The E 79 series comprised only two locomotives that were ordered by the Bavarian Reichsbahn group administration in 1923 to cope with the increased freight train weights on the Freilassing-Berchtesgaden route. Due to technical problems during development and production, they were not delivered until 1927 and were given the new Reichsbahn designation instead of the Bavarian designation EG 4. The body construction part came from Maffei in Munich and the electrical equipment was developed by Pöge Electricity AG in Chemnitz.

In order to be able to master the up to four percent steep inclines, the design envisaged heavy loomotives with a 1-C-1 wheel arrangement. However, since the necessary electrical equipment turned out to be significantly heavier than originally thought, the design was changed to the 2-D-1 wheel arrangement. Despite the two additional axles, the axle load reached almost 20 tonnes. The bogie was connected to the first coupled axle with a Krauss-Lotter bogie and the trailing axle was guided in a Bissel truck. Power was provided by two high-speed electric motors whose speed was reduced by a common reduction gear. This in turn transferred the power to two jackshafts, which finally drove the four axles with 1,250 mm wheels via coupling rods. 

In addition to freight trains, the two locomotives were also used to pull passenger trains, whereby the low power compared to other modern electric locomotives was noticeable. However, since they still had an adhesive weight of almost 80 tonnes, they were increasingly used as pusher locomotives on the steep and winding route. In the years that followed, the two machines were not really convincing in operation. In addition to the small number of locomotives, the procurement of spare parts was made more difficult by the fact that Pöge was not one of the typical companies that supplied assemblies for Reichsbahn locomotives. In addition, one of the two locomotives stood out in particular with excessively frequent defects. After delivery of the considerably lighter and nevertheless more powerful E 44, the two E 79s could be dispensed with and they were retired in 1941 and 1942 respectively.