BSt type 1927
| TM 33, TM 34, TM 36 "Schützenwagen" |
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|---|---|
 Rifle car
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| Numbering: | 3301–3600 (originally) 3300–3355 (TM 33) 3801–3850 (TM 34) 3401–3594 (TM 36) |
| Number: | 300 railcars |
| Manufacturer: | C&U , AEG |
| Year of construction (s): | 1927-1929 |
| Axis formula : | Bo |
| Gauge : | 1435 mm ( standard gauge ) |
| Length: | 11,600 mm |
| Width: | 2,130 mm |
| Bogie axle base: | 3,600 mm |
| Empty mass: | 20.3 t |
| Hourly output : | 80 kW |
| Motor type: | Paw storage motor |
| Power system : | 600 V = |
| Power transmission: | Overhead line |
| Number of traction motors: | 2 |
| Coupling type: | Albert coupling |
| Seats: | 28–32 (depending on the version) |
The 1927 design, known as the "Schützenwagen" , is a series of 300 center-entry railcars, originally with contactor control , developed in 1927 by the Christoph & Unmack , Niesky and AEG wagon construction company and transferred to the Berlin tram company with other wagon construction companies until 1929. Betriebs-GmbH , a predecessor company of the BVG . Due to serious structural safety deficiencies in the braking equipment, the entire series had to be taken out of service in 1931. After a fundamental renovation between 1933 and 1938, the later BVG referred to the vehicle series, which now differ in their technical parameters , as TM 33 , TM 34 and TM 36 . The TM cars were the last tram cars that were used by BVG-West until 1967. At BVG-Ost, these cars remained in regular service until 1971. With a vehicle length of 11.60 m with an axle base of 3.50 m, they were the longest two-axle vehicles in Berlin.
prehistory
Following the pattern of many cities at the time, Berlin also received a ten-piece series of tram cars in 1926, which instead of the entry platforms previously located at the end of the car were now equipped with an entrance area in the middle of the car. Since the respective cars only had one driver's cab, they could only be used as a double train. They were therefore often referred to as twin railcars. In the 1930s, the twin trains were separated and the vehicles were used as a one-way car with the type designation TEM 26 after the left-hand entrance door had been removed .
The positive experience with the twin cars prompted the BSBG to commission a larger series of the center entry type in 1927. Both technical and transport policy reasons played a role. The car boom that started in the USA had already led to the dismantling of tram networks in the Roaring Twenties . The German companies wanted to increase the attractiveness and profitability of the company by increasing the comfort for the passengers. Another suitable measure was seen to be an increase in the average cruising speed and the transition to trains made up of several multiple units. Another purchase of vehicles was necessary in Berlin anyway, as the vehicle fleet of the Berlin tram was in some cases significantly outdated. Even the predecessor series T 24 / T 25, with 500 railcars and 800 sidecars the largest tram series ever procured in Germany, could not compensate for the lack of modern vehicles; In addition, its construction had to bend to the tight economic framework and was anything but technically advanced due to its weak engine and simple chassis-free design.
The rifle cars had a rifle control as an important novelty, which also gave this car series its name. With this type of construction, the traction motor current did not flow via the drive switch - as is usually the case - only the contactor control current, which controlled contactors (electrical remote-controlled high-voltage switches) in each railcar, via which the drive motor current then flowed. It was planned to form trains in this way, which would have consisted of up to three railcars (with possibly two interconnected sidecars). This was just as important in the inner city area as well as in the case of heavy excursion traffic, because now trains could be flexibly reinforced without restricting the driving and braking performance : each car was a railcar. The sidecars mentioned above were center entry low-floor sidecars of the later types BM 28/35 or 28/37, which were supposed to run in trains with up to five cars (three railcars with two interconnected sidecars), but this type of operation did not get beyond the test stage. For the passenger, the low height of the car floor of 650 mm above track and street level was particularly evident for the time. The powerful motorization with 40 kW per axle enabled these trains to achieve the required reduction in average travel times and the transport company to save staff and trains because the circulation was accelerated.
Disaster after constructive defects in the brake control
The vehicles did not prove themselves in operation. The new type of braking equipment in particular led to a disaster . The service and emergency braking took place with a so-called short - circuit brake , which was supported by sand scattering. An electrically operated spring-loaded armature caliper brake was used as the second braking device, which acted as a holding brake when a train stopped and when the train was disconnected. It replaced the conventional handbrake operated by a crank. However, the spring-loaded brake applied in the event of mains and control current interruptions. Exactly this type of brake was the fate of the rifle car. Because in the event of a power failure, all contactors opened . As a result,
- the electric brake could no longer be operated because the contactors were de-energized
- the spring brake applied
- the sand spreaders failed
- the train was completely beyond the control of the driver.
Applying the spring-loaded brake
- could not bring the wagon train to a standstill in a very short time, because the braking power was too weak for that
- was not adjustable: the axles blocked on slippery rails, the train slipped.
If the train was de-energized in a situation where it had to be braked, an accident could hardly be avoided. Since the Berlin tram was still running with roller pantographs that jumped off the catenary relatively often, there were subsequently spectacular accidents that were discussed extensively in the press, which completely ruined the reputation of these new vehicles in a short time. It even happened that passengers demanded the use of other types on “their” lines and sometimes drivers refused to do service on rifle cars.
At first they made do with not using these railcars solo, in the hope that at least one pantograph would remain on the catenary, but this procedure ultimately proved to be unsuitable, because if there was a power failure in the catenary or both rods jumped off, the train came back in an uncontrollable state, accidents continued to occur. In accordance with the philosophy of their design, these trams did not have a brake that is operationally reliable even in the event of a power failure, as is the case with the conventional direct control of the traction motors in connection with a handbrake operated via a crank.
In 1931, the BVG had to take all 300 rifle cars out of service. She was forced to continue using wagons from the turn of the century that were actually intended to be retired and which were still equipped with open platforms, which of course contradicted the image of modern city traffic. As a first replacement measure, the BVG built center-entry cars of the type TM 31U in its own workshop, in which parts of Berolina cars were installed, as well as the relatively new traction motors of the type U3l .
The TM car series
TM 33
All of the new "rifle cars" were parked in the depots. The disputes with the designer of the electrical equipment (AEG) and the planning for the necessary modifications lasted a year and a half, which were then carried out by mutual agreement between the BVG and the AEG.
The catalog of requirements provided for the installation of a service brake that was independent of the overhead line voltage, as well as a separate driving and braking circuit for each railcar in one go, which should, however, still be controlled by a driving switch. The switching principle of the traction motors should again correspond to the usual design. This requirement was best met by a two-car compound control with continuous high-voltage drive and braking circuits. All, up to four, drive motors could be controlled with one drive switch. This is why these cars were now called composite trains, with which up to two railcars could be controlled from one drive switch, the formation of three-car trains - as originally planned - was no longer possible. First, AEG converted six cars on a trial basis. Particularly noticeable were the heavy power cables at the ends of the car, as well as the driver's cab windows, some of which were covered with sheet metal and thus reduced in size, as larger power switches now had to be installed. The conversion proved itself, so that in the course of 1933 another 50 composite cars were converted and put into service, which were given the type designation TM 33. Due to a lack of money, however, the expensive renovation was initially canceled. These vehicles were summarized in the number group 3300–3355.
TM 34
Of course, the other new vehicles should also be made operational again. Therefore, other former rifle cars were converted. In contrast to the previous TM 33 series, the next cars only received a cheaper single control and could therefore be used either as a solo car or with a sidecar. It was also seen as necessary, in addition to the center entry doors, to install another exit door on the right front in the direction of travel. When there was a large number of passengers, the central platform “clogged” slightly, so the BVG returned to the end-entry car (series T 33 U ) in a later series of conversions . In addition, there were modifications to the interior. The TM 34 were intended to be converted to composite construction at a later date, but that never happened. The TM 34 types were in use under the numbers 3801–3850.
TM 36
With the Olympic Games , which were awarded to Berlin in 1936, the tram was supposed to represent itself to the world in a modern form. However, in order to be able to retire the remaining four-axle wagons with open platforms, new wagons were still required. The remaining 194 rifle cars were to be converted for this purpose. The most extensive modification was carried out on this car. Briefly described, this type of vehicle is a symbiosis of the TM 33 and TM 34 car series. These cars again received the integrated control system that has meanwhile proven in the TM 33. In terms of car construction, the vehicles were also equipped with a front exit door on the right-hand side based on the model of the TM 34 series. In contrast to the previous series, the cables on the car roof were also routed in a cable duct and the roof area was given a pleasing cladding that visually upgraded the car. At the same time, these vehicles were used for outdoor advertising on tram vehicles in Berlin. They also got the typical beige from the beginning, which was to be introduced across the empire as a uniform color scheme for all local transport companies. The TM 36 cars were assigned the numbers 3401–3594.
Post-war development
The Second World War was not without consequences for the rifle cars. 72 wagons, almost a quarter of the stock, had been destroyed. Many composite cars lost their control and were only on the road - like the TM-34 series - as solo cars. When the Berlin tram network began to be converted from pole to pantograph operation , the appearance of all TM cars changed from 1948 onwards. In the course of the division of Berlin after the currency reform and the division of the BVG into a western and an eastern administration, the car park also became the Berlin tram, which affected the TM cars of all three sub-series. West-BVG reinstalled the network control in all composite cars. In East Berlin, the TM wagons were not prepared for network operation again, because the spare parts for the new equipment would now have to be obtained from the west.
The BVG-Ost, on the other hand, adjusted the car series again from 1952. All cables were laid in roof ducts according to the TM-36 model for the TM 33 and 34, but the cladding was removed from the TM 36. The electrical equipment was also standardized and provided with GDR technology. With that, the rifle cars were similar to each other and could only be distinguished by the car number.
In West Berlin, the composite trains were used as in pre-war times. They were often on the move with sidecars of various series as three-car trains. The tram lines to Spandau were a focus of the operation . There the TM composite trains carried the main load of the traffic until the end of the West Berlin tram on October 2, 1967. In the last two years of operation in West Berlin, the BVG relied exclusively on this type of construction, with the exception of the few new post-war vehicles. In the eastern part, the TM cars were in passenger service until 1970, after which many have been converted to work cars. Most of the TM cars were the basis for the new "Reko" vehicles from BVG-Ost, although only parts of the electrical equipment could be taken over. The car bodies were new builds.
A few TM cars have survived as museum vehicles. They are looked after in Berlin by the Berlin Heritage Association (DVN), and some railcars run on museum railways in the USA.
literature
- Ralf Ball: The Berlin type 1927 center entry car . In: Monument Preservation Association for Local Transport Berlin e. V. (Ed.): Tram history (s). From 3 to 23 . Verlag GVE, Berlin 1995, ISBN 3-89218-033-4 .
- Heinz Jung et al .: The “Schützenwagen” . In: Berliner Verkehrsblätter . Volume 3, 1963.
