For service on suburban and secondary lines, but also for light express trains, the BBÖ got 20 tank locomotives of the type DT 1 starting in 1935. Having a luggage compartment, their designation stood for “Dampftriebwagen” (steam railcar). Since they were mostly used on rural lines, they also got the nickname “Dorftrottel” (village idiot). The Slovenian Railways also ordered six similar, slightly heavier locomotives.
They had the wheel arrangement 2-4-2T, with a long driver wheelbase and both leading and trailing axles in Bissel frames. The weight distribution could be switched between a maximum axle load of 13 and 11 tonnes. The first ten were built as oil burners to enable one-man operation, but were later also converted to coal firing.
The DT 1 was often used in “Pendler” trains in the center of a maximum of four two-axle passenger cars, what allowed them to run in both directions. Apart from being used as the locomotive in light express trains, they were also used as heating locomotive, towed behind an electric locomotive in a heavier express train. This was necessary because World War I had brought many passenger cars into Austria which had no compatible heating or braking system for modern Austrian or German electric locomotives.
The Reichsbahn made them class 715. In this time, some were stationed at Munich or Rosenheim. After World War II, all 18 which were still existing came back to Austria. In the ÖBB, they now became class 3071 and were withdrawn in 1968. Today, DT 1.07 is being preserved and located at Strasshof.