Pantograph (rail)
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A pantograph (or "pan" or "panto") is an apparatus mounted on the roof of an electric
train In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and Passenger train, transport people or Rail freight transport, freight. Trains are typically pul ...
,
tram A tram (called a streetcar or trolley in North America) is a rail vehicle that travels on tramway tracks on public urban streets; some include segments on segregated right-of-way. The tramlines or networks operated as public transport are ...
or
electric bus An electric bus is a bus that is propelled using electric motors as opposed to an internal combustion engine. Electric buses can store the needed electricity on-board, or be fed continuously from an external source. The majority of buses ...
to collect power through contact with an
overhead line An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. It is known variously as: * Overhead catenary * Overhead contact system (OCS) * Overhead equipmen ...
. By contrast,
battery electric bus A battery electric bus is an electric bus that is driven by an electric motor and obtains energy from on-board batteries. Many trolleybuses use batteries as an auxiliary or emergency power source. In 2018, the National Renewable Energy Laborator ...
es and
trains In rail transport, a train (from Old French , from Latin , "to pull, to draw") 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 (often know ...
are charged at
charging stations A charging station, also known as a charge point or electric vehicle supply equipment (EVSE), is a piece of equipment that supplies electrical power for charging plug-in electric vehicles (including electric cars, electric trucks, electric b ...
. The pantograph is a common type of
current collector Electric current collectors are used by trolleybuses, trams, electric locomotives or EMUs to carry electrical power from overhead lines, electrical third rails, or ground-level power supplies to the electrical equipment of the vehicles. Those for ...
; typically, a single or double wire is used, with the return current running through the
rails Rail or rails may refer to: Rail transport *Rail transport and related matters *Rail (rail transport) or railway lines, the running surface of a railway Arts and media Film * ''Rails'' (film), a 1929 Italian film by Mario Camerini * ''Rail'' ( ...
. The term stems from the resemblance of some styles to the mechanical
pantograph A pantograph (, from their original use for copying writing) is a mechanical linkage connected in a manner based on parallelograms so that the movement of one pen, in tracing an image, produces identical movements in a second pen. If a line dr ...
s used for copying handwriting and drawings.


Invention

The pantograph, with a low-friction, replaceable
graphite Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large ...
contact strip or "shoe" to minimise lateral stress on the contact wire, first appeared in the late 19th century. Early versions include the bow collector, invented in 1889 by Walter Reichel, chief engineer at
Siemens & Halske Siemens & Halske AG (or Siemens-Halske) was a German electrical engineering company that later became part of Siemens. It was founded on 12 October 1847 as ''Telegraphen-Bauanstalt von Siemens & Halske'' by Werner von Siemens and Johann Ge ...
in Germany, and a flat slide-pantograph first used in 1895 by the
Baltimore and Ohio Railroad The Baltimore and Ohio Railroad was the first common carrier railroad and the oldest railroad in the United States, with its first section opening in 1830. Merchants from Baltimore, which had benefited to some extent from the construction of ...
The familiar diamond-shaped roller pantograph was devised and patented by John Q. Brown of the
Key System The Key System (or Key Route) was a privately owned company that provided mass transit in the cities of Oakland, Berkeley, Alameda, Emeryville, Piedmont, San Leandro, Richmond, Albany, and El Cerrito in the eastern San Francisco Bay Area fr ...
shops for their commuter trains which ran between
San Francisco San Francisco (; Spanish language, Spanish for "Francis of Assisi, Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the List of Ca ...
and the
East Bay The East Bay is the eastern region of the San Francisco Bay Area and includes cities along the eastern shores of the San Francisco Bay and San Pablo Bay. The region has grown to include inland communities in Alameda and Contra Costa counties ...
section of the
San Francisco Bay Area The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area Go ...
in
California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...
. They appear in photographs of the first day of service, 26 October 1903. For many decades thereafter, the same diamond shape was used by electric-rail systems around the world and remains in use by some today. The pantograph was an improvement on the simple
trolley pole A trolley pole is a tapered cylindrical pole of wood or metal, used to transfer electricity from a "live" (electrified) overhead wire to the control and the electric traction motors of a tram or trolley bus. It is a type of current collector. ...
, which prevailed up to that time, primarily because the pantograph allows an electric-rail vehicle to travel at much higher speeds without losing contact with the overhead lines, e.g. due to dewirement of the trolley pole. Notwithstanding this, trolley pole current collection was used successfully at up to on the
Electroliner The Electroliners are a pair of streamlined interurban trainsets built by the St. Louis Car Company in 1941. Initially numbered 801–802 and 803–804, they were operated by the Chicago North Shore and Milwaukee Railroad from 1941 to 1963, fo ...
vehicles of the
Chicago North Shore and Milwaukee Railroad The Chicago North Shore and Milwaukee Railroad (reporting mark CNSM), also known as the North Shore Line, was an interurban railroad that operated passenger and freight service over an route between the Chicago Loop and downtown Milwaukee, as w ...
, also known as the North Shore Line.


Modern use

The most common type of pantograph today is the so-called half-pantograph (sometimes 'Z'-shaped), which evolved to provide a more compact and responsive single-arm design at high speeds as trains got faster. Louis Faiveley invented this type of pantograph in 1955. The half-pantograph can be seen in use on everything from very fast trains (such as the
TGV The TGV (french: Train à Grande Vitesse, "high-speed train"; previously french: TurboTrain à Grande Vitesse, label=none) is France's intercity high-speed rail service, operated by SNCF. SNCF worked on a high-speed rail network from 1966 to 19 ...
) to low-speed urban tram systems. The design operates with equal efficiency in either direction of motion, as demonstrated by the
Swiss Swiss may refer to: * the adjectival form of Switzerland * Swiss people Places * Swiss, Missouri * Swiss, North Carolina *Swiss, West Virginia * Swiss, Wisconsin Other uses *Swiss-system tournament, in various games and sports *Swiss Internation ...
and
Austrian Austrian may refer to: * Austrians, someone from Austria or of Austrian descent ** Someone who is considered an Austrian citizen, see Austrian nationality law * Austrian German dialect * Something associated with the country Austria, for example: ...
railways whose newest high performance locomotives, the
Re 460 The Re 460 (popularly known as the Lok 2000) series are modern four-axle electric locomotives of the Swiss Federal Railways. Upon their entry into service in the early 1990s, they replaced the , Ae 4/7, and series units, and displaced many of t ...
and
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, operate with them set in the opposite direction. In Europe the geometry and shape of the pantographs are specified by
CENELEC CENELEC (french: Comité Européen de Normalisation Électrotechnique; en, European Committee for Electrotechnical Standardization) is responsible for European standardization in the area of electrical engineering. Together with ETSI (telecommun ...
, the European Committee for Electrotechnical Standardization.


Technical details

The electric transmission system for modern
electric rail A railway electrification system supplies electric power to Rail transport, railway trains and trams without an on-board Prime mover (locomotive), prime mover or local fuel supply. Electric railways use either electric locomotives (hauling pa ...
systems consists of an upper, weight-carrying wire (known as a
catenary In physics and geometry, a catenary (, ) is the curve that an idealized hanging chain or cable assumes under its own weight when supported only at its ends in a uniform gravitational field. The catenary curve has a U-like shape, superfici ...
) from which is suspended a contact wire. The pantograph is spring-loaded and pushes a contact shoe up against the underside of the contact wire to draw the current needed to run the train. The steel rails of the tracks act as the electrical return. As the train moves, the contact shoe slides along the wire and can set up standing waves in the wires which break the contact and degrade current collection. This means that on some systems adjacent pantographs are not permitted. Pantographs are the successor technology to
trolley pole A trolley pole is a tapered cylindrical pole of wood or metal, used to transfer electricity from a "live" (electrified) overhead wire to the control and the electric traction motors of a tram or trolley bus. It is a type of current collector. ...
s, which were widely used on early streetcar systems. Trolley poles are still used by
trolleybus A trolleybus (also known as trolley bus, trolley coach, trackless trolley, trackless tramin the 1910s and 1920sJoyce, J.; King, J. S.; and Newman, A. G. (1986). ''British Trolleybus Systems'', pp. 9, 12. London: Ian Allan Publishing. .or trol ...
es, whose freedom of movement and need for a two-wire circuit makes pantographs impractical, and some streetcar networks, such as the
Toronto streetcar system The Toronto streetcar system is a network of nine streetcar routes in Toronto, Ontario, Canada, operated by the Toronto Transit Commission (TTC). It is the busiest light-rail system in North America. The network is concentrated primarily in D ...
, which have frequent turns sharp enough to require additional freedom of movement in their current collection to ensure unbroken contact. However, many of these networks, including Toronto's, are undergoing upgrades to accommodate pantograph operation. Pantographs with overhead wires are now the dominant form of current collection for modern electric trains because, although more fragile than a
third rail 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 t ...
system, they allow the use of higher voltages. Pantographs are typically operated by compressed air from the vehicle's braking system, either to raise the unit and hold it against the conductor or, when springs are used to effect the extension, to lower it. As a precaution against loss of pressure in the second case, the arm is held in the down position by a catch. For high-voltage systems, the same air supply is used to "blow out" the
electric arc An electric arc, or arc discharge, is an electrical breakdown of a gas that produces a prolonged electrical discharge. The electric current, current through a normally Electrical conductance, nonconductive medium such as air produces a plasma (p ...
when roof-mounted
circuit breakers A circuit breaker is an electrical safety device designed to protect an electrical circuit from damage caused by an overcurrent or short circuit. Its basic function is to interrupt current flow to protect equipment and to prevent the risk ...
are used.


Single and double pantographs

Pantographs may have either a single or a double arm. Double-arm pantographs are usually heavier, requiring more power to raise and lower, but may also be more fault-tolerant. On railways of the former
USSR The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...
, the most widely used pantographs are those with a double arm ("made of two rhombs"), but, since the late 1990s, there have been some single-arm pantographs on Russian railways. Some streetcars use double-arm pantographs, among them the Russian KTM-5, KTM-8, LVS-86 and many other Russian-made trams, as well as some Euro-PCC trams in Belgium. American streetcars use either
trolley pole A trolley pole is a tapered cylindrical pole of wood or metal, used to transfer electricity from a "live" (electrified) overhead wire to the control and the electric traction motors of a tram or trolley bus. It is a type of current collector. ...
s or single-arm pantographs.


Metro systems and overhead lines

Most
rapid transit Rapid transit or mass rapid transit (MRT), also known as heavy rail or metro, is a type of high-capacity public transport generally found in urban areas. A rapid transit system that primarily or traditionally runs below the surface may be c ...
systems are powered by a
third rail 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 t ...
, but some use pantographs, particularly ones that involve extensive above-ground running. Most hybrid metro-tram or 'pre-metro' lines whose routes include tracks on city streets or in other publicly accessible areas, such as line 51 of the
Amsterdam Metro The Amsterdam Metro ( nl, Amsterdamse metro) is a rapid transit system serving Amsterdam, Netherlands, and extending to the surrounding municipalities of Diemen and Ouder-Amstel. Until 2019 it also served the municipality of Amstelveen but thi ...
, the
MBTA Green Line The Green Line is a light rail system run by the Massachusetts Bay Transportation Authority (MBTA) in the Boston, Massachusetts, metropolitan area. It is the oldest MBTA subway line, and with tunnel sections dating from 1897, the oldest subway ...
,
RTA Rapid Transit RTA Rapid Transit (generally known as The Rapid) is a rapid transit, light rail, and bus rapid transit system. The system is owned and operated by the Greater Cleveland Regional Transit Authority (GCRTA). The system serves Cleveland and surround ...
in Cleveland, Frankfurt am Main U-Bahn, and San Francisco's
Muni Metro Muni Metro is a light rail system serving San Francisco, California, United States. Operated by the San Francisco Municipal Railway (Muni), a part of the San Francisco Municipal Transportation Agency (SFMTA), Muni Metro served an average of 157 ...
, use overhead wire, as a standard third rail would obstruct street traffic and present too great a risk of electrocution. Among the various exceptions are several tram systems, such as the ones in
Bordeaux Bordeaux ( , ; Gascon oc, Bordèu ; eu, Bordele; it, Bordò; es, Burdeos) is a port city on the river Garonne in the Gironde department, Southwestern France. It is the capital of the Nouvelle-Aquitaine region, as well as the prefectur ...
,
Angers Angers (, , ) is a city in western France, about southwest of Paris. It is the prefecture of the Maine-et-Loire department and was the capital of the province of Anjou until the French Revolution. The inhabitants of both the city and the prov ...
,
Reims Reims ( , , ; also spelled Rheims in English) is the most populous city in the French department of Marne, and the 12th most populous city in France. The city lies northeast of Paris on the Vesle river, a tributary of the Aisne. Founded by ...
and
Dubai Dubai (, ; ar, دبي, translit=Dubayy, , ) is the most populous city in the United Arab Emirates (UAE) and the capital of the Emirate of Dubai, the most populated of the 7 emirates of the United Arab Emirates.The Government and Politics of ...
that use a proprietary underground system developed by
Alstom Alstom SA is a French multinational rolling stock manufacturer operating worldwide in rail transport markets, active in the fields of passenger transportation, signalling, and locomotives, with products including the AGV, TGV, Eurostar, Avelia ...
, called APS, which only applies power to segments of track that are completely covered by the tram. This system was originally designed to be used in the historic centre of Bordeaux because an overhead wire system would cause a visual intrusion. Similar systems that avoid overhead lines have been developed by Bombardier,
AnsaldoBreda Hitachi Rail Italy S.p.A. is a multinational rolling stock manufacturer company based in Pistoia, Italy. Formerly AnsaldoBreda S.p.A., a subsidiary of state-owned Finmeccanica, the company was sold in 2015 to Hitachi Rail of Japan. After the ...
, CAF, and others. These may consist of physical ground-level infrastructure, or use energy stored in battery packs to travel over short distances without overhead wiring. Overhead pantographs are sometimes used as alternatives to third rails because third rails can ice over in certain winter weather conditions. The MBTA Blue Line uses pantograph power for the entire section of its route that runs on the surface, while switching to third rail power before entering the underground portion of its route. The entire metro systems of
Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...
,
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,
Barcelona Barcelona ( , , ) is a city on the coast of northeastern Spain. It is the capital and largest city of the autonomous community of Catalonia, as well as the second most populous municipality of Spain. With a population of 1.6 million within ci ...
,
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,
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,
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,
Kobe Kobe ( , ; officially , ) is the capital city of Hyōgo Prefecture Japan. With a population around 1.5 million, Kobe is Japan's seventh-largest city and the third-largest port city after Tokyo and Yokohama. It is located in Kansai region, whic ...
,
Fukuoka is the sixth-largest city in Japan, the second-largest port city after Yokohama, and the capital city of Fukuoka Prefecture, Japan. The city is built along the shores of Hakata Bay, and has been a center of international commerce since ancie ...
,
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,
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,
Chennai Chennai (, ), formerly known as Madras ( the official name until 1996), is the capital city of Tamil Nadu, the southernmost Indian state. The largest city of the state in area and population, Chennai is located on the Coromandel Coast of th ...
,
Mumbai Mumbai (, ; also known as Bombay — the official name until 1995) is the capital city of the Indian state of Maharashtra and the ''de facto'' financial centre of India. According to the United Nations, as of 2018, Mumbai is the second- ...
and
Delhi Delhi, officially the National Capital Territory (NCT) of Delhi, is a city and a union territory of India containing New Delhi, the capital of India. Straddling the Yamuna river, primarily its western or right bank, Delhi shares borders w ...
use overhead wiring and pantographs (as well as certain lines of the metro systems in
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,
Chongqing Chongqing ( or ; ; Sichuanese dialects, Sichuanese pronunciation: , Standard Mandarin pronunciation: ), Postal Romanization, alternately romanized as Chungking (), is a Direct-administered municipalities of China, municipality in Southwes ...
,
Noida Noida, short for New Okhla Industrial Development Authority, is a planned city located in Gautam Buddha Nagar district of the Indian state of Uttar Pradesh. Noida is a satellite city of Delhi and is a part of the National Capital Region (NCR) o ...
,
Hyderabad Hyderabad ( ; , ) is the capital and largest city of the Indian state of Telangana and the ''de jure'' capital of Andhra Pradesh. It occupies on the Deccan Plateau along the banks of the Musi River (India), Musi River, in the northern part ...
,
Jakarta Jakarta (; , bew, Jakarte), officially the Special Capital Region of Jakarta ( id, Daerah Khusus Ibukota Jakarta) is the capital and largest city of Indonesia. Lying on the northwest coast of Java, the world's most populous island, Jakarta ...
,
Tokyo Tokyo (; ja, 東京, , ), officially the Tokyo Metropolis ( ja, 東京都, label=none, ), is the capital and largest city of Japan. Formerly known as Edo, its metropolitan area () is the most populous in the world, with an estimated 37.468 ...
,
Osaka is a designated city in the Kansai region of Honshu in Japan. It is the capital of and most populous city in Osaka Prefecture, and the third most populous city in Japan, following Special wards of Tokyo and Yokohama. With a population of 2. ...
,
Nagoya is the largest city in the Chūbu region, the fourth-most populous city and third most populous urban area in Japan, with a population of 2.3million in 2020. Located on the Pacific coast in central Honshu, it is the capital and the most pop ...
,
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,
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,
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, and
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). Pantographs were also used on the
Nord-Sud Company The Nord-Sud Company (English: North-South; french: Société du chemin de fer électrique souterrain Nord-Sud de Paris) was an operator of underground trains in Paris established in 1904, which built two lines (now Line 12 and part of Line ...
rapid transit lines in Paris until the other operating company of the time,
Compagnie du chemin de fer métropolitain de Paris The Compagnie du chemin de fer métropolitain de Paris S.A. (Paris Metropolitan Railway Company Ltd.), or CMP, was the forerunner of the RATP, the company managing the Paris Métro. Origin So as not to be dependent on the Chemin de fer de l ...
, bought out the company and replaced all overhead wiring with the standard third rail system used on other lines. Numerous railway lines use both third rail and overhead power collection along different portions of their routes, generally for historical reasons. They include the North London line and West London lines of
London Overground London Overground (also known simply as the Overground) is a Urban rail in the United Kingdom, suburban rail network serving London and its environs. Established in 2007 to take over Silverlink Metro routes, (via archive.org). it now serves a ...
, the Northern City Line of
Great Northern Great Northern may refer to: Transport * One of a number of railways; see Great Northern Railway (disambiguation). * Great Northern Railway (U.S.), a defunct American transcontinental railroad and major predecessor of the BNSF Railway. * Great ...
, three of the five lines in the Rotterdam Metro network, Metro-North Railroad's
New Haven Line The Metro-North Railroad New Haven Line is a commuter rail line running from New Haven, Connecticut to New York City. It joins the Harlem Line at Mount Vernon, New York and continues south to Grand Central Terminal in Manhattan. The New Haven ...
, and the
Chicago Transit Authority The Chicago Transit Authority (CTA) is the operator of mass transit in Chicago, Illinois, United States, and some of its surrounding suburbs, including the trains of the Chicago 'L' and CTA bus service. In , the system had a ridership of , ...
's Yellow Line. In this last case, the overhead portion was a remnant of the
Chicago North Shore and Milwaukee Railroad The Chicago North Shore and Milwaukee Railroad (reporting mark CNSM), also known as the North Shore Line, was an interurban railroad that operated passenger and freight service over an route between the Chicago Loop and downtown Milwaukee, as w ...
's high-speed Skokie Valley Route, and was the only line on the entire Chicago subway system to utilize pantograph collection for any length. As such, the line required railcars that featured pantographs as well as third rail shoes, and since the overhead was a very small portion of the system, only a few cars would be so equipped. The changeover occurred at the grade crossing at East Prairie, the former site of the Crawford-East Prairie station. Here, trains bound for Dempster-Skokie would raise their pantographs, while those bound for Howard would lower theirs, doing so at speed in both instances. In 2005, due to the cost and unique maintenance needs for what only represented a very small portion of the system, the overhead system was removed and replaced with the same third rail power that was used throughout the rest of the system, which allowed all of Chicago's railcars to operate on the line. All the pantographs were removed from the Skokie equipped cars. In 2010, the
Oslo Metro The Oslo Metro ( no, Oslo T-bane or or simply ) is the rapid transit system of Oslo, Norway, operated by Sporveien T-banen on contract from the transit authority Ruter. The network consists of five lines that all run through the city centre, wit ...
line 1 changed from third rail to overhead line power at Frøen station. Due to the many level crossings, it was deemed difficult to install a third rail on the rest of the older line's
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. After 2010 third rails were used in spite of level crossings. The third rails have gaps, but there are two contact shoes.


Three-phase supply

On some systems using three phase power supply, locomotives and power cars have two pantographs with the third-phase circuit provided by the running rails. In 1901 an experimental high-speed installation, another design from Walter Reichel at Siemens & Halske, used three vertically mounted overhead wires with the collectors mounted on horizontally extending pantographs.


Inclined pantographs

On lines where open wagons are loaded from above, the
overhead line An overhead line or overhead wire is an electrical cable that is used to transmit electrical energy to electric locomotives, trolleybuses or trams. It is known variously as: * Overhead catenary * Overhead contact system (OCS) * Overhead equipmen ...
may be offset to allow this; the pantographs are then mounted at an angle to the vertical.


Weaknesses

Contact between a pantograph and an overhead line is usually assured through a block of
graphite Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large ...
. This material conducts electricity while working as a
lubricant A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, t ...
. As graphite is brittle, pieces can break off during operation. Bad pantographs can seize the overhead wire and tear it down, so there is a two-way influence whereby bad wires can damage the pantograph and bad pantographs can damage the wires. To prevent this, a pantograph monitoring station can be used. At sustained high speeds, above , friction can cause the contact strip to become red hot, which in turn can cause excessive
arcing An electric arc, or arc discharge, is an electrical breakdown of a gas that produces a prolonged electrical discharge. The current through a normally nonconductive medium such as air produces a plasma; the plasma may produce visible light. An ...
and eventual failure. In the UK, the pantographs ( Brecknell Willis and Stone Faiveley) of vehicles are raised by air pressure and the graphite contact "carbons" create an air gallery in the pantograph head which release the air if a graphite strip is lost, activating the automatic drop device and lowering the pantograph to prevent damage. Newer electric traction units may use more sophisticated methods which detect the disturbances caused by arcing at the point of contact when the graphite strips are damaged. There are not always two pantographs on an
electric multiple unit An electric multiple unit or EMU is a multiple-unit train consisting of self-propelled carriages using electricity as the motive power. An EMU requires no separate locomotive, as electric traction motors are incorporated within one or a numbe ...
but, in cases where there are, the other one can be used if one is damaged; an example of this situation would be a Class 390 ''Pendolino''. The rear pantograph in relation to the direction of travel is often used as to avoid damaging both pantographs in case of entanglements: if the front pantograph was used, debris from an entanglement could cause damage to the rear pantograph, rendering both pantographs and the vehicle inoperable.


See also

*
Bow collector A bow collector is one of the three main devices used on tramcars to transfer electric current from the wires above to the tram below. While once very common in continental Europe, it was replaced by the pantograph or the trolley pole, itself o ...
*
Current collector Electric current collectors are used by trolleybuses, trams, electric locomotives or EMUs to carry electrical power from overhead lines, electrical third rails, or ground-level power supplies to the electrical equipment of the vehicles. Those for ...
* Pantographs and underbody collectors * Railway electrification system *
Trolley pole A trolley pole is a tapered cylindrical pole of wood or metal, used to transfer electricity from a "live" (electrified) overhead wire to the control and the electric traction motors of a tram or trolley bus. It is a type of current collector. ...


References

{{Authority control Locomotive parts Tram technology Electric buses