Württemberg D

In order to increase the speed of the express trains on the steep route from Bretten via Stuttgart to Ulm, the Royal Württemberg State Railways procured 15 units of type D from Maschinenfabrik Esslingen from 1898.

Their predecessors were four-coupled tender and tank locomotives that were no longer able to cope with the increasing train weights. A decision was made in favor of a six-coupled tender locomotive with a leading bogie, which was powered by a four-cylinder compound engine and had a relatively high boiler pressure for its time at 14 bars.

In order to deliver sufficient power even on inclines, the coupled wheels were given a diameter of only 1,630 mm and thus limited the top speed on the level to 90 km/h. The distinguishing features of the locomotives were the Belpaire firebox and the external low-pressure cylinders that were pulled far back.

The engine was of the de Glehn type, so the inner cylinders acted on the first set of coupled wheels and the outer ones on the second. As a result, a 250-tonne train was able to maintain a speed of 60 km/h on inclines of one percent.

After six locomotives had to be sold abroad after the First World War, the Reichsbahn numbers 38 101 to 38 108 were reserved for the rest. These numbers were intended for passenger locomotives instead of express trains, but the classification can be explained by the relatively low speed. However, they ware not renumbered because the locomotives were retired by 1924.