Kunze-Knorr-Bremse
The Kunze-Knorr-Bremse (Kk-Bremse) is an automatically acting and multi-release compressed air brake for freight, passenger and express trains. It was the first multi-release air brake for freight trains in Europe. When it was introduced after the First World War, it was possible to replace driving with handbrakes on in various European countries, even on freight trains. The Reichsbahn alone put the cost of equipping German freight cars with the Kunze-Knorr-Bremse from 1918 to 1927 at 478.4 million Reichsmarks . The Reichsbahn put the savings in operating costs made possible by the acceleration of freight traffic and the saving of brake personnel at almost 96.3 million Reichsmarks annually.
In Kunze-Knorr-Bremse, suggestions from the Prussian senior building officer Bruno Kunze (1854–1935) and preliminary work by the founder of Knorr-Bremse , Georg Knorr (1859–1911), were implemented. It was the first continuous air brake with which the braking force could not only be gradually increased, but also gradually released, even in long freight trains. This is achieved by combining a single and a two-chamber brake cylinder to form a composite brake. The single-chamber brake cylinder generates the main part of the braking force, the two-chamber cylinder ensures multiple solutions.
The Kunze-Knorr-Bremse was developed in three versions for freight trains (Kkg), passenger trains (Kkp) and express trains (Kks). The version for freight wagons offers the option of switching between empty and load braking when the load changes. In addition to the control valve, the passenger train version was equipped with an acceleration valve to increase the penetration speed and the option to switch between freight trains and passenger trains ( GP change ), but no load change due to the significantly smaller proportion of the total mass of passenger coaches. The express train brake received more than 100% larger brake cylinder diameters to achieve braking. This made it possible to bring trains to a stop even at speeds above the 90 to 110 km / h usual up to then within the distant signal distance of 700 meters. In order to prevent the wheel sets from locking when the coefficient of friction increases as a result of the falling speed, the Kks brake also had an additional friction-dependent brake pressure regulator. When it responds, the braking is reduced to 80% of the vehicle mass and thus to the same value as the Kkp brake. Both brake cylinders form a structural unit with the KK brake together with the control valve. The installation and removal of this approximately 70 kg unit in the overhead position requires at least three employees and is the main disadvantage of the small bore brake.
The Kunze-Knorr-Bremse was developed and manufactured by Knorr-Bremse AG in Berlin . It was also produced by their subsidiary, Süddeutsche Bremsen-AG, at the current headquarters of Knorr-Bremse AG in Munich . Overall, z. Partly under license, around 550,000 control valves for Kunze-Knorr-Bremse are manufactured. From around 1924 and finally in 1925, all freight cars on the Deutsche Reichsbahn that were not yet equipped with a Kunze-Knorr-Bremse were withdrawn from service.
In the 1930s it was replaced by Hildebrand-Knorr-Bremse (Hik). In many places, for example in the case of non-modernized Deutsche Reichsbahn wagons , it remained in regular operation until at least the 1960s. In particular, museum vehicles with KK brakes are occasionally in operation; this type of construction is still approved.
literature
- Wilhelm Hildebrand, The development of the automatic single-chamber compressed air brake on European mainline railways . Berlin 1927.
- Jan-Henrik Peters, Personnel Policy and Efforts to Rationalize the Deutsche Reichsbahn-Gesellschaft between 1924 and 1929 . Frankfurt am Main u. a. 1996.
- Jan-Henrik Peters, efforts to rationalize the Deutsche Reichsbahn-Gesellschaft between 1924 and 1929 , in: Zeitschrift für Unternehmensgeschichte 41, 1996, 187–200.
- Manfred Pohl, safety on rails and roads. The history of Knorr-Bremse AG . (English edition: Safety First by Road and Rail. The History of Knorr-Bremse AG .) Munich 2005.
Web links
- http://www.knorr-bremse.com Website of the Knorr-Bremse Group
- http://www.bremsenbude.de Air brakes on rail vehicles
Individual evidence
- ↑ Reichsbahndirektion in Mainz (ed.): Official Journal of the Reichsbahndirektion in Mainz of August 16, 1924, No. 34. Announcement No. 739, p. 419 and of June 27, 1925, No. 34. Announcement No. 648, p. 383.