After the Pommern provincial administration had taken over the operation from the firm Lenz in 1910 of the short line railroads operated in the region, new, more powerful locomotives were purchased from the locomotive builder Vulcan in Stettin in 1913 for these lines. Two units of these locomotive with the class "M" were put to use on the Rügen Short Line Railroad, where they turned in good results. With their performance of 200 horsepower and a maximum speed of 30 km/h / 19 mph, these approximately 23 metric ton locomotives were able to master all expected tasks. Due to the good results, another locomotive was ordered in 1925 – now however as a superheated steam locomotive, and it was given the class designation Mh. Identical with the earlier locomotives in terms of the basic principle, it had a somewhat higher performance with 235 horsepower. This locomotive was heavier by about 2 metric tons and somewhat larger than its predecessors. After the takeover of the Rügen Short Line Railroad by the DR in 1949, these 3 locomotives were assigned the road numbers 99 4631 through 99 4633. They were used on Rügen this way for a long time. At the start of the Nineties, road numbers 99 4632 and 99 4633 were given a thorough overhaul. Among other things, they were given new boilers and cylinders. After that, these locomotives were underway earlier in the DR paint scheme of black with red wheels. Road number 99 4632 was given a green paint scheme, but several years later it was back in black again. Since the summer of 2020, road number 99 4633 as 53 Mh has been underway in a very attractive dark green paint scheme.