Einheitsdampflokomotive - Development

Development

Following the merger of the state railways (Länderbahnen) in Germany into the Reich railway in 1920 and into the Deutsche Reichsbahn-Gesellschaft in 1924, the locomotive fleet of the new national railway administration still had 210 different types and classes of steam engine. This considerably hindered the flexible employment of locomotives within the railway network, and servicing and maintenance was very costly as a result of the large number of different spare parts that had to be stocked. In addition, production tolerances of individual components were so small that, often, even components for the same class of locomotive could only be used after further finishing work had been carried out.

On top of that, substantial reparations as a result of the First World War, 1914–18, considerably reduced the rolling stock of the German railways without regard to the variety of classes. Thus out of the 33,000 locomotives in the fleet (as at 1917), 8,000 had to be handed over. There was therefore a need to build new locomotives and to introduce a sensible degree of standardisation in procuring these new engines.

To that end a locomotive standards committee was convened by the Reichsbahn. Even representatives of the locomotive industry took part in this standardisation process. Initially the question was posed as to whether proven state railway classes should continue to be built or whether new, modern locomotives should be developed and ordered. Because the basic concepts for the new locomotives had not been decided, however, and in order to give the locomotive factories follow-on orders, it was decided in 1921 to continue to build proven state railway classes to begin with. These classes were given new Reichsbahn classifications. Amongst them were the Prussian P 8 (Class 38.10), the Prussian P 10 (Class 39), the Prussian G 12 (Class 58.10) and the Prussian T 20 (Class 95), all of which continued to be manufactured until 1925. The Bavarian S 3/6 (Class 18.5) was even procured right up to 1930. The Prussian G 12 (Class 58.10), which was not developed until 1917, effectively counted as the first German Einheitslok, because it was employed by almost all the state railways and built by several locomotive factories across the whole Reich.

Technical and economic factors, as well as the Reichsbahn's aim of improving main lines to handle a standard axle load of 20 tons, led to the decision to develop new types of locomotive. After heated debates in the locomotive committee (e.g. about the design of the boilers and fireboxes as well as the choice between two-cylinder layouts or four-cylinder compounds), the design principles and a programme for the development of standard Deutsche Reichsbahn locomotive classes emerged, of which the first were built in 1925. Playing a decisive role in these discussions was the head of the Grunewald Locomotive Research Office at that time, Richard Paul Wagner.

In fact the production of engines in the desired quantities could not be achieved at first, both for economic reasons and due to delays in the improvement of routes to take the higher axle loads. Of the classes with a 20 ton axle load - 01, 02, 43 and 44 - only small pre-production numbers were procured at first. Up to the end of the 1930s the state railway classes, taken over or re-ordered by the Reichsbahn, dominated the scene, in particular those of Prussian stock. The delay to the upgrade of routes also meant that additional classes with lower axle loads had to be developed, e.g. the classes 03 and 50.

In spite of the Deutsche Reichsbahn's ambitious plans, their actual acquisition of locomotives, even from 1925 onwards, only reached about one tenth of the average procurement quantities for the years 1914-1920 and it remained at this level until 1938. The causes of this were the world wide economic crises and the resulting reduction in demand for Reichsbahn's railway services. Not until 1930 was the 500th standard locomotive built (2% of the total fleet), in 1934 the 1000th engine was delivered (4% of the total) and in 1938 there were 1,500 Einheitsloks in existence (6% of the total).

Not until 1939 did the procurement quantities rise significantly. With the introduction of a production programme for simpler goods train locomotive designs, that led into the construction of the war locomotives (the Kriegsloks), engines with an axle load of 15 tons were built in significant quantities. Now, however, there was a different objective: supporting the conduct of the war. So by 1945 the total number of standard and war locomotives had climbed to about 14,500 (33% of the total fleet).

This state of affairs stood in stark contrast to the image promoted by the Deutsche Reichsbahn, that wanted to give the impression of a modern railway administration through its railway exhibitions, record speed runs, the introduction of the SVT network and proud photographic news reports. In fact the low level of procurement was responsible for the fact that the average age of the locomotive fleet continued to rise in the years from 1925 to 1938.