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 Russian coupler are
railway coupling
A coupling (or a coupler) is a mechanism typically placed at each end of a rolling stock, 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 ...
s used primarily in
Russia
Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...
and states influenced or not influenced by the former
Soviet Union
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...
, such as Finland, Iran, Poland and Mongolia.
Russian railways originally used
buffers and chain couplers during
Imperial era
The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post- Republican period of ancient Rome. As a polity, it included large territorial holdings around the Medite ...
, however these had several disadvantages: their draft load was limited, they were susceptible to buffer lock, and they were not semiautomatic like the North American
Janney couplers. Conversion to Janney couplers (as
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 ...
and
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 ...
had) was considered, as was development of a new design. The Willison coupler was patented in 1916 by
John Willison from
Derby, England. The
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 ...
company bought it and it started to be used in Germany for some heavy trains and some suburban trains in Paris. In the 1930s, the Soviets improved on this design and then decided to make this coupler standard across the Russian railway system.
Experimentation
In the late 1920s, the
UIC had established a working group for the replacement of the chain link coupler, which restricts the efficiency of freight railroads in a major way. Many railroads ran prototypes. In Germany, coal trains with
Scharfenberg couplers yielded unfavourable results in winter weather, other railroads did similar tests. But the UIC was not able to agree on one replacement. This failure of the UIC, which hampers freight operation in Europe even today, led to the decision by the Soviet Union to move forward without a standard being achieved in the talks.
The coupler was developed in (1932) and named SA3 (abbreviation of Russian , Soviet Automatic-Coupler 3rd Variant) and was an improved version of the Willison coupler, with better design of lock parts and mechanics. Conversion of rolling stock began in 1935. The Second World War delayed the introduction, so that the conversion was completed only 1957.
Operation
Helper locomotives at the end of the train are rarely used in the countries of the former Soviet Union. The load of the freight per train is not as heavy as on American railways.
Although the SA3 coupler is primarily used in the countries of the former Soviet Union, they are visible every day at the transshipping stations, at the eastern borders of the European Union (Poland, Slovakia and Hungary). Since
bogie exchange technology has progressed, this allows for cars with SA3 couplers to regularly operate on the standard gauge tracks. A special
converter car is inserted between standard and
Russian gauge cars for this operation, with different couplers (SA3 and standard) on either end. Although these coupling freight cars have room for cargo, they are always operated empty.
If the vehicle fitted with the SA3 retains its buffers, then a special adapter allows that vehicle to couple to another vehicle fitted with buffers and chain, provided that the buffers have the same spacing or gauge. This appears to be done in Iran.
On the
Uzhhorod–Košice broad-gauge track between
Košice
Košice ( , ; german: Kaschau ; hu, Kassa ; pl, Коszyce) is the largest city in eastern Slovakia. It is situated on the river Hornád at the eastern reaches of the Slovak Ore Mountains, near the border with Hungary. With a population of a ...
and
Uzhhorod
Uzhhorod ( uk, У́жгород, , ; ) is a city and municipality on the river Uzh in western Ukraine, at the border with Slovakia and near the border with Hungary. The city is approximately equidistant from the Baltic, the Adriatic and the ...
,
Ukraine
Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inva ...
, of which the major part is on Slovakian territory, SA3 couplings are used exclusively. The railway is used for ore and coal transports from
Kryvyi Rih
Kryvyi Rih ( uk, Криви́й Ріг , lit. "Curved Bend" or "Crooked Horn"), also known as Krivoy Rog (Russian: Кривой Рог) is the largest city in central Ukraine, the 7th most populous city in Ukraine and the 2nd largest by area. Kr ...
,
Ukraine
Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inva ...
to the
US Steel mill in Košice and coal to the power plant of
Vojany.
In addition, the heavy iron ore trains on the Swedish
Malmbanan began to use SA3 couplings in 1969 after problems with snapping chain couplers and a need for ever increasing capacity with higher train weights. Today,
IORE locomotives haul trains of 68
hopper car
A hopper car (US) or hopper wagon ( UIC) is a type of railroad freight car used to transport loose bulk commodities such as coal, ore, grain, and track ballast. Two main types of hopper car exist: covered hopper cars, which are equipped with ...
s of with a total weight of over over gradients of 1% in harsh weather conditions, from the
LKAB mine in
Kiruna
(; se, Giron ; fi, Kiiruna ) is the northernmost city in Sweden, situated in the province of Lapland. It had 17,002 inhabitants in 2016 and is the seat of Kiruna Municipality (population: 23,167 in 2016) in Norrbotten County. The city was ...
to the ice-free harbour of
Narvik
( se, Áhkanjárga) is the third-largest List of municipalities of Norway, municipality in Nordland Counties of Norway, county, Norway, by population. The administrative centre of the municipality is the Narvik (town), town of Narvik. Some of t ...
,
Norway
Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of ...
using couplings of the SA3 type without any problem. They tried out
Janney couplers, too, when moving beyond 8,000 tons because SA3 hasn't seen much use at such loads before that: in the Soviet Union, freight trains rarely exceeded 6,000 tons. The earlier
SJ Dm3 locomotives have buffers fitted; therefore, they can couple with rolling stock fitted with buffers and chain.
The longest and heaviest train with SA3 couplings ran on 20 February 1986 from Ekibastuz to the Urals, Soviet Union. The composition consisted of 439 coal wagons and several diesel locomotives distributed along the train with a mass of 43,400 tonnes and the total length of .
Heaviest regular load
The heaviest load for the SA3 in Ukraine is 12,000 tonnes.
Future
The new European Automatic Center Coupler (
C-AKv) has been based on this coupler, with the extended features of automatic brake and electric couplings. It also has vertical stability added, so that the coupling cannot fall down and damage the tracks or cause a derailment. It is compatible with the standard SA3 coupler and will have buffers needed for use with the standard
buffers and chain couplers under the long transition period. The electric plugs would be most useful with
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 ...
.
Usage
The former Soviet Union:
* ,
Armenian Railways
* ,
Azerbaijan Railways
Azerbaijan Railways ( az, Azərbaycan Dəmir Yolları) is the national state-owned rail transport operator in the Republic of Azerbaijan. The , gauge network is electrified at 3 kV (3,000 V) DC. The headquarters of the Azerbaij ...
* ,
Belarusian Railway
* ,
Eesti Raudtee
Eesti Raudtee or EVR is the national railway infrastructure company of Estonia. It owns a network of of broad gauge () railway throughout the country, including the used by the Elron commuter trains around Tallinn. Its sole shareholder is the ...
* ,
Georgian Railways
Georgian Railway LLC ( ka, საქართველოს რკინიგზა, tr) is the national railway company of Georgia.
A vital artery linking the Black Sea and the Caspian Sea, it sits on the shortest route between Europe and Ce ...
* ,
Kazakhstan Temir Zholy
Kazakhstan Temir Joly (KTJ; kk, Қазақстан Темір Жолы, Qazaqstan Temır Joly (QTJ)), also National Company Kazakhstan Temir Joly, is the national railway company of Kazakhstan.
Organization
Founded by the government in 2002 as ...
* ,
Kyrgyz Railways
* ,
Latvian Railways
JSC Latvian Railway ( lv, Latvijas dzelzceļš or LDz) was established on 2 September 1991 and is seen as the successor of the Latvian Railway Board (Latvian Railways) which was established on 5 August 1919.
Latvijas dzelzceļš is a state-owned ...
* ,
Lithuanian Railways
Lithuanian Railways ( lt, Lietuvos geležinkeliai), abbreviated LTG, is the national state-owned railway company of Lithuania. It operates most of the railway network in the country.
During 2020, Lithuanian Railways transported 3.34 mi ...
* ,
Calea Ferată din Moldova
Calea Ferată din Moldova (abbreviated as ''CFM'') is the sole railway operator in the Republic of Moldova, responsible for passenger and cargo transportation, as well as railway infrastructure maintenance within the country. The total length o ...
* ,
Russian Railways
Russian Railways (russian: link=no, ОАО «Российские железные дороги» (ОАО «РЖД»), OAO Rossiyskie zheleznye dorogi (OAO RZhD)) is a Russian fully state-owned vertically integrated railway company, both manag ...
* ,
Türkmendemirýollary
* ,
Rail transport in Tajikistan
* ,
Ukrainian Railways
Ukrainian Railways ( uk, Укрзалізниця, Ukrzaliznytsia, abbreviated as UZ) is a state-owned joint-stock company of rail transport in Ukraine, a monopoly that controls the vast majority of the railroad transportation in the country. ...
* ,
Uzbek Railways
The Uzbekistan Railways ( uz, Oʻzbekiston Temir Yoʻllari, script=latn) are the national rail carrier of Uzbekistan
Uzbekistan (, ; uz, Ozbekiston, italic=yes / , ; russian: Узбекистан), officially the Republic of Uzbekistan ( uz, ...
Other countries with extensive usage
* ,
Camrail
* ,
Rail transport in Finland
* ,
Trans-Gabon Railway
The Trans-Gabon Railway (french: Transgabonais) is the only railway in Gabon. It runs east from Owendo port station in Libreville to Franceville via numerous stations, the main ones being Ndjolé, Lopé, Booué, Lastoursville and Moand ...
(called Willison coupler)
* ,
Rail transport in Iran
* ,
Iraqi Republic Railways
Iraqi Republic Railways Company (IRR; ar, الشركة العامة لسكك الحديد العراقية) is the national railway operator in Iraq.
Network
IRR comprises of . IRR has one international interchange, with Chemins de Fer Syri ...
*
Mauritania Railway operated by Société Nationale Industrielle et Minière
* ,
Rail transport in Mongolia
* ,
Rail transport in Turkey
Some usage
* ; Miniature Willison used on some sugarcane
tramways and underground colliery railways.
* ;
Koninklijke Hoogovens (
Tata Steel Europe
Tata Steel Europe Ltd. (formerly Corus Group plc) was a steelmaking company headquartered in London, England, with its main operations in the United Kingdom and the Netherlands. The company was created in 2007, when Tata Group took over ...
): used on railways within the steel plant complex.
* and (
Malmbanan/
Ofotbanen
The Ofoten Line ( no, Ofotbanen) is a railway line in Narvik, Norway. It runs from the Port of Narvik to Riksgränsen on the Norway–Sweden border, where the line continues as the Ore Line via Kiruna and Gällivare to Luleå. The Ofoten Line i ...
); Used exclusively by heavy iron-ore trains.
* (
Broad Gauge Metallurgy Line
Broad Gauge Metallurgy Line ( pl, links=no, Linia Hutnicza Szerokotorowa, LHS) is the longest broad gauge railway line in Poland.
Except for this line and a few very short stretches near border crossings, Poland uses standard gauge. The single- ...
); The longest broad gauge railway line in Poland. It is used only for freight traffic, mainly iron ore and coal.
* (
Uzhhorod–Košice broad-gauge track); Heavy iron-ore transports from
Ukraine
Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inva ...
.
* ; Willison Coupler used in mining and tunneling railroads.
See also
*
C-AKv coupler
*
Draft gear
*
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 ...
*
Janney AAR couplers used by heaviest trains, of .
*
Intermat coupler
*
Longest trains
The length of a train may be measured in number of wagons (for bulk loads such as coal and iron ore) or in metres for general freight. Train lengths and loads on electrified railways, especially lower voltage 3000 V DC and 1500 V DC, are li ...
of
*
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 ...
*
Unicoupler/Intermat
*
Unilink coupler
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 desig ...
References
External
Adapter piece between SA3 couplerand
Janney coupler
{{Railway coupling
Soviet inventions
Couplers