated Kb I.

The cab was at the rear, but the hood was so small that it was easy to look past. In the driver's cab there was a control panel in each direction to make maneuvering in both directions easier. At both ends there was a very simple form of shunting coupler that coupled automatically and was released with a foot pedal. A braking system operated by compressed air for the entire train was also dispensed with, only the locomotive itself could be braked using a foot brake. A curiosity is that the locomotives of the first series were not allowed to leave the stations because they weighed eight tonnes and were too light to trigger some contacts. The reinforced models no longer had this problem with their ten tonnes.

After the war, the examples of the first series were quickly retired. The rest received 50 hp Deutz tractor engines between 1954 and 1962 and other standardizations. Nevertheless, their possible uses shrank as parcel traffic continued to decrease. They were now too weak to move the heavier unit trains, which is why in 1968 only a smaller number were included in the new numbering scheme as class 311.

At the Reichsbahn they only received new engines and from 1970 they became the class 100⁰. Here, too, most of the locomotives were decommissioned in the seventies while new small locomotives of performance class II were being built.