The firms of AEG and Borsig, who were the main manufacturers of these engines, together with Henschel, Hohenzollern, Krupp and BMAG previously Schwartzkopff, delivered a total of 231 examples of this Einheitsdampflokomotive between 1926 and 1938 for the fast passenger services of the Deutsche Reichsbahn.

Extensive measurement and trial runs were conducted, but after lengthy discussions the controversial decision finally fell in favour of the two-cylinder configuration, which was simpler to maintain but less powerful and less economical than the four-cylinder compounds.

The mass production of Class 01s was somewhat delayed at first because in the 1920s there were neither enough routes with the necessary axle load of 20 tons nor sufficiently large turntables.

To accommodate for the many routes with axle load restrictions too low for Class 01 service, in the early 1930s, a third variant was created: the Class 03 designed with a two-cylinder engine and axle load of 18 ton, of which no less than 298 were built.

Up to 1930, the first 90 engines were stationed at the locomotive depots of Essen, Nuremberg, Erfurt P, Berlin Ahb, Hamm, Magdeburg Hbf, Kassel, Hanover, Hamburg Altona, Bebra and Offenburg.

From 1931 they were also stabled at Frankfurt (M) 1, Berlin Leb, Braunschweig, Berlin Pog, Schneidemühl, Königsberg, Göttingen P, Paderborn, Dresden Alt, Breslau, Cologne Deutzerfeld, Hof and Halle P. Originally, the Class 01's top speed was restricted to 120 km/h.

The air and feed pumps were located in smokebox recesses behind the large Wagner smoke deflectors, which had been fitted from 01 077 onwards.

The Deutsche Bundesbahn converted their engines to the smaller Witte smoke deflectors and moved the pumps to the running board in the centre of the vehicle.

The Deutsche Reichsbahn in East Germany shied away from such major changes to the load distribution, so that only minor modifications in appearance can be seen even in their last years.

From 1962, the Reichsbahn repair shop (Reichsbahnausbesserungswerk) at Meiningen rebuilt 35 Class 01 engines for the DR under the direction of the research and trials division VES-M Halle.

All these locos were fitted with new Witte smoke deflectors with tapered edges, a new driver's cab and a new boiler, positioned higher on the frame.