The Kunze-Knorr brake (''Kunze-Knorr-Bremse'' or ''KK-Bremse'') is an automatic

compressed-air brake A railway air brake is a railway brake power braking system with compressed air as the operating medium. Modern trains rely upon a fail-safe air brake system that is based upon a design patented by George Westinghouse on April 13, 1869. The We ...

for goods, passenger and express trains. It was the first graduated brake for

goods trains A freight train, also called a goods train or cargo train, is a railway train that is used to carry cargo, as opposed to passengers. Freight trains are made up of one or more locomotives which provide propulsion, along with one or more railroad ...

Europe Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...

. When it was introduced after the

First World War World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...

, goods train brakes switched from hand operation to compressed-air in various European countries. The

Deutsche Reichsbahn The ''Deutsche Reichsbahn'' (), also known as the German National Railway, the German State Railway, German Reich Railway, and the German Imperial Railway, was the Weimar Republic, German national Rail transport, railway system created after th ...

alone put the cost of equipping German goods wagons with Kunze-Knorr brakes between 1918 and 1927 at 478.4 million

Reichsmark The (; sign: ℛ︁ℳ︁; abbreviation: RM) was the currency of Germany from 1924 until the fall of Nazi Germany in 1945, and in the American, British and French occupied zones of Germany, until 20 June 1948. The Reichsmark was then replace ...

s. The operating cost savings from faster goods services and having fewer brakemen was assessed by the Reichsbahn at almost 96.3 million

annually.

Inventors

The Kunze-Knorr brake brought together the ideas of Prussian senior surveyor, Bruno Kunze (1854–1935), and preparatory work by the founder of

Knorr-Bremse Knorr-Bremse AG is a German manufacturer of braking systems for rail and commercial vehicles that has operated since 1905. Other products in the company's portfolio include intelligent door systems, control components, air conditioning system ...

, Georg Knorr (1859–1911). It was the first, continuous, compressed-air brake that, even on long goods trains, enabled the brake force not only to be applied gradually, but also released again gradually. By combining a single-stage and a two-stage brake cylinder with a compound brake a significant increase in brake effort was achieved.

Brake versions

Three versions of the brake were developed: for goods trains (KKgbr), passenger trains (KKpbr) and express trains (KKsbr). The goods wagon variant offered the option of switching between empty and loaded braking. The passenger train version was given an accelerator valve (''Beschleunigungsventil'') as well as a control valve. The express train brake had, in addition, a brake pressure regulator in order to prevent the wheels locking when braking quickly.

Knorr-Bremse

The Kunze-Knorr brake was developed and manufactured by the firm of Knorr-Bremse AG in

Berlin Berlin ( ; ) is the Capital of Germany, capital and largest city of Germany, by both area and List of cities in Germany by population, population. With 3.7 million inhabitants, it has the List of cities in the European Union by population withi ...

. It was also produced by their subsidiary company Süddeutsche Bremsen-AG at what is nowadays the head office of Knorr-Bremse AG in

Munich Munich is the capital and most populous city of Bavaria, Germany. As of 30 November 2024, its population was 1,604,384, making it the third-largest city in Germany after Berlin and Hamburg. Munich is the largest city in Germany that is no ...

. A total of about 550,000 Kunze-Knorr brake control valves were made, some under licence. In the 1930s they were superseded by the Hildebrand-Knorr brake (''Hik'' brake). In many places, including the

East Germany East Germany, officially known as the German Democratic Republic (GDR), was a country in Central Europe from Foundation of East Germany, its formation on 7 October 1949 until German reunification, its reunification with West Germany (FRG) on ...

, they were still regularly in use until the 1960s.

Literature

Wilhelm Hildebrand, Die Entwicklung der selbsttätigen Einkammer-Druckluftbremse bei den europäischen Vollbahnen. Berlin 1927. Jan-Henrik Peters, Personalpolitik und Rationalisierungsbestrebungen der Deutschen Reichsbahn-Gesellschaft zwischen 1924 und 1929. Frankfurt am Main u.a. 1996. Jan-Henrik Peters, Rationalisierungsbestrebungen der Deutschen Reichsbahn-Gesellschaft zwischen 1924 und 1929, in: Zeitschrift für Unternehmensgeschichte 41, 1996, 187–200. Manfred Pohl, Sicherheit auf Schiene und Straße. Die Geschichte der Knorr-Bremse AG. (engl. Ausgabe: Safety First by Road and Rail. The History of Knorr-Bremse AG.) München 2005.

External links

* http://www.knorr-bremse.com Website of the Knorr-Bremse company (German) * http://www.bremsenbude.de Compressed-air brakes on railway vehicles (German) {{Railway brakes Railway brakes Rolling stock of Germany Rail freight transport in Germany

Inventors

Brake versions

Knorr-Bremse

Literature

See also

External links