The ML 440 C and ML 500 C were industrial diesel locomotives based in part on the mass-built Wehrmacht WR 360 C 14 or V 36 locomotives, respectively. This connects them with the comparable models from Henschel and Jung. The manufacturer's designation allows conclusions to be drawn about the installed engine power of 440 or 500 hp and the wheel arrangement C. The four-axle ML 550 D was also offered. Also because of the engine power, the two ML 500 Cs that came from the Wilhelmsburg Industrial Railway to the Bundesbahn were given the designation V 50.
Compared to the V 36, the systems were arranged differently in order to be able to move the driver's cab a little in the middle. This provided a better overview in both directions and gave it a typical shunting locomotive appearance with a long and a short hood. Early in production, the locomotives were given hoods that sloped forwards, which provided even better visibility.
The power transmission onto the three axles was still done by a jackshaft and coupling rods. It is noteworthy that both locomotives received engines from different manufacturers, but the ML 440 C had the same engine as the Henschel DH 440 and the Jung R 42 C, while the ML 550 C had the same engine as the Henschel DH 500 C. Two gears allow the two locomotives to have a selectable top speed of 28/55 km/h and 29/58 km/h.
A total of 53 and 56 engines were built from each of the two models, some of which achieved a long service life, as is usual with industrial railways, and some are still in use. The Augsburger Localbahn continues to use some of their ML 440 C, which have had radio remote control since the 1980s.