A (US and
CanadaCanada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean...
)
classification yard or (UK and
CanadaCanada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean...
)
marshalling yard (including
hump yards) is a railroad
yardA 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 stationsA 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 carA railroad car or railway carriage 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
switchesA 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.
A (US and
CanadaCanada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean...
)
classification yard or (UK and
CanadaCanada is a country occupying most of northern North America, extending from the Atlantic Ocean in the east to the Pacific Ocean in the west and northward into the Arctic Ocean...
)
marshalling yard (including
hump yards) is a railroad
yardA 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 stationsA 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 carA railroad car or railway carriage 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
switchesA 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 trainA unit train, also called a block train, is a railroad 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,
automobileAn automobile, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor...
s from the
plantA factory or manufacturing plant is an industrial building where workers 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||-||-||-||-||-||-||-||-|}A port is a facility for receiving ships and/or transferring cargo. It is usually found at the edge of an ocean, sea, river, or lake. The best ports have deep water in channels or berths, and protection from the wind and waves...
, or
coalCoal is a readily combustible black or brownish-black sedimentary rock normally occurring in rock strata in layers or veins called coal beds. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
from a
mineMining is the extraction of valuable minerals or other geological materials from the earth, usually from an ore body, vein or seam. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock salt and potash...
to the
power plantA power station is an industrial facility for the generation of electric power....
. 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
EuropeEurope 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 water divide of the Ural Mountains, the Ural River, the Caspian Sea, the Caucasus Mountains , and the Black Sea to the southeast...
several major classification yards in
ItalyItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
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 (
SwitzerlandSwitzerland , officially the Swiss Confederation , is a federal republic consisting of 26 states named cantons, with Bern as the seat of the federal authorities...
) or Valea lui Traian (
ConstanţaConstanţa is the oldest living city in Romania, founded around 600 BC. The city is located in the Dobruja region of Romania, on the Black Sea coast...
,
RomaniaRomania is a country located in Southeastern and Central Europe, North of the Balkan Peninsula, on the Lower Danube, within and outside the Carpathian arch, bordering on the Black Sea. Almost all of the Danube Delta is located within its territory...
– this is an incomplete yard with 32 tracks which was planned to be a hump yard but has no hump). In
ArgentinaArgentina, officially the Argentine Republic , is the second largest country in South America, constituted as a federation of 23 provinces and an autonomous city, Buenos Aires. It is the eighth largest country in the world by land area and the largest among Spanish-speaking nations, though Mexico,...
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
retardersIn 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
pneumaticallyPneumatics is the use of pressurized gas to effect mechanical motion.Pneumatics is that branch of technology,which deals with the study and application of use of pressurised gas to affect mechanical motion....
(e.g. in the USA,
FranceFrance , officially the French Republic , is a country located in Western Europe, with several overseas islands and territories located on other continents. Metropolitan France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean...
,
BelgiumThe Kingdom of Belgium is a country in northwest Europe. It is a founding member of the European Union and hosts its headquarters, as well as those of other major international organizations, including NATO...
,
RussiaRussia , officially known as both Russia and the Russian Federation , is a country in northern Eurasia . It is a semi-presidential republic, comprising 83 federal subjects...
or
ChinaChina is a cultural region, an ancient civilization, and, depending on perspective, a national or multinational entity extending over a large area in East Asia....
) or
hydraulicallyHydraulics 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
GermanyGermany , officially the Federal Republic of Germany , is a country in Central Europe. It is bordered to the north by the North Sea, Denmark, and the Baltic Sea; to the east by Poland and the Czech Republic; to the south by Austria and Switzerland; and to the west by France, Luxembourg, Belgium,...
,
ItalyItaly , officially the Italian Republic , is a country located on the Italian Peninsula in Southern Europe and on the two largest islands in the Mediterranean Sea, Sicily and Sardinia. Italy shares its northern, Alpine boundary with France, Switzerland, Austria and Slovenia...
or the
NetherlandsThe Netherlands is a country in Northwestern Europe, constituting the major portion of the Kingdom of the Netherlands. It is a parliamentary democratic constitutional monarchy. The Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east...
).
Classification bowls consist of in 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 which there 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 YardBailey 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 Ed H. Bailey....
in North Platte,
NebraskaNebraska is a state located on the Great Plains of the Midwestern United States. The state's capital is Lincoln and its largest city is Omaha....
, USA. Other large US hump yards include Argentine Yard in
Kansas CityKansas City is the largest city in the U.S. state of Missouri. It encompasses in parts of Jackson, Clay, Cass, and Platte counties. It is one of two county seats of Jackson County, the other being Independence, just to the city's east...
,
MissouriMissouri is a state in the Midwest region of the United States bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. Missouri is the 18th most populous state with a 2008 estimated population of 5,911,605. It comprises 114 counties and one independent city....
, the 2nd largest in the world, Elkhart Young Yard in
ElkhartElkhart 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...
,
IndianaIndiana is a U.S. state, the 19
th admitted to the Union. It is located in the Great Lakes region, and with approximately 6.3 million residents, is ranked 16
th in population and 17
th in population density. Indiana is ranked 38
th in land area, and is the...
,
Clearing YardThe 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
ChicagoChicago is the largest city in the U.S. state of Illinois, and with more than 2.8 million people, the 3rd largest city in the United States...
,
IllinoisIllinois , the 21st state admitted to the United States of America, is the most populous and demographically diverse Midwestern state and the fifth most populous state in the nation...
, Englewood Yard in Houston,
TexasTexas is the second-largest U.S. state in both area and population, and the largest state in the contiguous United States.The name had wide usage among native Americans, meaning "friends" or "allies"...
, and Waycross Rice Yard in
WaycrossWaycross is the county seat of, and only incorporated city in, Ware County in the U.S. state of Georgia. The population was 15,333 at the 2000 Census. A small portion of the city extends into Pierce County. According the U.S...
,
GeorgiaGeorgia is a state in the United States. One of the original Thirteen Colonies that revolted against British rule in the American Revolution, it had been the last of the Thirteen Colonies to be established, in 1733. Georgia was the fourth state to ratify the United States Constitution, on January...
. Notably, in Europe, Russia and China, all important classification yards are hump yards. Europe's largest hump yard is that of Maschen near
HamburgHamburg is the second-largest city in Germany and the sixth-largest city in the European Union...
, Germany; it is only slightly smaller than Bailey Yard. The second largest is in the port of
Antwerp||-||-||-||}Antwerp is a city and municipality in Belgium and the capital of the Antwerp province in Flanders, one of Belgium's three regions. Antwerp's total population is 472,071 and its total area is , giving a population density of 2,308 inhabitants per km²...
, 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.
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 BritainGreat Britain is an island lying to the northwest of Continental Europe. It is the ninth largest island in the world, and the largest European island. With a population of about 59.6 million people, it is the third most populated island on Earth. Great Britain is surrounded by over 1000 smaller...
,
DenmarkDenmark is a Scandinavian country in Northern Europe and the senior member of the Kingdom of Denmark. It is the southernmost of the Nordic countries; southwest of Sweden and south of Norway, and it is bordered to the south by Germany. Denmark borders both the Baltic and the North Sea...
,
NorwayNorway , officially the Kingdom of Norway, is a country in Northern Europe occupying the western portion of the Scandinavian Peninsula, as well as Jan Mayen and the Arctic archipelago of Svalbard under the Spitsbergen Treaty...
,
Japanis an island country in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, People's Republic of 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
AustraliaAustralia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the continental mainland , the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans...
, 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 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
ZawiercieZawiercie 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.- History :...
on the
Warsaw-Vienna RailwayThe 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
RussiaRussia , officially known as both Russia and the Russian Federation , is a country in northern Eurasia . It is a semi-presidential republic, comprising 83 federal subjects...
, now in
PolandPoland , officially the Republic of Poland , is a country in Central Europe . Poland is 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; none seem to be in operation today. The largest active gravity yard is Nürnberg (
NurembergNuremberg is a city in the German state of Bavaria, in the administrative region of Middle Franconia. It is situated on the Pegnitz river and the Rhine-Main-Danube Canal and is Franconia's largest city. It is located about 170 kilometres north of Munich, at 49.27° N 11.5° E. The population is...
) 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.
External links