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 Rail freight transport is the use of railroads and trains to transport cargo as opposed to human passengers. A freight train, cargo train, or goods train is a group of freight cars (US) or goods wagons (International Union of Railways) hauled ...

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

. When it was introduced after the

First World War World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was List of wars and anthropogenic disasters by death toll, one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, ...

, 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 German national railway system created after the end of World War I from the regiona ...

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

Reichsmark The (; sign: ℛℳ; abbreviation: RM) was the currency of Germany from 1924 until 20 June 1948 in West Germany, where it was replaced with the , and until 23 June 1948 in East Germany, where it was replaced by the East German mark. The Reich ...

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 in the field for over 110 years. Other products in Group's portfolio include intelligent door systems, control components, air c ...

, 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 and largest city of Germany by both area and population. Its 3.7 million inhabitants make it the European Union's most populous city, according to population within city limits. One of Germany's sixteen constitu ...

. 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 ( ; german: München ; bar, Minga ) is the capital and most populous city of the German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the third-largest city in Germany, after Berlin and ...

. 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 the German Democratic Republic (GDR; german: Deutsche Demokratische Republik, , DDR, ), was a country that existed from its creation on 7 October 1949 until German reunification, its dissolution on 3 October 1990. In t ...

, 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