Dual electrification is a system whereby a railway line is supplied power both via overhead catenary and a third rail. This is done to enable trains that use either system of power to share the same railway line, for example in the case of mainline and suburban trains (as used at Hamburg S-Bahn between 1940 and 1955). [1]
The system is usually used only in exceptional cases as it can lead to problems caused by the interaction of the electric circuits; for example, where one system is powered with direct current and another by alternating current (AC), premagnetisation of the substation transformers of the AC system can occur.
A similar arrangement to dual electrification is one in which both means of powering a train are present, but not live simultaneously. Such arrangements can be found in frontier stations and in sections of railway used for running tests.
Commuter rail or suburban rail is a passenger rail transport service that primarily operates within a metropolitan area, connecting commuters to a central city from adjacent suburbs or commuter towns. Commuter rail systems are considered heavy rail, using electric or diesel trains. Distance charges or zone pricing may be used.
An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, electric multiple units, trolleybuses or trams. The generic term used by the International Union of Railways for the technology is overhead line. It is known variously as overhead catenary, overhead contact line (OCL), overhead contact system (OCS), overhead equipment (OHE), overhead line equipment, overhead lines (OHL), overhead wiring (OHW), traction wire, and trolley wire.
The Northern City Line is a commuter railway line in England, which runs from Moorgate station to Finsbury Park in London with services running beyond. It is part of the Great Northern Route services, and operates as the south-eastern branch of the East Coast Main Line (ECML). It is underground from Moorgate to Drayton Park in Highbury, from which point it runs in a cutting until joining the ECML south of Finsbury Park. Its stations span northern inner districts of Greater London southwards to the City of London, the UK's main financial centre. Since December 2015, its service timetable has been extended to run into the late evenings and at weekends, meeting a new franchise commitment for a minimum of six trains per hour until 23:59 on weekdays and four trains per hour at weekends.
The S-Bahn is a hybrid urban-suburban rail system serving a metropolitan region predominantly in German-speaking countries. Some of the larger S-Bahn systems provide service similar to rapid transit systems, while smaller ones often resemble commuter or even regional rail systems. The name S-Bahn derives from Schnellbahn, Stadtbahn or Stadtschnellbahn.
King's Cross Thameslink station is a closed railway station in central London, England. It is located on Pentonville Road, around 250 metres (0.2 mi) east of King's Cross mainline station. At the time of closure, in 2007, it was served by Thameslink trains and managed by First Capital Connect. Services have been transferred to a new station underneath St Pancras.
A third rail, also known as a live rail, electric rail or conductor rail, is a method of providing electric power to 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.
Moorgate is a central London railway terminus and connected London Underground station on Moorgate in the City of London. Main line railway services for Hertford, Welwyn Garden City and Stevenage are operated by Great Northern, while the Underground station is served by the Circle, Hammersmith & City, Metropolitan and Northern lines.
Railway electrification is the use of electric power for the propulsion of rail transport. Electric railways use either electric locomotives, electric multiple units or both. Electricity is typically generated in large and relatively efficient generating stations, transmitted to the railway network and distributed to the trains. Some electric railways have their own dedicated generating stations and transmission lines, but most purchase power from an electric utility. The railway usually provides its own distribution lines, switches, and transformers.
The Hamburg S-Bahn is a rapid transit railway system in the Hamburg Metropolitan Region. Together, the S-Bahn, the Hamburg U-Bahn, the AKN railway and the regional railway form the backbone of railway public transport in the city and the surrounding area. The network has operated since 1907 as a commuter rail system, under the direction of the state railway, and is a member of the Hamburger Verkehrsverbund. There are four lines, serving 68 stations, on 147 kilometres (91 mi) of route. On an average working day the S-Bahn transports about 590,000 passengers; in 2010 about 221 million people used the S-Bahn.
A pantograph is an apparatus mounted on the roof of an electric train, tram or electric bus to collect power through contact with an overhead line. The term stems from the resemblance of some styles to the mechanical pantographs used for copying handwriting and drawings.
The New Haven Line is a 72.7 mi (117.0 km) commuter rail line operated by the Metro-North Railroad in the U.S. states of New York and Connecticut. Running from New Haven, Connecticut, to New York City, the New Haven Line joins the Harlem Line in Mount Vernon, New York, and continues south to Grand Central Terminal in Manhattan. The New Haven Line carries 125,000 passengers every weekday and 39 million passengers a year. The busiest intermediate station is Stamford, with 8.4 million passengers, or 21% of the line's ridership.
The New Canaan Branch is an 8.2-mile (13 km) long branch line of the Metro-North Railroad New Haven Line that begins from a junction east of downtown Stamford, Connecticut, north to New Canaan. It opened in 1868 as the New Canaan Railroad.
Railroad electrification in the United States began at the turn of the 20th century and comprised many different systems in many different geographical areas, few of which were connected. Despite this situation, these systems shared a small number of common reasons for electrification.
The Great Northern route, formerly known as Great Northern Electrics, is the name given to suburban rail services run on the southern end of Britain's East Coast Main Line and its associated branches. Services operate to or from London King's Cross and London Moorgate. Destinations include Hertford North, Welwyn Garden City, Stevenage, and Cambridge, and in peak hours, additional services run to Peterborough and King's Lynn. Services run through parts of Greater London, Hertfordshire, Bedfordshire, Cambridgeshire, and Norfolk.
Railway electrification in Great Britain began in the late 19th century. A range of voltages has been used, employing both overhead lines and conductor rails. The two most common systems are 25 kV AC using overhead lines, and the 750 V DC third rail system used in Southeast England and on Merseyrail. As of October 2023, 6,065 kilometres (3,769 mi) (38%) of the British rail network was electrified.
The Thameslink Programme, originally Thameslink 2000, was a £6 billion project in south-east England to upgrade and expand the Thameslink rail network to provide new and longer trains between a wider range of stations to the north and to the south of London. The development facilitated new cross-London journeys, which means that passengers no longer have to change trains in London. Work included platform lengthening, station remodelling, new railway infrastructure, and new rolling stock. The project was originally proposed in 1991 following the successful introduction of the initial Thameslink service in 1988. After many delays, planning permission was granted in 2006 and funding was approved in October 2007. Work started in 2009 and was completed on 18 September 2020, although trains over the new routes began running in 2018.
Railway electric traction describes the various types of locomotive and multiple units that are used on electrification systems around the world.
Rapid transit in Germany consists of four U-Bahn systems and 14 S-Bahn systems. The U-Bahn, commonly understood to stand for Untergrundbahn, are conventional rapid transit systems that run mostly underground, while the S-Bahn or Stadtschnellbahn are commuter rail services, that may run underground in the city center and have metro-like characteristics in Munich, Hamburg and Berlin which they only have to a lesser extent in other cities. There are also over a dozen semi-metro or Stadtbahn systems that are rapid transit in the city center and light rail outside.
A battery electric multiple unit (BEMU), battery electric railcar or accumulator railcar is an electrically driven multiple unit or railcar whose energy is derived from rechargeable batteries driving the traction motors.
The New York, New Haven and Hartford Railroad pioneered electrification of main line railroads using high-voltage, alternating current, single-phase overhead catenary. It electrified its mainline between Stamford, Connecticut, and Woodlawn, New York, in 1907 and extended the electrification to New Haven, Connecticut, in 1914. While single-phase AC railroad electrification has become commonplace, the New Haven's system was unprecedented at the time of construction. The significance of this electrification was recognized in 1982 by its designation as a Historic Mechanical Engineering Landmark by the American Society of Mechanical Engineers (ASME).
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