A classification yard (
American English
American English, sometimes called United States English or U.S. English, is the set of variety (linguistics), varieties of the English language native to the United States. English is the Languages of the United States, most widely spoken lang ...
, as well as the
Canadian National Railway
The Canadian National Railway Company () is a Canadian Class I freight railway headquartered in Montreal, Quebec, which serves Canada and the Midwestern and Southern United States.
CN is Canada's largest railway, in terms of both revenue a ...
), marshalling yard (
British
British may refer to:
Peoples, culture, and language
* British people, nationals or natives of the United Kingdom, British Overseas Territories and Crown Dependencies.
* British national identity, the characteristics of British people and culture ...
,
Hong Kong
Hong Kong)., Legally Hong Kong, China in international treaties and organizations. is a special administrative region of China. With 7.5 million residents in a territory, Hong Kong is the fourth most densely populated region in the wor ...
,
Indian, and
Australian English
Australian English (AusE, AusEng, AuE, AuEng, en-AU) is the set of variety (linguistics), varieties of the English language native to Australia. It is the country's common language and ''de facto'' national language. While Australia has no of ...
, and the former
Canadian Pacific Railway
The Canadian Pacific Railway () , also known simply as CPR or Canadian Pacific and formerly as CP Rail (1968–1996), is a Canadian Class I railway incorporated in 1881. The railway is owned by Canadian Pacific Kansas City, Canadian Pacific Ka ...
) or shunting yard (Central Europe) is a
railway yard used to accumulate
railway car
A railroad car, railcar ( American and Canadian English), railway wagon, railway carriage, railway truck, railwagon, railcarriage or railtruck (British English and UIC), also called a train car, train wagon, train carriage or train truc ...
s on one of several tracks. First, a group of cars is taken to a track, sometimes called a ''lead'' or a ''drill''. From there, the cars are sent through a series of
switches
In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type o ...
called a ''ladder'' onto the classification tracks. Some larger yards may put the lead on an artificially built hill called a ''hump'' to use the force of gravity to propel the cars through the ladder.
Freight trains that consist of unrelated cars must be made into a train grouped according to their destinations; this
shunting is done at the starting point. Some trains drop and pick up cars along their route in classification yards or at industrial sidings. In contrast is a
unit train
A unit train, also called a block train or a trainload service, is a train in which all cars (wagons) carry the same commodity and are shipped from the same origin to the same destination, without being split up or stored en route.
They are disti ...
that carries, for example,
automobile
A car, or an automobile, is a motor vehicle with wheels. Most definitions of cars state that they run primarily on roads, Car seat, seat one to eight people, have four wheels, and mainly transport private transport#Personal transport, peopl ...
s from the
plant
Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...
to a
port
A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manch ...
, or
coal
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.
Coal i ...
from a
mine to the
power plant
A power station, also referred to as a power plant and sometimes generating station or generating plant, is an industrial facility for the electricity generation, generation of electric power. Power stations are generally connected to an electr ...
.
Flat
Flat yards are constructed on ground too flat to allow a free-fall operation. After a push by a locomotive, freight cars coast to their desired location.
Gravity
Gravity yards were invented in the 19th century, saving shunting engines and instead letting the cars roll by gravity was seen as a major benefit, whereas the larger amount of manual work required to stop the rolling cars in the classification tracks was judged to be not that important. Gravity yards were a historical step in the development of classification yards. They were later judged as inferior to hump yards because it became clear that shunting engines were needed anyway (at least in inclement weather like strong winds or icy temperatures when the oil in the bearings became thick) and because manual labor was becoming increasingly expensive. Thus, only a few gravity yards were ever built, sometimes requiring massive earthwork (one example is the first German gravity yard at Dresden). The historic technique of a gravity yard is today partly presented in
Chemnitz
Chemnitz (; from 1953 to 1990: Karl-Marx-Stadt (); ; ) is the third-largest city in the Germany, German States of Germany, state of Saxony after Leipzig and Dresden, and the fourth-largest city in the area of former East Germany after (East Be ...
-Hilbersdorf gravity yard (museum).
Most gravity yards were built in Germany (especially in the kingdom of
Saxony
Saxony, officially the Free State of Saxony, is a landlocked state of Germany, bordering the states of Brandenburg, Saxony-Anhalt, Thuringia, and Bavaria, as well as the countries of Poland and the Czech Republic. Its capital is Dresden, and ...
) and Great Britain (such as Edgehill, 1873), a few also in some other European countries, for example
Łazy yard near
Zawiercie
Zawiercie () () is a town in southern Poland located in the Silesian Voivodeship with 49,334 inhabitants (2019). It is situated in the Kraków-Częstochowa Upland near the source of the Warta River. The town lies near the historical region of Sil ...
on the
Warsaw–Vienna Railway (in
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukrai ...
). In the US, there were very few old gravity yards; one of the few gravity yards in operation today is CSX's
Readville Yard south of
Boston, Massachusetts
Boston is the capital and most populous city in the Commonwealth (U.S. state), Commonwealth of Massachusetts in the United States. The city serves as the cultural and Financial centre, financial center of New England, a region of the Northeas ...
.
Hump

Hump yards are the largest and most effective classification yards, with the largest
shunting capacity, often several thousand cars a day. They work similarly to gravity yards, but the falling gradient is limited to a small part of the yard, namely the hump. It is the heart of the yard—a lead track on a small hill over which an engine pushes the cars. Single cars, or a block of coupled cars, are uncoupled at or just before the crest of the hump and roll by gravity onto their destination tracks in the area of the yard where the cars are sorted, called the classification bowl. The first hump in Germany (Leipzig) was built in 1858 and in France (Saint-Etienne) in 1863.

The speed of the cars rolling down from the hump into the classification bowl must be regulated according to whether they are full or empty, heavy or light freight, varying number of axles, whether there are few or many cars on the classification tracks, and varying weather conditions, including temperature, wind speed, and direction. In regard to speed regulation, there are two types of hump yards—with or without mechanization by
retarders. In the old non-retarder yards, braking was usually done in Europe by railroaders who laid skates onto the tracks. The skate or
wheel chock was manually (or, in rare cases, mechanically) placed on one or both of the rails so that the treadles or rims of the wheel or wheels caused frictional retardation and resulted in the halting of the railway car. In the United States, riders in cars did this braking. In modern retarder yards, this work is done by mechanized "rail brakes," called retarders, which brake cars by gripping their wheels. They are operated either
pneumatically
Pneumatics (from Greek 'wind, breath') is the use of gas or pressurized air in mechanical systems.
Pneumatic systems used in industry are commonly powered by compressed air or compressed inert gases. A centrally located and electrically- ...
or
hydraulically. Pneumatic systems are prevalent in the United States,
France
France, officially the French Republic, is a country located primarily in Western Europe. Overseas France, Its overseas regions and territories include French Guiana in South America, Saint Pierre and Miquelon in the Atlantic Ocean#North Atlan ...
,
Belgium
Belgium, officially the Kingdom of Belgium, is a country in Northwestern Europe. Situated in a coastal lowland region known as the Low Countries, it is bordered by the Netherlands to the north, Germany to the east, Luxembourg to the southeas ...
,
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...
and
China
China, officially the People's Republic of China (PRC), is a country in East Asia. With population of China, a population exceeding 1.4 billion, it is the list of countries by population (United Nations), second-most populous country after ...
, while hydraulic systems are used in
Germany
Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...
,
Italy
Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...
and the
Netherlands
, Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...
.
Classification bowls in Europe typically consist of 20 to 40 tracks, divided into several fans or balloons of tracks, usually with eight classification tracks following a retarder in each one, often 32 tracks altogether. In the United States, many classification bowls have more than 40 tracks, frequently divided into six to ten classification tracks in each balloon loop.
Bailey Yard in
North Platte, Nebraska, United States, the world's largest classification yard, is a hump yard. Other large American hump yards include Argentine Yard in
Kansas City, Kansas
Kansas City (commonly known as KCK) is the third-most populous city in the U.S. state of Kansas and the county seat of Wyandotte County. It is an inner suburb of the older and more populous Kansas City, Missouri, after which it is named. As ...
, Robert Young Yard in
Elkhart, Indiana
Elkhart ( ) is a city in Elkhart County, Indiana, United States. The population was 53,923 at the 2020 census. The city is located east of South Bend, Indiana. It is the most populous city in the Elkhart–Goshen metropolitan area, which in tu ...
,
Clearing Yard in
Chicago
Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...
,
Illinois
Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...
, Englewood Yard in
Houston
Houston ( ) is the List of cities in Texas by population, most populous city in the U.S. state of Texas and in the Southern United States. Located in Southeast Texas near Galveston Bay and the Gulf of Mexico, it is the county seat, seat of ...
,
Texas
Texas ( , ; or ) is the most populous U.S. state, state in the South Central United States, South Central region of the United States. It borders Louisiana to the east, Arkansas to the northeast, Oklahoma to the north, New Mexico to the we ...
, and Waycross Rice Yard in
Waycross, Georgia
Waycross is the county seat of and only incorporated city in Ware County in the U.S. state of Georgia. The population was 13,942 in the 2020 census.
Waycross gets its name from the city's location at key railroad junctions; lines from six di ...
. Notably, in Europe, Russia, and China, all major classification yards are hump yards. Europe's largest hump yard is that of
Maschen near
Hamburg
Hamburg (, ; ), officially the Free and Hanseatic City of Hamburg,. is the List of cities in Germany by population, second-largest city in Germany after Berlin and List of cities in the European Union by population within city limits, 7th-lar ...
, Germany; it is only slightly smaller than Bailey Yard. The second largest is in the port of
Antwerp
Antwerp (; ; ) is a City status in Belgium, city and a Municipalities of Belgium, municipality in the Flemish Region of Belgium. It is the capital and largest city of Antwerp Province, and the third-largest city in Belgium by area at , after ...
, Belgium. Most hump yards are single yards with one classification bowl, but some, mostly very large, hump yards have two of them, one for each direction, and thus are double yards, such as the Maschen, Antwerp, Clearing, and Bailey yards.
Almost all gravity yards have been retrofitted with humps and are worked as hump yards. Examples include
Chemnitz
Chemnitz (; from 1953 to 1990: Karl-Marx-Stadt (); ; ) is the third-largest city in the Germany, German States of Germany, state of Saxony after Leipzig and Dresden, and the fourth-largest city in the area of former East Germany after (East Be ...
Hilbersdorf (today
Saxon Railway Museum), Dresden Friedrichstadt and Nürnberg (
Nuremberg
Nuremberg (, ; ; in the local East Franconian dialect: ''Nämberch'' ) is the Franconia#Towns and cities, largest city in Franconia, the List of cities in Bavaria by population, second-largest city in the States of Germany, German state of Bav ...
) Rbf (Rbf: ''Rangierbahnhof'', "classification yard"), in Germany.
Unique locomotives
Hump yards sometimes require unique locomotives, for example, where larger frames may ground. For this and other reasons, one can sometimes find locomotives specifically made or converted to work a hump yard. For example, the
British Rail Class 13 was converted from a pair of
British Rail Class 08 to provide more power than one could get with a single Class 08. The class 13s were built because of the risk of grounding with larger units like the
British Rail Class 20. Special locomotives for hump yards in the US were for example the EMD TR family (
EMD TR,
EMD TR1,
EMD TR2,
EMD TR3,
EMD TR4,
EMD TR5 and
EMD TR6). These are often referred to as ''
master and slave'' in GB and ''cow–calf'' in the US.
Image gallery
File:Kornwestheim Ablaufberg 20060318.jpg, A switcher locomotive pushing a car over the hump at Kornwestheim yard
File:MannheimRangierbahnhof 2018-08-10 Luftbild.jpg, Mannheim Rangierbahnhof, Germany, two-sided nearly symmetrical systems for opposing directions
File:Trainyard.bradleygee.jpg, North Yard in Denver, Colorado
Denver ( ) is a List of municipalities in Colorado#Consolidated city and county, consolidated city and county, the List of capitals in the United States, capital and List of municipalities in Colorado, most populous city of the U.S. state of ...
, a typical U.S. classification yard in 2009
File:CNW yard, Chicago.jpg, Chicago and North Western Railway
The Chicago and North Western was a Railroad classes#Class I, Class I railroad in the Midwestern United States. It was also known as the "North Western". The railroad operated more than of track at the turn of the 20th century, and over of t ...
's Proviso Yard in Chicago, Illinois
Chicago is the List of municipalities in Illinois, most populous city in the U.S. state of Illinois and in the Midwestern United States. With a population of 2,746,388, as of the 2020 United States census, 2020 census, it is the List of Unite ...
, December 1942
File:201805 Nanxiang Station Yard III.jpg, Nanxiang Classification Yard in Shanghai, China
See also
*
List of rail yards
This article is a list of important rail yards in geographical order. These listed may be termed Classification, Freight, Marshalling, Shunting, or Switching yards, which are cultural terms generally meaning the same thing no matter which part of ...
*
Siding (rail)
References
Further reading
*International Railway Journal (IRJ), New York. ''Special editions about hump yards in various countries:'' issues II/66, II/70, VI/75, II/80.
*
* Rhodes, Michael: ''The Illustrated History of British Marshalling Yards.'' Sparkford: Haynes Oxford Publishing & Co, 1988. . Out of print.
* Kraft, Edwin: ''The Yard: Railroading's Hidden Half.'' In:
Trains
A train (from Old French , from Latin">-4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ... , from Latin , "to pull, to draw") is a series of connected vehicles th ...
(vol. 62) 2002. Part I: VI/02, pp. 46–67; Part II: VII/02, pp. 36–47. .
* Wegner, Robert: ''Classification yards. Map of the Month.'' In: Trains IV/2003, pp. 42–43.
* Rhodes, Michael: ''North American Railyards.'' St. Paul (US): Motorbooks International (MBI Publishing Company) 2003. .
External links
Time-lapse video of German hump-shunting yard operation
{{Authority control
Articles containing video clips
Rail yards
Railway sidings
Railway stations by type