The vehicles were developed for night journeys and operations on the
North-South Railway. In order to increase the area of the
evaporator, the
boiler was increased in length to 3,080 mm and in diameter to 1,219 mm. In addition, the weight and the
boileroverpressure were raised. These were the first engines to have an outside
frame with outside
cylinders. This class was used widely, especially in
south Germany and in
Austria. All the engines bar one were retired by 1883. The survivor was initially converted to a
0-6-0, and later a
0-4-2wheel arrangement.