German Reichsbahn T 38 3255

To increase the efficiency of steam locomotives, Richard Paul Wagner had the idea to mount an exhaust turbine not on the locomotive, but in the tender. He designed a tender with the wheel arrangement 2-4-4, where the exhaust from the cylinders of the locomotive powered a 600 hp turbine that was connected to a crank shaft and two axles. After the steam had been cooled to ambient temperature, it was separated from oil and fed back into the water tank. A second, smaller turbine was installed for reversing.

The locomotive used for trials was a Prussian P 8 that received some modifications. Since the exhaust steam was fed into the tender by a pipe, a fan was mounted in the smokebox to create the draft needed by the fire. The cone-shaped smokebox door was not mounted for aerodynamic reasons, but due to the space needed by the fan.

After the trial runs started in late 1927 it became clear that the efficiency of the boiler got worse due to the modifications. In 1931, the reverse turbine was removed and the steam lines were optimized for increased power and decreased coal consumption. The combination of locomotive and tender remained a one-off, but was used for some years in schedules made for the class 39 2-8-2. In 1937, the tender was scrapped and the modifications made to the locomotive undone. Afterwards it was used as regular passenger locomotive 38 3255.