In the last decade of the 19th century the Württemberg State Railways (K.W.St.E.), known for its thrift, gave serious thought to rationalizing operations on branch lines and during off-peak hours. In November of 1895, it order a first steam powered rail car (DW 1) from the firm Societé Serpollet in Paris. A special feature of this two-axle unit was the Serpollet boiler, which allowed particularly economical one-man operation. This boiler consisted of a system of tubes, which were installed a fireproof cabinet. Six additional units with Serpollet boilers (DW 2-7) were delivered between 1899 and 1903 by the firm Maschinenfabrik Esslingen (ME). However, the operating results were not satisfactory due to the poor steaming qualities of the cars. A new boiler development by Maschinenfabrik Esslingen under the direction of the chief designer Kittel in 1904 resulted in a critical improvement. The Kittel boiler was a vertical evaporative tube boiler with a corrugated flue fire box. A large super heater was located above the boiler, which now provided sufficient performance. Between 1905 and 1909 Maschinenfabrik Esslingen (ME) delivered nine steam powered rail cars (DW 8-14, 16, 17) with Kittel boilers to the K.W.St.E. Between 1904 and 1908 the Serpollet cars, road nos. DW 1-7, were equipped with Kittel boilers; road no. DW 1 also acquired a new road number, DW 15. The Baden State Railroad bought eight similar units in 1914/15 with the road numbers 1000-1007. They differed in several details from the Württemberg cars: symmetrical boiler location on the center axle, a larger wheel base of 5.5 meters / 18 feet, a different window arrangement, entry steps on the front with step housings, a lower coal bunker, and a larger fuel capacity. All of the Baden, but only a few of the Württemberg cars, were taken over by the DRG. When these units were given new road numbers in 1930, there were still 14 on the roster, and they were assigned the numbers DT 1-14.
Thirteen powered rail cars survived World War II. Nine remained in the West Zone; of them seven were retired over the course of 1949. In 1950, the German Federal Railroad still had two units on its roster: road no. DT 1 (former no. 1000) and road no. DT 8 (former no. 1007). The latter lingered on tenaciously and was even used in shuttle service until the end of 1953 on the Baden route Müllheim - Neuenburg. It was stored on January 2, 1954 and retired on March 3, 1954. Road nos. DT 2, 3, and 9 (former nos. 1001, 1002, and DW 15) remained after 1945 on the French State Railways. The first two units were in use there until 1956 with the road numbers XDR 10.102 and 10.103 in Mulhouse as personnel powered rail cars. The former road no. DT 6 (former no. 1005) came in 1949 to the roster of the DR (East Germany) after the nationalization of the Oderbruch Railroad as road no. DT 151; however it remained in storage and was scrapped in November of 1957 in Frankfurt/Oder. One Kittel powered rail car delivered in Switzerland is preserved there in operational condition.
In operation the Kittel steam powered rail cars turned in excellent results. Their quiet running and their ability to accelerate were praised above all else. In test runs they even reached speeds of 70 km/h / 44 mph. The performance qualities of these small powered rail cars were demonstrated on grades of 1% that were negotiated at a speed of 25 km/h / 16 mph with two passenger cars in tow and 150 passengers on board.