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A classification yard (American English, as well as the Canadian National Railway), marshalling yard (British, Hong Kong, Indian, and Australian English, as well as the Canadian Pacific Railway) or shunting yard (Central Europe) is a railway yard found at some freight train stations, used to separate railway cars onto 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 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, which carries, for example, automobiles from the plant to a port, or coal from a mine to the power plant. This shunting is done partly at the starting and final destinations and partly (for long-distance hauling) in classification yards.
Flat yards are constructed on flat ground, or on a gentle slope, not enough to allow a free-fall operation without locomotives. Freight cars are pushed by a locomotive and coast to their required location. [1]
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 and 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 labour was getting relatively more and more 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-Hilbersdorf gravity yard (museum). [2]
Most gravity yards were built in Germany (especially in the kingdom of Saxony) and in Great Britain (so Edgehill, 1873), [3] a few also in some other European countries, for example Łazy yard near Zawiercie on the Warsaw–Vienna Railway (in Poland). 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.
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. [4] 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 regards to speed regulation, there are two types of hump yards—with or without mechanisation 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 this braking was done by riders on the cars. In the modern retarder yards this work is done by mechanized "rail brakes" called retarders, which brake the cars by gripping the wheels. They are operated either pneumatically or hydraulically. Pneumatic systems are prevalent in the United States, France, Belgium, Russia and China, while hydraulic systems are used in Germany, Italy and the Netherlands. [5]
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, which are often 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, Robert Young Yard in Elkhart, Indiana, Clearing Yard in Chicago, Illinois, Englewood Yard in Houston, Texas, and Waycross Rice Yard in Waycross, Georgia. Notably, in Europe, Russia and China, all major classification yards are hump yards. Europe's largest hump yard is that of Maschen near Hamburg, 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.[ citation needed ]
Almost all gravity yards have been retrofitted with humps and are worked as hump yards. Examples include Chemnitz Hilbersdorf (today Saxon Railway Museum), Dresden Friedrichstadt and Nürnberg (Nuremberg) Rbf (Rbf: Rangierbahnhof, "classification yard"), in Germany.
A train is a series of connected vehicles that run along a railway track and transport people or freight. Trains are typically pulled or pushed by locomotives, though some are self-propelled, such as multiple units or railcars. Passengers and cargo are carried in railroad cars, also known as wagons or carriages. Trains are designed to a certain gauge, or distance between rails. Most trains operate on steel tracks with steel wheels, the low friction of which makes them more efficient than other forms of transport.
A rail yard, railway yard, railroad yard (US) or simply yard, is a series of tracks in a rail network for storing, sorting, or loading and unloading rail vehicles and locomotives. Yards have many tracks in parallel for keeping rolling stock or unused locomotives stored off the main line, so that they do not obstruct the flow of traffic. Cars or wagons are moved around by specially designed yard switcher locomotives (US) or shunter locomotives (UK), a type of locomotive. Cars or wagons in a yard may be sorted by numerous categories, including railway company, loaded or unloaded, destination, car type, or whether they need repairs. Yards are normally built where there is a need to store rail vehicles while they are not being loaded or unloaded, or are waiting to be assembled into trains. Large yards may have a tower to control operations.
Rail freight transport is the use of railways and trains to transport cargo as opposed to human passengers.
Shunting, in railway operations, is the process of sorting items of rolling stock into complete trains, or the reverse. In the United States this activity is known as switching.
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.
Alfred Edward Perlman was a railroad executive, having served as president of the Penn Central Transportation Company and its predecessor, the New York Central Railroad, and later, president of the Western Pacific railroad presiding over its successful turnaround before being absorbed into the present day Union Pacific system.
Enola Yard is a large rail yard located in East Pennsboro Township, Pennsylvania, along the western shore of the Susquehanna River in Harrisburg, Pennsylvania.
The DB Class V90 locomotive is a German diesel-hydraulic locomotive for shunting and freight hauling.
The Knowle and Dorridge rail crash was a fatal rail crash that occurred at Dorridge railway station in Warwickshire, England, on 15 August 1963. Three people died in the crash after a signalman's error routed a small freight train into the path of an express passenger train which slowed but could not stop before colliding with it.
Maschen Marshalling Yard near Maschen south of Hamburg on the Hanover–Hamburg railway in Germany is the largest marshalling yard in Europe, its size only being exceeded worldwide by the Bailey Yard in the US state of Nebraska.
Feltham marshalling yard, also known as Feltham hump yard, was a large railway marshalling yard designed for the concentration of freight traffic to and from South West London, and for transfer to other marshalling yards in London. It was built on the Waterloo–Reading line. It opened in 1918 and was closed by British Railways on 6 January 1969.
Chemnitz-Hilbersdorf is the name of a former freight yard and a halt on the Dresden–Werdau railway in the city of Chemnitz in the German state of Saxony. The halt is today served by Regionalbahn services on the Dresden–Zwickau route as well as by local trains of City-Bahn Chemnitz to Hainichen and central Chemnitz (C15). Both lines run hourly, together they offer a service approximately every 30 minutes in each direction.
Leipzig-Engelsdorf marshalling yard is the central marshalling yard in the Leipzig rail node in the German state of Saxony. Until it was closed in 1994, there was also a marshalling yard at Leipzig-Wahren station. It is located on the Leipzig–Dresden, Engelsdorf–Leipzig-Connewitz and Leipzig-Wahren–Engelsdorf railways in the Leipzig suburb of Engelsdorf. The halts of Leipzig Werkstättenstraße and Leipzig-Engelsdorf Hp are located in the marshalling yard area. It was called Bahnhof Engelsdorf until December 2016.
Dresden-Friedrichstadt station is a freight yard that is, along with the two passenger stations of Dresden Hauptbahnhof and Dresden-Neustadt, a central component of the railway node of Dresden in the German state of Saxony. The station precinct, which is located in the Dresden district of Friedrichstadt, also includes a locomotive depot and a regional passenger station.
Dringhouses Yard was a railway freight marshalling yard on the East Coast Main Line (ECML), south of York railway station in England. The yard was built during the First World War to help with the increase in traffic caused by the support to the British war effort. The yard was modernised in the 1960s, being fitted with a hump (knuckle), to ease shunting operations. It was closed to all traffic in 1987 after the loss of local railfreight traffic around York.
Cedar Hill Yard is a classification yard located in New Haven, North Haven and Hamden, Connecticut, United States. It was built by the New York, New Haven and Hartford Railroad in the early 1890s in and around New Haven's Cedar Hill neighborhood, which gave the yard its name. Electrical catenary for electric locomotives was added to the yard in 1915. To handle increasing traffic as a result of World War I, the yard was greatly expanded between 1917 and 1920 with additional construction along both sides of the Quinnipiac River. The construction project added two humps where railroad cars were sorted into trains by gravity. The yard was further modernized in the 1920s, becoming one of the busiest railroad yards in the United States, and the most important yard in the entire New Haven Railroad system.
The Mannheim Rangierbahnhof is a marshalling yard in Mannheim, Baden-Württemberg, Germany. It is the second-largest marshalling yard in Germany after the Maschen Marshalling Yard.
Northup Avenue Yard is a rail yard located in Providence and Pawtucket, Rhode Island, in the United States. The location has been the site of a rail yard since at least 1899. It was significantly expanded by the New York, New Haven and Hartford Railroad between 1918 and 1921 and made into a hump yard. The hump was removed around 1970, after Penn Central Transportation Company took over the New Haven in 1969. Under Penn Central, the yard was downsized and the hump removed. Conrail superseded Penn Central in 1976 and sold off the yard to the Providence and Worcester Railroad in 1982.
The Argentine Yard is a classification yard of the BNSF Railway in Kansas City, Kansas. With 60 directional tracks and an area of over 3 km2, it is the largest classification yard in the BNSF network. It is located between the Kansas River to the north and the Argentine district of Kansas City (Kansas) to the south, about ten kilometers west of downtown Kansas City, Missouri.