 Although there was already a very powerful locomotive for operations on the mountain lines in the Ore Mountains ("Erzgebirge") of eastern Germany in the shape of the ten-coupled ex-Saxon Class 99.67-71, there was a further requirement for an even more powerful class.So it fell to the newly formed Reichsbahn railway division of Dresden to procured an "Einheitslok" with a track gauge.The Standardisation Office of the German Locomotive Union in Berlin-Tegel prepared the design for this class.