HOME

TheInfoList



OR:

A coupling (or a coupler) is a mechanism typically placed at each end of a railway vehicle that connects them together to form a train. A variety of coupler types have been developed over the course of railway history. Key issues in their design include strength, reliability, ease of making connections and operator safety. The equipment that connects the couplings to the vehicles is the draft gear or draw gear and these must absorb the stresses of coupling and train acceleration.


Nomenclature

Compatible and similar couplings or couplers are frequently referred to using widely differing make, brand, or regional names, or nicknames, 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.


Buffers and chain

The basic type of coupling on railways following the British tradition is the buffer and chain coupling. A large chain of three links connects hooks on the adjoining wagons. These couplings followed earlier tramway practice but were made more regular. Buffers on the frame of the wagon absorbed impact loads, as the train over-ran a slowing locomotive. The simple chain could not be tensioned and this slack coupling allowed a lot of back-and-forth movement and banging between vehicles, and jarring when starting trains. While acceptable for mineral wagons, this coupling gave an uncomfortable ride for passenger coaches, and so the chain was improved by replacing the centre link with a turnbuckle that draws the vehicles together, giving the ''screw coupling''. A simplified version of this, quicker to attach and detach, still used three links but with the centre link given a T-shaped slot. This could be turned lengthwise to lengthen it, allowing coupling, then turned vertically to the shorter slot position, holding the wagons more tightly together. Higher speeds associated with fully-fitted freight made the screw-tensioned form a necessity. The earliest ' dumb buffers' were fixed extensions of the wooden wagon frames, but later spring buffers were introduced. The first of these were stiff cushions of leather-covered horsehair, later steel springs and then hydraulic damping. This coupling is still widespread in Western and Central Europe and in parts of Northern Africa, Middle East and South Asia.


Link and pin

The link-and-pin coupling was the original style of coupling used on North American railways. After most railroads converted to semi-automatic Janney couplers, the link-and-pin survived on
forest railway A forest railway, forest tram, timber line, logging railway or logging railroad is a mode of railway transport which is used for forestry tasks, primarily the transportation of felling, felled logs to sawmills or railway stations. In most cases th ...
s. While simple in principle, the system suffered from a lack of standardisation regarding size and height of the links, and the size and height of the pockets. The link-and-pin coupler consisted of a tube-like body that received an oblong link. During coupling, a rail worker had to stand between the cars as they came together and guide the link into the coupler pocket. Once the cars were joined, the employee inserted a pin into a hole a few inches from the end of the tube to hold the link in place. This procedure was exceptionally dangerous and many brakemen lost fingers or entire hands when they did not get them out of the way of the coupler pockets in time. Many more were killed as a result of being crushed between cars or dragged under cars that were coupled too quickly. Brakemen were issued with heavy clubs that could be used to hold the link in position, but many brakemen would not use the club, and risked injury. The link-and-pin coupler proved unsatisfactory because: * It made a loose connection between the cars, with too much
slack action 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 of ...
. * There was no standard design, and train crews often spent hours trying to match pins and links while coupling cars. * Crew members had to go between moving cars during coupling, and were frequently injured and sometimes killed. * The links and pins were often pilfered due to their value as scrap metal, resulting in substantial replacement costs. John H. White suggests that the railroads considered this to be more important than the safety issue at the time. * When a car happened to be turned 180 degrees one would have to look for a link. * Railroads progressively began to operate trains that were heavier than the link-and-pin system could cope with. In Britain link-and-pin couplers were common on narrow gauge industrial and military railways, and eventually evolved into a form that could be reliably coupled when the train was stationary. Some preserved railways still use stock featuring a variety of link-and-pin couplers. The nowadays well established Scharfenberg coupler can be seen as evolved from the link-and-pin, by having double link-and-pin couplers and the links fixed with one per direction and the pins automatic.


Link, pin and buffer

File:From Ship - panoramio - ---=XEON=--- (3).jpg, Link, pin and buffer on
rail crane A railroad crane (North America: crane car or wrecker; UK: breakdown crane) is a type of crane used on a railroad for one of three primary purposes: freight handling in goods yards, permanent way (PW) maintenance, and accident recovery work. ...
File:Panama and the canal in picture and prose (1913) (14596913228).jpg, left, Link and pin coupler on a 1913
Panama Canal The Panama Canal ( es, Canal de Panamá, link=no) is an artificial waterway in Panama that connects the Atlantic Ocean with the Pacific Ocean and divides North and South America. The canal cuts across the Isthmus of Panama and is a condui ...
locomotive A locomotive or engine is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, motor coach, railcar or power car; the ...
, the buffers at this end have been removed File:08-130 Esclusas de Miraflores (23).jpg, Link and pin on a Panama canal mule. One link for two mules


Albert coupler

To avoid safety issues, Karl Albert, then director at the Krefeld Tramway, developed the Albert coupler during 1921. The Albert coupler was created as a key and slot coupler with two pins. Cars to be coupled were pushed together, both couplings moving to the same side. One pin was inserted, then the cars were pulled to straighten the coupling and the other pin inserted. This operation required less exact shunting. Due to the single-piece design, only minimal slack was possible. The system became quite popular with tram systems and narrow gauge lines. During the 1960s most cities replaced them with automatic couplers. But even in modern cars, Albert couplers get installed as emergency couplers for towing a faulty car.


Miller Hook and Platform

The link and pin was replaced in North American passenger car usage during the latter part of the 19th century by the assemblage known as the Miller Platform, which included a new coupler called the Miller Hook. The Miller Platform (and hook coupler) was used for several decades before being replaced by the Janney coupler.


Norwegian

Norwegian (or meat chopper) couplings consist of a central buffer with a mechanical hook that drops into a slot in the central buffer. There may also be a U-shaped securing latch on the opposite buffer which is fastened over the top of the hook to secure it. The Norwegian is found only on
narrow gauge railway A narrow-gauge railway (narrow-gauge railroad in the US) is a railway with a track gauge narrower than standard . Most narrow-gauge railways are between and . Since narrow-gauge railways are usually built with tighter curves, smaller struct ...
s of , or less, such as the
Isle of Man Railway The Isle of Man Railway (IMR) ( gv, Raad Yiarn Vannin) is a narrow gauge steam-operated railway connecting Douglas with Castletown and Port Erin on the Isle of Man. The line is narrow gauge and long. It is the remainder of what was ...
,
Western Australian Government Railways Western Australian Government Railways (WAGR) was the operator of railway services in the state of Western Australia between October 1890 and June 2003. Owned by the state government, it was renamed a number of times to reflect extra responsi ...
,
Tanzania Tanzania (; ), officially the United Republic of Tanzania ( sw, Jamhuri ya Muungano wa Tanzania), is a country in East Africa within the African Great Lakes region. It borders Uganda to the north; Kenya to the northeast; Comoro Islands ...
, the
Ffestiniog Railway The Ffestiniog Railway ( cy, Rheilffordd Ffestiniog) is a heritage railway based on narrow-gauge, located in Gwynedd, Wales. It is a major tourist attraction located mainly within the Snowdonia National Park. The railway is roughly long a ...
, the
Lynton and Barnstaple Railway The Lynton and Barnstaple Railway (L&B) opened as an independent railway in May 1898. It was a single track, narrow gauge railway and was slightly over long running through the rugged and picturesque area bordering Exmoor in North Devo ...
and the
Welsh Highland Railway The Welsh Highland Railway (WHR) or Rheilffordd Eryri is a long, restored narrow gauge heritage railway in the Welsh county of Gwynedd, operating from Caernarfon to Porthmadog, and passing through a number of popular tourist destinations ...
where low speeds and reduced train loads allow a simpler system. The Norwegian coupler allows sharper curves than the buffer-and-chain, which is an advantage on those railways. On railway lines where rolling stock always points the same way, the mechanical hook may be provided only on one end of each wagon. Similarly, the hand brake handles may also be on one side of the wagons only. Norwegian couplings are not particularly strong, and may be supplemented by auxiliary side chains. Not all Norwegian couplings are compatible with one another as they vary in height, width, and may or may not be limited to one hook at a time.


Lloyd coupler

The Lloyd coupler is similar to the Norwegian coupler.


Radial couplers

Two versions of radial coupler were used in South Africa. One, the Johnston coupler, commonly known as a bell link-and-pin coupler, was introduced in 1873 and is similar in operation to and compatible with link-and-pin couplers, but bell-shaped with a circular coupler face. The other, the bell-and-hook coupler, was introduced in 1902 and is similar to the Norwegian coupler, but also with a circular coupler face and with a coupler pocket which is open at the top of the coupler face to accommodate the drawhook.Suid-Afrikaanse Vervoerdienste (South African Transport Services) (1983). ''Passassierswa- en Trokhandboek (Passenger Carriage and Truck Manual), Vol 1, Hoofstukke 1-15 (Chapters 1-15)''. South African Transport Services, 1983. Chapter 13.


Johnston coupler

The Johnston coupler, commonly known as a bell link-and-pin coupler from its bell shape, was first introduced in the
Cape of Good Hope The Cape of Good Hope ( af, Kaap die Goeie Hoop ) ;''Kaap'' in isolation: pt, Cabo da Boa Esperança is a rocky headland on the Atlantic coast of the Cape Peninsula in South Africa. A common misconception is that the Cape of Good Hope is ...
in 1873, following the establishment of the
Cape Government Railways The Cape Government Railways (CGR) was the government-owned railway operator in the Cape Colony from 1874 until the creation of the South African Railways (SAR) in 1910. History Private railways The first railways at the Cape were privately ow ...
(CGR) in 1872 and the decision by the Cape government to expand the railways into the interior and to
convert Conversion or convert may refer to: Arts, entertainment, and media * "Conversion" (''Doctor Who'' audio), an episode of the audio drama ''Cyberman'' * "Conversion" (''Stargate Atlantis''), an episode of the television series * "The Conversion" ...
the existing tracks from to Cape gauge. All new Cape gauge locomotives and rolling stock acquired from 1873 were equipped with these or similar couplers, beginning with the CGR 0-4-0ST of 1873, a construction locomotive named ''Little Bess''. The
Natal Government Railways The Natal Government Railways (NGR) was formed in January 1877 in the Colony of Natal. In 1877, the Natal Government Railways acquired the Natal Railway Company for the sum of £40,000, gaining the line from the Point to Durban and from Durban ...
(NGR), established in the
Colony of Natal The Colony of Natal was a British colony in south-eastern Africa. It was proclaimed a British colony on 4 May 1843 after the British government had annexed the Boer Natalia Republic, Republic of Natalia, and on 31 May 1910 combined with three o ...
in 1875, followed suit and all locomotives and rolling stock acquired by that railway were equipped with Johnston couplers, beginning with the
NGR Class K 2-6-0T The Natal Government Railways Class K 2-6-0T of 1877 was a South African steam locomotive from the pre-Union era in the Natal Colony. The Natal Government Railways was established in terms of Act 4 of 1875. All the assets of the Natal Railway ...
in 1877.Espitalier, T.J.; Day, W.A.J. (1944). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter III - Natal Government Railways''. South African Railways and Harbours Magazine, May 1944. pp. 337-340. Likewise, in 1889, when the first locomotives were obtained by the newly established Netherlands-South African Railway Company in the ''Zuid-Afrikaansche Republiek'', they were fitted with Johnston couplers.Espitalier, T.J.; Day, W.A.J. (1944). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter IV - The N.Z.A.S.M.''. South African Railways and Harbours Magazine, October 1944. pp. 762, 764. Unlike the narrow gauge railways of the CGR, those of the NGR also made use of Johnston couplers. The first of these narrow gauge lines came into operation in 1906, when the first NGR Class N 4-6-2T locomotives entered service on the
Weenen Weenen (Dutch for "wept") is the second oldest European settlement in KwaZulu-Natal, South Africa. It is situated on the banks of the Bushman River. The farms around the town grow vegetables, lucerne, groundnuts, and citrus fruit. History The p ...
branch out of
Estcourt Estcourt () is a town in the uThukela District of KwaZulu-Natal Province, South Africa. The main economic activity is farming with large bacon and processed food factories situated around the town. The N3 freeway passes close to the town, link ...
.Espitalier, T.J.; Day, W.A.J. (1944). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter III - Natal Government Railways'' (Continued). South African Railways and Harbours Magazine, September 1944. p. 669. Coupling and uncoupling were done manually, which posed a high risk of serious injury or death to crew members, who had to go between moving vehicles to guide the link into the coupler pocket during coupling. Johnston couplers gradually began to be replaced on the
South African Railways Transnet Freight Rail is a South African rail transport company, formerly known as Spoornet. It was part of the South African Railways and Harbours Administration, a state-controlled organisation that employed hundreds of thousands of people ...
from 1927, but not on narrow gauge rolling stock. All new Cape gauge locomotives and rolling stock acquired from that year were equipped with AAR knuckle couplers. Conversion of all older rolling stock was to take several years and both coupler types could still be seen on some vehicles into the late 1950s. During the transition period, knuckle couplers on many locomotives had a horizontal gap and a vertical hole in the knuckle itself to accommodate, respectively, a link and a pin, to enable it to couple to vehicles which were still equipped with the older Johnston couplers.South African Railways & Harbours/Suid Afrikaanse Spoorweë en Hawens (15 Aug 1941). ''Locomotive Diagram Book/Lokomotiefdiagramboek, 2′0″ & 3′6″ Gauge/Spoorwydte, Steam Locomotives/Stoomlokomotiewe''. SAR/SAS Mechanical Department/Werktuigkundige Dept. Drawing Office/Tekenkantoor, Pretoria. pp. 6a-7a, 25.


Bell-and-hook coupler

The bell-and-hook coupling system was first introduced in the Cape of Good Hope in 1902, when two CGR Type A 2-6-4T locomotives were acquired as construction engines on the new narrow gauge Avontuur Railway which was being constructed out of
Port Elizabeth Gqeberha (), formerly Port Elizabeth and colloquially often referred to as P.E., is a major seaport and the most populous city in the Eastern Cape province of South Africa. It is the seat of the Nelson Mandela Bay Metropolitan Municipality, So ...
through the
Langkloof The Langkloof is a 160 km long valley in South Africa, lying between Herold, a small village northeast of George, and The Heights - just beyond Twee Riviere. History The kloof was given its name by Isaq Schrijver in 1689, and more thoroug ...
. In South Africa, these couplers were used on only the narrow gauge lines in the Cape of Good Hope.Espitalier, T.J.; Day, W.A.J. (1944). ''The Locomotive in South Africa - A Brief History of Railway Development. Chapter II - The Cape Government Railways'' (Continued). South African Railways and Harbours Magazine, April 1944. pp. 253-257. The coupler is similar to the Norwegian coupler. It is a radial coupler with a coupler pocket which is open at the top of the coupling face. Instead of a link and pins, it makes use of a drawhook which, upon coupling, slides over the drawhook pin in the coupler of the next vehicle in the train. To prevent the drawhook of the mating coupler from accidental uncoupling, the coupler bell is equipped with a drawhook guard, commonly known as a bridle, above the coupler pocket. Usual practice was to have a drawhook fitted to only one of the mating couplers and train crews therefore carried spare drawhooks and drawhook pins on the locomotive. While automatic coupling is possible, this rarely happens and manual assistance is required during coupling. Uncoupling is done manually by lifting the drawhook by hand to release it. The coupler could be adapted to be compatible with the Johnston coupler by replacing the drawhook with a U-shaped adapter link, which was attached using the same drawhook pin. Bell-and-hook couplers began to be replaced on the Avontuur Railway upon the introduction of Class 91-000 diesel-electric locomotives on the narrow gauge system in 1973. All new narrow gauge rolling stock acquired for that line from that year were equipped with Willison couplers. Older rolling stock were not converted and an adapter was used to enable coupling between the two types. The drawhook on the bell-and-hook coupler would be replaced with the adapter, which was attached using the same drawhook pin. File:Bell-and-hook coupler.jpg, left, Bell-and-hook coupler File:Bell-and-hook coupler & Willison adapter.jpg, Bell-and-hook coupler with Willison adapter File:Willison adapter b.jpg, left, Willison coupler adapter for bell-and-hook couplers File:Bell-and-hook coupler & Johnston adapter.jpg, Bell-and-hook coupler with Johnston coupler adapter link instead of a hook


Automatic couplers

There are a number of automatic train couplings, most of which are mutually incompatible. The level of automation varies and can be divided into categories: * mechanical coupling of vehicles only, requires manual connection of pneumatic and electrical lines; * mechanical coupling of vehicles with automatic connection of pneumatic lines, requires manual connection of electrical lines; * mechanical coupling of vehicles with automatic connection of pneumatic and electrical lines (but not data transmission lines); * mechanical coupling of vehicles with automatic connection of pneumatic and electrical lines (including data transmission lines); * mechanical coupling of vehicles with automatic connection of pneumatic and electrical lines (including data transmission lines) and automatic uncoupling capability.


Buckeye/Janney/MCB/ARA/AAR/APTA couplers

The Janney coupler, later the Master Car Builders Association (MCB) coupler, now the
Association of American Railroads The Association of American Railroads (AAR) is an industry trade group representing primarily the major freight Rail transport, railroads of North America (Canada, Mexico and the United States). Amtrak and some regional Commuter rail in North Am ...
(AAR) coupler, is also commonly known as a ''buckeye'', ''knuckle'', or ''Alliance'' coupler. The AAR/APTA TypeE, TypeF, and TypeH couplers are all compatible Janney couplers, but used for different rail cars (general freight, tank cars, rotary hoppers, passenger, etc.). The knuckle coupler or Janney coupler was invented by Eli H. Janney, who received a
patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...
in 1873 (). It is also known as a ''buckeye coupler'', notably in the United Kingdom, where some rolling stock (mostly for passenger trains) is fitted with it. Janney was a dry goods clerk and former
Confederate Army The Confederate States Army, also called the Confederate Army or the Southern Army, was the military land force of the Confederate States of America (commonly referred to as the Confederacy) during the American Civil War (1861–1865), fighti ...
officer from
Alexandria, Virginia Alexandria is an independent city in the northern region of the Commonwealth of Virginia, United States. It lies on the western bank of the Potomac River approximately south of downtown Washington, D.C. In 2020, the population was 159,467. ...
, who used his lunch hours to whittle from wood an alternative to the link and pin coupler. The term ''buckeye'' comes from the nickname of the US state of
Ohio Ohio () is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Of the List of states and territories of the United States, fifty U.S. states, it is the List of U.S. states and territories by area, 34th-l ...
, the "Buckeye State" and the Ohio Brass Company which originally marketed the coupling. In 1893, satisfied that an automatic coupler could meet the demands of commercial railroad operations and, at the same time, be manipulated safely, the
United States Congress The United States Congress is the legislature of the federal government of the United States. It is Bicameralism, bicameral, composed of a lower body, the United States House of Representatives, House of Representatives, and an upper body, ...
passed the Safety Appliance Act. Its success in promoting switchyard safety was stunning. Between 1877 and 1887, approximately 38% of all railworker accidents involved coupling. That percentage fell as the railroads began to replace link and pin couplers with automatic couplers. By 1902, only two years after the SAA's effective date, coupling accidents constituted only 4% of all employee accidents. Coupler-related accidents dropped from nearly 11,000 in 1892 to just over 2,000 in 1902, even though the number of railroad employees steadily increased during that decade. When the Janney coupler was chosen to be the North American standard, there were 8,000 patented alternatives to choose from. The only significant disadvantage of using the Janney design is that sometimes the drawheads need to be manually aligned. Many AAR coupler designs exist to accommodate requirements of various car designs, but all are required to have certain dimensions in common which allow for one design to couple to any other.AAR Manual of Standards and Recommended Practices, Section S, Part III:Coupler and Yoke Details, Issue 06/2007 The Janney coupler is used in the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
,
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...
,
Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
,
Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the n ...
,
India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...
,
Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the no ...
,
Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...
,
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island coun ...
,
South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
,
Saudi Arabia Saudi Arabia, officially the Kingdom of Saudi Arabia (KSA), is a country in Western Asia. It covers the bulk of the Arabian Peninsula, and has a land area of about , making it the fifth-largest country in Asia, the second-largest in the Ara ...
,
Cuba Cuba ( , ), officially the Republic of Cuba ( es, República de Cuba, links=no ), is an island country comprising the island of Cuba, as well as Isla de la Juventud and several minor archipelagos. Cuba is located where the northern Caribb ...
,
Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...
,
Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
,
Portugal Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of th ...
,
China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...
and elsewhere. The Janney coupler generally provides only mechanical coupling, only Type H adds automatic connections of pneumatic and electrical lines.


Changes since 1873


Bazeley coupler


Henricot coupler

The Henricot coupler is a variation on the Janney coupler, introduced by Belgian engineer and entrepreneur of Court-Saint-Étienne. It is used on certain EMUs of the National Railway Company of Belgium, including the ). Image:AM75 Série 800 SNCB.jpg, Henricot coupler on an SNCB Class 75 EMU with separate air brake and head-end power connections File:Attelage Henricot.jpg, Henricot coupler on a Belgian EMU File:NMBS 837.JPG, Closeup of Henricot coupler


Willison/SA3 coupler

The Willison coupler was developed in the US in 1916 to address issues present in the Janney coupling. The Russian SA3 coupler works according to the same principles as the AAR coupler but the two types are incompatible. It was introduced in the Soviet Union in 1932 based on a British patent and has since been used on the whole network, including
Mongolia Mongolia; Mongolian script: , , ; lit. "Mongol Nation" or "State of Mongolia" () is a landlocked country in East Asia, bordered by Russia to the north and China to the south. It covers an area of , with a population of just 3.3 million ...
. Finnish locomotives have Unilink couplers that can couple to UIC couplers used in Finnish stock and SA3 couplers used in Russian stock. It is also used on the networks of
Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...
and on Malmbanan in Sweden for ore trains. Some gauge cane tramway vehicles in
Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...
have been fitted with miniature Willison couplers. It was introduced on the narrow gauge Avontuur Railway of the South African Railways in 1973. * Russian trains are rarely longer than about and rarely exceed a maximum tonnage of about . The heaviest trains using these couplers are on Malmbanan where they are up to . * Maximum force the SA3 coupler is able to carry, both tensile and compressive, is about . * The maximum allowed tractive effort to the SA-3 is limited to () by Russian white papers. * The proposed European automatic coupler is compatible with the Russian coupler but with automatic air, control and power connections. Implementation is permanently delayed except for a few users. See
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 ...
below. * The SA3 resembles a left-handed fist. The SA3 coupler is one of the strongest couplers in the world – maximum tonnage of a train that uses this type of coupler is about 8000 t – but provides only mechanical coupling. Adding automatic electrical and pneumatic connectivity is a complex challenge. There are many variations and brand names for these couplers. CAF is working on an automatic coupler based on SA3, a possible replacement of the buffers and chain coupling on European railways.


Unicoupler/Intermat

Unicoupler has been developed by Knorr from West Germany in the 1970s, in parallel with a compatible counterpart, the Intermat coupler, by VEB Waggonbau Bautzen from East Germany. The Unicoupler/Intermat coupler can automatically couple two pneumatic lines and up to six electrical connections. This coupler is mechanically compatible with
SA-3 The S-125 ''Neva/Pechora'' (russian: С-125 "Нева"/"Печора", NATO reporting name SA-3 ''Goa'') is a Soviet surface-to-air missile system that was designed by Aleksei Isaev to complement the S-25 and S-75. It has a shorter effective ra ...
and Willison couplers (but pneumatic and electrical connections must be done manually). The Unicoupler is also known as AK69e. Maximum tonnage of a train that uses this type of coupler is about 6000 t. AK69e and Intermat adoption failure has been attributed to economic performance. it has found limited use, it's been adopted by the
Iranian Railways , majoroperators =RAI, Tooka rail, Samand rail , ridership =21 million , passkm =13 billion , freight =31 million tonnes , tonkm =22 billion tonnes , infrastructure = , length = , doublelength = 142 ...
and is also used in Germany on trains transporting iron ore between Hamburg and Salzgitter.


C-AKv

The C-AKv coupler (also called Transpact) is a newer compact Willison coupler developed by
Faiveley Transport Faiveley Transport (), formerly Faiveley, is an international manufacturer and supplier of equipment for the railway industry founded in 1919. It introduced the single-arm pantograph in 1955. The company has subsidiaries in more than 24 countr ...
. It is mechanically compatible with the
SA3 coupler SA3 couplers (also known as СА3 or СА-3 couplers per the typical foundry stamp on top of these couplers, meaning "Советская Автосцепка, 3" in Russian or "Soviet Auto-latch 3" in English) or Willison coupler and Russia ...
(but pneumatic and electrical connections must be done manually), fully compatible with the Unicoupler and, if additional buffers are mounted, it can be coupled with the conventional European screw coupling as well. The C-AKv coupler can automatically couple two pneumatic lines. its use is limited to trains transporting ore between Rotterdam and Dillingen steelworks and lignite between Wählitz and Buna in Germany.


Z-AK

The Z-AK coupler is yet another Willison coupler developed by
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 ...
. It was designed in response to the obvious failure of the Unicoupler/Intermat. It is compatible with the buffers and screw coupling. It is one of only few automatic couplers that cannot carry tensile forces, railway vehicles using this type of coupler must be equipped with buffers as well.


Unilink coupler

The Unilink coupler is a coupler compatible with SA3 and
screw coupling Buffers and chain couplers (also known as "buffers and screw", "screw", "screwlink", and "English" couplers) are the de facto UIC standard railway stock coupling used in the EU and UK, and on some surviving former colonial railways, such as in ...
, which is used e.g. in
Finland Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bot ...
. It is an SA3 coupler with an additional horn that allows hooking up of the chain, and also with an adapter that connects the hook to the SA3 head. Rolling stock equipped with Unilink couplers is also equipped with side buffers.


Multi-function couplers

Multi-function couplers (MFCs), or fully automatic couplers, make all connections between the rail vehicles (mechanical, air brake, and electrical) without human intervention, in contrast to autocouplers, or semi-automatic couplers, which just handle the mechanical aspects. The majority of trains fitted with these types of couplers are multiple units, especially those used in
mass transit Public transport (also known as public transportation, public transit, mass transit, or simply transit) is a system of transport for passengers by group travel systems available for use by the general public unlike private transport, typical ...
operations. There are a few designs of fully automatic couplers in use worldwide, including the Scharfenberg coupler, various knuckle hybrids such as the Tightlock (used in the UK), the Wedgelock coupling, Dellner couplings (similar to Scharfenberg couplers in appearance), BSI coupling (Bergische Stahl Industrie, now
Faiveley Transport Faiveley Transport (), formerly Faiveley, is an international manufacturer and supplier of equipment for the railway industry founded in 1919. It introduced the single-arm pantograph in 1955. The company has subsidiaries in more than 24 countr ...
) and the Schaku-Tomlinson Tightlock coupling. There are a number of other automatic train couplings similar to the Scharfenberg coupler, but not necessarily compatible with it. Older US transit operators continue to use these non-Janney electro-pneumatic coupler designs and have used them for decades.


Westinghouse H2C

The Westinghouse H2C coupler, whose predecessor the H2A was first used on the
BMT Standard The AB Standard was a New York City Subway car class built by the American Car and Foundry Company and Pressed Steel Car Company between 1914 and 1924. It ran under the operation of the Brooklyn Rapid Transit Company (BRT) and its successors, whi ...
s and later the R1 through R9 classes, is currently used on the R32, R42, R62, R62A, R68, and R68A class subway cars of the
New York City Subway The New York City Subway is a rapid transit system owned by the government of New York City and leased to the New York City Transit Authority, an affiliate agency of the state-run Metropolitan Transportation Authority (MTA). Opened on October ...
. The A ends of the cars typically have the Westinghouse coupler and the B ends use either a semi-permanent drawbar, or a Westinghouse coupler.


WABCO N-Type

The WABCO N-Type coupler was first developed for the prototype
Pittsburgh Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Wester ...
Skybus system with the initial model N-1 as applied only to the three Skybus cars. The updated model N-2 with a larger gathering range was first applied to the new "Airporter" rapid transit cars on the Cleveland Rapid Transit line. The model N-2 used lightweight draft gear slung below the center sill, to allow for the wide swings required to go around sharp curves. This made the N-2 unsuitable for main line railroad use so an updated version N-2-A was developed for that market. The first of these were fitted in 1968 to the
UAC TurboTrain The UAC TurboTrain was an early high-speed rail, high-speed, gas turbine train manufactured by United Aircraft that operated in Canada between 1968 and 1982 and in the United States between 1968 and 1976. Amtrak disposed of the trains in 1980. It ...
with 228 electrical contacts and the Budd Metropolitan EMU with 138 contacts. Starting in the 1970s the N-2-A was fitted to the entire
SEPTA The Southeastern Pennsylvania Transportation Authority (SEPTA) is a regional public transportation authority that operates bus, rapid transit, commuter rail, light rail, and electric trolleybus services for nearly 4 million people in five c ...
Silverliner Silverliner is the name given to a series of electric multiple unit (EMU) railcars in commuter rail service in the Philadelphia area since 1958. As of the introduction of the Silverliner V in 2009–2010, there have been 5 generations o ...
family of MU's, the NJT
Arrow An arrow is a fin-stabilized projectile launched by a bow. A typical arrow usually consists of a long, stiff, straight shaft with a weighty (and usually sharp and pointed) arrowhead attached to the front end, multiple fin-like stabilizers ...
series of MU's and the
Metro-North Railroad Metro-North Railroad , trading as MTA Metro-North Railroad, is a suburban commuter rail service run by the Metropolitan Transportation Authority (MTA), a public authority of the U.S. state of New York and under contract with the Connectic ...
/
Long Island Rail Road The Long Island Rail Road , often abbreviated as the LIRR, is a commuter rail system in the southeastern part of the U.S. state of New York, stretching from Manhattan to the eastern tip of Suffolk County on Long Island. With an average week ...
M series of MU railcars. The N-2 was also used by the
PATCO Speedline The PATCO Speedline (signed in Philadelphia as the Lindenwold Line and also known colloquially as the PATCO High Speed Line) is a rapid transit route operated by the Port Authority Transit Corporation (PATCO), which runs between Philadelphia, Pe ...
, but was replaced due to issues with the electrical contacts. Later WABCO would create a new model N-3 for the
BART Bart is a masculine given name, usually a diminutive of Bartholomew, sometimes of Barton, Bartolomeo, etc. Bart is a Dutch and Ashkenazi Jewish surname, and derives from the name ''Bartholomäus'', a German form of the biblical name ''Bartho ...
system with a gathering range which required a rectangular funnel. The WABCO N-type is sometimes referred to as the pin and cup coupler or spear coupler.


Tomlinson

The Tomlinson coupler was developed by the
Ohio Brass Company Ohio () is a state in the Midwestern region of the United States. Of the fifty U.S. states, it is the 34th-largest by area, and with a population of nearly 11.8 million, is the seventh-most populous and tenth-most densely populated. The sta ...
for mass transit applications, but eventually found use in some mainline railroad vehicles as well. It consists of two squared metal hooks that engage with each other in a larger rectangular frame with air line connections above and below. Since the coupler's development the manufacturing arm of Ohio Brass was purchased by WABCO which now manufacturers the line along with the N-type. The Tomlinson coupler is the most widely used fully automatic heavy rail coupling in North America having been adopted by the
Washington Metro The Washington Metro (or simply Metro), formally the Metrorail,Google Books search/preview
,
Massachusetts Bay Transportation Authority The Massachusetts Bay Transportation Authority (abbreviated MBTA and known colloquially as "the T") is the public agency responsible for operating most public transportation services in Greater Boston, Massachusetts. The MBTA transit network ...
,
PATCO Speedline The PATCO Speedline (signed in Philadelphia as the Lindenwold Line and also known colloquially as the PATCO High Speed Line) is a rapid transit route operated by the Port Authority Transit Corporation (PATCO), which runs between Philadelphia, Pe ...
, SEPTA
Broad Street Subway The Broad Street Line (BSL), also known as the Broad Street subway (BSS), Orange Line, or Broad Line, is a subway line owned by the city of Philadelphia and operated by the Southeastern Pennsylvania Transportation Authority (SEPTA). The line ru ...
,
Los Angeles Metro Rail The Los Angeles Metro Rail is an urban rail transit system serving Los Angeles County, California, United States. It consists of seven lines, including five light rail lines (the A, C, E, K, L lines) and two rapid transit (known locally as ...
, Baltimore Metro, Miami Metro, MARTA Rail and the
New York City Subway The New York City Subway is a rapid transit system owned by the government of New York City and leased to the New York City Transit Authority, an affiliate agency of the state-run Metropolitan Transportation Authority (MTA). Opened on October ...
for its R44/ R46 fleet and all modern classes starting with the R142. For applications outside of rapid transit the coupler had to be significantly enlarged to meet the increased strength requirements first appearing in this capacity on the
Budd Metroliner The Budd Metroliner was a class of American electric multiple unit (EMU) railcar designed for first-class, high-speed service between New York City and Washington, D.C. on the Northeast Corridor. They were designed for operation up to : what wou ...
and later on the
Illinois Central The Illinois Central Railroad , sometimes called the Main Line of Mid-America, was a railroad in the Central United States, with its primary routes connecting Chicago, Illinois, with New Orleans, Louisiana, and Mobile, Alabama. A line also c ...
Highliner The Highliner is a bilevel Electric Multiple Unit railcar. The original series of railcars were built in 1971 by the St. Louis Car Company for commuter service on the Illinois Central Railroad, in south Chicago, Illinois, with an additional bat ...
fleet. Its relative lack of strength is one reason the N-Type has been more successful in the mainline railroad arena. Outside the United States, the Tomlinson coupler is used on
Tokyo Metro The is a major rapid transit system in Tokyo, Japan, operated by the Tokyo Metro Co. With an average daily ridership of 6.84 million passengers, the Tokyo Metro is the larger of the two subway operators in the city; the other being the Toe ...
's
Ginza Ginza ( ; ja, 銀座 ) is a district of Chūō, Tokyo, located south of Yaesu and Kyōbashi, west of Tsukiji, east of Yūrakuchō and Uchisaiwaichō, and north of Shinbashi. It is a popular upscale shopping area of Tokyo, with numerous i ...
and Marunouchi Lines and on the heavy capacity
Taipei Metro Taipei Mass Rapid Transit (MRT), branded as Metro Taipei, is a rapid transit system serving the areas of Taipei and New Taipei in Taiwan, operated by the government-owned Taipei Rapid Transit Corporation, which also operates the Maokong Gondo ...
lines.


Scharfenberg coupler

The Scharfenberg coupler (german: Scharfenbergkupplung or ) is probably the most commonly used type of fully automatic coupling. Designed in 1903 by Karl Scharfenberg in Königsberg, Germany (today Kaliningrad, Russia), it has gradually spread from transit trains to regular passenger service trains, although outside Europe its use is generally restricted to mass transit systems. The Schaku coupler is superior in many ways to many other automatic couplers because it makes the pneumatic and electrical connections automatically and is capable of automatic uncoupling. However, there is no standard for the placement of these electro-pneumatic connections. Some rail companies have them placed on the sides while others have them placed above the mechanical portion of the Schaku coupler. Small air cylinders, acting on the rotating heads of the coupler, ensure the Schaku coupler engagement, making it unnecessary to use shock to get a good coupling. Joining portions of a passenger train can be done at very low speed (less than in the final approach), so that the passengers are not jostled about. Rail equipment manufacturers such as Bombardier offer the Schaku coupler as an option on their mass transit systems and their passenger cars and locomotives. In North America all the trains of the
Montreal Metro The Montreal Metro (french: Métro de Montréal) is a rubber-tired underground rapid transit system serving Greater Montreal, Quebec, Canada. The metro, operated by the Société de transport de Montréal (STM), was inaugurated on October 14, ...
are equipped with it, as are new light rail systems in
Denver Denver () is a consolidated city and county, the capital, and most populous city of the U.S. state of Colorado. Its population was 715,522 at the 2020 census, a 19.22% increase since 2010. It is the 19th-most populous city in the Unit ...
,
Baltimore Baltimore ( , locally: or ) is the most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic, and the 30th most populous city in the United States with a population of 585,708 in 2020. Baltimore was ...
and
New Jersey New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delawa ...
. It is also used on light rail vehicles in Portland,
Minneapolis Minneapolis () is the largest city in Minnesota, United States, and the county seat of Hennepin County. The city is abundant in water, with thirteen lakes, wetlands, the Mississippi River, creeks and waterfalls. Minneapolis has its origin ...
, the Vancouver Skytrain, and
Line 3 Scarborough Line 3 Scarborough (originally known as the Scarborough RT or SRT) is a light rapid transit line that is part of the Toronto subway system in Toronto, Ontario, Canada. The line runs entirely within the suburban district of Scarborough, encompas ...
in
Toronto Toronto ( ; or ) is the capital city of the Canadian province of Ontario. With a recorded population of 2,794,356 in 2021, it is the most populous city in Canada and the fourth most populous city in North America. The city is the anch ...
. It also equips all the dedicated rolling stock used for the shuttle services in the
Channel Tunnel The Channel Tunnel (french: Tunnel sous la Manche), also known as the Chunnel, is a railway tunnel that connects Folkestone (Kent, England, UK) with Coquelles ( Hauts-de-France, France) beneath the English Channel at the Strait of Dover ...
. Maximum tonnage under .
Voith The Voith Group is a German manufacturer of machines for the pulp and paper industry, technical equipment for hydropower plants and drive and braking systems. The family-owned company, which operates worldwide and has its headquarters in Heid ...
and
Dellner Dellner Couplers AB is a Swedish original equipment manufacturer of train connection systems as couplers, gangway systems and dampers. The headquarter of the company is located in Vika in the Falun Municipality. Dellner is owned by the investme ...
are working on an automatic coupler based on Schaku, a possible replacement of the buffers and chain coupling on European railways.


Automatic Buffing Contact Coupler

* Automatic Buffing Contact (ABC) Coupler


Dellner coupler

The Swedish-made Dellner coupling, is a proprietary version of the Scharfenberg coupler, connecting vehicle, pneumatics and electronics at the same time. The patented energy absorption D-BOX technology allows coupling at speeds of up to with no structural damage, and up to with deformation but with the vehicles remaining on track. The patented D-REX system provides
Ethernet Ethernet () is a family of wired computer networking technologies commonly used in local area networks (LAN), metropolitan area networks (MAN) and wide area networks (WAN). It was commercially introduced in 1980 and first standardized in 1 ...
high speed data connection at speeds of 100 Mbit/s.


Ward coupler

Ward coupler


Wedgelock coupler

The Wedgelock is the standard coupler on London Underground trains. The origin of the Wedgelock principle is unclear; however, there are a number of variants, many of which were once produced by the now-defunct
Associated Equipment Company Associated Equipment Company (AEC) was a British vehicle manufacturer that built buses, motorcoaches and trucks from 1912 until 1979. The name Associated Equipment Company was hardly ever used; instead it traded under the AEC and ACLO brands. ...
(AEC) in
Southall Southall () is a large suburban county of West London, England, part of the London Borough of Ealing and is one of its seven major towns. It is situated west of Charing Cross and had a population of 69,857 as of 2011. It is generally divided ...
, London. Wedgelock intellectual property was acquired in 1979 by Radenton later (in 1994) to become Radenton Scharfenberg. Basic design and coupling principle: The older coupler design has a body consisting of two horizontal steel plates separated by shaped blocks to create two pockets the one on the right (driver's perspective) has a vertical pin to anchor a shaped hook protruding forward of a front plate bolted to the body. The second void in the left of the body contains a cylindrical pin with a large flat to create a D-shaped cross-section. The hook is free to swing left and right through an arc of about 5 degrees and can engage with the D-pin in an opposing coupler. During coupling, once opposing front plates are in contact, a pneumatic actuator within the left-hand void drives a (partially) wedge-shaped block behind the outer edge of the opposing hook to engage it with the host D-pin. The sloping wedge geometry occupies the central horizontal third of the block and contacts a similar horizontal sloping groove in the opposing hook merely to engage it with the D-pin. The upper and lower thirds of the wedge have pockets machined to create faces parallel to the longitudinal axis of the coupler. As the wedge is caged by body structure it is these faces which prevent sideways movement of the opposing hook and therefore prevent uncoupling. A relatively lightweight spring is enough to maintain the wedge position in the event of a loss of compressed air to the deploy side of the actuator (also known as the wedge-engine). Uncoupling is achieved by air directed to the retract side of the wedge-engines on both couplers to retract the wedges and free the hooks; uncoupling is completed by simply moving the vehicles apart. In the event of a loss of retract air, the wedges can be moved manually to allow uncoupling.


Schwab coupler

The , made by Schwab Verkehrstechnik AG,
Schaffhausen Schaffhausen (; gsw, Schafuuse; french: Schaffhouse; it, Sciaffusa; rm, Schaffusa; en, Shaffhouse) is a town with historic roots, a municipality in northern Switzerland, and the capital of the canton of the same name; it has an estimate ...
, is used on Stadler Kiss and SZU Be 510. It has been offered in four versions: * Schwab coupler (FK-15-12) for
standard gauge A standard-gauge railway is a railway with a track gauge of . The standard gauge is also called Stephenson gauge (after George Stephenson), International gauge, UIC gauge, uniform gauge, normal gauge and European gauge in Europe, and SGR in E ...
trainsets can be found on "
Stadler GTW The Stadler GTW is an articulated railcar for local transport made by Stadler Rail of Switzerland. GTW stands for Gelenktriebwagen (articulated railcar). History The Biel–Täuffelen–Ins-Bahn near Bern, Switzerland was looking for a light ...
" and " Stadler FLIRT" trainsets of the SBB (GTW and FLIRT), Thurbo (GTW), BLS (GTW), (FLIRT) and SOB (FLIRT). * Schwab coupler (FK-9-6) for tram and metro trains, among other things * Schwab coupler (FK-5.5-4 and FK-3-2.5) for narrow gauge railcars * Schwab coupler (FK-15-10) for
standard gauge A standard-gauge railway is a railway with a track gauge of . The standard gauge is also called Stephenson gauge (after George Stephenson), International gauge, UIC gauge, uniform gauge, normal gauge and European gauge in Europe, and SGR in E ...
multiple unit A multiple-unit train or simply multiple unit (MU) is a self-propelled train composed of one or more carriages joined together, which when coupled to another multiple unit can be controlled by a single driver, with multiple-unit train cont ...
s are compatible with Scharfenberg type 10 The Schwab coupler is superior in many ways to many other automatic couplers because it makes the pneumatic and electrical connections automatically and is capable of automatic uncoupling. it is used primarily in Switzerland in regional rail passenger transport. Wabtec is working on an automatic coupler based on Schwab, a possible replacement of the buffers and chain coupling on European railways.


Shibata coupler

The Shibata coupler is a variation of the Scharfenberg coupler which was developed by
Japanese Government Railways The Japanese Government Railways (JGR) was the national railway system directly operated by the Japanese Ministry of Railways ( ja, 鉄道省, Tetsudō-shō, ) until 1949. It was a predecessor of Japanese National Railways and the later Japan R ...
(JGR) engineer in the 1930s for electric trains. It is the standard coupler type for all passenger trains in Japan as well as on commuter and subway trains in South Korea.
Shinkansen The , colloquially known in English as the bullet train, is a network of high-speed railway lines in Japan. Initially, it was built to connect distant Japanese regions with Tokyo, the capital, to aid economic growth and development. Beyond l ...
(bullet train) rolling stock utilize a variation of the Shibata coupler developed by Sumitomo Metal Industries in the 1960s which uses rotary tight-lock pins, and which coincidentally bears a closer resemblance to the Scharfenberg coupler rather than the Shibata coupler. File:Michaku.jpg, Shibata close contact ("Mitchaku") coupler File:E4-Shinkansen-Coupler.jpg, Shibata rotary coupler on
E4 Series Shinkansen The was a high-speed shinkansen train type operated by East Japan Railway Company (JR East) in Japan. They were the second series of completely bi-level Shinkansen trainsets to be built in Japan (the other being the E1 series). They previousl ...


Dual couplings and match wagons

Sometimes a wagon with one coupling system needs to be coupled to wagons with another coupling type This may be needed when taking metro rolling stock from its manufacturer to the city where it is to be used. There are two solutions: * use a
barrier vehicle 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 matc ...
(s) which has different couplings at either end. * use a coupling adaptor. * use a match wagon which has the same dual coupling at both ends. Only some kinds of couplings coexist on the end of a wagon at the same time, because amongst other reasons they need to be at the same height. For example, in the Australian state of
Victoria Victoria most commonly refers to: * Victoria (Australia), a state of the Commonwealth of Australia * Victoria, British Columbia, provincial capital of British Columbia, Canada * Victoria (mythology), Roman goddess of Victory * Victoria, Seychelle ...
, engines had the AAR coupler, with buffers, and the chain mounted on a lug cast into the AAR coupler. A
barrier vehicle 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 matc ...
/ wagon in Britain and " transition car" in North America) has different kinds of couplings at each end. If a pair of
barrier vehicle 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 matc ...
s is used, a rake of wagons using coupling A can be inserted into a train otherwise using coupling B. A coupling adaptor or compromise coupler might couple to an AAR coupling on a wagon, and present, for example, a meatchopper coupler or rapid transit coupler to the next wagon. Such an adaptor might weigh . An adapter piece allows a Janney coupler mate with an
SA3 coupler SA3 couplers (also known as СА3 or СА-3 couplers per the typical foundry stamp on top of these couplers, meaning "Советская Автосцепка, 3" in Russian or "Soviet Auto-latch 3" in English) or Willison coupler and Russia ...


Dual coupling


Sets of carriages

Automatic couplers like the Janney are safer in a collision because they help prevent the carriages telescoping. British Rail therefore decided to adopt a Janney variant for its passenger carriages, with the coupler able to swing out of the way for coupling to engines with the traditional buffer and chain system. In New South Wales, sets of carriages were permanently coupled with a fixed bar, since the carriages were disconnected only at the workshops. Freight cars are sometimes coupled in pairs or triplets, using bar couplings in between.
Articulated An articulated vehicle is a vehicle which has a permanent or semi-permanent pivot joint in its construction, allowing it to turn more sharply. There are many kinds, from heavy equipment to buses, trams and trains. Steam locomotives were sometim ...
sets of carriages or wagons share the intermediate bogies, and have no need for couplings in the intermediate positions.


Brake couplings

Couplings are needed for any continuous braking systems.


Electronically controlled brakes

Electronically controlled pneumatic brakes Electronically controlled pneumatic brakes are a type of modern railway braking system which offer improved performance compared to traditional railway air brakes. Overview Traditional train braking systems use pneumatic valves to control and ...
(ECP) need a method of connecting electrically adjacent wagons, both for power and for command signals, and this can be done by plugs and sockets, or by very short range radio signals.


Draw gear

A draw gear (also known as a draft gear) is the assembly behind the coupling at each end of the
wagon A wagon or waggon is a heavy four-wheeled vehicle pulled by draught animals or on occasion by humans, used for transporting goods, commodities, agricultural materials, supplies and sometimes people. Wagons are immediately distinguished from ...
to take care of the compression and tension
force In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a ...
s between the wagons of trains. Early draw gears were made of wood, which was gradually replaced by steel. Janney couplers have the draft gear in a centersill to absorb the pushing and pulling forces (
slack action 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 of ...
). There is also a draw gear behind tightlock couplers,
SA3 coupler SA3 couplers (also known as СА3 or СА-3 couplers per the typical foundry stamp on top of these couplers, meaning "Советская Автосцепка, 3" in Russian or "Soviet Auto-latch 3" in English) or Willison coupler and Russia ...
s, C-AKv couplers, Scharfenberg couplers, and other multi-function couplers. In the case of buffers and chain couplers, the draw gear behind the hooks, if any, will absorb the tension, while the side buffers will absorb the compression. Some couplers may not have a draw gear.


Model railway couplers

On model railroads couplers vary according to scale, and have evolved over many years. Early model trains were coupled using various hook-and-loop arrangements, which were frequently asymmetrical, requiring all cars to be pointing in the same direction. In the larger scales, working scale or near-scale models of Janney couplers were quite common, but proved impractical in HO and smaller scales. For many years, the "X2F" or "Horn-Hook" coupler was quite common in
HO scale HO or H0 is a rail transport modelling scale using a 1:87 scale (3.5 mm to 1 foot). It is the most popular scale of model railway in the world. The rails are spaced apart for modelling standard gauge tracks and trains in HO. NMRA"Mo ...
, as it could be produced as a single piece of moulded plastic. Similarly, for many years, a "lift-hook" coupler known as the ''Rapido'' and developed by
Arnold Arnold may refer to: People * Arnold (given name), a masculine given name * Arnold (surname), a German and English surname Places Australia * Arnold, Victoria, a small town in the Australian state of Victoria Canada * Arnold, Nova Scotia U ...
, a German manufacturer of N-scale model trains, was commonly used in that scale. The chief competitor of both these couplers, more popular among serious modellers, was the Magne-Matic, a magnetically released knuckle coupler developed by Keith and Dale Edwards, and manufactured by Kadee, a company they started. While they closely resemble miniature Janney couplers, they are somewhat different mechanically, with the knuckle pivoting from the center of the coupler head, rather than from the side. A steel pin, designed to resemble an air brake hose, allows the couplers to be released magnetically; the design of the coupler head prevents this from happening unless the train is stopped or reversed with a mated pair of couplers directly over an uncoupling magnet. An earlier, mechanically tripped version of the design had a straight pin extending down from the knuckle itself, which engaged a diamond-shaped mechanical "ramp" between the rails, which had to be raised above rail height when uncoupling was desired. Once the Kadee patents ran out, a number of other manufacturers began to manufacture similar (and compatible) magnetic knuckle couplers. Recently, an exact-scale HO model of the AAR coupler has been designed and manufactured by Frank Sergent. This design uses a tiny stainless steel ball to lock the knuckle closed. Uncoupling is achieved by holding a magnetic wand over the coupler pair to draw the balls out of the locking pockets. In
O scale O scale (or O gauge) is a scale commonly used for toy trains and rail transport modelling. Introduced by German toy manufacturer Märklin around 1900, by the 1930s three-rail alternating current O gauge was the most common model railroad sca ...
, an exact-scale working miniature version of the "Alliance" coupler was manufactured from the 1980s by GAGO models in Australia. Since 2002 it has been marketed by the Waratah Model Railway Company. European modellers tend to use scale hook and chain couplings. In British 00 scale (similar to H0 scale) models the 'tension lock' coupler developed by Tri-ang is standard. This is similar in operation to the meatchopper type of coupling. Remote uncoupling is possible by using a sprung ramp between the rails. The design of the hooks is such that the couplings will not uncouple when under tension (instead depressing the ramp). When the train is pushed over the ramp, it will lift the coupling hooks as the train passes over. By halting the train over the ramp, it is split at this point. While it works well, it is often seen as ugly and obtrusive (although smaller designs are available, these are not always fully compatible with other models) and many British modellers prefer to retrofit either Kadee types or working hook and chain couplings. A recent development is an interchangeable coupling which plugs into a standardised socket, known as NEM 362 and which can be easily unplugged as required. This allows the modeller to easily standardise on whatever coupling is desired, without individual manufacturers needing to change their coupling type. In
7 mm scale 7 mm scale, also known as British 0 scale is a model railway scale of 1:43.5 (or 7 mm to 1 ft; hence its name). The scale is thus different from O scale, American 0 scale (1:48) and O scale, European 0 scale (1:45) For standard ga ...
, scale working
Norwegian coupling A Norwegian coupling (or meat chopper) or claw hammer coupling or pickaxe coupling is a manual coupling consisting of a central buffer with a mechanical hook that drops into a slot in the central buffer. The system is only found on narrow gauge ...
s are now being manufactured by Zamzoodled in the UK. A comparison of coupler types was published in "An introduction to Couplers".


Accidents

Different kinds of coupling have different accident rates. * The
Murulla rail accident The Murulla rail accident involved the collision of the Sydney-bound ''Northern Mail'' with runaway goods wagons near Murrurundi, New South Wales, in the Upper Hunter Valley on 13 September 1926; 26 persons died. A goods train had become divided ...
of 1926 involved the breakage of a "drawhook" leading to a runaway and then a collision. Drawhooks imply " buffers and chain couplers". *
Round Oak rail accident The Round Oak railway accident happened on 23 August 1858 between Brettell Lane railway station, Brettell Lane and Round Oak railway station, Round Oak railway stations, on the Oxford, Worcester and Wolverhampton Railway. The breakage of a defec ...
– 1858 – coupling broke and the rear of train rolled back.


See also

*
Buckeye Steel Castings Buckeye Steel Castings was a Columbus, Ohio steelmaker best known today for its longtime president, Samuel P. Bush, who was the grandfather of President George H. W. Bush and great-grandfather of President George W. Bush. Buckeye, named for the O ...
* Drawbar *
Gangway connection A gangway connection (or, more loosely, a corridor connection) is a flexible connector fitted to the end of a railway coach, enabling passengers to move from one coach to another without danger of falling from the train. Origins: Coaches in Br ...
*
Gender of connectors and fasteners In electrical and mechanical trades and manufacturing, each half of a pair of mating connectors or fasteners is conventionally assigned the designation male or female. The female connector is generally a receptacle that receives and holds th ...
* Jane's World Railways, lists the coupler(s) used on any railway system *
Railway coupling by country 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 ...
*
Railway coupling conversion 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 inco ...
*
Slack action 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 of ...
*
Three-point hitch The three-point hitch (British English: three-point linkage) is a widely used type of hitch for attaching ploughs and other implements to an agricultural or industrial tractor. The three points resemble either a triangle, or the letter A. Three-p ...


Notes


References


Sources

* * *
Norfolk & Western Railway Co. v. Hiles (95-6), 516 U.S. 400 (1996)
( U.S. Supreme Court decision by Justice
Clarence Thomas Clarence Thomas (born June 23, 1948) is an American jurist who serves as an associate justice of the Supreme Court of the United States. He was nominated by President George H. W. Bush to succeed Thurgood Marshall and has served since 1 ...
)
Eli Janney — The Janney Coupler
(based on above case)
Dellner Couplers AB — Automatic and Semi-Permanent Couplers

Vancouver SkyTrain Light Rail Network, Canada
(these two for Dellner data)
JANE'S WORLD RAILWAYS


*


External links


FREIGHT VEHICLE COUPLERS AND DRAFT GEAR

Adapter piece between Janney coupler
and
SA3 coupler SA3 couplers (also known as СА3 or СА-3 couplers per the typical foundry stamp on top of these couplers, meaning "Советская Автосцепка, 3" in Russian or "Soviet Auto-latch 3" in English) or Willison coupler and Russia ...
] {{Authority control Locomotive parts Couplers