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Blog- Ze German way ov railways - Five-Coupled Jack of All Trades: Deutsche Bundesbahn class 50 steam locomotive from Roco

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Evening all!


As the first posting related to what I'd like to call the "Glorious Heritage" department, I should like to introduce you to a model of the class 50 steam locomotive, which, while designed as a freight locomotive, proved itself to be one of the most versatile and well-designed steam locomotives to have been rolled out in Germany. First introduced before World War II, it continued providing much-needed motive power service after the war, and not only in Germany but also in neighbouring countries.


Being part of the locomotive family commonly designated as „Einheitslokomotiven“, this class shared numerous fundamental design properties with other contemporary classes, beginning with the very capable class 01 4-6-2 express locos first introduced in 1925. This series of locomotives, which would eventually cover pretty much all areas of operation from fast mainline passenger to branch line and shunting work, was intended to replace large numbers of older locomotives inherited from the numerous German state railways which existed before being grouped into Deutsche Reichsbahn in 1924. Of course, there would eventually turn out to be various problems during this process, part of which can most certainly be attributed to the global economic troubles which occurred from the late 1920s onwards. Specifically, permanent way projects such as rebuilds of older lines to allow for greater axle loads would frequently suffer from long delays, which eventually resulted in various amendments to the Einheitslokomotiven procurement programme. Two cases in point would be those of the previously mentioned class 01 express locos and mighty class 44 2-10-0 three cylinder freight locos, both of which had a somewhat limited route availability due to its axle load of 20 tonnes. Consequently, additional types such as the class 03 4-6-2 express locomotives and the class 41 2-8-2 universal engines needed to be developed, none of which were to exceed an axle load of 18 tonnes.


As a matter of fact, the class 50 2-10-0 locomotives were another of these types which were intended to obviate the problems raised by lacking progress in route modernisation. On the other hand, as the Nazi government was getting the country into gear for what would eventually erupt into World War II, this class was explicitly meant as a precursor to later Austerity designs, of which the class 52 2-10-0 locos introduced from 1942 onwards would turn out to be the most numerous. This class was, in fact, a direct derivative from the 50, with various design simplifications to allow for easier maintenance and higher production rates.


Production of the class 50 locomotives commenced in 1939, and would, in fact, continue after the war. In all, 3,164 locomotives were built, and would soon prove to be an important asset for the post-war German railways and several neighbouring countries. Deutsche Bundesbahn took the largest share of the 50 fleet, having 2,159 of these engines available, while the GDR‘s Deutsche Reichsbahn ended up retaining only 350 of them. Consequently, the post-war Reichsbahn was much more dependent on the 52s, of which a significantly larger number was available, and which were used much longer than these locos had originally been meant to. Due to being an Austerity design, the 52s were essentially considered to be expendable from the beginning, and would most likely have been quickly replaced by non-Austerity designs, had Nazi Germany been victorious and the war ended within the then-expected timeframe.


Given the 50‘s importance and potential, the post-war period even saw a number of further improvements added to the already sound basic design, though some of these should be considered experimental and were eventually not implemented in large numbers. Deutsche Bundesbahn, for example, had 31 locos fitted with a Franco-Crosti type preheater, which were designated as class 50.40, meaning they were given running numbers in the 4000 range. In 1959, ten locos were also fitted with smaller grates in an attempt to evaluate whether this would also decrease coal consumption and how this might impact the locos‘ operational performance. While these Crosti engines achieved a 22% decrease in coal consumption, the preheaters proved to be strongly affected by corrosion within just a few years, leading to all 31 locos having to be temporarily withdrawn in 1961. As the repairs turned out to be very costly, no further Crosti rebuilds were ever applied to any DB steam engines. In addition, 50 1503, one of the Crosti rebuilds, was also fitted with a Giesl type chimney.


When computer-formatted running numbers were introduced in 1968, there was the problem of how four-digit consecutive numbers could be integrated into the new system, which allowed for three-digit class numbers and consecutive numbers only. Eventually, it was decided that the first digit of the consecutive number should be merged into the class number. In practice, this meant that locos with a consecutive number between 1000 and 1999 now appeared to be designated as class 051; those in the range from 2000 to 2999 ended up being designated as class 052; and those in the 3000 range were designated as 053.


Meanwhile, Deutsche Reichsbahn treated 208 of their 50s to the well-known „Reko“ programme, which saw these locos fitted with the newly designed Type 50E boiler and a variety of other modifications such as a mixing preheater, larger radiating surface and improved drafting gear. Also, many of these „Reko“ 50s, which as a whole were referred to as class 50.35, were fitted with Giesl chimneys. As was generally the case with the Reichsbahn‘s Reko engines, performance was significantly improved.

Seventy-two 50.35s were converted to oil firing between 1966 and 1971, and were summarily withdrawn in 1981 due to soaring fuel oil prices. These locos were known as class 50.50.


In addition, Deutsche Reichsbahn also went down the same route they – and Deutsche Bundesbahn, in an odd case of parallel development – had chosen when they decided to obtain an evolved version of the class 23 2-6-2 passenger engines which was based on a design first presented in 1941, but of which only two pre-production locos were ever built due to wartime circumstances. As it were, Deutsche Reichsbahn thus ordered a similarly refined version of the 50, which was designated as class 50.40. Eighty-eight engines were built from 1956 till 1960, featuring newly designed boilers similar to those used on the various „Reko“ engines, and were also coupled to newly designed tenders.


Speaking of tenders: One of the most interesting upgrades carried out on a large batch of Bundesbahn 50s involved their tenders being rebuilt to carry a guard‘s cabin to the rear of the coal bunker, which obviated the need for a guard‘s van to be consisted in. This cabin was fully enclosed and featured heating as well as a seat and a desk for the guard, and also was sufficiently lit for the guard to be able to handle paperwork. In all, a total of 735 tenders were thus rebuilt, which of course did take away some coal capacity. Similarly, the Austrian Federal Railways converted a large batch of their 50s to cabin tenders. In my understanding, freight trains in post-war Germany but were required to carry a guard only in certain cases, and not to serve as a brakeman as most, if not all, wagons were fitted by that time. Thus, guards were mainly there to provide for an additional set of eyes to be kept on the train, and also in order to assist when shunting was required at any time during the loco‘s turn – such as on the numerous trip freights and pickup workings which still existed in the 1950s and 1960s.

The last Bundesbahn 50s, which had been allocated to the Wedau depot in Duisburg, were retired in 1977, which was the year when scheduled steam operation ceased in West Germany. Meanwhile, Deutsche Reichsbahn continued operating these locos until 1987.


As previously mentioned, the 50 was part of the „Einheitslokomotiven“ family, and thus followed the same set of design principles as several other contemporary types. Common features within this locomotive family included sectional frames, long boilers with large contact heating area, generously dimensioned superheaters and smokeboxes, piston valves and Heusinger valvegear, and standardised bogies, boiler sections and cabs for higher maintenance efficiency. The 50 in particular was designed as a 2-10-0 or 1‘E configured locomotive with a two-cylinder superheated engine, which in turn featured cylinders with a 25.9“ (660 mm) stroke and 23.6“ (600 mm) bore. The boiler had 113 fire tubes with a length of 17‘ (5.2 metres) and 35 flue tubes; a grate area of 41.9 square feet (3.89 sq. metres), superheater surface of 742 sq. ft (68.94 sq. metres), and evaporation surface of 177.83 sq. metres (1,914 sq. ft). Boiler pressure was set at 16 bar (232 psi), and engine output was indexed at 1,625 hp. Brakes were a single-lapping indirect Knorr design with settings G and P and direct loco brake controls.


As the 50 was explicitly meant to also work branch lines, where turntables were not normally available, it was designed such that its top speed of 80 kph (50 mph) was available both forward and in reverse. This also resulted in a bulkhead with windscreens on both sides being installed on the tender towards the rear end of the cab, in order to protect the engine crew from the weather when running in reverse.

The tenders used with this class in DB service included the standardised 2‘2‘ T 26 type with a water capacity of 26 cubic metres (5,719 gallons) and two four-wheel bogies, as well as the so-called „tub tender“ with a tub-shaped, self-supporting water bunker, which was created during World War II to save building materials. This kind of tender, while lacking some water capacity due to the shape of the bunker, continued to be widely used in the post-war period, and with a variety of classes.


Technical specifications


Configuration – 1'E h2, G 56.15

Overall length and height – 22.94 m and 4.5 m (75.3 ft and 14.8 ft)

Overall wheelbase – 9.2 m (30.2 ft)


Service weight (without tender) – 86.9 tonnes (85.5 long tonnes)

Adhesion weight – 75.3 tonnes (74.1 long tonnes)

Axle load – 15.1 tonnes (14.9 long tons)


Rated power output – 1,625 hp


Driver diameter – 1,400 mm (55.1 in)

Carrying wheel diameter – 850 mm (33.5 in)


Bore and stroke – 600 x 660 mm (23.6 x 26 in)


Boiler pressure – 16 bar

Grate area – 3.89 sq. m (41.9 sq. ft)

Superheater surface – 68.94 sq. m (742.1 sq. ft)

Vaporisation surface – 177.83 sq. m (1,914.1 sq. ft)


Braking gear – Single-lapping Knorr brake with settings G and P and direct shunting brake (K-GP mZ)



The model is certainly one of the longest running to be produced by Roco, with the first class 50 model having been released in 1992. There have been dozens of variants to have been produced over the years, representing pretty much all eras and a broad selection of the countless varieties which I suppose are a natural result of a class to have been built in the thousands.


Even today, the model represents a high standard of detailing for a RTR steam locomotive, and has been re-tooled several times over its long total production period. As there are various 50s – and 52s, not to neglect this sister class – to have been preserved, I felt like this class would be a good choice for representing a heritage locomotive which could see service not only on railtours and charters. Rather, 52 4867 of the Frankfurt Historic Railway Association has been known to work PW material services on various occasions in order to earn some additional money for their owners, so the idea of putting a preserved locomotive to work in revenue service was just as appealing.


Furthermore, there is a broad range of aftermarket detailing parts for steam locomotives like the Roco 50, so I may well decide to enhance it further some time, using some Weinert bits or possibly RP-25 wheelsets.


However, one key criterion for me had been to obtain one of those models representing a 50 with cabin tender, if at all possible. And indeed, it had been possible.


The specific model I obtained was offered with reference #43294, and as purchased was lettered as 052 440-5.






First of all, have a look at the locomotive from the fireman's and engineer's side respectively. As you can see, the locomotive is marked as 052 440-5, so that if you remember the peculiarities of numbering this class which was built in more than 3,000 examples, the loco's original identity used to be 50 2440.






To allow for adequate curve running abilities, the driving wheels on the model can displace laterally, broadly mirroring the chassis configuration on the real 50 where the leading wheelset and the first set of drivers were grouped into a Krauss-Helmholtz bogie, and where the fifth set of drivers could also displace laterally. Furthermore, the third set had thinned flanges.


Note that 50 2440 – sticking to its "actual" identity – is presented after being outfitted with the Indusi train protection system, with the transceivers being attached immediately below the cab on either side of the locomotive in order to ensure Indusi functionality in both directions.





This broadside view should give you an idea of the peculiar cabin tenders, most of which were rebuilt from standard 2'2' T26 type tenders. It is worth noting that these tenders were exchanged between locomotives with some degree of frequency. Without the guard's cabin, the coal bunker extended further aft, roughly above the third wheelset.


Also note that – as was standard on all 50s – the cab was fully enclosed for weather protection in both directions. Depending on the tender type, the rear cab bulkhead was either part of the tender's body – as is the case with the cabin tender – or of the cab assembly proper. The latter solution needed to be adopted on those 50s coupled to tub tenders.


It is common on most Roco tender locomotives that the motor is located in the tender, driving the tender wheelsets which therefore cannot be set up as actual bogies. On many – especially older – 50 variants, the motor also powers the locomotive's wheelsets through a drive shaft across the gap between the locomotive and tender.





The 50's front view is most visibly characterised by the cylinder blocks and the Witte type smoke deflectors. It is worth mentioning that the add-on parts for the model include a drawbar with integrated coupler pocket which you can install on the locomotive's front end to allow for full bi-directional operation.





The "other face" at the rear end of the tender is in turn characterised by the large windscreens of the guard's cabin. On this end, a coupler pocket is available by default.




And finally, a pair of semi-top-down views on the locomotive from the fireman's and engineer's side respectively. As these photos put focus on the extensive boiler armatures, I might point your attention to the sand and steam dome configuration, of which there were numerous variations during the 50's production run.


Those locomotives built from approximately 1942 onwards were explicitly intended as a transitional design between the basic 50 and the 52, which, as mentioned further up, was an Austerity design closely related to the 50. As such, those 50s built from that point already comprised various design simplifications which were intended to become standard on the 52s. These included items like the deletion of the first pair of cab side windows and smoke deflectors, smokebox support skirt, or the introduction of full disk wheels on the carrying wheelset. The dome design and arrangement also began to vary during that time, generally gravitating towards a smaller number of domes, and a more angular dome shape which was more easily fabricated. It would but far exceed the scope of this posting to call out each and every of these modifications in detail.








Once again, thanks for reading and I hope you found this little profile informative!


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