DR series ET 125
| DR series ET / EB 125 DR series ET 166, 276 DB series 477 |
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 ET 166 047 in the Erkner railcar hangar
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| Numbering: | DR: 4501–4518 / 8501–8518 DR ET / EB 125 001–018 DR ET / EB 166 035–052 |
| Number: | 4 + 10 + 4 |
| Manufacturer: | wagenbauig ET: O&K ; EB: Wegmann electrical ET: SSW , AEG ; EB: SSW |
| Year of construction (s): | 1935, 1936, 1938 |
| Retirement: | until 2003 |
| Axis formula : | Bo'Bo '+ 2'2' |
| Genre : | C4 esT + BC4 es |
| Gauge : | 1435 mm ( standard gauge ) |
| Length over coupling: | 35,460 mm |
| Length: | ET: 17,300 mm EB: 17,000 mm |
| Trunnion Distance: | 11,800 mm |
| Bogie axle base: | 2500 mm |
| Service mass: | 72.3 t / 70.1 t / 67.3 t |
| Friction mass: | 40.8 t |
| Wheel set mass : | 13.1 t / 12.6 t / 12.3 t |
| Top speed: | 120 km / h |
| Hourly output : | 560 kW |
| Driving wheel diameter: | 900 mm |
| Impeller diameter: | 900 mm |
| Power system : | 750 V = |
| Power transmission: | Lateral power rail coated from below |
| Number of traction motors: | 4 (GBM710) |
| Coupling type: | Scharfenberg |
| Seats: | 121/120/119 |
| Floor height: | 1100 mm |
The ET 125 series, called from 1941 onwards , later adapted to the 276.0 (DR) and 277 (477) series, were electric multiple units that were used for a particularly fast S-Bahn connection in the direct current network of Berlin 1934/35, 1936 and 1938 were built. The wagons were popularly known as bank trains . After the war, at the end of which the high-speed journeys were discontinued and not resumed, they were rebuilt and adapted to the ET / EB 166 series. Among other things, they lost the more powerful traction motors in 1949/50. From the 1970s they were included in the modernization program and converted into the 277 series (after 1991 477/877). In this condition they ran on the Berlin S-Bahn network until 2003.
history
With the conversion of the Wannsee Railway to electrical operation in 1933, the banker trains between Potsdamer Bahnhof and Wannsee were also to be operated electrically. The banker trains were suburban trains that ran without stopping between the Potsdam (long-distance) train station and the Zehlendorf train station and continued with a stop to the southwestern villa suburbs of Berlin and ended in Wannsee.
In Zehlendorf, the banker trains stopped at the platform of the main line . South of the station they switched to the suburban tracks of the Alte Wannseebahn, the section via Zehlendorf West (today Mexikoplatz ), Schlachtensee and Nikolassee to Wannsee, in order to stop at every station in these villa suburbs.
A bridge structure was built to transfer the trains coming from Wannsee towards Berlin over the main tracks at Zehlendorf station, after initially there was only an intersection at the same level.
The banker trains were an additional service offered by the railway during rush hour business trips to the Wannsee railway. In the Potsdamer Bahnhof – Zehlendorf section, they ran on the long-distance tracks in mixed traffic with, among other things, the Berlin – Magdeburg express trains.
As part of the electrification of the Wannsee Railway in 1933, it was only logical to switch the steam-powered bank trains , which had been in service since 1903, to electrical operation. Therefore, the tracks of the main line used by the banker trains (including the connecting tracks in Zehlendorf) were switched to electrical operation.
Furthermore, a new vehicle series had to be created with which on the one hand the travel speed could be increased significantly on the section from Potsdamer Bahnhof to Zehlendorf , on the other hand the section from Zehlendorf to Wannsee could also be used in mixed traffic with conventional S-Bahn trains.
In accordance with these requirements, a test train consisting of four quarter trains was initially created (type 1934, delivered in 1935; DR numbers esT 3796 / es 6308, esT 3797 / es 6306, esT 3798 / es 6309, esT 3799 / es 6307; from 1936 esT 4501–4504 / es 6501–6504; from 1938 esT 4501–4504 / es 8501–8504; from 1941 DR numbers ET / EB 125 001–004). This was followed by a series of ten quarter trains (type 1935 a, delivered in 1936; DR numbers esT 4505–4508 / es 6505–6508; from 1938 esT 4505–4514 / es 8505–8514; from 1941 DR numbers ET / EB 125 005 –014) and another four quarter trains in 1938 (type 1937 I, DR numbers esT 4515–4518 / es 8515–8518; DR numbers ET / EB 125 015–018). All three series were designed for a top speed of 120 km / h.
There is no evidence for the claim, which is often widespread in secondary literature, that the trains were designed for a significantly higher speed of more than 120 km / h. The Deutsche Reichsbahn subjected the quarter trains to extensive testing. Among other things, she examined the interaction of pantographs and busbars at high speeds as well as the travel lock device. With the last series delivered, the Deutsche Reichsbahn attempted inductive train control on the main railway tracks around 1939/40 .
The maximum speed of up to 120 km / h was approved from 1938 for two car trains of the type 1935 a (the third circuit was a train for 80 km / h, which only drove on the banker route in the morning) and could only be used on the long-distance tracks between Potsdam Train station and Zehlendorf are driven. In 1939 there were 14 train journeys into town (in the morning even every twenty minutes), while out of town there were only seven train journeys every hour in the afternoon. This express service was operated until the beginning of 1945.
From 1941 the series were designated as ET / EB 125. The trains of the ET / EB 125 series were not only used on the accelerated circuits, but also in normal S-Bahn traffic on the Wannseebahn.
In 1949 the ET / EB 125 series was adapted to the ET / EB 166 series and received, among other things, the usual GBM 700 type traction motors with an output of 90 kW. They were classified as ET / EB 166 035 to 052 in the order in which they were converted. In 1970 the cars were renamed the 276.0 series. Almost all of them were based in the Wannsee depot in what was then West Berlin. However, the number of the 276 series and thus the number of "banker trains" in the Wannsee depot had already been reduced significantly since the beginning of 1979. After the Berlin S-Bahn strike in 1980 , the remaining trains were withdrawn from the Wannsee depot and used in the eastern part of the city from then on. At the Reichsbahn repair shop in Schöneweide, they were reconstructed together with the other vehicles of the 276.0 series and assigned to the 277 series (from 1992: 477/877). The test train of the type 1934 was excluded from this because of the different bases.
Whereabouts
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Two quarter trains from the test train from 1935 have been preserved:
- A motor car and a sidecar (276 035/036 ex ET / EB 125 001) were bought by a private person in the early 1990s. Railcar 276 035 went on permanent loan to the German Museum of Technology in Berlin in 1994 . The sidecar was parked in the Hundekehle railcar hangar until November 2016 and then in the Wendisch Rietz railway park. On September 6, 2019, the 276 036 sidecar also arrived on loan at the Museum of Technology. So now the complete quarter of the first sample train of the banker type is there.
- The other quarter train was looked after by the Historical S-Bahn Berlin Association (276 031/032 ex ET / EB 166 047 ex ET / EB 125 003), but scrapped in 2016 due to its poor condition and lack of preservation options. Only the driver's cab head of the railcar, which is placed on the outer wall of the Twh Erkner, has been preserved.
technical features
In terms of the basic operational, wagon construction and electrical design, the ET 125 largely corresponded to the two Wannsee ET 165.8 test quarter trains delivered in 1933 . However, the car body and bogies were completely welded constructions (with the sheet metal walls still being riveted in), and the end of the car was given a round, more elegant head shape. As with the mentioned test quarter trains, the car body was lengthened slightly over the head pieces of the floor frame without becoming longer in terms of overall dimensions compared to other S-Bahn series. Only railcars and sidecars were built, the control cars that were initially envisaged were dispensed with.
The Reichsbahn tested various components on the 1934 design: American gooseneck bogies (converted to standard bogies in 1936), festoon and pearl chain lighting (later converted to the standard version with opal glass lamps), normal heating and suction ventilation as well as warm air heating with combined ventilation (around 1940, normal heating and Suction ventilation converted), load-dependent braking system (later removed), damping device to improve the smoothness of running on straight stretches (in favor of damping buffers at the close coupling end). The four quarter trains of the test train were not fully operational until 1940 because of many technical defects.
Slightly modified car bodies (slightly changed dimensions, more pleasing front with better proportions) were given to the 1935 a series and the almost identical Olympic trains of the 1935 series ( DR series ET 166 ). The Deutsche Reichsbahn tested bogies with a larger wheelbase of 2600 mm (instead of 2500 mm) on them, but this did not result in better running smoothness, which is why the normal version was returned to later series. The load-dependent brake also did not prove itself here.
The types 1934, 1935 and 1935 a had a separate driver's cab door on the Beimann side. In later series of pre-war production (as in the case of types 1937 I and II), this was again dispensed with because, among other things, the staff complained of penetrating wind.
In order to enable a top speed of 120 km / h, the banker trains had GBM 710 drive motors with 140 kW hourly output instead of the GBM 700 with 90 kW as in the ET 165. The increase in speed was not achieved by changing the gear ratio, but by an increase in the motor speed with simultaneous field weakening is achieved (1200 revolutions per minute instead of 800). In addition, the control was changed from broken approach (ET 165) to a half-broken one.
See also
literature
- Historic S-Bahn eV (Hrsg.): Trains of the Berlin S-Bahn. The elegant round heads . GVE, Berlin 2003, ISBN 3-89218-477-1 .
- Carl Wilhelm Schmiedeke: The car park of the Berlin S-Bahn . Lokrundschau-Verlag, Hamburg 1997, ISBN 3-931647-05-6 .
Web links
- List of the surviving S-Bahn vehicles of the historical S-Bahn Berlin association
- S-Bahn-Galerie.de - ET 125 series - Bankier type
Individual proof
- ^ Olaf Hackhausen: LOK Report - sidecar from the bank train prototype arrives in the DTM. Retrieved September 7, 2019 .
- ↑ News in brief - museums / vehicles / associations . In: Berliner Verkehrsblätter . No. 12 , 2019, pp. 250 .