Prussian T 33

The class T 33 locomotives comprise four small batches of a total of 13 narrow-gauge locomotives that were developed for the Feldabahn between Dorndorf and Kaltennordheim in Thuringia. This route was in the Grand Duchy of Saxe-Weimar-Eisenach, but since the Prussian State Railways had taken over as many railways as possible in the small Thuringian area towards the end of the nineteenth century, the development and procurement of the T 33 was also carried out under Prussian direction. However, a local company, the Christian Hagans machine works in Erfurt, was commissioned to manufacture the machines.

The design of T 3 was used in many places, because so many parts of this tank locomotive, which was procured in very large numbers, could be reused at low cost. Thus, the first series from 1908 in particular looked very similar to its model, but was a bit lighter. Another difference to the T 3 was the Heusinger valve gear, which at the time of development had prevailed on almost all new locomotives. A saturated engine was used, which simplified the maintenance of the locomotives at the expense of economy.

In the second batch from 1912, the weight was increased by around 5.5 tonnes with roughly the same power in order to have a larger adhesive mass available. In addition, the grat area was increased a little. Two further, almost identical batches of two and four pieces each were delivered in late 1912 and 1914. In addition to a different arrangement of some assemblies, they had a larger evaporation heating surface.