The OM range by Deutz consisted of small diesel shunters for industrial railways built in the thirties and early forties. They were powered by two-stroke engines with one to four cylinders. Their development focused on simple construction and cheap maintenance. Most had two axles, where one was powered by a chain and the other was connected to the first one by coupling rods.
The most numerous model was the OMZ 122 R with 176 produced, where the Z stood for two (zwei) cylinders. While the 1 denoted the first generation of the engine and 22 denoted the cylinder stroke in centimeters, R stood for standard gauge (Regelspur). There were also narrow gauge variants like the OMZ 122 F that was developed for field railways and had a gauge of 600 mm. It only had half the weight of the standard gauge variant and a somewhat lower power.
