The E 927 was an electric locomotive for the Silesian mountain routes, which the Prussian State Railways ordered before the First World War. Due to the war, they were not put into operation until 1923, when the Deutsche Reichsbahn already existed. Their original designation was EG 571 ab to EG 579 ab, with the “ab” indicating that they were double locomotives.
The specifications stipulated that the locomotive should be able to pull 1,200 tonnes at a gradient of one percent and 500 tonnes at two percent, and at the same speeds that the steam locomotives of the time could reach. In order to meet these requirements, the then still new technology of the axle bearing single axle drive was used.
Both halves of the locomotive had a driver's cab in the middle, in front of which was a narrower hood with a transformer and other equipment. This arrangement restricted visibility considerably, since the driver could only look past the hood through narrow windows. Behind the driver's cabs were luggage compartments, which also contained some electrical equipment. The transition between the locomotive halves was closed with bellows.
In use on the Silesian Mountain Railway, the machines proved themselves despite the many gradients of up to two percent and tight curve radii of up to 184 meters. In February 1945 they were moved to Central Germany because of the approaching Soviet troops. After the war, eight of the nine examples came to the Reichsbahn, where they initially had to be handed over to the Soviet Union. After six returned, they were used until 1962.