UIC central buffer coupling
The UIC central buffer coupling is an automatic central buffer coupling which was developed in the 1960s as a replacement for the screw coupling commonly used on European railways . Because Europe was split into two political blocs at the time, two types of construction were developed under the leadership of the UIC on the one hand and the OSJD on the other, but they are compatible with each other.
It saves the laborious coupling work and makes it possible to move much heavier trains. For this reason, it is still in use today for ore transports for DB Cargo Deutschland AG .
history
The clutch is based on the model of the Soviet SA-3 clutch and thus the principle of the Willison clutch . In order to obtain a vertically rigid connection and to enable a simultaneous coupling of the air and power lines, the rigging organs with the line couplings are located under the actual Willison coupling.
Two versions of the new coupling that were compatible with each other were developed. In Western Europe, Unicupler GmbH, a subsidiary of Knorr-Bremse in Munich , developed the AK69e . VEB Waggonbau Bautzen developed the Intermat in cooperation with Soviet engineers for the OSJD area .
An essential difference to the SA-3 and also to the original Janney coupling is the vertical mobility with spring-loaded suspension necessary for the rigid principle. With the Intermat type, the spring is supported on a bracket below the head piece; with the Unicupler type, the coupling head rests on a spring-loaded slide rail in the head piece.
The development of a central buffer coupling for European standards began in 1955 by the Deutsche Reichsbahn and VEB Waggonbau Bautzen . The coupling to be developed should be able to be coupled with the type SA-3, it should also couple compressed air and later also electrical lines and be designed uniformly for passenger trains, freight wagons and locomotives. The requirement to connect lines caused the abandonment of the rigid principle of the SA-3 coupling. In 1963 the Soviet railways also took part and a joint design office was established. At around the same time, Western European railway administrations and manufacturers started work on a European central buffer coupling. From the beginning, however, it was clear that only a uniform design had a chance of general introduction. Both sides tried to persuade the other side to license their own patents for a fee. However, it was recognized that this would have increased costs even further. In 1968 it was agreed that both developments should be made compatible, that each side could use the patents of the other free of charge and that the costs of development should be distributed more widely. Up to this point in time these had practically only been raised by the DR and the SŽD.
In 1970, the clutches, which differed slightly in detail, had proven their operational reliability and stability as well as their compatibility both on test stands and in use. A Europe-wide introduction has been postponed again and again. Since the coupling is not compatible with the screw coupling without tools , a simultaneous change would have been necessary, which some member states could not manage financially. The mixed coupling, which was also developed as a system component, was only approved for shunting at the time. In the meantime, it has become suitable for train operations thanks to continuous use in Finland, where practically all mainline locomotives are equipped with SA-3s, but most of the wagons are equipped with screw couplings, and also when pulling ore trains in Germany and the Netherlands with locomotives without automatic couplings or during transfers from Ore wagons with coupling wagons proved. A simultaneous changeover would no longer be necessary.
The mixed coupling is inserted into the coupling head from above, locked by a pawl, the lug is placed over the towing hook of the vehicle with a screw coupling and brought into the lower position of the step plate to shorten it. To uncouple, the coupling head is unlocked in the usual way. This releases the mixed coupling, it hangs on the towing hook of the opposite vehicle. On the head of the vehicle with a central buffer coupling there is a receptacle onto which the mixed coupling is attached when not in use.
Parallel to the development of the couplings, new vehicles were prepared for the installation of the central buffer coupling. The floor frame had to be put in a position to absorb compressive forces in the central axis, at the same time it was necessary to abandon the continuous tie rod. At the same time, space had to be created for the spring device. One consequence of this was the reduction of the wheel diameter on the wagons from the original standard size of 1000 millimeters to initially 920 millimeters. The head pieces were also prepared for installation. These can be recognized by a box-shaped opening that is covered with a screw-in draw hook guide. After the changeover date has been finally set, the preparations should be made so that the changeover would have been possible without welding and cutting work. After the introduction of the central buffer coupling became increasingly unlikely in the 1980s, some manufacturers reduced the degree of preparation again (»reduced installation level«, recognizable by the continuous buffer beam). For reasons of space, different recordings were provided for locomotives, steam locomotives should no longer be converted.
In the meantime, many of the pre-equipped vehicles have already been taken out of service. The effort involved represents a lost investment of an unknown amount.
As a compromise, the Z-AK pulling coupling , which can be coupled with the screw coupling, was proposed, which is also derived from the SA-3 , but still requires side buffers and does not offer the advantages of a real central buffer coupling such as higher load capacity, better running safety and less wheel and buffer wear . Therefore, the Z-AK is now considered to have failed.
Since 2002, the C-AKv coupling, a simplified, full-fledged central buffer coupling, has been in trial use, which can be coupled to the screw coupling without an adapter.
Individual evidence
- ↑ Eberhard Hoffmann: Approval attempts with the automatic train coupling (Z-AK) . In: Railway technical review . tape 49 , no. 4 . Hestra Verlag GmbH & Co. KG, 2000, ISSN 0013-2845 , p. 222-230 .
Web links
- History and description of the Intermat
- Stefan Hagenlocher: Automatic coupling systems in rail freight transport - an overview. (PDF, 2.7 MB) hwh Gesellschaft für Transport- und Unternehmensberatung mbH, February 25, 2015, accessed on December 25, 2015 .
literature
- Kilian T. Elsasser: "The introduction of the automatic coupling requires long-term planning." - A story of the failure of the European railways . In: Monika Burri , Kilian T. Elsasser, David Gugerli (eds.): The internationality of the railroad 1850-1970 (= interferences - studies on the cultural history of technology ). tape 7 . Chronos, Zurich 2007, ISBN 3-0340-0648-9 ( PDF file; 0.5 MB [accessed January 5, 2012]).
- Erich Schmidt: The way to the European automatic central buffer coupling . In: Glaser's annals . No. 10 , 1965.
- Georg Link: The automatic central buffer coupling for railway vehicles in Europe before its completion . In: The Railway Engineer . No. 10 , 1969.