Steam locomotive class 78 of the Deutsche Bundesbahn.

■ Factory-fitted with a DCC decoder for digital operation
■ Version equipped with extension on coal tender
■ Ventilator superstructure on top of the driver's cab

The Prussian T 18 was the last tender locomotive developed for the Prussian state railways. The locomotive was originally conceived for services on the island of Rügen as a replacement for the T 12 and the T 10. The locomotive emerged when, in 1912, a certain class of locomotive was conceived that was to handle express and passenger trains in border areas or in commuter services on short distances. The design of a tender locomotive with symmetrical chassis was envisaged because, unlike a tow-tender-locomotive, it was able to run equally fast forwards and backwards and also could be operated on return journeys without having to be turned on a turntable. Its power and top speed were to be the same as those of the P 8. Robert Garbe designed this 2'C2' tender locomotive to reach a top speed of 100 km/h with a 17-ton axle load and contracted the Vulkan Werke in Stettin to build it. It was given the designation T 18.