A third rail is a method of providing electricity to power a railway through a continuous rigid conductor alongside the railway track or between the rails. "Railroad" and "Railway" both redirect here For other uses see Railroad (disambiguation. It is used typically in a mass transit or rapid transit system, which has alignments in own corridors, fully or almost fully segregated from the outside environment. A rapid transit, underground, subway, elevated railway or metro(politan system is an electric passenger railway A list of lines or networks equipped with a third rail is provided further below. Third rail systems generally supply direct current to power the trains. Direct current ( DC) is the unidirectional flow of Electric charge. In the early 1900s the third rail system was used to power early rollercoasters such as the Rough Riders (rollercoaster) in Coney Island, New York. The roller coaster is a popular Amusement ride developed for Amusement parks and modern Theme parks LaMarcus Adna Thompson patented the first Rough Riders was a rollercoaster built by WF Mangels and located on Coney Island 's Bowery from 1907 to 1916 Coney Island is a Peninsula, formerly an island in southernmost Brooklyn, New York City, USA with a Beach on the Atlantic Ocean
The third rail system of electrification is unrelated to the third rail used in dual-gauge railways. Dual-gauge or mixed-gauge Railway is a special configuration of railway track, allowing trains of different gauges to use the same track
History
Third-rail electric systems are, apart from on-board batteries, the oldest means of supplying electric power to trains on railways using own corridors, particularly in cities. In electronics a battery is a combination of two or more Electrochemical cells which store chemical Energy which can be converted into electrical energy A train is a connected series of vehicles that move along a track ( Permanent way) to transport freight or passengers from one place to another Overhead power supply was initially almost exclusively used on tramway-like railways, though it also appeared slowly on mainline systems. (This statement describes the general trend; early particular cases may have been different. )
An experimental electric train using this method of power supply was developed by the German firm of Siemens & Halske and shown at the Berlin Industrial Exhibition of 1879. This pioneer electric railway had its third rail placed between running rails. At some early electric railways, though, one of the running rails could be the current conductor, as was the case of the 1883-opened Volk's Electric Railway in Brighton. Volk's Electric Railway (VER is the oldest operating electric railway in the world (the worlds first electric railway in Lichterfelde from 1881 is not operating anymore Soon it was given an additional power rail in 1886 (the railway is still operating). The Giant's Causeway Tramway followed, equipped with an elevated outside third rail in 1883 (but later converted to overhead wire pickup). The Giant's Causeway Tramway, operated by the Giant's Causeway Portrush and Bush Valley Railway & Tramway Company Ltd, was a pioneering gauge electric Narrow gauge The first railway to use the central third rail was the Bessbrook & Newry Tramway, opened in Ireland in 1885 but now, like the Giant's Causeway line, closed. Also in the 1880s third-rail systems began to be used in public urban transport. Trams were first to benefit from it, but they used conductors built in conduit below the road surface (see Conduit current collection), and usually on selected parts of the networks. Conduit current collection was a system of Electric current collection used by electric Trams where the power supply was carried in a channel under the roadway rather This was first tried in Cleveland (1884) and in Denver (1885) and later spread to many big tram networks (e. g. Manhattan, Chicago, Washington DC, London, Paris, all closed) and Berlin (the third rail system in the city was abandoned in the first years of the 20th century after heavy snowfall)) .
A third rail supplied power to the world's first electric underground railway, the City & South London Railway, which opened in 1890 (now part of the Northern Line of the London Underground). The Northern line is a deep-level tube line on the London Underground, coloured black on the Tube map. In 1893 the world's second third-rail powered city railway opened in Britain, the Liverpool Overhead Railway (closed 1956 and dismantled). The Liverpool Overhead Railway (known locally as the Dockers' Umbrella in Liverpool, England, opened on February 4 1893. The first US third-rail powered city railway in revenue use was the 1895-opened Metropolitan West Side Elevated, which soon became part of the Chicago 'L'. The 'L' (variously and sometimes, styled "L" El EL or L) is a Rapid transit system that serves the city of In 1901, Granville Woods, a prominent African-American inventor, was granted a U.S. Patent 687,098, covering various proposed improvements to third rail systems. Granville T Woods ( April 23, 1856 &ndash January 30, 1910) was an African American Inventor. African Americans or Black Americans are citizens or residents of the United States who have origins in any of the black populations of Africa An inventor is a person who creates or discovers a new method form device or other useful means This has been cited to claim that he invented the third rail system of current distribution. However, by that time there had been numerous other patents for electrified third-rail systems, including Thomas Edison's U.S. Patent 263,132 of 1882, and third rails had been in successful use for over a decade, in installations including the rest of Chicago 'elevateds', as well as these in Brooklyn, New York (if not to mention the development outside the US). Brooklyn (named after the Dutch town Breukelen) is one of the five boroughs of New York City. To what extent Woods' ideas were adopted is thus a matter of controversy. [2]
In Paris, third rail appeared in 1900 in the main-line tunnel connecting the Gare d'Orsay to the rest of the CF Paris-Orléans network. Gare d'Orsay is a former Parisian Railway station and hotel built in 1900 to designs by Victor Laloux, Lucien Magne and Émile Bénard Main-line third rail electrification was later expanded to some suburban services.
Top contact third rail (see below) seems to be the oldest form of power collection. Railways pioneering in using other less hazardous types of third rail were the New York Central Railroad on the approach to its NYC's Grand Central Terminal (1907 — another case of a third-rail mainline electrification) and the Hochbahn in Hamburg (1912) — both had bottom contact rail. The New York Central Railroad, known simply as the New York Central in its publicity was a Railroad operating in the Northeastern United States. "Grand Central Station" redirects here For other uses see Grand Central. The Hamburg U-Bahn is a Rapid transit system serving the city of Hamburg, Germany. However, the Manchester-Bury Line of the Lancashire & Yorkshire Railway tried the side contact rail (1917). The Lancashire and Yorkshire Railway (L&YR was a major British railway company before the 1923 Grouping. These technologies appeared in wider use only at the turn of the 1920s and in the 1930s on, e. g. , large-profile lines of the Berlin U-Bahn, the Berlin S-Bahn and the Moscow Metro. The Berlin de U-Bahn (de Untergrundbahn underground railway is a major part of the Public transport system of the German capital Berlin. The Berlin S-Bahn is a Rapid transit system operated by S-Bahn Berlin GmbH, a subsidiary of the Deutsche Bahn. The Moscow Metro (Московское метро which spans almost the entire Russian capital, is the world's second most heavily used Rapid-transit The Hamburg S-Bahn has used a side contact third rail at 1200 V dc since 1939.
In 1956 world's first rubber-tired railway line, Line 11 of Paris Metro, opened. The conductor rail evolved into a pair of guiding rails required to keep the bogie in proper position on the new type of track. This solution was modified on the 1971-opened Namboku Line of Sapporo Subway, where a centrally placed guiding/return rail was used plus one power rail placed laterally as on conventional railways (see photo). is the Rapid transit system in Sapporo Hokkaido, Japan. It is operated by the Sapporo City Transportation Bureau.
The third rail technology at street tram lines has recently been revived in the new system of Bordeaux (2004). The Bordeaux tramway network (French Tramway de Bordeaux) consists of three lines serving the city of Bordeaux in southwestern France. This is a completely new technology (see below).
Third rail is by no means obsolete. There are, however, countries (particularly Japan, South Korea, India, Spain) more eager to adopt overhead wiring to their urban railways. But in the same time there were (and still are) many new third rail systems built elsewhere, including technologically advanced countries (i. e. Copenhagen Metro, Taipei Metro, Wuhan Metro). The Copenhagen Metro, also known simply as the Metro, is a rail Rapid transit system serving Copenhagen, Frederiksberg and Tårnby The Taipei Rapid Transit System ( also known as the MRT (Metropolitan Rapid Transit or the Taipei Metro ( is a Rapid transit system serving a The Wuhan Metro ( is an elevated and underground metro system in the city of Wuhan, China. Bottom powered railways (it may be too specific to use the term 'third rail') are also usually these having rubber-tyred trains, no matter if it is a heavy metro (except two other lines of Sapporo Subway) or a small capacity people mover (PM). is the Rapid transit system in Sapporo Hokkaido, Japan. It is operated by the Sapporo City Transportation Bureau. For the private automobile see People carrier A people mover or automated people mover (APM is a fully automated grade-separated Practically the only type of railways where third rail is no longer used in new systems is regional and long distance rail, which require higher speeds and voltages.
The world speed record for a third rail train is 174 km/h attained on 11 April 1988 by a Class 442 (5Wes). Events 491 - Flavius Anastasius becomes Byzantine Emperor, with the name of Anastasius I. Year 1988 ( MCMLXXXVIII) was a Leap year starting on Friday (link displays 1988 Gregorian calendar) The British Rail Class 442 Wessex Electric (or 5WES) Electrical multiple units were introduced in 1988 on the South Western Main
Using the running rails for power supply
The first idea for feeding electricity to a train from an external source was by using both rails on which a train runs, whereby each rail is a conductor for each pole insulated by the sleepers. This method is used by most model trains, however it does not work so well for large trains as the sleepers are not good insulators, furthermore the use of insulated wheels or insulated axles is required. As most insulation materials have worse static properties compared with metals used for this purpose, this results in a less stable train vehicle. Nevertheless, it was sometimes used at the beginning of the development of electric trains. The following systems used it:
However some trains used for rides for children at beer festivals also use this method for power supply. The Gross Lichterfelde Tramway was the first electrical tramway of the world The Ungerer Tramway was the first electrical tramway in Munich
Technical aspects
The third rail is usually located outside the two running rails, but occasionally runs between them. The electricity is transmitted to the train by means of a sliding shoe, which is held in contact with the rail. On many systems an insulating cover is provided above the third rail to protect employees working near the track; sometimes the shoe is designed to contact the side (called side running) or bottom (called bottom running) of the third rail, allowing the protective cover to be mounted directly to its top surface. When the shoe slides on top, it is referred to as top running. When the shoe slides on the bottom it is not affected by the build-up of snow or leaves.
As with overhead wires, the return current on a third-rail system usually flows through one or both running rails, and leakage to ground is not considered serious. Where trains run on rubber tires, as on parts of the Paris Métro, Mexico City Metro and Santiago Metro, and on all of the Montreal Métro, live guide bars must be provided to feed the current. The Mexico City Metro (formally Sistema de Transporte Colectivo Metro or STC Metro) is a Rubber-tyred metro system that serves Metro de Santiago is South America's most extensive metro system The Montreal Metro is a Rubber-tired metro system and the main form of Public transportation in the city of Montreal, Quebec, Canada The return is effected through the rails of the conventional track between these guide bars (see rubber-tired metro). A rubber-tyred metro (or rubber-tired in non-British English is a form of Rapid transit system that uses a mix of road and rail technology Another design, with a third rail (current feed, outside the running rails) and fourth rail (current return, half way between the running rails), is used by a few steel-wheel systems, see fourth rail. Railway electrification supplies electrical energy to railway Locomotives and Multiple units so they can operate without having a Reciprocating The London Underground is the largest of these, see railway electrification in Great Britain. The London Underground is a Metro system serving a large part of Greater London and neighbouring areas of Essex, Hertfordshire and Buckinghamshire Railway electrification in Great Britain describes the past and present electrification systems used to supply traction current to railways and tramways in Great Britain
On line M1 of the Milan Metro the third rail is used as the return electrical line (with potential near the ground) and the live electrical connection is made with a sliding block on the side of the car contacting an electrical bar parallel to the track approximately 1 m (3') above rail level. The Milan transportation system (Italian Rete metropolitana di Milano) is the transport network of Milan, Italy. In this manner there are four rails. In the northern part of the line the more common overhead line system is used. Overhead lines or overhead wires are used to transmit Electrical energy to Trams Trolleybuses or Trains at a distance from the
The third rail is an alternative to overhead lines that transmit power to trains by means of pantographs attached to the trains. Overhead lines or overhead wires are used to transmit Electrical energy to Trams Trolleybuses or Trains at a distance from the A pantograph is a device that collects electric current from Overhead lines for electric Trains or Trams The term stems from the resemblance to pantograph Whereas overhead-wire systems can operate at 25 kV or more, using alternating current (AC), the smaller clearance around a live rail imposes a maximum of about 1200 V (Hamburg S-Bahn), and direct current (DC) is used. 25 kV 50 Hz AC is a type of Railway electrification system. An alternating current ( AC) is an Electric current whose direction reverses cyclically as opposed to Direct current, whose direction remains constant History The Hamburg S-Bahn developed 1932 from the Hamburg-Altonaer Stadt- und Vorortbahn Hamburg&ndashAltona&ndashBlankenese (at that time still independent cities which Direct current ( DC) is the unidirectional flow of Electric charge. Trains on some lines or networks use both power supply modes (cf. below, "Compromise systems").
One method for reducing current losses (and thus increase the spacing of feeder/sub stations, a major cost in third rail electrification) is to use a composite conductor rail of a hybrid aluminium/steel design. The aluminium is a better conductor of electricity, and a running face of stainless steel gives better wear.
There are several ways of attaching the stainless steel to the aluminium. The oldest is a co-extruded method, where the stainless steel is extruded with the aluminium. This method has suffered, in isolated cases, from de-lamination (where the stainless steel separates from the aluminium); this is said to have been eliminated in the latest co-extruded rails. A second method is an aluminium core, upon which two stainless steel sections are fitted as a cap and linear welded along the centre line of the rail. Because aluminium has a higher coefficient of thermal expansion than steel, the aluminium and steel must be positively locked to provide a good current collection interface. When the Temperature of a substance changes the energy that is stored in the Intermolecular bonds between atoms changes A third method rivets aluminum bus strips to the web of the steel rail. The photo on the right depicts such a rail.
Advantages of third rail
Cost
Third-rail systems are cheaper to install than overhead wire systems, less prone to weather damage (other than flooding and icing, which cause major problems), and better able to fit into areas of reduced vertical clearance, such as tunnels and bridges. In many countries they were perceived as key means of reducing construction costs of tunnels, hence their popularity at underground railways.
Visual appeal
Third-rail systems cause less visual intrusion: they do not need overhead lines, which some people perceive as unsightly. Overhead lines or overhead wires are used to transmit Electrical energy to Trams Trolleybuses or Trains at a distance from the Singapore, for example, has banned overhead wires on lines outside tunnels. Singapore Urban street railways have been built, for example in Bordeaux, that carry the conductor rail within a slotted box in the center of the track (conduit current collection), primarily to avoid unsightly overhead wires and poles. ( Gascon: Bordèu) is a port city in southwest France, with one million inhabitants in its metropolitan area at a 2008 estimate Conduit current collection was a system of Electric current collection used by electric Trams where the power supply was carried in a channel under the roadway rather These resemble the cable slot for a street cable car as seen in San Francisco. A cable car or cable railway is a Mass transit system using rail cars that are propelled by a continuously moving cable running at a constant speed The City and County of San Francisco is the fourth most populous city Rather than a mechanical grip, an insulated electrical pickup extends into the slot.
Robustness
Third-rail systems are more robust than overhead line systems, as the conductor rail is able to take higher mechanical forces than the contact wire of an overhead line system. The shoegear on a train is designed to shear off if it hits the conductor rail too hard, but as a train has many sets of shoegear, it is able to continue its journey. By contrast a pantograph is more likely to get tangled up in the overhead wires and not be able to continue its journey.
Maintenance access
Because it lies near the ground within easy reach, instead of many feet up in the air, a third rail system allows easy maintenance.
Compatibility
Many railways use a third rail and DC power, even where overhead lines would otherwise be practical, due to the high cost of retrofitting. Every expansion of such system must cope with the problem of compatibility. It usually leads for the choice of already existing technology.
Disadvantages of third rail
Third-rail systems have a number of problems and disadvantages, including:
Safety
An unguarded electrified rail carrying more than 50 volts is a safety hazard, and some people have been killed by touching the rail or by stepping on it while attempting to cross the tracks. However, such incidents are usually the result of carelessness on the part of the victim. The principal hazard is probably associated with level crossings. The term level crossing (also called a railroad crossing, road through railroad, railway crossing, train crossing or grade crossing While their number on third rail lines is normally reduced to none, they still occur at some systems, particularly on rural and suburban portions of the network. One notable example of a Metro line running a third rail at ground level is the outer ends of the present Brown Line and Pink Line of the Chicago 'L', running on street level in a densely populated neighborhood. The Brown Line (Ravenswood Service of the Chicago Transit Authority Chicago 'L' Rapid transit system is an 11 The Pink Line (Douglas-Loop Service is a rapid transit line in Chicago, run by the Chicago Transit Authority (CTA as part of the Chicago 'L' system The 'L' (variously and sometimes, styled "L" El EL or L) is a Rapid transit system that serves the city of The conductor is discontinued in the level crossing area. Pedestrians may be discouraged from trespassing into railway area by means of perforated panels difficult to step on (cattle-cum-trespass guards). A cattle grid or cattle guard – also known as a vehicle pass or in New Zealand, a cattle stop – is a type of obstacle used to They are laid between rails alongside the road.
Intercity ground level third rail systems are the norm in the southeast of England, and level crossings are handled in a fashion similar to the Chicago system. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland A few interurban electric railways attempted to utilize third rail in the USA, but these were quickly abandoned as impractical outside New York City commuter lines such as the Long Island Rail Road. In Australia "interurban" is a general term for Intercity rail. The City of New York Both the US and UK intercity systems address safety through extensive fencing and warning signage.
There are urban legends that people have died while urinating on the third rail (the urine stream supposedly completes an electrical circuit that electrocutes the victim); a non-continuous stream has been demonstrated by MythBusters (Season 1, Episode 3) to be unable to conduct electricity [3]. An urban legend or urban myth is a form of modern Folklore consisting of stories thought to be factual by those circulating them Urination, also known as micturition, voiding, and more rarely emiction, is the process of disposing Urine from the Urinary bladder MythBusters is a Popular science Television program produced by Australian firm Beyond Television Productions originally for the This myth may be partially perpetuated by a 1977 incident that occurred in Chicago where an intoxicated pedestrian suffered a fatal electrocution injury while trespassing to urinate on the grade-level CTA Brown Line near Kedzie Avenue. However, the death occurred as a result of the passenger making physical contact with the third rail, not as a result of an electrical circuit being completed via his urine stream[4].
Solutions to safety issues
- A new tramway in Bordeaux, France surmounts the safety problem by using a third rail divided into insulated segments only a few metres long. A tram, tramcar, trolley, trolley car, or streetcar is a railborne vehicle, of lighter weight and construction than a Train ( Gascon: Bordèu) is a port city in southwest France, with one million inhabitants in its metropolitan area at a 2008 estimate This article is about the country For a topic outline on this subject see List of basic France topics. Each segment is live only while completely covered by a tram, so there is no risk of a person or animal coming into contact with a live rail (see Third-rail power for trams and stud contact electrification for more information). For specific light rail systems many of which use the words "light rail" as part of their name see List of light-rail transit systems. The Stud Contact System is a once obsolete Ground-level power supply system for electric Trams Studs were set in the road at intervals and connected to a buried This system would not be suitable for higher speeds, and the cost of breaking the live rail into short sections is considerable. This system was developed mainly for aesthetic reasons, to avoid overhead wires in front of the town hall.
- Other safety precautions can be made to reduce the risk of the third rail. Many subways, such as the BART and the Washington Metro, use sheaths to cover their third rails and always place the rail on the further side of the track away from where passengers would normally be. If someone falls on the tracks, there is room to return safely to the platform (or crawl under the platform) without stepping on the third rail.
Limited capacity
A relatively low voltage is necessary in a third-rail system — otherwise, electricity would arc from the rail to the ground or the running rails — but the resulting higher current (sometimes upwards of 3,000 amperes) causes more proportional voltage drop per mile, meaning that electrical feeder sub-stations have to be set up at frequent intervals along the line (generally no more than 10 miles (16 km) apart), increasing operating costs. A 1992 report, prepared for the California Department of Transportation by Morrison-Knudsen Corporation, states that typical spacing of substations supplying a 600 volt DC track is one mile apart, and the cost of electrifying with third rail is nearly double that of overhead catenary. The California Department of Transportation ( Caltrans) is a Government department in the U Washington Group International was an American corporation which provided integrated engineering construction and management services to businesses and governments around the world [1] The low voltage also means that the system is prone to overload, which makes such systems unsuitable for freight or high-speed trains demanding high amounts of power. These limitations of third-rail systems have largely restricted their use to mass transit systems. Capacity is also limited by speed restrictions. Testing on the southern region of British Rail during the late 1980s/early 1990s established that third rail could handle 160 km/h (100 mph)and that third rail could provide reliable current collection. Testing at greater speeds was not tried as the track tested has a maximum speed of 160 km/h (100 mph). [2]
By comparison, overhead wires can provide 50 kV, and can take roughly ten times the power.
Infrastructure restrictions
Junctions and other pointwork make it necessary to leave gaps in the live rail at times, as do level crossings. The term level crossing (also called a railroad crossing, road through railroad, railway crossing, train crossing or grade crossing This is not usually a problem, as most third-rail rolling stock has multiple current collection shoes along the length of the train, but under certain circumstances it is possible for a train to become "gapped" — stalled with none of its shoes in contact with the live rail. When this happens, it is usually necessary for the train to be shunted back onto a live section either by a rescue locomotive or another service train, although in some circumstances it is possible to use jumper cables to temporarily hook the train's current collectors to the nearest section of live rail. Given that gapping tends to happen at complex, important junctions, it can be a major source of disruption. On the Chicago Transit Authority system the jumper cables are known as stingers; they are insulated poles with a wired contact that may be manually pressed against contact shoes to restart a gapped train. Chicago Transit Authority, also known as CTA, is the operator of mass transit within the City of Chicago, Illinois. Other such problems are implementation-specific, usually have workarounds. Another infrastructure restriction of third rail is that the rail and its safety cover decrease the structure gauge and in turn the loading gauge, potentially blocking access to certain types of equipment. The structure gauge, also called the minimum clearance outline, is the minimum size of Tunnels and Bridges as well as the minimum size of the doors that allow A loading gauge is the envelope or contoured shape within which all Railroad cars, Locomotives coaches Buses Trucks and other
When David Gunn became General Manager of the Washington DC Metro Rail system, he proposed to alleviate crowding by running much more frequent trains as two-car trains instead of the practice the transit authority had of running four-car trains. David Gunn may be David L Gunn (fl 1990s American (& Canadian railroad administrator David Gunn (actor (fl General Manager or GM for short is a descriptive term for certain executives in a Business operation He had to publicly drop this idea, with some embarrassment, when it was pointed out to him that two-car trains can operate only in specific areas of the system because each car only has one shoe, on the same side of the car. Even with the practice of having each car pointing in the opposite direction so that there is a shoe on each side of the train, there are many places in the system where a two-car train would end up gapped.
Inefficient contact
Fallen leaves, snow and other debris on the conductor rail can reduce the efficiency of the contact between the conductor rail and the pickup shoes, leaving trains stalled because of the lack of power. Bottom-contact third rail, as used on the Metro-North Railroad (see Technical aspects above), and numerous other transit systems including the Docklands Light Railway in London and the Market-Frankford Line in Philadelphia, is highly resistant to this problem. The Metro-North Commuter Railroad Company, or MTA Metro-North Railroad, or more commonly Metro-North, is a Suburban commuter rail service The Docklands Light Railway (DLR is a Light rail system serving the redeveloped Docklands area of East London England. London ( ˈlʌndən is the capital and largest urban area in the United Kingdom. The Market–Frankford Line ( MFL) (also called the Market–Frankford Subway–Elevated Line ( MFSE) El or Blue Line) is a Rapid Philadelphia (ˌfɪləˈdɛlfiə
Older systems adopted top-contact third rail before they realised that there would be problems with leaves, etc. , while newer systems have learned from this mistake and use side or bottom contact. However, some relatively new systems in North America, such as the TTC in Toronto, use top-covered top-contact third rails on above-ground portions of its subway system; rarely is the system delayed by electrical problems even after heavy snows. The Toronto Transit Commission ( TTC) is a Public transport authority that operates Buses streetcars, subways and Rapid transit Toronto (təˈrɒntoʊ colloquially pronounced or) is the largest city in Canada and is the provincial capital of Ontario Problems generally arise in other aspects of the system (frozen switches for example) long before snow interferes significantly with electrical pickup. Some systems are less susceptible to this problem due to having mostly underground trackage, or less severe weather.
Compromise systems
Several systems use third rail for part of the system, and other systems such as overhead catenary or diesel power for the remainder. In Physics and Geometry, the catenary is the theoretical Shape of a hanging flexible Chain or Cable when supported at its ends and These may exist because of the connection of separately-owned railways using the different systems, local ordinances, or other historical accidents.
USA
In New York City, electric trains that must use third rail leaving Grand Central Terminal on the former New York Central Railroad (now Metro-North Railroad) switch to overhead lines at Pelham when they need to operate out onto the former New York, New Haven and Hartford Railroad (now Metro North's New Haven Line) line to Connecticut. The City of New York "Grand Central Station" redirects here For other uses see Grand Central. The New York Central Railroad, known simply as the New York Central in its publicity was a Railroad operating in the Northeastern United States. The Metro-North Commuter Railroad Company, or MTA Metro-North Railroad, or more commonly Metro-North, is a Suburban commuter rail service Overhead lines or overhead wires are used to transmit Electrical energy to Trams Trolleybuses or Trains at a distance from the The New York New Haven and Hartford Railroad was a railroad that operated in the northeast United States from 1872 to 1969 Metro-North's New Haven Line runs from New Haven Connecticut southwest to Woodlawn New York on the Harlem Line, where New Haven Line trains Connecticut ( is a state located in the New England region of the northeastern United States of America. The switch is made "on the fly" controlled from the engineer's position.
Also in New York City, due to a prohibition on diesel emissions in tunnels, Metro-North, Long Island Rail Road and Amtrak use diesel locomotives that can also be electrically powered by third-rail. The Metro-North Commuter Railroad Company, or MTA Metro-North Railroad, or more commonly Metro-North, is a Suburban commuter rail service The National Railroad Passenger Corporation, Doing business as Amtrak, is a Government-owned corporation that was organized on May 1, 1971 This kind of locomotive (for example the P32AC-DM or the EMD/Siemens built DM30AC of LIRR), can transition between the two modes while underway. GE Genesis (officially Trademarked GENESIS) is a series of passenger Locomotives produced by GE Transportation Systems, a subsidiary of General The third-rail auxiliary system is not as powerful as the diesel engine, so on open-air (non-tunnel) trackage run the engines typically run in diesel mode, even where third rail power is available. This does not hold true for the DM30ACs, where the electric mode is much more powerful than the diesel.
In Manhattan, New York City, and in Washington, D.C., local ordinances required electrified street railways to draw current from a third rail and return the current to a fourth rail, both installed in a continuous vault underneath the street and accessed by means of a collector that passed through a slot between the running rails. Manhattan Island, in New York Harbor, is much the largest part of the Borough of Manhattan, one of the Five Boroughs which form the City of New York Washington DC ( formally the District of Columbia and commonly referred to as Washington, the District, or simply D When streetcars on such systems entered territory where overhead lines were allowed, they stopped over a pit where a man detached the collector (plow) and the motorman placed a trolley pole on the overhead. Overhead lines or overhead wires are used to transmit Electrical energy to Trams Trolleybuses or Trains at a distance from the See Operation Motorman for the British Army operation in Northern Ireland A motorman is the person who operates an electrified trolley For the weapon see Trolley pole (weapon. trolley pole is a tapered cylindrical pole of Wood or Metal, used to transfer Electricity Some sections of the former London tram system also used the conduit current collection system, also with some tramcars that could collect power from both overhead and under-road sources. London ( ˈlʌndən is the capital and largest urban area in the United Kingdom. Conduit current collection was a system of Electric current collection used by electric Trams where the power supply was carried in a channel under the roadway rather
The Blue Line of Boston's MBTA uses third rail electrification from the start of the line downtown to Airport, where it switches to overhead catenary for the remainder of the line to Wonderland. The Blue Line is one of four subway lines of the MBTA. It runs from northeast to southwest extending from Wonderland station in Revere Massachusetts The Massachusetts Bay Transportation Authority ( MBTA) is "a body politic and corporate and a political subdivision" of the Commonwealth of Massachusetts The Airport Station on the MBTA Blue Line provides a Mass transit connection to Logan International Airport (BOS Dual power supply method was also used on some US interurban railways that made use of newer third rail in suburban areas, and existing overhead streetcar (trolley) infrastructure to reach downtown, for example the Skokie Swift in Chicago. In Australia "interurban" is a general term for Intercity rail. The Yellow Line (Skokie Swift Service, is part of the Chicago Transit Authority 's Chicago 'L' Heavy rail rapid transit system in Chicago Illinois
UK
- See also: Railway electrification in Great Britain
Several types of British trains operate on both overhead and third rail systems, including class 313, 319, 325, 377/2 and formerly by 373 Eurostar trains. Railway electrification in Great Britain describes the past and present electrification systems used to supply traction current to railways and tramways in Great Britain Class 313 Electric multiple units were built by BREL at York Works from 1976 - 77, these being the first second-generation The British Rail Class 319 dual-voltage Electric multiple units (EMU were built by BREL York in two batches from 1987–88 and 1990 The British Rail Class 325 is a dual-voltage Alternating current (AC Electric multiple unit (EMU Train used for postal train services The Class 377 Electrostar Electric multiple units were built by Bombardier Transportation (previously ADtranz) at their Derby Works, from The British Rail Class 373 or TGV-TMST train is an Electric multiple unit that operates Eurostar 's High-speed rail service between Eurostar is a High-speed train service in Western Europe connecting London and Kent in the United Kingdom, with Paris
The Eurostar uses overhead electrical power (at 25 kV AC) in the Channel Tunnel and along High Speed 1, with a pantograph height change required between HS1 and the Channel Tunnel (which is at a unique height). Eurostar is a High-speed train service in Western Europe connecting London and Kent in the United Kingdom, with Paris The Channel Tunnel (Le tunnel sous la Manche also known as the Chunnel, is a undersea rail tunnel linking Folkestone, Kent in England with (The trains are also required to cope with height changes for the French urban and TGV lines. ) Until 14 November 2007, at Fawkham Junction a transition was made on the fly to 750 V DC for the journey through the London suburbs on the standard commuter lines into Waterloo using the third rail system. Events 1533 - Conquistadors from Spain under the leadership of Francisco Pizarro arrive in Cajamarca, Inca Year 2007 ( MMVII) was a Common year starting on Monday of the Gregorian calendar in the 21st century. Fawkham Junction ( is a railway junction that currently connects High Speed 1 with the Kent Rail Network. London ( ˈlʌndən is the capital and largest urban area in the United Kingdom. There are now 25 KV overhead wires all the way into St. Pancras International station, and the class 373 Eurostar trains have had their third-rail current collector shoes removed. St Pancras railway station is a major railway station situated in the St Pancras area of Central London between the British Library and King's Cross
Also in London, the North London Line changes its power supply several times between Richmond and Stratford. The North London Line is a railway line in roughly a circular arc which ran through the inner suburbs of north London, England from Richmond Richmond station is a London Underground and National Rail station located in Richmond in the London Borough of Richmond upon Thames in Stratford station is a Railway station in Stratford, Newham, East London on National Rail, London Underground and The cross-city Thameslink service runs on Southern Region third rail from Farringdon station southwards and on overhead line northwards from Farringdon to Bedford: this change-over is made while stationary. Thameslink is a fifty-station line in the British railway system running north to south from Bedford to Brighton through the Snow Hill tunnel Farringdon station is a London Underground and National Rail station in Clerkenwell, just north of the City of London in the London Borough
Continental Europe
The older lines in the west of the Oslo T-bane system were built with overhead lines (some since converted to third rail) while the eastern lines were built with third rail. Oslo T-bane is the Rapid transit system of Oslo, Norway operated by Oslo T-banedrift on contract from the transit authority Ruter. Trains operating on the older lines can operate both with third rail and overhead lines. To mitigate investment costs, the Rotterdam Metro, basically a third-rail powered system, has been given some outlying branches built on surface as light rail (called 'Sneltram' in Dutch), with numerous level crossings protected with barriers and traffic lights. The Rotterdam Metro is a Rapid transit system operated in Rotterdam by RET. For specific light rail systems many of which use the words "light rail" as part of their name see List of light-rail transit systems. These branches have overhead wires. Similarly, in Amsterdam one 'Sneltram' route goes on Metro tracks and passes to surface alignment in the suburbs, which it shares with standard trams. The Amsterdam Metro is a Rapid transit system in Amsterdam, Netherlands. In most recent developments, the RandstadRail project also requires Rotterdam Metro trains to run under wires on their way along the former mainline railway to The Hague. RandstadRail is a Light rail project in the southern area of the Randstad Conurbation in the west of The Netherlands.
The new tramway in Bordeaux (France) uses a novel system with a third rail in the center of the track. ( Gascon: Bordèu) is a port city in southwest France, with one million inhabitants in its metropolitan area at a 2008 estimate This article is about the country For a topic outline on this subject see List of basic France topics. The third rail is separated into 8 m (26 ' 3 ") long conducting and 3 m (9 ' 10 ") long isolation segments. Each conducting segment is attached to an electronic circuit which will make the segment live once it lies fully beneath the tram (activated by a coded signal sent by the train) and switch it off before it becomes exposed again. This system (called "Alimentation par Sol" (APS), meaning "current supply via ground") is used in various locations around the city but especially in the historic centre: elsewhere the trams use the conventional overhead lines, see also ground-level power supply. Ground-level power supply, also known as surface current collection and Alimentation par Sol ( APS) is a modern method of third-rail electrical Overhead lines or overhead wires are used to transmit Electrical energy to Trams Trolleybuses or Trains at a distance from the Ground-level power supply, also known as surface current collection and Alimentation par Sol ( APS) is a modern method of third-rail electrical In summer 2006 it was announced that two new French tram systems would be using APS over part of their networks. These will be Angers and Reims, with both systems expected to open around 2009–2010. Angers is a city in the Maine-et-Loire department in northwestern France about 300 km south-west of Paris. Reims (alternative English spelling Rheims; riːmz in English and /ʁɛ̃s/ in French) is a city of the Champagne-Ardenne région of northern
The French Fréjus line to Modane was electrified with 1500 V DC third rail, later converted to overhead wires at the same voltage. The Fréjus railway is the international rail connection from Torino, Italy to Modane, France. Modane (Modana is a commune of the Savoie département in France. Stations had overhead wires from the beginning.
Conversions from and to third rail
Despite various technical possibilities of operating stock with dual power collecting modes, the desire to achieve full compatibility of entire networks seems to have been the decisive cause of conversions from third rail to overhead supply (or vice versa).
Suburban corridors in Paris from Gare Saint-Lazare, Gare des Invalides (both CF Ouest) and Gare d'Orsay (CF PO), were electrified from 1924, 1901, 1900 respectively. Invalides is a station of the Paris Métro and RER, located near and named after Les Invalides. Gare d'Orsay is a former Parisian Railway station and hotel built in 1900 to designs by Victor Laloux, Lucien Magne and Émile Bénard The Chemin de Fer de Paris à Orléans, often abbreviated to CF Paris-Orléans, was an early French railway company. They all changed to overhead wires by stages after they became part of a wide scale electrification project of the SNCF network in the 1960s–70s. SNCF ( Société Nationale des Chemins de fer Français) (French National Railway Company is a French public enterprise
In Manchester area, the Bury Line (originally L&YR) was first electrified with overhead wires (1913), then changed to third rail (1917, cf. The Lancashire and Yorkshire Railway (L&YR was a major British railway company before the 1923 Grouping. Railway electrification in Great Britain) and again in 1992 to overhead wires in the course of its adaptation for the Manchester Metrolink. Railway electrification in Great Britain describes the past and present electrification systems used to supply traction current to railways and tramways in Great Britain Manchester Metro redirects here - for the Manchester Metroshuttle free bus routes see Metroshuttle or First Manchester Manchester Metrolink Trams in city centre streets, carrying collector shoes projecting from their bogies, were considered too dangerous for pedestrians and motor traffic to attempt dual-mode technology (in Amsterdam and Rotterdam Sneltram vehicles go out to surface in suburbs, not in busy central areas). The same thing happened to the West Croydon — Wimbledon Line in Greater London (originally electrified by the Southern Railway) when Croydon Tramlink was opened in 2000. The Southern Railway (SR was a British railway company established in the 1923 Grouping. Tramlink (initially known as Croydon Tramlink) is a Tramway system serving the South London area of United Kingdom.
Three lines of five making up the core of Barcelona Metro network changed to overhead power supply from third rail. The Barcelona Metro ( Catalan and Spanish: Metro de Barcelona) part of the Mass transit Public transport system of This operation was also done by stages and completed in 2003.
The opposite took place in south London. The South London Line of the LBSCR network between Victoria and London Bridge was electrified with catenary in 1909. The London Brighton and South Coast Railway (LB&SCR (commonly known as "the Brighton line" was a Railway company in the United Kingdom from 1846 to 1923 The system was later extended to Crystal Palace, Coulsdon North and Sutton. Coulsdon North is a closed Railway station on the Brighton Main Line. In the course of main-line third rail electrification in south-east England, the lines were converted by 1929.
The first overhead electric trains appeared on the de:Hamburg-Altonaer Stadt- und Vorortbahn in 1907. Thirty years later, the main-line railway operator, Deutsche Reichsbahn, influenced by the success of the third-rail Berlin S-Bahn, decided to switch what was now called Hamburg S-Bahn to third rail. The Berlin S-Bahn is a Rapid transit system operated by S-Bahn Berlin GmbH, a subsidiary of the Deutsche Bahn. History The Hamburg S-Bahn developed 1932 from the Hamburg-Altonaer Stadt- und Vorortbahn Hamburg&ndashAltona&ndashBlankenese (at that time still independent cities which The process began in 1940 and was not finished until 1955.
In 1976–1981 the third-rail Viennese U-Bahn U4 Line substituted the Donaukanallinie and Wientallinie of the Stadtbahn, built c1900 and first electrified with overhead wires in 1924. The Vienna U-Bahn is a Rapid transit (metro system consisting of five lines mostly running underground except for the central section of line U6 The Wiener Stadtbahn ( German for "Vienna Metropolitan Railway" was a public transportation system operated under this name from 1898 to 1989 This was part of a big project of consolidated U-Bahn network construction. The other electric Stadtbahn line, whose conversion into heavy rail stock was rejected, still operates under wires with light rail cars (as U6), though it has been thoroughly modernised and significantly extended. As the platforms on the Gürtellinie were not suitable for raising without much intervention into historic Otto Wagner's station architecture, the line would anyway remain incompatible with the rest of the U-Bahn network. Otto Koloman Wagner ( 13 July 1841 – 11 April 1918) was an Austrian Architect. Therefore an attempt of conversion to third rail would have been pointless. In Vienna, paradoxically, the wires were retained for aesthetic (and economic) reasons.
The western portion of the Skokie Swift of the Chicago 'L' changed from catenary wire to third rail in 2004, making it fully compatible with the rest of the system. The Yellow Line (Skokie Swift Service, is part of the Chicago Transit Authority 's Chicago 'L' Heavy rail rapid transit system in Chicago Illinois The 'L' (variously and sometimes, styled "L" El EL or L) is a Rapid transit system that serves the city of
The reasons for building the overhead powered Tyne & Wear Metro network roughly on lines of the long-gone third-rail Tyneside Electrics system in Newcastle area are likely to have roots in economy and psychology rather than in the pursue of compatibility. The Tyne and Wear Metro is a metro system serving stations in Newcastle upon Tyne, Gateshead, South Tyneside North Tyneside and Sunderland, The Tyneside Electric refers to the suburban railways on Tyneside that were electrified by the North Eastern Railway from 1904 onwards and formed one of the earliest At the time of the Metro opening (1980) there were no third-rail light rail vehicles on the market and the latter technology was confined to much more costly heavy rail stock. Also the far-going change of image was desired: the memories of the last stage of operation of the Tyneside Electrics were far from being favourable. This was the construction of the system from scratch after 11 years of ineffective diesel service.
Simultaneous use of third rail and overhead wire
A railway can be electrified with an overhead wire and a third rail at the same time. This was the case, for example, on the Hamburg S-Bahn between 1940 and 1955. A modern example is Birkenwerder Railway Station near Berlin, which has third rail on both sides and overhead wire. However, such systems have problems with the influence of the different supplies. If one supply is DC and the other AC, an undesired premagnetization of the AC transformers can occur. For this reason, double electrification is usually avoided. Double electrification is a system whereby a Railway line is supplied power both via Overhead catenary and a Third rail.
The border station of Modane on the French-Italian Fréjus railway was electrified at both 1500 V DC third rail for French trains and with overhead wires (initially three-phase, later 3000 V DC) for Italian trains. The Fréjus railway is the international rail connection from Torino, Italy to Modane, France. When the French part of the line was converted to overhead wires, the voltage of the wires was dropped to 1500 V DC. Now Italian trains run in Modane feed with 1500 V DC instead of 3000, with half of their power.
Third rail in model trains
In 1906, the famous Lionel electric trains became the first model trains to use a third rail to power the locomotive. Lionel track uses a third rail in the center, while the two outer rails are electrically connected together. This solved the problem two-rail model trains have when the track is arranged to loop back on itsef, as ordinarily this causes a short-circuit. (Even if the loop was gapped, the locomotive would create a short and stop as it crossed the gaps. ) Lionel electric trains also operate on alternating current. The use of alternating current means that a Lionel locomotive cannot be reversed by changing polarity; instead, the locomotive sequences among several states (forward, neutral, backward, for example) each time it is started. Märklin three-rail trains use a short spike of voltage to reverse a relay within the locomotive while it is stopped.
Most model train sets today use only two rails, and supply locomotives with direct current. The voltage and polarity of the current controls the speed and direction of the train. A growing exception is DCC (Digital Command Control), where bi-polar DC is delivered to the rails at a constant voltage, along with digital signals that are decoded within the locomotive; the signals carry addresses that indicate which locomotive is being commanded when multiple locomotives are present on the same track. Digital Command Control (DCC systems are used to operate locomotives on a Model railroad (railway
Some model railroads realistically mimic the third rail configurations of their full-sized counterparts; such models may or may not actually draw power from the third rail (most do not).
List of systems using third rail
See List of rail transport systems using third rail for a complete list. See also Third rail Third rail railways predominantly operate in urban contexts
See also
Notes
External links
- Thomas Edison's third rail patent (1882)
- Lightrail without wires - Paper on Bordeaux' new Tram with street level third rail (by the Transportation Research Board of the National Academies)
- Details of the UK 3rd/4th rail design. Conduit current collection was a system of Electric current collection used by electric Trams where the power supply was carried in a channel under the roadway rather Railway electrification supplies electrical energy to railway Locomotives and Multiple units so they can operate without having a Reciprocating Ground-level power supply, also known as surface current collection and Alimentation par Sol ( APS) is a modern method of third-rail electrical See also Third rail Third rail railways predominantly operate in urban contexts This is a list of rapid transit systems around the world Such systems are commonly called metros subways elevated railways rapid rail or underground railways This is an alphabetical listing of countries and cities that have commuter or suburban railways Railway electrification in Great Britain describes the past and present electrification systems used to supply traction current to railways and tramways in Great Britain A rubber-tyred metro (or rubber-tired in non-British English is a form of Rapid transit system that uses a mix of road and rail technology The Stud Contact System is a once obsolete Ground-level power supply system for electric Trams Studs were set in the road at intervals and connected to a buried The use of a Third rail in Model railroading is a technique that is sometimes applied in order to facilitate easier wiring For specific light rail systems many of which use the words "light rail" as part of their name see List of light-rail transit systems.
- The "third rail" A short history.
- Morrison-Knudsen 1992
Dictionary
third rail
-noun
- The electrified rail that runs besides, or between train tracks to power electric trains.
- (by extension) anything that is dangerous to come into contact with, or is best avoided
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