Passenger car E4 K.W.St.E.

The fourth class was introduced in South Germany following pressure from Prussia at the timetable change on May 1st, 1907. Württemberg initially managed the conversion of older third-class carriages. The first rebuilt carriages for the fourth class were put into service from 1908. 265 such carriages were made until 1912, and afterwards a further 130 until 1914 with minor changes to the drive and the lighting. The prominent difference between both type series was the number of gas containers under the carriage floor; the older series had one and the newer series two.