The DR Class 50.35-37 is a class of 208 2-10-0 "Decapod" type steam locomotives that were built for the railways in Germany in 1956.
History[]
At the end of the 1930s, it was decided that a more suitable boiler material was found, in the form of St 47 K-Mo steel, that would allow the boiler pressure to be increased up to a maximum of 20 bar without significantly raising the total weight of the boiler. The newly developed steel had a higher strength than the type of steel (St 34) used hitherto, but its disadvantage was that it had considerably worse conductivity.
In the harsh everyday work of steam locomotives, the material had became very quickly fatigued, so that boilers made of the new steel had to be replaced after only a few years. The Class 50, too, was given such a boiler to begin with. Even though its condition was less critical than with other classes, it urgently needed replacing by the end of the 1950s.
As a result of this, the Deutsche Reichsbahn of East Germany had the 50E replacement boiler developed on the basis of the new boilers equipping the Class 23.10 / 50.40, although because the locomotive frames were different it was given a 500 mm longer boiler barrel.
This was later used on the rebuilds (the so-called Rekoloks), which saw the conversion of Class 23 engines, as well as conversions of the Class 52s into 52.80s and the Class 58s into 58.30s.
Between 1958 and 1962, a total of 208 Class 50 locomotives were given such a boiler, along with a mixer preheater, a larger radiative heating area and improved suction draught, which also raised its performance. Many engines were also equipped with Giesl ejectors. These Reko locomotives were allocated to sub-class 50.35 and given operating numbers 50 3501 to 50 3708. In their last years of operation these engines often ran with the new 2'2' T 28 tenders.
The engines were soon gathered together in the railway divisions of the northwest. After the conversion of engines to oil-fired Class 50.50, the remaining coal-fired ones were concentrated in the Magdeburg division. Replacing older locomotives as well as oil-fired ones, they returned to the Dresden and Schwerin divisions again by the end of the 1970s. The last regular standard gauge steam train was hauled by a Class 50.35 locomotive.
This was number 50 3559, which headed an official farewell service on 29 October 1988 on a round trip from Halberstadt to Magdeburg, Thale and back to Halberstadt. No. 50 3559 is used in Liblar as a restaurant. There are several Class 50.35 locomotives, several of them still working, belonging to Deutsche Bahn AG and as well as the respective railways and railway museums, such as Nos. 50 3501, 50 3539, 50 3564, 50 3576, 50 3616, 50 3648, 50 3654, 50 3695 and 50 3708.