The D VI was a four-coupled tank locomotive for light railways, which had been developed together with the D VII. It was intended for railway lines with a maximum axle load of up to 12 tonnes on the level, while its sister was intended for branch lines with more gradients. Between 1880 and 1894, Krauss and Maffei delivered a total of 53 vehicles.
Despite the small size, the locomotives benefited from modern developments. Vacuum brakes were already installed in the first examples, later even air brakes. For easier accessibility during maintenance, running boards were used for the first time on a Bavarian locomotive. Sometimes there was also a gangway to the train. Initially, there were no storage tanks on the side, instead 500 kg of coal were accommodated in the cab and 1.8 m³ of water were in the frame, which was designed as a water tank. The last nine received storage tanks on both sides of the boiler, which increased the capacities to 800 kg or 2.3 m³.
With 26 locomotives, the Reichsbahn received about half of the originally built ones, which were then classified as class 9875. Their service there ended in the 1920s, but a few were sold to industrial railways. The last one was the former 98 7508 that was in use at the Raubling peat works until 1964. This locomotive is now maintained by the DGEG and again carries the number 1222 of the K.Bay.Sts.B. and the name “Berg”.