Classification yard
Encyclopedia
British English
British English, or English , is the broad term used to distinguish the forms of the English language used in the United Kingdom from forms used elsewhere...
and Canadian English) is a railroad yard
Rail yard
A rail yard, or railroad yard, is a complex series of railroad tracks for storing, sorting, or loading/unloading, railroad cars and/or locomotives. Railroad yards have many tracks in parallel for keeping rolling stock stored off the mainline, so that they do not obstruct the flow of traffic....
found at some freight train stations
Goods station
A goods station is, in the widest sense, a railway station which is exclusively or predominantly where goods of any description are loaded or unloaded from ships or road vehicles and/or where goods wagons are transferred to local sidings.A station where goods are not specifically received or...
, used to separate railroad car
Railroad car
A railroad car or railway vehicle , also known as a bogie in Indian English, is a vehicle on a rail transport system that is used for the carrying of cargo or passengers. Cars can be coupled together into a train and hauled by one or more locomotives...
s on to one of several tracks. First the cars are taken to a track, sometimes called a lead or a drill. From there the cars are sent through a series of switches
Railroad switch
A railroad switch, turnout or [set of] points is a mechanical installation enabling railway trains to be guided from one track to another at a railway junction....
called a ladder onto the classification tracks. Larger yards tend to 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 isolated cars must be made into trains and divided according to their destinations. Thus the cars must be shunted several times along their route in contrast to a unit train
Unit train
A unit train, also called a block train, is a railway train in which all the cars making it up are shipped from the same origin to the same destination, without being split up or stored en route...
, which carries, for example, automobile
Automobile
An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
s from the plant
Factory
A factory or manufacturing plant is an industrial building where laborers manufacture goods or supervise machines processing one product into another. Most modern factories have large warehouses or warehouse-like facilities that contain heavy equipment used for assembly line production...
to a port
Port
A port is a location on a coast or shore containing one or more harbors where ships can dock and transfer people or cargo to or from land....
, or coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
from a mine
Mining
Mining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
to the power plant
Power station
A power station is an industrial facility for the generation of electric energy....
. This shunting is done partly at the starting and final destinations and partly (for long-distance-hauling) in classification yards.
Types of classification yards
There are three types of classification yards: flat-shunted yards, hump yards and gravity yards.Flat-shunted yards
Here, the tracks lead into a flat shunting neck at one or both ends of the yard where the cars are pushed to sort them into the right track. There are many medium-sized flat yards in the USA and also some which are quite large such as (Houston-) Settegast, Decatur, East Joliet etc.In Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
, several major classification yards in Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
have never had a hump, such as Verona Porta Nuova, Foggia or Villa San Giovanni (Fascio Bolano); other large European flat yards are, for example, Olten (Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
) or Valea lui Traian (Constanţa
Constanta
Constanța is the oldest extant city in Romania, founded around 600 BC. The city is located in the Dobruja region of Romania, on the Black Sea coast. It is the capital of Constanța County and the largest city in the region....
, Romania
Romania
Romania is a country located at the crossroads of Central and Southeastern Europe, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea...
– this is an incomplete yard with 32 tracks which was planned to be a hump yard but has no hump). In Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
, all classification yards with the exception of Villa Maria are flat yards, though some of them have 30 or more tracks.
Hump yards
These are the largest and most effective classification yards with the largest shunting capacity – often several thousand cars a day. The heart of these yards is the hump: a lead track on a hill (hump) over which the cars are pushed by the engine. Single cars, or some coupled cars in a block, are uncoupled just before or at the crest of the hump and roll by gravity into their destination tracks in the classification bowl (the tracks where the cars are sorted).The speed of the cars rolling down from the hump into the classification bowl must be regulated because of the different natural speed of the wagons (full or empty, heavy or light freight, number of axles), the different filling of the tracks (whether there are presently few or many cars on it) and different weather conditions (temperature, wind speed and direction). As concerns speed regulation there are two types of hump yards: without or with mechanisation by retarders
Retarder (railroad)
In rail transport, a retarder is a device installed in a classification yard used to reduce the speed of freight cars as they are sorted into trains. Each retarder consists of a series of stationary brakes surrounding a short section of each rail on the track that grip and slow the cars' wheels...
. In the old non-retarder yards braking was usually done in Europe by railroaders who lay skates onto the tracks, or in the USA by riders on the cars. In the modern retarder yards this work is done by mechanized "rail brakes" called retarders. They are operated either pneumatically
Pneumatics
Pneumatics is a branch of technology, which deals with the study and application of use of pressurized gas to effect mechanical motion.Pneumatic systems are extensively used in industry, where factories are commonly plumbed with compressed air or compressed inert gases...
(e.g. in the USA, France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
or China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
) or hydraulically
Hydraulics
Hydraulics is a topic in applied science and engineering dealing with the mechanical properties of liquids. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the engineering uses of fluid properties. In fluid power, hydraulics is used for the generation, control,...
(e.g. in Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
or the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
).
Classification bowls consist of, on average, 20 to 40 tracks divided into several fans or balloons of tracks, in Europe usually with eight classification tracks following a retarder in each one, often 32 tracks altogether. In the USA, also, many classification bowls have more than 40 tracks (up to 72) of which they are often divided into six to ten tracks in each balloon loop, compared with eight in Europe.
The world's largest classification yard is a hump yard: Bailey Yard
Bailey Yard
Bailey Yard is the world’s largest railroad classification yard. Owned and operated by the Union Pacific Railroad , Bailey Yard is located in North Platte, Nebraska. The yard is named after former Union Pacific President Edd H. Bailey....
in North Platte, Nebraska
Nebraska
Nebraska is a state on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha, on the Missouri River....
, USA. Other large US hump yards include Argentine Yard in Kansas City
Kansas City, Kansas
Kansas City is the third-largest city in the state of Kansas and is the county seat of Wyandotte County. It is a suburb of Kansas City, Missouri, and is the third largest city in the Kansas City Metropolitan Area. The city is part of a consolidated city-county government known as the "Unified...
, Kansas
Kansas
Kansas is a US state located in the Midwestern United States. It is named after the Kansas River which flows through it, which in turn was named after the Kansa Native American tribe, which inhabited the area. The tribe's name is often said to mean "people of the wind" or "people of the south...
, the 2nd largest in the world, Robert Young Yard in Elkhart
Elkhart
Elkhart is the name of some places in the United States of America:*Elkhart, Illinois*Elkhart, Indiana*Elkhart, Iowa*Elkhart, Kansas*Elkhart, Texas*Elkhart County, Indiana*Elkhart Lake, Wisconsin...
, Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...
, Clearing Yard
Belt Railway of Chicago
The Belt Railway of Chicago , headquartered in Chicago, is the largest switching terminal railroad in the United States. It is co-owned by six Class I railroads — BNSF Railway, Canadian National Railway, Canadian Pacific Railway, CSX Transportation, Norfolk Southern Railway, and Union...
in Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...
, Illinois
Illinois
Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...
, Englewood Yard in Houston, Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, and Waycross Rice Yard in Waycross
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 14,725 at the 2010 Census. A small portion of the city extends into Pierce County. According the U.S...
, Georgia
Georgia (U.S. state)
Georgia is a state located in the southeastern United States. It was established in 1732, the last of the original Thirteen Colonies. The state is named after King George II of Great Britain. Georgia was the fourth state to ratify the United States Constitution, on January 2, 1788...
. Notably, in Europe, Russia and China, all important classification yards are hump yards. Europe's largest hump yard is that of Maschen
Maschen Marshalling Yard
Maschen Marshalling Yard near Maschen south of Hamburg on the Hanover–Hamburg railway is the largest marshalling yard in Europe, its size only being exceeded worldwide by the Bailey Yard in the US state of Nebraska....
near Hamburg
Hamburg
-History:The first historic name for the city was, according to Claudius Ptolemy's reports, Treva.But the city takes its modern name, Hamburg, from the first permanent building on the site, a castle whose construction was ordered by the Emperor Charlemagne in AD 808...
, Germany; it is only slightly smaller than Bailey Yard. The second largest is in the port of Antwerp, 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, thus are double yards, such as the Maschen, Antwerp, Clearing, and Bailey yards. According to the PRRT&HS PRR Chronology, the first hump yard in the US was opened May 11, 1903 as part of the Altoona Yards at Bells Mills (East Altoona).
However, due to the transfer of freight transport from rail to road and the containerization of rail freight transport for economical reasons, hump yards are generally in decline. In Great Britain
Great Britain
Great Britain or Britain is an island situated to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island, as well as the largest of the British Isles...
, Denmark
Denmark
Denmark is a Scandinavian country in Northern Europe. The countries of Denmark and Greenland, as well as the Faroe Islands, constitute the Kingdom of Denmark . It is the southernmost of the Nordic countries, southwest of Sweden and south of Norway, and bordered to the south by Germany. Denmark...
, Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
and Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, for example, all hump yards have already been closed.
Gravity yards
These are operated similarly to hump yards but, in contrast to the latter, the whole yard is set up on a continuous falling gradient and there is less use of shunting engines. Typical locations of gravity yards are places where it was difficult to build a hump yard due to the topographyTopography
Topography is the study of Earth's surface shape and features or those ofplanets, moons, and asteroids...
. Most gravity yards were built in Germany and Great Britain, sometimes also in some other European countries, for example Łazy yard near Zawiercie
Zawiercie
Zawiercie is a city in the Silesian Voivodeship of southern Poland with 55,800 inhabitants . It is situated in the Kraków-Częstochowa highland near the source of the Warta River...
on the Warsaw-Vienna Railway
Warsaw-Vienna Railway
The Warsaw-Vienna Railway was a railway system which operated in Congress Poland, a part of the Russian Empire, from 1845 until 1912, when it was nationalized by the Russian government...
(originally in Russian Empire
Russian Empire
The Russian Empire was a state that existed from 1721 until the Russian Revolution of 1917. It was the successor to the Tsardom of Russia and the predecessor of the Soviet Union...
, now in Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
). In the USA, there were only very few old gravity yards; one of the few gravity yards in operation today is CSX's Readville Yard south of Boston, Massachusetts. The largest active gravity yard is Nürnberg (Nuremberg
Nuremberg
Nuremberg[p] is a city in the German state of Bavaria, in the administrative region of Middle Franconia. Situated on the Pegnitz river and the Rhine–Main–Danube Canal, it is located about north of Munich and is Franconia's largest city. The population is 505,664...
) Rbf (Rbf: Rangierbahnhof, "classification yard"), Germany. Gravity yards also have a very large capacity but they need more staff than hump yards and thus they are the most uneconomical classification yards.