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57-609: Central Branch may refer to: Central Branch (Long Island Rail Road) Central Branch Union Pacific Railroad Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title Central Branch . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Central_Branch&oldid=927696490 " Category : Disambiguation pages Hidden categories: Short description

114-511: A "conductor rail") for the purpose. On most systems, the conductor rail is placed on the sleeper ends outside the running rails, but in some systems a central conductor rail is used. The conductor rail is supported on ceramic insulators (known as "pots"), at top contact or insulated brackets , at bottom contact, typically at intervals of around 10 feet (3.0 m). The trains have metal contact blocks called collector shoes (also known as contact shoes or pickup shoes) which make contact with

171-532: A 750 V DC third-rail system. The section from Vuosaari to Vuosaari harbour is not electrified, as its only purpose is to connect to the Finnish rail network, whose gauge differs only by a couple of millimetres from that of the metro. The route has been previously used by diesel shunting locomotives moving new metro trains to the electrified section of the line. The new tramway in Bordeaux (France) uses

228-457: A British Class 442 EMU . In the event of a collision with a foreign object, the beveled end ramps of bottom running systems can facilitate the hazard of having the third rail penetrate the interior of a passenger car. This is believed to have contributed to the death of five passengers in the Valhalla train crash of 2015. Modern systems, such as ground-level power supply (first used in

285-423: 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. A third method rivets aluminium bus strips to the web of the steel rail. As with overhead wires, the return current usually flows through one or both running rails, and leakage to ground

342-498: A changeover to third rail made at Drayton Park railway station . A third rail is still used in the tunnel section of the route, because the size of the tunnels leading to Moorgate station was too small to allow for overhead electrification. The North Downs Line is not electrified on those parts of the line where the North Downs service has exclusive use. The electrified portions of the line are: The Helsinki Metro uses

399-521: A dual purpose in that it was to service Stewart's Bethpage Brickworks (within the hamlet now called Old Bethpage ), which was supplying the building materials to the Garden City construction site. The railroad also supplied the new residents of Garden City with both commuter service to Long Island City , where they could then connect to ferries into Manhattan. Service along the Babylon extension also

456-476: A high traffic density. Because of mechanical limitations on the contact to the third rail, trains that use this method of power supply achieve lower speeds than those using overhead electric wires and a pantograph . Nevertheless, they may be preferred inside cities as there is no need for very high speed and they cause less visual pollution . The third rail is an alternative to overhead lines that transmit power to trains by means of pantographs attached to

513-615: A less stable train vehicle. Nevertheless, it was sometimes used at the beginning of the development of electric trains. The oldest electric railway in the world, Volk's Railway in Brighton, England, was originally electrified at 50 volts DC using this system (it is now a three-rail system). Other railway systems that used it were the Gross-Lichterfelde Tramway and the Ungerer Tramway . The third rail

570-496: A level crossing at the Kedzie station in an apparent attempt to urinate. The end ramps of conductor rails (where they are interrupted, or change sides) present a practical limitation on speed due to the mechanical impact of the shoe, and 161 km/h (100 mph) is considered the upper limit of practical third-rail operation. The world speed record for a third rail train is 175 km/h (109 mph) attained on 11 April 1988 by

627-410: A novel system with a third rail in the centre of the track. The third rail is separated into 10 m (32 ft 9 + 3 ⁄ 4  in) long conducting and 3 m (9 ft 10 + 1 ⁄ 8  in) 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

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684-431: A railway locomotive or train, through a semi-continuous rigid conductor placed alongside or between the rails of a railway track . It is used typically in a mass transit or rapid transit system, which has alignments in its own corridors, fully or almost fully segregated from the outside environment. Third-rail systems are usually supplied from direct current electricity. Modern tram systems with street-running avoid

741-562: A sheltered platform and was the last station in service along this branch, discontinued on June 26, 1972. Today, there are several freight customers located along the branch, which is served several times weekly by the New York & Atlantic Railway . It was along this stretch of the Central Branch that Mile-a-Minute Murphy set a record in 1899, pedalling a bicycle for one mile behind a train in less than one minute. As part of

798-438: A smooth engagement of the train's contact shoes. The position of contact between the train and the rail varies: some of the earliest systems used top contact, but later developments use side or bottom contact, which enabled the conductor rail to be covered, protecting track workers from accidental contact and protecting the conductor rail from frost, ice, snow and leaf-fall. Because third-rail systems, which are located close to

855-640: A third rail (current feed, outside the running rails) and fourth rail (current return, midway between the running rails), is used by a few steel-wheel systems; see fourth rail . The London Underground is the largest of these (see railway electrification in Great Britain ). The main reason for using the fourth rail to carry the return current is to avoid this current flowing through the original metal tunnel linings which were never intended to carry current, and which would suffer electrolytic corrosion should such currents flow in them. Another four-rail system

912-508: A train from an external source was by using both rails on which a train runs, whereby each rail is a conductor for each polarity, and is insulated by the sleepers . This method is used by most scale model trains ; however, it does not work as well for large trains as the sleepers are not good insulators. Furthermore, the electric connection requires insulated wheels or insulated axles, but most insulation materials have poor mechanical properties compared with metals used for this purpose, leading to

969-404: Is a power surge or a break in the wires. Depending on train and track geometry, gaps in the conductor rail (e.g., at level crossings and junctions) could allow a train to stop in a position where all of its power pickup shoes are in gaps, so that no traction power is available. The train is then said to be "gapped". Another train must then be brought up behind the stranded train to push it on to

1026-655: Is different from Wikidata All article disambiguation pages All disambiguation pages Central Branch (Long Island Rail Road) The Central Branch is a rail line owned and operated by the Long Island Rail Road (LIRR) in the U.S. state of New York , extending from 40°44′02″N 73°28′12″W  /  40.734°N 73.470°W  / 40.734; -73.470 just east of Bethpage station to 40°41′46″N 73°20′28″W  /  40.696°N 73.341°W  / 40.696; -73.341 just west of Babylon station . It

1083-523: Is line M1 of the Milan Metro , where current is drawn by a lateral, flat bar with side contact, with return via a central rail with top contact. Along some sections on the northern part of the line an overhead line is also in place, to allow line M2's trains (that use pantographs and higher voltage, and have no contact shoes) to access a depot located on line M1. In depots, line M1 trains use pantographs because of safety reasons, with transition made near

1140-659: Is not considered serious. Where trains run on rubber tyres, as on parts of the Lyon Metro , Paris Métro , Mexico City Metro , Santiago Metro , Sapporo Municipal Subway , and on all of the Montreal Metro and some automated guideway transit systems (e.g. the Astram Line ), a live rail must be provided to feed the current. The return is effected through the rails of the conventional track between these guide bars ( see rubber-tyred metro ). Another design, with

1197-459: Is usually located outside the two running rails, but on some systems it is mounted 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" or "under-running") of

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1254-838: The Bethpage station with the Montauk Branch ( Babylon Branch service) at Belmont Junction west of the Babylon station . This allows non-electric Montauk Branch trains that begin or end east of Babylon to use the Main Line from Bethpage to Jamaica . The branch is colored as part of the Ronkonkoma Branch on some LIRR maps, but these trains appear on Babylon and Montauk Branch timetables. There were two stations along this stretch: Farmingdale (later renamed South Farmingdale ) and Breslau. The South Farmingdale station had

1311-717: The Nassau Veterans Memorial Coliseum and Eisenhower Park until Bethpage Junction and then southeast to Babylon via the Babylon Extension. In 1925 the Stewart's Central branch was severed from its connection to the Babylon extension with the reconfiguration of Bethpage Junction . The portion of the line from Garden City to just west of the disconnection at Bethpage Junction were called the Central Extension. The Babylon Extension

1368-575: The New York metropolitan area ; the SEPTA Market–Frankford Line in Philadelphia ; and London's Docklands Light Railway . Electric traction trains (using electric power generated at a remote power station and transmitted to the trains) are considerably more cost-effective than diesel or steam units, where separate power units must be carried on each train. This advantage is especially marked in urban and rapid transit systems with

1425-814: The Pyrenees also features a third rail. Many suburban lines that ran out of the Paris Saint Lazare station used third-rail (bottom contact) feed. To mitigate investment costs, the Rotterdam Metro , basically a third-rail-powered system, has been given some outlying branches built on surface tracks as light rail (called sneltram  [ nl ] in Dutch), with numerous level crossings protected with barriers and traffic lights. These branches have overhead wires. The RandstadRail project also requires Rotterdam Metro trains to run under wires along

1482-546: The loading gauge . There is also a risk of pedestrians walking onto the tracks at level crossings and accidentally touching the third rail, unless grade separation is fully implemented. In the United States, a 1992 Supreme Court of Illinois decision affirmed a $ 1.5 million verdict against the Chicago Transit Authority for failing to stop an intoxicated person from walking onto the tracks at

1539-452: The tramway of Bordeaux in 2003), avoid the safety problem by segmenting the powered rail, with each segment being powered only when fully covered by the vehicle which utilizes its power. Third-rail systems using top contact are prone to accumulations of snow, or ice formed from refrozen snow, and this can interrupt operations. Some systems operate dedicated de-icing trains to deposit an oily fluid or antifreeze (such as propylene glycol ) on

1596-606: The 2020–2024 MTA Capital Program, the Central Branch is proposed to be electrified with third rail . This will alleviate service disruptions by allowing electric trains to travel between the Ronkonkoma and Babylon Branches, which are both electrified. If implemented, this project would mark the first LIRR electrification project since the Ronkonkoma Branch in 1985–1987. The current Central Branch right of way dates back to 1873 when Alexander Stewart chartered and built

1653-677: The Belgian high-speed section and Brussels Midi station or 1.5 kV DC on the railway lines in the south of France for seasonal services. As originally delivered, the Class 373 units were additionally fitted with 750 V DC collection shoes , designed for the journey in London via the suburban commuter lines to Waterloo . A switch between third-rail and overhead collection was performed while running at speed, initially at Continental Junction near Folkestone, and later on at Fawkham Junction after

1710-534: The Central Railroad of Long Island. A line of tracks was built by the CRRLI from Flushing to Bethpage Junction, and later extended to the Babylon shoreline via the aforementioned Babylon Extension. At Garden City a spur line was also built to service residents of Hempstead . At the time, Stewart was building Garden City, one of the first planned suburban communities in the United States. The railroad had

1767-593: The Southern Region third rail network from Farringdon southwards and on overhead line northwards to Bedford , Cambridge and Peterborough . The changeover is made whilst stationary at Farringdon when heading southbound, and at City Thameslink when heading northbound. On the Moorgate to Hertford and Welwyn suburban service routes, the East Coast Main Line sections are 25 kV AC, with

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1824-461: The actual spacing depends on the carrying capacity, maximum speed, and service frequency of the line. One method for reducing current losses (and thus increase the spacing of feeder/substations, 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

1881-420: The conductor rail to prevent the frozen build-up. The third rail can also be heated to alleviate the problem of ice. Unlike overhead line equipment, third-rail systems are not susceptible to strong winds or freezing rain , which can bring down overhead wires and hence disable all trains. Thunderstorms can also disable the power with lightning strikes on systems with overhead wires , disabling trains if there

1938-465: The conductor rail, or a jumper cable may be used to supply enough power to the train to get one of its contact shoes back on the live rail. Avoiding this problem requires a minimum length of trains that can be run on a line. Locomotives have either had the backup of an on-board diesel engine system (e.g., British Rail Class 73 ), or have been connected to shoes on the rolling stock (e.g. Metropolitan Railway ). The first idea for feeding electricity to

1995-556: The conductor rail. The traction current is returned to the generating station through the running rails. In North America, the conductor rail is usually made of high conductivity steel or steel bolted to aluminium to increase the conductivity. Elsewhere in the world, extruded aluminium conductors with stainless steel contact surface or cap, is the preferred technology due to its lower electrical resistance, longer life, and lighter weight. The running rails are electrically connected using wire bonds or other devices, to minimise resistance in

2052-743: The depots away from revenue tracks. Third rail electrification is less visually obtrusive than overhead electrification . Several systems use a third rail for part of the route, and other motive power such as overhead catenary or diesel power for the remainder. These may exist because of the connection of separately owned railways using the different motive systems, local ordinances, or other historical reasons. Several types of British trains have been able to operate on both overhead and third-rail systems, including British Rail Class 313 , 319 , 325 , 350 , 365 , 375/6 , 377/2 , 377/5 , 377/7 , 378/2 , 387 , 373 , 395 , 700 and 717 EMUs, as well as Class 92 locomotives. Network Rail claims to run

2109-401: The electric circuit. Contact shoes can be positioned below, above, or beside the third rail, depending on the type of third rail used: these third rails are referred to as bottom-contact, top-contact, or side-contact, respectively. The conductor rails have to be interrupted at level crossings , crossovers , and substation gaps. Tapered rails are provided at the ends of each section to allow

2166-623: The fact that there are already overhead electric wires on part of the route for freight and Regional Eurostar services, led to the change. Also in London, the West London Line changes power supply between Shepherd's Bush and Willesden Junction , where it meets the North London Line. South of the changeover point, the WLL is third rail electrified, north of there, it is overhead . The cross-city Thameslink service runs on

2223-460: The ground, present electric shock hazards, high voltages (above 1500 V) are not considered safe. A very high current must therefore be used to transfer adequate power to the train, resulting in high resistive losses , and requiring relatively closely spaced feed points ( electrical substations ). The electrified rail threatens electrocution of anyone wandering or falling onto the tracks. This can be avoided by using platform screen doors , or

2280-495: The main lines to serve north and mid Kent. As a consequence, these trains are dual-voltage enabled, as the majority of the routes along which they travel are third-rail electrified. In London, the North London Line changes from third rail to overhead electrification between Richmond and Stratford at Acton Central . The entire route originally used third rail, but several technical electrical earthing problems, plus

2337-550: The opening of the first section of the Channel Tunnel Rail Link . Between Kensington Olympia railway station and North Pole depot , further switchovers were necessary. The dual-voltage system did cause some problems. Failure to retract the shoes when entering France caused severe damage to the trackside equipment, causing SNCF to install a pair of concrete blocks at the Calais end of both tunnels to break off

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2394-401: The risk can be reduced by placing the conductor rail on the side of the track away from the platform, when allowed by the station layout. The risk can also be reduced by having a coverboard , supported by brackets , to protect the third rail from contact, although many systems do not use one. Where coverboards are used, they reduce the structure gauge near the top of rail. This in turn reduces

2451-424: The risk of electrocution by the exposed electric rail by implementing a segmented ground-level power supply , where each segment is electrified only while covered by a vehicle which is using its power. The third-rail system of electrification is not related to the third rail used in dual-gauge railways. Third-rail systems are a means of providing electric traction power to trains using an additional rail (called

2508-415: 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

2565-498: The third rail shoes if they had not been retracted. An accident occurred in the UK when a Eurostar driver failed to retract the pantograph before entering the third-rail system, damaging a signal gantry and the pantograph. On 14 November 2007, Eurostar's passenger operations were transferred to St Pancras railway station and maintenance operations to Temple Mills depot, making the 750 V DC third rail collection equipment redundant and

2622-560: The third rail shoes were removed. The trains themselves are no longer fitted with a speedometer capable of measuring the speed in miles per hour (the indication used to automatically change when the collector shoes were deployed). In 2009, Southeastern began operating domestic services over High Speed 1 trackage from St Pancras using its new Class 395 EMUs. These services operate on the High Speed line as far as Ebbsfleet International or Ashford International , before transferring to

2679-444: The third rail, allowing the protective cover to be mounted directly to its top surface. When the shoe slides along the top surface, it is referred to as "top running". When the shoe slides along the bottom surface, it is less affected by the build-up of snow, ice, or leaves, and reduces the chances of a person being electrocuted by coming in contact with the rail. Examples of systems using under-running third rail include Metro-North in

2736-570: 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 ). 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. The French Culoz–Modane railway

2793-480: The trains. 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, with some systems using 1500 V ( Line 4, Guangzhou Metro , Line 5, Guangzhou Metro , Line 3, Shenzhen Metro ), and direct current (DC) is used. Trains on some lines or networks use both power supply modes (see § Mixed systems below). All third-rail systems throughout

2850-437: The world are energised with DC supplies. Some of the reasons for this are historical. Early traction engines were DC motors, and the then-available rectifying equipment was large, expensive and impractical to install onboard trains. Also, transmission of the relatively high currents required results in higher losses with AC than DC. Substations for a DC system will have to be (typically) about 2 kilometres (1.2 miles) apart, though

2907-546: The world's largest third-rail network. On the southern region of British Rail, freight yards had overhead wires to avoid the electrocution hazards of a third rail. The locomotives were fitted with a pantograph as well as pick-up shoes. The Class 373 used for international high-speed rail services operated by Eurostar through the Channel Tunnel runs on overhead wires at 25 kV AC for most of its journey, with sections of 3 kV DC on Belgian lines between

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2964-667: Was built in 1873 as part of the Babylon Extension of the Central Railroad of Long Island (CRRLI), which was owned by Alexander Turney Stewart . The branch was mostly unused following the 1876 merger of the CRRLI and the LIRR, but in 1925 it was rebuilt and reconfigured to connect Bethpage and Babylon stations. The Central Branch connects the Main Line ( Ronkonkoma Branch service) at Beth Interlocking southeast of

3021-636: Was electrified with 1500 V DC third rail, later converted to overhead wires at the same voltage. Stations had overhead wires from the beginning. The French branch line which serves Chamonix and the Mont Blanc region ( Saint-Gervais-le-Fayet to Vallorcine ) is third rail (top contact) and metre gauge. It continues in Switzerland, partly with the same third-rail system, partly with an overhead line. The 63 km (39 mi) long Train Jaune line in

3078-455: Was fully rebuilt, also in 1925, with the main purpose of providing a connection between the two main trunk lines of the LIRR, the Main Line and Montauk Branch, and thus became known as the aforementioned Central Branch. In 1939 the Central Extension between Garden City and the end of line in Bethpage was abandoned for regular passenger service. During World War II the eastern portion of the rail

3135-558: Was known as the Creedmoor Branch until service ended in the late 1960s and the tracks removed from the LIRR map in the early 1970s. The LIRR used the Central's right of way between Floral Park and Garden City along with the Central's spur line to Hempstead to make up what is the railroad's current day Hempstead Branch . Past the Garden City station the Central Branch continued on a straight path through central Nassau County past

3192-518: Was popular for excursions to the Babylon shoreline and to ferries to Fire Island . In 1876 the CRRLI was acquired by the LIRR and Stewart's line became known as the LIRR's Central Branch. The portion from Flushing to the Creedmoor Rifle Range, which became Creedmoor State Hospital ) was abandoned in 1879, although the tracks were not removed until World War I. The portion from Creedmoor to Floral Park survived as freight service and

3249-400: Was removed and sold for scrap. After World War II a portion of the track was rebuilt to move materials for the construction of Levittown , however, it never again reached Bethpage Junction (thus, nor Babylon), and those tracks too were soon removed. Third rail A third rail , also known as a live rail , electric rail or conductor rail , is a method of providing electric power to

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