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From time to time, a railway decides that it needs to upgrade its coupling system from one that is proving unsatisfactory, to another that meets future requirements. This can be done gradually, which can create many problems with transitional incompatibilities, or overnight, which requires much planning.
The European network has traditionally been formed of many independent national railway networks with buffer and chain used near universally to allow the interchange of rolling stock. The European Union Technical Specifications for Interoperability (TSIs) for high-speed passenger rolling stock mandate the use of Scharfenberg Type 10-compatible couplings. The Type 10 includes "horns" to aid coupling on curves and include a function to provide standardised automatic air-brake connections; the coupling horn is often visible poking out at the front of the nose of high-speed trains.
For European freight, the TSIs mandate buffer and chain couplings at specified heights. The European system links to the former Soviet Russian-gauge network, where SA3 automatic couplers are used. Some research has been undertaken to choose an automatic freight coupler compatible with the Soviet one, but owing to widescale replacement cost, no action has been taken to implement the conversion, except for some trial installations. In many heavy-haul applications, such as for coal and iron ore, either US AAR-type couplers or Soviet SA-3 couplers are used. Conversion is made harder to justify because the existing buffer and chain coupling is almost universal.
Meanwhile, drawgear of new rolling stock is being built at a height suitable for conversion. The proposed European C-AKv freight coupler is compatible with the SA3 coupler but adds integrated air and electrical connections. This standard would need to be revised to allow for the unforeseen development of electronically controlled pneumatic brakes.
In Germany all freight wagon have been built with a UIC automatic coupler option since 1976. [1] This mounting option can be used to deploy the C-Akv coupler when a conversion is implemented. A further advantage in such a scenario is, that the C-Akv coupler can also function like the hook and air connectors for a hook-and-chain coupler, ad long as the vehicle with the C-Akv coupler still has buffers.
Russian Empire and later Soviet Union used buffer and chain couplings, albeit with possibly wider centres for the buffers, until conversion to automatic SA3 couplers. The SA3 coupler was introduced in 1932, based on a British invention from 1916. Some wagons were equipped with SA-3 couplers in the 1930s (they could be coupled with chain coupling), but all cars received automatic couplers in 1957. [2] [3]
Once Congress passed the Safety Appliance Act in 1893, mandating conversion from the link and pin coupler to the Janney coupler, railroads in the United States had only a few years to implement the change. The railroads in North America, except for mass transit, form one unitary system, and uniformity of couplers is important for smooth interchange of rolling stock.
Railways in Central and South America are fragmented by gauge, geography, and financial and technical heritage. While some systems have adopted the American Janney coupler, others retain the British buffer and hook (buffer and chain) coupler (see above).
Japan converted its British-derived buffer and chain couplings to the American Janney coupling over a period of a few days [note 1] in the early 1920s, [note 2] after considerable preparation. Today, most (if not all) EMUs including high-speed Shinkansen trains, and some DMUs use the Shibata type coupling system, while locomotive-hauled trains use the Janney coupling and Tightlock coupling system.
The Norwegian coupling was the most common type of couplers used on the railways of the Dutch East Indies and later Indonesia. Due to the drawbacks of Norwegian couplers, the Indonesian State Railways adopted the Janney couplers starting in 1951. [note 3] [4] To allow interoperability with the older rolling stock equipped with Norwegian couplers, early Janney couplers would have gap which allowed the use of Norwegian coupler adaptor called "Perdijk" device. [5] The Norwegian couplers disappeared from mainline service in the early 1980s, and nowadays only used by heritage trains. The majority of coupling systems today consisted of Janney couplers, with Shibata and Scharfenberg couplers used on EMUs.
The Manila Tranvía system first adopted the use of British buffers and chain couplers with the acquisition of the Manila Railway Manila class in 1885. After American rolling stock became more common under the Manila Railroad during the late 1920s, Janney couplers were adopted as the standard, and were first adopted on the locally-assembled RMC class railcars of 1928. World War II-era and post-war locomotives such as the Manila Railroad 800 class of 1944 only use Janney couplers. Today's Philippine National Railways, which succeeded the Manila Railroad, also uses Janney couplers for all of its rolling stock.[ citation needed ]
Starting in the 1990s, both Scharfenberg and Shibata couplers are being adopted on electrified rapid transit lines in Metro Manila. The first use of the Scharfenberg coupler was for the Manila MRT Line 3 in 1999. Meanwhile, the first use of the Shibata coupler was for the LRT Line 2. In the future, Shibata couplers are also expected for use on the MRT Line 7, the Metro Manila Subway, and the North–South Commuter Railway (NSCR). The NSCR is so far the only PNR line that will use Shibata couplers, with the future South Long Haul project continuing to use Janney couplers for its rolling stock.
Australia, with its breaks of gauge, has always had different couplers on different systems, and has generally adopted gradual conversion. Conversion to the Janney coupling is now virtually complete. Commonwealth Railways started with Janney couplings on its 1,435 mm (4 ft 8+1⁄2 in) standard gauge Trans-Australian line, and some railways, like the former Victorian Railways and the Queensland Railways, used dual couplers. Older couplers remain on Heritage railways.
While the Middle East is mostly standard gauge, three different couplings appear to be in use (not counting Scharfenberg couplings on EMU trains). These are buffer-and-chain, American, and Russian types.
South of the Sahara, Janney (AAR) and chopper couplings (not necessarily of compatible types) appear to account for most couplings. The preferred and proposed UAR standard is the American Janney (AAR) coupling. [6]
Coupler may refer to:
A coupling or coupler is a mechanism, typically located at each end of a rail vehicle, that connects them together to form a train. The equipment that connects the couplers to the vehicles is the draft gear or draw gear, which must absorb the stresses of the coupling and the acceleration of the train.
A buffer stop, bumper, bumping post, bumper block or stopblock (US), is a device to prevent railway vehicles from going past the end of a physical section of track.
Rail freight transport is the use of railways and trains to transport cargo as opposed to human passengers.
A buffer is a part of the buffers-and-chain coupling system used on the railway systems of many countries, among them most of those in Europe, for attaching railway vehicles to one another.
Type H Tightlock couplers are a variety of Janney coupler, typically used on North American mainline passenger rail cars. They have mechanical features that reduce slack in normal operation and prevent telescoping in derailments, yet remain compatible with other Janney types used by North American freight railroads.
The African Union of Railways is an organisation under the auspices of the new African Union dealing with railways. It is similar to the International Union of Railways (UIC).
The Scharfenberg coupler is a commonly used type of fully automatic railway coupling.
SA3 couplers or Willison coupler and Russian coupler are railway couplings used primarily in Russia and states influenced by the former Soviet Union, such as Finland, Poland, and Mongolia.
In railroading, slack action is the amount of free movement of one car before it transmits its motion to an adjoining coupled car. This free movement results from the fact that in railroad practice cars are loosely coupled, and the coupling is often combined with a shock-absorbing device, a "draft gear", which, under stress, substantially increases the free movement as the train is started or stopped. Loose coupling is necessary to enable the train to bend around curves and is an aid in starting heavy trains, since the application of the locomotive power to the train operates on each car in the train successively, and the power is thus utilized to start only one car at a time.
The railcar couplers or couplings listed, described, and depicted below are used worldwide on legacy and modern railways. Compatible and similar designs are frequently referred to using widely differing make, brand, regional or nick names, which can make describing standard or typical designs confusing. Dimensions and ratings noted in these articles are usually of nominal or typical components and systems, though standards and practices also vary widely with railway, region, and era. Transition between incompatible coupler types may be accomplished using dual couplings, a coupling adapter or a barrier wagon.
A barrier vehicle (BV), barrier wagon, match wagon or translator coach is used to convert between non-matching railway coupler types. This allows locomotives to pull railway vehicles or parts of a train with a different type of coupler. A match wagon has an identical dual coupling at both ends.
The C-AKv is a fully automatic coupler design, also known as the Faiveley Transpact; it is a hybrid compatible with both buffers and chain couplers and Russian SA3 couplers, intended as an option for the long delayed EU transition to center buffer couplers. C-AKv is an abbreviation of Compact Automatische Kupplung vereinfacht in German, translating to Compact Automatic Coupler simplified in English.
Janney couplers are a semi-automatic form of railway coupling that allow rail cars and locomotives to be securely linked together without rail workers having to get between the vehicles. They are also known as American, AAR, APT, ARA, MCB, knuckle, Buckeye, tightlock or Centre Buffer Couplers.
A Norwegian coupling or coupler, is a manually operated coupling at each end of some narrow-gauge railway rolling stock. It consists of a central buffer incorporating a hook that drops into a slot in the opposing central buffer. The system is only found on narrow gauge railways with a gauge of 1067 mm or less on which low speeds and train loads allow a simpler system than, for example, knuckle couplers. Norwegian couplings are not particularly strong, and may be supplemented by auxiliary chains. Not all Norwegian couplings are compatible with one another since they vary in height and width. Some may permit a hook from both rail vehicles to be in place; others may be limited to one.
Buffers and chain couplers are the de facto International Union of Railways (UIC) standard railway coupling used in the EU and UK, and on some railways in other parts of the world, such as in South America and India, on older rolling stock. Buffers and chain couplers are an assembly of several devices: buffers, hooks and links, or turnbuckle screws.
Different types of railroad rolling stock have different couplers depending on the purpose and type of equipment being used and its intended destination. European rolling stock tend to use buffers and chain couplers while American rolling stock uses a Janney coupler or "knuckle coupler". These are incompatible with each other, but where some railroads have obtained older, less expensive used rolling stock from different countries or regions, instead of having to standardize on one form of coupler, it may be useful to be able to use either type of coupler on a piece of rolling stock without having to remove anything.
The Manila Railroad 800 class USA were 45 United States Army Transportation Corps class S118 steam locomotives used by the Manila Railroad Company and the Philippine National Railways. Originally built by Vulcan Iron Works and the American Locomotive Works for the United States Army during the Second Philippines Campaign, they were later used to pull freight trains and temporary passenger trains. After the dieselization of the Manila Railroad network in the mid-1950s, they were relegated to work trains until the last unit was scrapped after appearing in a 1989 World War II movie.
The balance lever coupling, also known as rocking lever coupling or compensating coupling, is a type of central buffer coupling that has found widespread use, especially in narrow-gauge railways. In Switzerland this type of coupling is called a central buffer with two screw couplings, abbreviated to Zp2, or referred to as a central buffer coupling with coupling hooks on the side
Digital automatic coupling (DAC) is a type of railway coupling developed in the 2020's to replace the English buffers and chain couplings, initially in Europe.
