Electric locomotive
Encyclopedia
- "Electric Trains" redirects here. For the 1995 Squeeze single, see Electric Trains (song)Electric Trains (song)"Electric Trains" is a song by Squeeze, released as their second single from their eleventh album, Ridiculous. It peaked at number 44 in the UK Singles Chart.Two versions of the single were released, each with entirely different B-sides.-CD #1:...
.
An electric locomotive is a locomotive
Locomotive
A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...
powered by electricity from overhead lines
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
, a third rail
Third rail
A third rail is a method of providing electric power to a railway 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...
or an on-board energy storage device (such as a chemical battery
Battery (electricity)
An electrical battery is one or more electrochemical cells that convert stored chemical energy into electrical energy. Since the invention of the first battery in 1800 by Alessandro Volta and especially since the technically improved Daniell cell in 1836, batteries have become a common power...
or fuel cell
Fuel cell
A fuel cell is a device that converts the chemical energy from a fuel into electricity through a chemical reaction with oxygen or another oxidizing agent. Hydrogen is the most common fuel, but hydrocarbons such as natural gas and alcohols like methanol are sometimes used...
). Electrically propelled locomotives with on-board fuelled prime mover
Prime mover (locomotive)
In engineering, a prime mover is an engine that converts fuel to useful work. In locomotives, the prime mover is thus the source of power for its propulsion. The term is generally used when discussing any locomotive powered by an internal combustion engine...
s, such as diesel engine
Diesel engine
A diesel engine is an internal combustion engine that uses the heat of compression to initiate ignition to burn the fuel, which is injected into the combustion chamber...
s or gas turbine
Gas turbine
A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled to a downstream turbine, and a combustion chamber in-between....
s, are classed as diesel-electric or gas turbine electric locomotives because the electric generator/motor combination only serves as a power transmission system
Transmission (mechanics)
A machine consists of a power source and a power transmission system, which provides controlled application of the power. Merriam-Webster defines transmission as: an assembly of parts including the speed-changing gears and the propeller shaft by which the power is transmitted from an engine to a...
. Electricity is used to eliminate smoke and take advantage of the high efficiency of electric motors; however, the cost of railway electrification means that usually only heavily used lines can be electrified.
Characteristics
One advantage of electrification is the lack of pollution from the locomotives themselves. Electrification also results in higher performance, lower maintenance costs and lower energy costs for electric locomotives.Power plants, even if they burn fossil fuels, are far cleaner than mobile sources such as locomotive engines. Also the power for electric locomotives can come from clean and/or renewable sources
Renewable energy
Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable . About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3.4% from...
, including geothermal power
Geothermal power
Geothermal energy is thermal energy generated and stored in the Earth. Thermal energy is the energy that determines the temperature of matter. Earth's geothermal energy originates from the original formation of the planet and from radioactive decay of minerals...
, hydroelectric power
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
, nuclear power
Nuclear power
Nuclear power is the use of sustained nuclear fission to generate heat and electricity. Nuclear power plants provide about 6% of the world's energy and 13–14% of the world's electricity, with the U.S., France, and Japan together accounting for about 50% of nuclear generated electricity...
, solar power
Solar power
Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available...
and wind turbine
Wind turbine
A wind turbine is a device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator or wind charger. If the mechanical energy is used to drive machinery, such as for grinding grain or...
s. Electric locomotives are also quiet compared to diesel locomotives since there is no engine and exhaust noise and less mechanical noise. The lack of reciprocating parts means that electric locomotives are easier on the track, reducing track maintenance.
Power plant capacity is far greater than what any individual locomotive uses, so electric locomotives can have a higher power output than diesel locomotives and they can produce even higher short-term surge power for fast acceleration. Electric locomotives are ideal for commuter rail service with frequent stops. They are used on high-speed lines, such as ICE
InterCityExpress
The Intercity-Express or ICE is a system of high-speed trains predominantly running in Germany and neighbouring countries. It is the highest service category offered by DB Fernverkehr and is the flagship of Deutsche Bahn...
in Germany, Acela in the US, Shinkansen
Shinkansen
The , also known as THE BULLET TRAIN, is a network of high-speed railway lines in Japan operated by four Japan Railways Group companies. Starting with the Tōkaidō Shinkansen in 1964, the network has expanded to currently consist of of lines with maximum speeds of , of Mini-shinkansen with a...
in Japan, China Railway High-speed
China Railway High-speed
China Railway High-speed ; ) is the high-speed rail system operated by China Railways.Hexie Hao is the designation for high-speed trains running on this rail system. At the middle of the run, all trains were marked "CRH" on the centre of the head vehicle and the side of the walls of each vehicle...
in China and TGV
TGV
The TGV is France's high-speed rail service, currently operated by SNCF Voyages, the long-distance rail branch of SNCF, the French national rail operator....
in France. Electric locomotives are also used on freight routes that have a consistently high traffic volume, or in areas with advanced rail networks.
Electric locomotives benefit from the high efficiency of electric motors, often above 90%. Additional efficiency can be gained from regenerative braking, which allows kinetic energy
Kinetic energy
The kinetic energy of an object is the energy which it possesses due to its motion.It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes...
to be recovered during braking to put some power back on the line. Newer electric locomotives use AC motor-inverter drive systems that provide for regenerative braking.
The chief disadvantage of electrification is the cost for infrastructure (overhead power lines or electrified third rail, substations, control systems). Public policy in the US currently interferes with electrification—higher property taxes are imposed on privately owned rail facilities if they have electrification facilities. Also, US regulations on diesel locomotives are very weak compared to regulations on automobile emissions or power plant emissions.
In Europe and elsewhere, railway networks are considered part of the national transport infrastructure, just like roads, highways and waterways, and therefore are often financed by the state. Operators of the rolling stock pay fees according to rail use. This makes possible the large investments required for the technically and in the long-term also, economically advantageous electrification. Because railroad infrastructure is privately owned in the US, railroads are unwilling to make the necessary investments for electrification.
History
Aberdeen
Aberdeen is Scotland's third most populous city, one of Scotland's 32 local government council areas and the United Kingdom's 25th most populous city, with an official population estimate of ....
. It was powered by galvanic cell
Galvanic cell
A Galvanic cell, or Voltaic cell, named after Luigi Galvani, or Alessandro Volta respectively, is an electrochemical cell that derives electrical energy from spontaneous redox reaction taking place within the cell...
s ('batteries'). Davidson later built a larger locomotive named Galvani which was exhibited at the Royal Scottish Society of Arts
Royal Scottish Society of Arts
The Royal Scottish Society of Arts is a learned society in Scotland, dedicated to the study of science and technology. It was founded as The Society for the Encouragement of the Useful Arts in Scotland by Sir David Brewster in 1821 and dedicated to "the promotion of invention and enterprise"...
Exhibition in 1841. The 7-ton vehicle had two direct-drive reluctance motor
Reluctance motor
A reluctance motor is a type of electric motor that induces non-permanent magnetic poles on the ferromagnetic rotor. Torque is generated through the phenomenon of magnetic reluctance.A reluctance motor, in its various incarnations, may be known as a:...
s, with fixed electro-magnets acting on iron bars attached to a wooden cylinder mounted on each axle, and simple commutators
Commutator (electric)
A commutator is a rotary electrical switch in certain types of electric motors or electrical generators that periodically reverses the current direction between the rotor and the external circuit. In a motor, it applies power to the best location on the rotor, and in a generator, picks off power...
. It hauled a load of 6 tons at 4 miles per hour for a distance of 1½ miles. The machine was tested on the Edinburgh and Glasgow Railway
Edinburgh and Glasgow Railway
The Edinburgh and Glasgow Railway was a railway built to link Glasgow and Edinburgh. The Act of Parliament for building the railway received its Royal Assent in 1838 which was open on 28 July 1863. Services started between Glasgow Queen Street and Haymarket on 21 February 1842. The line was...
in September of the following year but the limited electric power available from batteries prevented its general use. It was destroyed by railway workers, who saw it as a threat to their security of employment.
The first electric passenger train was presented by Werner von Siemens at Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...
in 1879. The locomotive was driven by a 2.2 kW series wound motor and the train, consisting of the locomotive and three cars, reached a maximum speed of 13 km/h. During four months, the train carried 90,000 passengers on a 300 metre long circular track. The electricity (150 V DC) was supplied through a third, insulated rail situated between the tracks. A contact roller was used to collect the electricity from the third rail.
The world's first electric tram line opened in Lichterfelde near Berlin, Germany, in 1881. It was built by Werner von Siemens (see Gross-Lichterfelde Tramway
Gross-Lichterfelde Tramway
The Gross Lichterfelde Tramway was the world's first electric tramway. It was built by the Siemens & Halske company in Lichterfelde, a suburb of Berlin, and went in service on 16 May 1881....
and Berlin Straßenbahn
Berlin Straßenbahn
The Berlin tram network is the main tram system in Berlin, Germany. It is one of the oldest tram networks in the world having its origins in 1865 and is operated by , which was founded in 1929. It is notable for being one of the largest tram systems; there are 22 tram lines operate across a...
).
In Britain, Volk's electric railway was opened in 1883 in Brighton (see Volk's Electric Railway
Volk's Electric Railway
Volk's Electric Railway is the oldest operating electric railway in the world. It is a narrow gauge railway that runs along a length of the seafront of the English seaside resort of Brighton...
). Also in 1883, Mödling and Hinterbrühl Tram
Mödling and Hinterbrühl Tram
Mödling and Hinterbrühl Tram or Mödling and Hinterbrühl Local Railway was an electric tramway in Austria, running from Mödling to Hinterbrühl, in the southwest of Vienna. The gauge was 1000 mm...
was opened near Vienna in Austria. It was the first tram and railway in the world in regular service that was run with electricity served by an overhead line.
Five years later, in the US electric trolleys
Tram
A tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...
were pioneered in 1888 on the Richmond Union Passenger Railway
Richmond Union Passenger Railway
The Richmond Union Passenger Railway, in Richmond, Virginia, was the first practical electric trolley system, and set the pattern for most subsequent electric trolley systems around the world. It is an IEEE milestone in engineering....
, using equipment designed by Frank J. Sprague.
Much of the early development of electric locomotion was driven by the increasing use of tunnels, particularly in urban areas. Smoke from steam locomotives was noxious and municipalities were increasingly inclined to prohibit their use within their limits. Thus the first successful working, the City and South London Railway underground
Rapid transit
A rapid transit, underground, subway, elevated railway, metro or metropolitan railway system is an electric passenger railway in an urban area with a high capacity and frequency, and grade separation from other traffic. Rapid transit systems are typically located either in underground tunnels or on...
line in the UK, was prompted by a clause in its enabling act prohibiting use of steam power. This line opened in 1890, using electric locomotives built by Mather and Platt. Electricity quickly became the power supply of choice for subways, abetted by the Sprague's invention of multiple-unit train control
Multiple-unit train control
Multiple-unit train control, sometimes abbreviated to multiple-unit or MU, is a method of simultaneously controlling all the traction equipment in a train from a single location, whether it is a Multiple unit comprising a number of self-powered passenger cars or a set of locomotives.A set of...
in 1897. Surface and elevated rapid transit
Rapid transit
A rapid transit, underground, subway, elevated railway, metro or metropolitan railway system is an electric passenger railway in an urban area with a high capacity and frequency, and grade separation from other traffic. Rapid transit systems are typically located either in underground tunnels or on...
systems generally used steam until forced to convert by ordinance.
The first use of electrification on a mainline was on a four-mile stretch of the Baltimore Belt Line
Baltimore Belt Line
The Baltimore Belt Line was constructed by the Baltimore and Ohio Railroad in the 1890s to connect the railroad's newly constructed line to Philadelphia with the rest of the railroad at Baltimore, Maryland. It included the Howard Street Tunnel, the Mount Royal Station and the first mainline...
of the Baltimore and Ohio Railroad
Baltimore and Ohio Railroad
The Baltimore and Ohio Railroad was one of the oldest railroads in the United States and the first common carrier railroad. It came into being mostly because the city of Baltimore wanted to compete with the newly constructed Erie Canal and another canal being proposed by Pennsylvania, which...
(B&O) in 1895. This track connected the main portion of the B&O to the newly built line to New York and it required a series of tunnels around the edges of Baltimore's downtown. Parallel tracks on the Pennsylvania Railroad
Pennsylvania Railroad
The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....
had shown that coal smoke from steam locomotive
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
s would be a major operating issue, as well as a public nuisance. Three Bo+Bo units were initially used, at the south end of the electrified section; they coupled onto the entire train, locomotive and all and pulled it through the tunnels. Railroad entrances to New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...
required similar tunnels and the smoke problems were more acute there. A collision in the Park Avenue tunnel in 1902 led the New York State legislature to outlaw the use of smoke-generating locomotives south of the Harlem River
Harlem River
The Harlem River is a navigable tidal strait in New York City, USA that flows 8 miles between the Hudson River and the East River, separating the boroughs of Manhattan and the Bronx...
after 1 July 1908. In response, electric locomotives began operation in 1904 on the New York Central Railroad
New York Central Railroad
The New York Central Railroad , known simply as the New York Central in its publicity, was a railroad operating in the Northeastern United States...
. In the 1930s, the Pennsylvania Railroad
Pennsylvania Railroad
The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....
, which also had introduced electric locomotives because of the NYC regulation, electrified its entire territory east of Harrisburg, Pennsylvania
Harrisburg, Pennsylvania
Harrisburg is the capital of Pennsylvania. As of the 2010 census, the city had a population of 49,528, making it the ninth largest city in Pennsylvania...
.
The Chicago, Milwaukee, St. Paul and Pacific Railroad
Chicago, Milwaukee, St. Paul and Pacific Railroad
The Milwaukee Road, officially the Chicago, Milwaukee, St. Paul and Pacific Railroad , was a Class I railroad that operated in the Midwest and Northwest of the United States from 1847 until its merger into the Soo Line Railroad on January 1, 1986. The company went through several official names...
(the Milwaukee Road), the last transcontinental line to be built, electrified its lines across the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
and to the Pacific Ocean starting in 1915. A few East Coast lines, notably the Virginian Railway
Virginian Railway
The Virginian Railway was a Class I railroad located in Virginia and West Virginia in the United States. The VGN was created to transport high quality "smokeless" bituminous coal from southern West Virginia to port at Hampton Roads....
and the Norfolk and Western Railway
Norfolk and Western Railway
The Norfolk and Western Railway , a US class I railroad, was formed by more than 200 railroad mergers between 1838 and 1982. It had headquarters in Roanoke, Virginia for most of its 150 year existence....
, found it expedient to electrify short sections of their mountain crossings. However, by this point, electrification in the United States was more associated with dense urban traffic and the use of electric locomotives declined in the face of dieselization. Diesels shared some of the electric locomotive’s advantages of over steam and the cost of building and maintaining the power supply infrastructure, which had always worked to discourage new installations, brought on the elimination of most mainline electrification outside the Northeast. Except for a few captive systems (e.g. the Black Mesa and Lake Powell
Black Mesa and Lake Powell
The Black Mesa and Lake Powell Railroad is a electrified private railroad operating in Northern Arizona, USA within the Navajo Nation which transports coal from the Peabody Energy's Kayenta Mine near Kayenta, Arizona to the Navajo Generating Station power plant at Page, Arizona...
), by 2000 electrification was confined to the Northeast Corridor
Northeast Corridor
The Northeast Corridor is a fully electrified railway line owned primarily by Amtrak serving the Northeast megalopolis of the United States from Boston in the north, via New York to Washington, D.C. in the south, with branches serving other cities...
and some commuter service; even there, freight service was handled by diesels. The centre of development shifted to Europe, where electrification was widespread.
Introduction of alternating current
The first practical ACAlternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....
electric locomotive was designed by Charles Brown
Charles Eugene Lancelot Brown
thumb|200pxCharles Eugene Lancelot Brown founded BBC Brown Boveri with Walter Boveri.He was born in Winterthur and was one of 6 children. His mother was Swiss and his father, a British engineer, was the founder of SLM - Schweizerische Lokomotiv- und Maschinenfabrik...
, then working for Oerlikon, Zürich. In 1891, Brown had demonstrated long-distance power transmission, using three-phase AC
Three-phase electric power
Three-phase electric power is a common method of alternating-current electric power generation, transmission, and distribution. It is a type of polyphase system and is the most common method used by grids worldwide to transfer power. It is also used to power large motors and other heavy loads...
, between a hydro-electric plant
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
at Lauffen am Neckar and Frankfurt am Main West railway station, a distance of 280 km. Brown, using the experience he had gained while working for Jean Heilmann
Heilmann locomotive
The Heilmann locomotives were a series of three experimental steam-electric locomotives produced in the 1890s for the French Chemins de Fer de l'Ouest . A prototype was built in 1894 and two larger locomotives were built in 1897...
on steam-electric locomotive designs, had observed that three-phase motors had a higher power-to-weight ratio than DC
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
motors and, because of the absence of a commutator
Commutator (electric)
A commutator is a rotary electrical switch in certain types of electric motors or electrical generators that periodically reverses the current direction between the rotor and the external circuit. In a motor, it applies power to the best location on the rotor, and in a generator, picks off power...
, were simpler to manufacture and maintain. However, they were much larger than the DC motors of the time and could not be mounted in underfloor bogie
Bogie
A bogie is a wheeled wagon or trolley. In mechanics terms, a bogie is a chassis or framework carrying wheels, attached to a vehicle. It can be fixed in place, as on a cargo truck, mounted on a swivel, as on a railway carriage/car or locomotive, or sprung as in the suspension of a caterpillar...
s: they could only be carried within locomotive bodies. In 1896, Oerlikon installed the first commercial example of the system on the Lugano Tramway. In 1896-1898, Kálmán Kandó designed a short three phase AC traction tramway in Evian-les-Bains (France). Three-phase motors, which run at constant speed and provide regenerative braking
Regenerative brake
A regenerative brake is an energy recovery mechanism which slows a vehicle or object down by converting its kinetic energy into another form, which can be either used immediately or stored until needed...
, are well suited to steeply graded routes and the first mainline three-phase locomotives were installed by Brown (by then in partnership with Walter Boveri
Brown, Boveri & Cie
Brown, Boveri & Cie was a Swiss group of electrical engineering companies.It was founded in Baden, Switzerland, in 1891 by Charles Eugene Lancelot Brown and Walter Boveri who worked at the Maschinenfabrik Oerlikon. In 1970 BBC took over the Maschinenfabrik Oerlikon...
) in 1899 on the 40 km Burgdorf—Thun line, Switzerland. Each thirty-tonne locomotive had two 110 kW motors run by three-phase 750 V 40 Hz fed from double overhead lines. The first implementation of industrial frequency single-phase AC supply for locomotives came from Oerlikon in 1901, using the designs of Hans Behn-Eschenburg and Emil Huber-Stockar; installation on the Seebach-Wettingen line of the Swiss Federal Railways was completed in 1904. The 15 kV, 50 Hz 345 kW, 48 tonne locomotives used transformers and rotary converters to power DC traction motors.
Italian railways were the first in the world to introduce electric traction for the entire length of a mainline rather than just a short stretch. The 106 km Valtellina line was opened on 4 September 1902, designed by Kálmán Kandó and a team from the Ganz works.. The electrical system was three-phase at 3 kV 15 Hz. The voltage was significantly higher than used earlier and it required new designs for electric motors and switching devices. The three-phase, two wire system was used on several railways in Northern Italy and became known as "the Italian system". Kandó was invited in 1905 to undertake the management of Societa Italiana Westinghouse and subsequently led the development of several Italian electric locomotives. During the period of electrification of the Italian railways, tests were made as to which type of power to use: in some sections there was a 3,600 V 16⅔ Hz three-phase power supply, in others there was 1,500 V DC, 3 kV DC and 10 kV AC 45 Hz supply. After WW2, 3kV DC power was chosen for the entire Italian railway system. (Nowadays, 1,500 V DC is still used on some lines near France and 25kV 50 Hz is used on high speed trains)
Kálmán Kandó
Kálmán Kandó de Egerfarmos et Sztregova was a Hungarian engineer, and a pioneer in the development of electric railway traction.-Education:...
working with both the Ganz
Ganz
The Ganz electric works in Budapest is probably best known for the manufacture of tramcars, but was also a pioneer in the application of three-phase alternating current to electric railways. Ganz also made / makes: ships , bridge steel structures , high voltage equipment...
works and Societa Italiana Westinghouse
Westinghouse Electric (1886)
Westinghouse Electric was an American manufacturing company. It was founded in 1886 as Westinghouse Electric Company and later renamed Westinghouse Electric Corporation by George Westinghouse. The company purchased CBS in 1995 and became CBS Corporation in 1997...
, introduced an electro-mechanical converter
Rotary phase converter
A rotary phase converter, abbreviated RPC, is an electrical machine that produces three-phase electric power from single-phase electric power. This allows three phase loads to run using generator or utility-supplied single-phase electric power....
, allowing the use of three-phase motors powered from single-phase alternating current, thus eliminating the need for two overhead conductor wires.
In 1923, the first phase-converter locomotive in Hungary was constructed on the basis of Kandó’s designs and serial production began soon after. The first installation, at 16 kV 50 Hz, was in 1932 on the 56 km section of the Hungarian State Railways between Budapest and Komárom
Komárom
Komárom is a city in Hungary on the right bank of the Danube in Komárom-Esztergom county.The city of Komárom was formerly a separate suburban village called...
. This proved successful and the electrification was extended to Hegyeshalom
Hegyeshalom
Hegyeshalom is a village of approximately 3600 inhabitants in the Győr-Moson-Sopron county of Hungary, on the border with Austria and less than 15 km from the border with Slovakia.- History :...
in 1934.
In Europe, electrification projects initially focused on mountainous regions for several reasons: coal supplies were difficult, hydroelectric power was readily available, and electric locomotives gave more traction on steeper lines. This was particularly applicable in Switzerland, where today close to 100% of lines are electrified. An important contribution to the wider adoption of AC traction came from SNCF
SNCF
The SNCF , is France's national state-owned railway company. SNCF operates the country's national rail services, including the TGV, France's high-speed rail network...
of France after World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
. The company had assessed the industrial-frequency AC line routed through the steep Höllental Valley, Germany, which was under French administration following the war. After trials, the company decided that the performance of AC locomotives was sufficiently developed to allow all its future installations, regardless of terrain, to be of this standard, with its associated cheaper and more efficient infrastructure. The SNCF decision, ignoring as it did the 2000 miles (3,218.7 km) of high-voltage DC already installed on French routes, was influential in the standard selected for other countries in Europe.
The 1960s saw the electrification of many European main lines (Eastern Europe included). European electric locomotive's technology had improved steadily from the 1920s onwards. By comparison, the Milwaukee Road class EP-2
Milwaukee Road class EP-2
The Milwaukee Road's class EP-2 comprised five electric locomotives built by General Electric in 1919. They were often known as Bipolars, which referred to the bipolar electric motors they used. Among the most distinctive and powerful electric locomotives of their time, they epitomized the...
(1918) weighed 240 t, with a power of 3,330 kW and a maximum speed of 112 km/h; in 1935, German E 18 had a power of 2,800 kW, but weighed only 108 tons and had a maximum speed of 150 km/h. On 29 March 1955, French locomotive CC 7107
SNCF Class CC 7100
SNCF's CC 7100 class are part of a series of electric locomotives built by Alsthom. The prototype 'CC 7000' were built in 1949 and the production series locomotives CC 7101-CC 7158 followed during 1952–1955...
reached a speed of 331 km/h. In 1960 the SJ Class Dm 3
SJ Dm3
Dm and Dm3 is a series of locomotives used by Statens Järnvägar and later Malmtafik i Kiruna for pulling iron ore trains on Malmbanan in Sweden and Ofotbanen in Norway. A total of 39 double-locomotives were delivered between 1953 and 1971, built by ASEA. A further 19 center locomotives were...
locomotives introduced on the Swedish Railways produced a record 7,200 kW. Locomotives capable of commercial passenger service at 200 km/h appeared in Germany and France in the same period. Further improvements resulted from the introduction of electronic control systems, which permitted the use of increasingly lighter and more powerful motors that could be fitted entirely inside the bogies (standardising from the 1990s onwards on asynchronous three-phase motors, fed through GTO-inverters).
In the 1980s, development of very high-speed service brought a revival of electrification. The Japanese Shinkansen
Shinkansen
The , also known as THE BULLET TRAIN, is a network of high-speed railway lines in Japan operated by four Japan Railways Group companies. Starting with the Tōkaidō Shinkansen in 1964, the network has expanded to currently consist of of lines with maximum speeds of , of Mini-shinkansen with a...
and the French TGV
TGV
The TGV is France's high-speed rail service, currently operated by SNCF Voyages, the long-distance rail branch of SNCF, the French national rail operator....
were the first systems for which devoted high-speed lines were built from scratch. Similar programs were undertaken in Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
and Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
; in the United States the only new mainline service was an extension of electrification over the Northeast Corridor from New Haven, Connecticut
New Haven, Connecticut
New Haven is the second-largest city in Connecticut and the sixth-largest in New England. According to the 2010 Census, New Haven's population increased by 5.0% between 2000 and 2010, a rate higher than that of the State of Connecticut, and higher than that of the state's five largest cities, and...
to Boston, Massachusetts, though new light rail
Light rail
Light rail or light rail transit is a form of urban rail public transportation that generally has a lower capacity and lower speed than heavy rail and metro systems, but higher capacity and higher speed than traditional street-running tram systems...
systems, using electrically powered cars, continued to be built.
On 2 September 2006, a standard production Siemens Electric locomotive of the Eurosprinter type ES64-U4
EuroSprinter
The EuroSprinter family of electric locomotives is a modular concept of locomotives for the European market built by Siemens. The internal Siemens product name is ES 64, with ES for EuroSprinter and the number 64 indicating the 6,400 kW power at rail.Additional information is given in the name...
(ÖBB
ÖBB
The Austrian Federal Railways is the national railway system of Austria, and the administrators of Liechtenstein's railways...
Class 1216) achieved a speed of 357 km/h, the record for a locomotive-hauled train, on the new line between Ingolstadt and Nuremberg.
Electric locomotive types
- Rechargeable energy storage systemRechargeable energy storage systemA rechargeable energy storage system or RESS is a system that stores energy for delivery of power and which is rechargeable.Production storage systems use electric rechargeable traction batteries, electric double-layer capacitors or flywheel energy storage.This term of art is used in US legislation...
s, as battery or ultracapacitor-powered miningMiningMining is the extraction of valuable minerals or other geological materials from the earth, from an ore body, vein or seam. The term also includes the removal of soil. Materials recovered by mining include base metals, precious metals, iron, uranium, coal, diamonds, limestone, oil shale, rock...
locomotives. - A stationary source, such as a third railThird railA third rail is a method of providing electric power to a railway 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...
or overhead wireOverhead linesOverhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
.
This is in marked contrast to a diesel-electric locomotive, which combines an onboard diesel engine
Prime mover (locomotive)
In engineering, a prime mover is an engine that converts fuel to useful work. In locomotives, the prime mover is thus the source of power for its propulsion. The term is generally used when discussing any locomotive powered by an internal combustion engine...
with an electrical power transmission
Power transmission
Power transmission is the movement of energy from its place of generation to a location where it is applied to performing useful work.Power is defined formally as units of energy per unit time...
or store (battery, ultracapacitor) system.
The distinguishing design features of electric locomotives are:
- The type of electrical power used, either alternating currentAlternating currentIn alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....
or direct currentDirect currentDirect current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
. - The method for store (batteries, ultracapacitors) or collecting (transmission) electrical power.
- The means used to mechanically couple the traction motors to the driving wheels (drivers).
Direct and alternating current
The most fundamental difference lies in the choice of directDirect current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
(DC) or alternating current
Alternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....
(AC). The earliest systems used direct current as, initially, alternating current was not well understood and insulation material for high voltage lines was not available. Direct current locomotives typically run at relatively low voltage (600 to 3,000 volts); the equipment is therefore relatively massive because the currents involved are large in order to transmit sufficient power. Power must be supplied at frequent intervals as the high currents result in large transmission system losses.
As alternating current motors were developed, they became the predominant type, particularly on longer routes. High voltages (tens of thousands of volts) are used because this allows the use of low currents; transmission losses
Copper loss
Copper loss is the term often given to heat produced by electrical currents in the conductors of transformer windings, or other electrical devices. Copper losses are an undesirable transfer of energy, as are core losses, which result from induced currents in adjacent components...
are proportional to the square of the current (e.g. twice the current means four times the loss). Thus, high power can be conducted over long distances on lighter and cheaper wires. Transformers in the locomotives transform this power to a low voltage and high current for the motors.
A similar high voltage, low current system could not be employed with direct current locomotives because there is no easy way to do the voltage/current transformation for DC so efficiently as achieved by AC transformers.
AC traction still occasionally uses dual overhead wires instead of single phase lines. The resulting three-phase
Three-phase
In electrical engineering, three-phase electric power systems have at least three conductors carrying voltage waveforms that are radians offset in time...
current drives induction motor
Induction motor
An induction or asynchronous motor is a type of AC motor where power is supplied to the rotor by means of electromagnetic induction. These motors are widely used in industrial drives, particularly polyphase induction motors, because they are robust and have no brushes...
s, which do not have sensitive commutators
Commutator (electric)
A commutator is a rotary electrical switch in certain types of electric motors or electrical generators that periodically reverses the current direction between the rotor and the external circuit. In a motor, it applies power to the best location on the rotor, and in a generator, picks off power...
and permit easy realisation of a regenerative brake
Regenerative brake
A regenerative brake is an energy recovery mechanism which slows a vehicle or object down by converting its kinetic energy into another form, which can be either used immediately or stored until needed...
. Speed is controlled by changing the number of pole pairs in the stator circuit, with acceleration controlled by switching additional resistors in, or out, of the rotor circuit. The two-phase lines are heavy and complicated near switches, where the phases have to cross each other. The system was widely used in the northern part of Italy until 1976 and is still in use on some Swiss rack railway
Rack railway
A rack-and-pinion railway is a railway with a toothed rack rail, usually between the running rails. The trains are fitted with one or more cog wheels or pinions that mesh with this rack rail...
s. The simple feasibility of a fail safe electric brake is an advantage of the system, while the speed control and the two-phase lines are problematic.
Rectifier
A rectifier is an electrical device that converts alternating current , which periodically reverses direction, to direct current , which flows in only one direction. The process is known as rectification...
locomotives, which used AC power transmission and DC motors, were common, though DC commutators had problems both in starting and at low velocities. Today's advanced electric locomotives use brushless three-phase AC induction motors. These polyphase machines are powered from GTO
Gate turn-off thyristor
A gate turn-off thyristor is a special type of thyristor, a high-power semiconductor device. GTOs, as opposed to normal thyristors, are fully controllable switches which can be turned on and off by their third lead, the GATE lead.-Device description:...
-, IGCT
IGCT
The Integrated Gate-Commutated Thyristor is a power semiconductor electronic device, used for switching electric current in industrial equipment. It is related to the gate turn-off thyristor. Like the GTO thyristor, the IGCT is a fully controllable power switch, meaning that it can be turned...
- or IGBT-based inverters. The cost of electronic devices in a modern locomotive can be up to 50% of the total cost of the vehicle.
Electric traction allows the use of regenerative braking, in which the motors are used as brakes and become generators that transform the motion of the train into electrical power that is then fed back into the lines. This system is particularly advantageous in mountainous operations, as descending locomotives can produce a large portion of the power required for ascending trains.
Most systems have a characteristic voltage and, in the case of AC power, a system frequency. Many locomotives over the years were equipped to handle multiple voltages and frequencies as systems came to overlap or were upgraded. American FL9 locomotives were equipped to handle power from two different electrical systems and could also operate as conventional diesel-electrics.
While recently designed systems invariably operate on alternating current, many existing direct current
Direct current
Direct current is the unidirectional flow of electric charge. Direct current is produced by such sources as batteries, thermocouples, solar cells, and commutator-type electric machines of the dynamo type. Direct current may flow in a conductor such as a wire, but can also flow through...
systems are still in use – e.g. in South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
and the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
(750 V and 1,500 V); Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
, Japan
Japan
Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...
, Mumbai
Mumbai
Mumbai , formerly known as Bombay in English, is the capital of the Indian state of Maharashtra. It is the most populous city in India, and the fourth most populous city in the world, with a total metropolitan area population of approximately 20.5 million...
, Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
(1,500 V); Slovenia
Slovenia
Slovenia , officially the Republic of Slovenia , is a country in Central and Southeastern Europe touching the Alps and bordering the Mediterranean. Slovenia borders Italy to the west, Croatia to the south and east, Hungary to the northeast, and Austria to the north, and also has a small portion of...
, Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
, Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
, Poland
Poland
Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...
, Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
, Spain
Spain
Spain , officially the Kingdom of Spain languages]] under the European Charter for Regional or Minority Languages. In each of these, Spain's official name is as follows:;;;;;;), is a country and member state of the European Union located in southwestern Europe on the Iberian Peninsula...
(3,000 V) and the cities of Washington DC (750 V).
Power transmission
Electrical circuits require two connections (or for three phase AC
Three-phase
In electrical engineering, three-phase electric power systems have at least three conductors carrying voltage waveforms that are radians offset in time...
, three connections). From the very beginning, the trackwork itself was used for one side of the circuit. Unlike model railroads, however, the trackwork normally supplies only one side, the other side(s) of the circuit being provided separately.
The original Baltimore and Ohio Railroad
Baltimore and Ohio Railroad
The Baltimore and Ohio Railroad was one of the oldest railroads in the United States and the first common carrier railroad. It came into being mostly because the city of Baltimore wanted to compete with the newly constructed Erie Canal and another canal being proposed by Pennsylvania, which...
electrification used a sliding shoe in an overhead channel, a system quickly found to be unsatisfactory. It was replaced with a third rail
Third rail
A third rail is a method of providing electric power to a railway 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...
system, in which a pickup (the "shoe") rode underneath or on top of a smaller rail parallel to the main track, somewhat above ground level. There were multiple pickups on both sides of the locomotive in order to accommodate the breaks in the third rail required by trackwork. This system is preferred in subways because of the close clearances it affords.
However, railways generally tend to prefer overhead lines
Overhead lines
Overhead lines or overhead wires are used to transmit electrical energy to trams, trolleybuses or trains at a distance from the energy supply point...
, often called "catenaries" after the support system used to hold the wire parallel to the ground. Three collection methods are possible:
- Trolley poleTrolley poleA trolley pole is a tapered cylindrical pole of wood or metal, used to transfer electricity from a "live" overhead wire to the control and propulsion equipment of a tram or trolley bus. The use of overhead wire in a system of current collection is reputed to be the 1880 invention of Frank J....
: a long flexible pole, which engages the line with a wheel or shoe. - Bow collectorBow collectorA 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 has now been largely replaced by the pantograph.-Origins:...
: a frame that holds a long collecting rod against the wire. - PantographPantograph (rail)A pantograph for rail lines is a hinged electric-rod device that collects electric current from overhead lines for electric trains or trams. The pantograph typically connects to a one-wire line, with the track acting as the ground wire...
: a hinged frame that holds the collecting shoes against the wire in a fixed geometry.
Of the three, the pantograph method is best suited for high-speed operation. Some locomotives are equipped to use both overhead and third rail collection (e.g. British Rail Class 92
British Rail Class 92
The British Rail Class 92 is a dual-voltage electric locomotive which can run on 25 kV AC from overhead wires or 750 V DC from a third rail. It was designed specifically to operate services through the Channel Tunnel between Britain and France...
).
Driving the wheels
Traction motor
Traction motor refers to an electric motor providing the primary rotational torque of a machine, usually for conversion into linear motion ....
s to the wheels. Early locomotives used often jackshaft drives. In this arrangement, the traction motor is mounted within the body of the locomotive and drives the jackshaft through a set of gears. This system was employed because the first traction motors were too large and heavy to mount directly on the axles. Due to the number of mechanical parts involved, frequent maintenance was necessary. The jackshaft drive was abandoned for all but the smallest units when smaller and lighter motors were developed,
Several other systems were devised as the electric locomotive matured. The Buchli drive
Buchli drive
The Buchli drive is a transmission system used in electric locomotives. It was named after its inventor, Swiss engineer Jakob Buchli [Deutsch]. The drive is a fully spring-loaded drive, in which each floating axle has an individual motor, that is placed in the spring mounted locomotive frame...
was a fully spring-loaded system, in which the weight of the driving motors was completely disconnected from the driving wheels. First used in electric locomotives from the 1920s, the Buchli drive was mainly used by the French SNCF
SNCF
The SNCF , is France's national state-owned railway company. SNCF operates the country's national rail services, including the TGV, France's high-speed rail network...
and Swiss Federal Railways. The quill drive
Quill drive
A quill drive is a mechanism that allows a drive shaft to shift its position relative to its driving shaft. It consists of a hollow driving shaft with a driven shaft inside it...
was also developed about this time and mounted the traction motor above or to the side of the axle and coupled to the axle through a reduction gear and a semi-flexible hollow shaft - the quill. The Pennsylvania Railroad GG1
PRR GG1
The PRR GG1 is a class of electric locomotives that was built for the Pennsylvania Railroad for use in the northeastern United States. A total of 140 GG1s were constructed by its designer General Electric and the Pennsylvania's Altoona Works from 1934 to 1943....
locomotive used a quill drive. Again, as traction motors continued to shrink in size and weight, quill drives gradually fell out of favour.
Another drive example was the "bi-polar
Bipolar electric motor
A bipolar electric motor is an electric motor with only two poles to its stationary field. They are an example of the simple brushed DC motor, with a commutator. This field may be generated by either a permanent magnet or a field coil....
" system, in which the motor armature was the axle itself, the frame and field assembly of the motor being attached to the truck (bogie) in a fixed position. The motor had two field poles, which allowed a limited amount of vertical movement of the armature. This system was of limited value since the power output of each motor was limited. The EP-2
Milwaukee Road class EP-2
The Milwaukee Road's class EP-2 comprised five electric locomotives built by General Electric in 1919. They were often known as Bipolars, which referred to the bipolar electric motors they used. Among the most distinctive and powerful electric locomotives of their time, they epitomized the...
bi-polar electrics used by the Milwaukee Road compensated for this problem by using a large number of powered axles.
Modern electric locomotives, like their Diesel-electric counterparts, almost universally use axle-hung traction motors, with one motor for each powered axle. In this arrangement, one side of the motor housing is supported by plain bearings riding on a ground and polished journal that is integral to the axle. The other side of the housing has a tongue-shaped protuberance that engages a matching slot in the truck (bogie) bolster, its purpose being to act as a torque reaction device, as well as a support. Power transfer from motor to axle is effected by spur gearing, in which a pinion
Pinion
A pinion is a round gear used in several applications:*usually the smallest gear in a gear drive train, although in the case of John Blenkinsop's Salamanca, the pinion was rather large...
on the motor shaft engages a bull gear on the axle. Both gears are enclosed in a liquid-tight housing containing lubricating oil. The type of service in which the locomotive is used dictates the gear ratio employed. Numerically high ratios are commonly found on freight units, whereas numerically low ratios are typical of passenger engines.
Wheel arrangements
Whyte notation
The Whyte notation for classifying steam locomotives by wheel arrangement was devised by Frederick Methvan Whyte and came into use in the early twentieth century encouraged by an editorial in American Engineer and Railroad Journal...
system for classifying steam locomotive
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
s is not adequate for describing the varieties of electric locomotive arrangements, though the Pennsylvania Railroad
Pennsylvania Railroad
The Pennsylvania Railroad was an American Class I railroad, founded in 1846. Commonly referred to as the "Pennsy", the PRR was headquartered in Philadelphia, Pennsylvania....
applied classes
Class (locomotive)
Class refers to a group of locomotives built to a common design for a single railroad. Often members of a particular class had detail variations between individual examples, and these could lead to subclasses. Sometimes technical alterations move a locomotive from one class to another...
to its electric locomotives as if they were steam or concatenations of such. For example, the PRR GG1
PRR GG1
The PRR GG1 is a class of electric locomotives that was built for the Pennsylvania Railroad for use in the northeastern United States. A total of 140 GG1s were constructed by its designer General Electric and the Pennsylvania's Altoona Works from 1934 to 1943....
class indicates that it is arranged like two 4-6-0
4-6-0
Under the Whyte notation for the classification of steam locomotives, 4-6-0 represents the wheel arrangement of four leading wheels on two axles in a leading truck, six powered and coupled driving wheels on three axles, and no trailing wheels. This wheel arrangement became the second-most popular...
class G locomotives that are coupled back-to-back.
In any case, the UIC classification
UIC classification
The UIC classification of locomotive axle arrangements describes the wheel arrangement of locomotives, multiple units and trams. It is set out in the International Union of Railways "Leaflet 650 - Standard designation of axle arrangement on locomotives and multiple-unit sets". It is used in much...
system was typically used for electric locomotives, as it could handle the complex arrangements of powered and unpowered axles and could distinguish between coupled and uncoupled drive systems.
Japan
Cape gauge
Cape gauge is a track gauge of between the inside of the rail heads and is classified as narrow gauge. It has installations of around .The gauge was first used by Norwegian engineer Carl Abraham Pihl and the first line was opened in 1862.- Nomenclature :...
, of which 13280 kilometres (8,251.8 mi) is electrified; of 1435 mm (56.5 in) standard gauge
Standard gauge
The standard gauge is a widely-used track gauge . Approximately 60% of the world's existing railway lines are built to this gauge...
, all electrified; of 1372 mm (54 in) Scotch gauge
Scotch gauge
Scotch gauge was the name given to a track gauge, that was adopted by early 19th century railways mainly in the Lanarkshire area of Scotland. It differed from the gauge of that was used on some early lines in England; and from the standard gauge of...
, all electrified; of 762 mm (30 in) narrow gauge
Narrow gauge
A narrow gauge railway is a railway that has a track gauge narrower than the of standard gauge railways. Most existing narrow gauge railways have gauges of between and .- Overview :...
, all electrified.
Electrification systems used by the JR group, Japan's formerly state owned operators, are 1,500V DC and 20kV AC for conventional lines and 25kV AC for Shinkansen. Electrification with 600V DC and 750V DC are also seen in private lines. The frequency of the AC power supply is 50 Hz
Hertz
The hertz is the SI unit of frequency defined as the number of cycles per second of a periodic phenomenon. One of its most common uses is the description of the sine wave, particularly those used in radio and audio applications....
in Eastern Japan and 60 Hz in Western Japan.
Japan has come close to complete electrification largely due to the relatively short line distances and mountainous terrain which make electrical service a particularly economical investment. Additionally, the mix of freight to passenger service is weighted much more toward passenger service (even in rural areas) than in many other countries, and this has helped drive government investment into electrification of many remote lines.
Electrification began in earnest for local railways in the 1920s and main lines electrification began following World War II using a universal 1,500V DC standard and eventually, a 20kV standard for rapid intercity main lines (this is often overlaying 1,500V DC lines) and a 25kV AC standard for high-speed Shinkansen
Shinkansen
The , also known as THE BULLET TRAIN, is a network of high-speed railway lines in Japan operated by four Japan Railways Group companies. Starting with the Tōkaidō Shinkansen in 1964, the network has expanded to currently consist of of lines with maximum speeds of , of Mini-shinkansen with a...
lines). Because most of the electrification infrastructure was destroyed in the war, the only variances to this standard with significant traffic are a few of the older subway lines in Tokyo and Osaka. The Tōkaidō Main Line
Tokaido Main Line
The is the busiest trunk line of the Japan Railways Group , connecting Tōkyō and Kōbe stations. It is long, not counting its many freight feeder lines around the major cities...
, Japan's busiest line, completed electrification in 1956 and Tōkaidō Shinkansen was complete in 1964. By the mid 1970s, most main lines had been converted. During the 1970s and into the 1980s, when a fast growing Japanese economy encouraged massive infrastructure spending, almost every line with any significant traffic was electrified. Though the massive debts incurred for these upgrades (along with the more publicised expense of Shinkansen
Shinkansen
The , also known as THE BULLET TRAIN, is a network of high-speed railway lines in Japan operated by four Japan Railways Group companies. Starting with the Tōkaidō Shinkansen in 1964, the network has expanded to currently consist of of lines with maximum speeds of , of Mini-shinkansen with a...
expansions) led to the privatization and break-up of the national rail company. By the time of the breakup in 1987, electric service had penetrated to every line with significant traffic. In the 1990s, and 2000s, rural infrastructure was the focus of a lot of government stimulus funding and this included some rail electrification on infrequently used lines, as well as quite a lot of funding for further expanding the Shinkansen network (which, as with all high speed trains, is electric). The latter was mostly in the form of loans rather than direct investment as in the former.
Malaysia
Keretapi Tanah MelayuKeretapi Tanah Melayu
Keretapi Tanah Melayu Berhad or Malayan Railways Limited is the main rail operator in Peninsular Malaysia. The railway system dates back to the British colonial era, when it was first built to transport tin...
of Malaysia operated 25 kV AC electric multiple unit
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 number of the carriages...
services, starting from their KTM Komuter
KTM Komuter
KTM Komuter is a commuter train service in Malaysia operated by Keretapi Tanah Melayu . It was introduced in 1995 to provide local rail services in Kuala Lumpur and the surrounding Klang Valley suburban areas. It is popular with commuters into the city, who thus avoid being caught in road traffic...
in 1995. In December 2009, a fleet of new ETS are arrived.
Australia
Both Victorian RailwaysVictorian Railways
The Victorian Railways operated railways in the Australian state of Victoria from 1859 to 1983. The first railways in Victoria were private companies, but when these companies failed or defaulted, the Victorian Railways was established to take over their operations...
and New South Wales Government Railways
New South Wales Government Railways
The New South Wales Government Railways was the government department that operated the New South Wales Government's railways until the establishment of the Public Transport Commission in 1972. Although later known officially as the Department of Railways, New South Wales, it was still generally...
, which pioneered electric traction in Australia in the early 20th century and continue to operate 1,500 V DC Electric Multiple Unit
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 number of the carriages...
services, have withdrawn their fleets of main line
Main line (railway)
The Mainline or Main line of a railway is a track that is used for through trains or is the principal artery of the system from which branch lines, yards, sidings and spurs are connected....
electric locomotives.
In both states, the use of electric locomotives on principal interurban routes proved to be a qualified success. In Victoria, because only one major line (the Gippsland line
Orbost railway line
The Orbost railway line is a railway serving the Latrobe Valley and Gippsland regions of Victoria, Australia...
) had been electrified, the economic advantages of electric traction were not fully realised due to the need to change locomotives for trains that extended beyond the range of the electrified network. VR's entire electric locomotive fleet was withdrawn from service by 1987 and the Gippsland line electrification was dismantled by 2004. Similarly, the new fleet of 86 class locomotives introduced to NSW in 1983 had a relatively short life as the costs of changing locomotives at the extremities of the electrified network, together with the higher charges levied for electricity use, saw diesel-electric locomotives make inroads into the electrified network and the electric locomotive fleet was progressively withdrawn. Electric power car
Power car
A power car is a railroad vehicle that is closely related to the locomotive. What differentiates the two is their construction or their use. A true locomotive can be physically separated from its train and does nothing but provide propulsion . A power car, on the other hand, is frequently an...
trains are still used for urban passenger services.
Queensland Rail
Queensland Rail
Queensland Rail, also known as QR, is a government-owned railway operator in the state of Queensland. Under the control of the Queensland Government, Queensland Rail operates the inner-city and long-distance passenger services, as well as some freight operations and gives railway access to other...
, conversely, implemented electrification relatively recently and utilises the more recent 25 kV AC
25 kV AC
The 25 kV Alternating current railway electrification system is commonly used in railways worldwide, especially for high-speed rail.-Overview:This electrification system is ideal for railways that cover long distances and/or carry heavy traffic...
technology with around 1,000 km of the QR narrow gauge
Narrow gauge
A narrow gauge railway is a railway that has a track gauge narrower than the of standard gauge railways. Most existing narrow gauge railways have gauges of between and .- Overview :...
network now electrified. It operates a fleet of electric locomotives to transport coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
for export, the most recent of which are those of the 3,000 kW (4,020 HP) 3300/3400 Class. Queensland Rail is currently rebuilding its 3100 and 3200 class locos into the 3700 class, which use AC traction and only need three locomotives on a coal train rather than five. Queensland Rail is getting thirty 3800 class locomotives from Siemens in Munich, Germany, which will arrive during late 2008 to 2009. QRNational (Queensland Rail's Coal and Freight after separation) has increased the order of 3800 class locomotives from Germany. They continue to arrive late into 2010.
Europe
It should also be noted that diesel locomotives have little power compared to electric locomotives, given the same weight and dimensions. For instance, the 2,200 kW of a modern British Rail Class 66
British Rail Class 66
The Class 66 is a six axle diesel electric freight locomotive developed in part from the British Rail Class 59, for use on the railways of the UK. Since its introduction the class has been successful and has been sold to British and other European railway companies...
were already met in 1927 by the electric SBB-CFF-FFS Ae 4/7
SBB-CFF-FFS Ae 4/7
The Ae 4/7 was a universal locomotive of the Swiss Federal Railways, employing the so-called Buchli drive.Last but not least thanks to this drive construction, invented by Jakob Buchli, it was one of the longest-lasting locomotives...
(2,300 kW), which is even a bit lighter. However, for low speeds, tractive effort is more important than power. This is why diesel engines are competitive for slow freight traffic (as it is common in the US) but not for passenger or mixed passenger/freight traffic like on many European railway lines, especially where heavy freight trains must be run at comparatively high speeds (80 km/h or more).
These factors led to high degrees of electrification in most European countries. In some countries like Switzerland, even electric shunters are common and many private sidings can be served by electric locomotives. During World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, when materials to build new electric locomotives were not available, the Swiss Federal Railways installed electric heating elements, fed from the overhead supply, in the boilers of some steam shunters to deal with the shortage of imported coal.
The recent political developments in many European countries to enhance public transit have led to another boost for electric traction. High-speed trains like the TGV
TGV
The TGV is France's high-speed rail service, currently operated by SNCF Voyages, the long-distance rail branch of SNCF, the French national rail operator....
, ICE
InterCityExpress
The Intercity-Express or ICE is a system of high-speed trains predominantly running in Germany and neighbouring countries. It is the highest service category offered by DB Fernverkehr and is the flagship of Deutsche Bahn...
, AVE
AVE
Alta Velocidad Española is a service of high-speed rail in Spain operated by Renfe, the Spanish national railway company, at speeds of up to . The name is literally translated from Spanish as "Spanish High Speed", but also a play on the word , meaning "bird".AVE trains run on a network of...
and Pendolino
Pendolino
Pendolino is an Italian family of tilting trains used in Italy, Spain, Portugal, Slovenia, Finland, Russian Federation, the Czech Republic, the United Kingdom, Slovakia, Switzerland, China and shortly in Romania and Poland...
can only be run economically using electric traction and the operation of branch lines is usually less in deficit when using electric traction, due to cheaper and faster rolling stock and more passengers due to more frequent service and more comfort. In addition, gaps of un-electrified track are closed to avoid replacing electric locomotives by diesels for these sections. The necessary modernisation and electrification of these lines is possible due to financing of the railway infrastructure by the state.
India
In India, both AC and DC type of electrified train systems operate today. A 1,500 V DC-based train system is only operating in the Mumbai area. It is being converted to the 25 kV AC system. The rest of the India, where routes are electrified fully, operate under the 25 kV AC overhead wire.As of 2006, Indian railways haul 80% of freight and 85% of passenger traffic with electric locomotives.
Russia and former USSR
RussiaRussia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
and other countries of the former USSR have a mix of 3,300 V DC and 25 kV AC electric railroads due to historical reasons.
The special "junction stations" (around 15 over the whole former USSR - Vladimir
Vladimir
Vladimir is a city and the administrative center of Vladimir Oblast, Russia, located on the Klyazma River, to the east of Moscow along the M7 motorway. Population:...
, Mariinsk near Krasnoyarsk etc.) were equipped with contact wiring switchable from DC to AC. Locomotive replacement is essential at these stations and is performed together with the contact wiring switching.
Most Soviet, Czech (USSR ordered the passenger electric locomotives to Czech Skoda factory), Russian and Ukrainian locomotives can only operate as DC or as AC. For instance, VL80
VL80
The VL80 is a Soviet built electric AC mainline freight locomotive. The initials VL are those of Vladimir Lenin , after whom the class is named.-History:...
is an AC machine, with VL10 being something like a DC version of VL80. There were some half-experimental small-series like VL82, which could switch from AC to DC and were used in small amounts around the city of Kharkov in Ukraine
Ukraine
Ukraine is a country in Eastern Europe. It has an area of 603,628 km², making it the second largest contiguous country on the European continent, after Russia...
. Also, the latest Russian passenger locomotive EP10 is dual-system.
Historically, first the 3,300 V DC wiring was used due to vehicle simplicity. The first experimental track was in Georgian mountains, then the suburban zones of the largest cities were electrified for motor-car locomotive-less trains to be used - very advantageous due to much better dynamic of such a train compared to the steam one, which is important for the suburban service with frequent stops. Then the large mountain line between Ufa
Ufa
-Demographics:Nationally, dominated by Russian , Bashkirs and Tatars . In addition, numerous are Ukrainians , Chuvash , Mari , Belarusians , Mordovians , Armenian , Germans , Jews , Azeris .-Government and administration:Local...
and Chelyabinsk
Chelyabinsk
Chelyabinsk is a city and the administrative center of Chelyabinsk Oblast, Russia, located in the northwestern side of the oblast, south of Yekaterinburg, just to the east of the Ural Mountains, on the Miass River. Population: -History:...
was electrified.
For some time, electric railways were only considered to be suitable for suburban or mountain lines. In around 1950, a decision was made (according to the legend - by Joseph Stalin
Joseph Stalin
Joseph Vissarionovich Stalin was the Premier of the Soviet Union from 6 May 1941 to 5 March 1953. He was among the Bolshevik revolutionaries who brought about the October Revolution and had held the position of first General Secretary of the Communist Party of the Soviet Union's Central Committee...
) to electrify the highly loaded plain prairie line of Omsk
Omsk
-History:The wooden fort of Omsk was erected in 1716 to protect the expanding Russian frontier along the Ishim and the Irtysh rivers against the Kyrgyz nomads of the Steppes...
-Novosibirsk
Novosibirsk
Novosibirsk is the third-largest city in Russia, after Moscow and Saint Petersburg, and the largest city of Siberia, with a population of 1,473,737 . It is the administrative center of Novosibirsk Oblast as well as of the Siberian Federal District...
. After this, electrifying the major railroads with 3,000 V DC became a mainstream.
25 kV AC contact wiring started in the USSR in around 1960, when the industry managed to build the rectifier-based AC-wire DC-motor locomotive (all Soviet and Czech AC locomotives were such; only the post-Soviet ones switched to electronically controlled induction motors). The first major line with AC power was Mariinsk-Krasnoyarsk-Tayshet-Zima; the lines in European Russia like Moscow-Rostov-on-Don followed.
In 1990s, some DC lines were rebuilt as AC ones to allow the usage of the huge 10 MWt AC locomotive of VL85. The line around Irkutsk
Irkutsk
Irkutsk is a city and the administrative center of Irkutsk Oblast, Russia, one of the largest cities in Siberia. Population: .-History:In 1652, Ivan Pokhabov built a zimovye near the site of Irkutsk for gold trading and for the collection of fur taxes from the Buryats. In 1661, Yakov Pokhabov...
is one of them. The DC locomotives freed by this rebuild were transferred to St. Petersburg region.
The Trans-Siberian Railway
Trans-Siberian Railway
The Trans-Siberian Railway is a network of railways connecting Moscow with the Russian Far East and the Sea of Japan. It is the longest railway in the world...
has been partly electrified since 1929 and entirely electric hauled since 2002. The system is 25 kV AC 50 Hz after the junction station of Mariinsk near Krasnoyarsk, 3,000 V DC before it and train weights are up to 6,000 tonnes.
United States
For most large systems, the cost of electrifying the whole system is impractical and generally only some divisions are electrified. In the United States, only certain dense urban areas and some mountainous areas were electrified and the latter have all been discontinued. The junction between electrified and non-electrified territory is the locale of engine changes; for example, AmtrakAmtrak
The National Railroad Passenger Corporation, doing business as Amtrak , is a government-owned corporation that was organized on May 1, 1971, to provide intercity passenger train service in the United States. "Amtrak" is a portmanteau of the words "America" and "track". It is headquartered at Union...
trains had extended stops in New Haven, Connecticut
New Haven, Connecticut
New Haven is the second-largest city in Connecticut and the sixth-largest in New England. According to the 2010 Census, New Haven's population increased by 5.0% between 2000 and 2010, a rate higher than that of the State of Connecticut, and higher than that of the state's five largest cities, and...
as diesel and electric locomotives were swapped, a delay which contributed to the electrification of the remaining segment of the Northeast Corridor
Northeast Corridor
The Northeast Corridor is a fully electrified railway line owned primarily by Amtrak serving the Northeast megalopolis of the United States from Boston in the north, via New York to Washington, D.C. in the south, with branches serving other cities...
in 2000.
In North America, the flexibility of diesel locomotives and the relative low cost of their infrastructure has led them to prevail except where legal or other operational constraints dictate the use of electricity. An example of the latter is the use of electric locomotives by Amtrak and commuter railroads in The Northeast (e.g. New Jersey Transit
New Jersey Transit
The New Jersey Transit Corporation is a statewide public transportation system serving the United States state of New Jersey, and New York, Orange, and Rockland counties in New York State...
New York corridor uses ALP-46
ALP-46
The ALP-46 is an electric locomotive built in Germany by Bombardier between 2001 and 2002 for use in the United States. It is derived from the German Class 101. New Jersey Transit is the only railroad to operate this model locomotive...
electric locomotives, due to the prohibition on diesel operation in the Hudson and East River Tunnels
East River Tunnels
The East River Tunnels are 4 single-track railroad tunnels that extend from the eastern end of Pennsylvania Station under 32nd and 33rd Streets in Manhattan and cross the East River to Long Island City in Queens. The tracks carry Long Island Rail Road and Amtrak trains travelling to and from Penn...
leading to Penn Station
Pennsylvania Station (New York City)
Pennsylvania Station—commonly known as Penn Station—is the major intercity train station and a major commuter rail hub in New York City. It is one of the busiest rail stations in the world, and a hub for inbound and outbound railroad traffic in New York City. The New York City Subway system also...
).
Canada
No railways in Canada use electric locomotives on their lines as of January 2011.Agence métropolitaine de transport
Agence métropolitaine de transport
The Agence métropolitaine de transport is the umbrella organization that plans, integrates, and coordinates public transportation services across Canada's Greater Montreal Region, including the Island of Montreal, Laval , and communities along both the North Shore of the Rivière des Mille-Îles...
(AMT) has ordered the ALP-45DP
ALP-45DP
The ALP-45DP is a dual-mode locomotive currently being built by Bombardier Transportation. It was unveiled to the public on September 21, 2010 at Innotrans 2010.-New Jersey Transit:...
dual mode electro-diesel locomotive
Electro-diesel locomotive
An Electro-diesel locomotive is powered either from an electricity supply or by using the onboard diesel engine...
s for use on the Repentigny-Mascouche Line (AMT)
Repentigny-Mascouche Line (AMT)
The Repentigny-Mascouche Line. is a commuter rail line, proposed to be operated in the Greater Montreal Quebec, Canada area, by the Agence métropolitaine de transport, or AMT , the umbrella organization that plans, integrates, and coordinates public transportation services across this...
. The locomotives will run as electric while in the poorly ventilated Mount Royal Tunnel
Mount Royal Tunnel
The Mount Royal Tunnel is a railway tunnel located in Montreal, Quebec, Canada. It connects the city's Gare Centrale/Central Station, located downtown, with the north side of the Island of Montreal and Laval, passing through Mount Royal. Since 1995, the only trains using the tunnel are commuter...
only and as diesel elsewhere.
GO Transit
GO Transit
GO Transit is an inter-regional public transit system in Southern Ontario, Canada. It primarily serves the Greater Toronto and Hamilton Area conurbation, with operations extending to several communities beyond the GTHA proper in the Greater Golden Horseshoe...
has completed a study on electrifying some of their commuter rail lines (Georgetown/Air Rail Link & Lakeshore), but so far, no target date or purchases have been initiated.
Battery locomotives
A battery locomotive (or battery-electric locomotive) is a type of electric locomotive powered by on-board batteries; a kind of battery electric vehicleBattery electric vehicle
A battery electric vehicle, or BEV, is a type of electric vehicle that uses chemical energy stored in rechargeable battery packs. BEVs use electric motors and motor controllers instead of, or in addition to, internal combustion engines for propulsion.A battery-only electric vehicle or...
. Such locomotives are used where a conventional diesel or electric locomotive would be unsuitable. An example of use is the hauling of maintenance trains on electrified lines when the electricity supply is turned off, such as by the London Underground battery-electric locomotives
London Underground battery-electric locomotives
London Underground Battery-electric locomotives, most commonly known as battery locomotives are used for hauling engineers' trains, as they can operate when the electric traction current is switched off...
.
Another use for battery locomotives is in industrial facilities – as an alternative to the fireless locomotive
Fireless locomotive
A fireless locomotive is a type of locomotive designed for use under conditions restricted by either the presence of flammable material or the need for cleanliness...
– where a combustion-powered locomotive (i.e., steam-
Steam locomotive
A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...
or diesel-
Diesel locomotive
A diesel locomotive is a type of railroad locomotive in which the prime mover is a diesel engine, a reciprocating engine operating on the Diesel cycle as invented by Dr. Rudolf Diesel...
powered) could cause a safety issue, due to the risks of fire, explosion or fumes in a confined space. Battery locomotives are preferred for mines where gas could be ignited by trolley-powered
Trolley pole
A trolley pole is a tapered cylindrical pole of wood or metal, used to transfer electricity from a "live" overhead wire to the control and propulsion equipment of a tram or trolley bus. The use of overhead wire in a system of current collection is reputed to be the 1880 invention of Frank J....
units arcing
Electric arc
An electric arc is an electrical breakdown of a gas which produces an ongoing plasma discharge, resulting from a current flowing through normally nonconductive media such as air. A synonym is arc discharge. An arc discharge is characterized by a lower voltage than a glow discharge, and relies on...
at the collection shoes, or where electrical resistance
Electrical resistance
The electrical resistance of an electrical element is the opposition to the passage of an electric current through that element; the inverse quantity is electrical conductance, the ease at which an electric current passes. Electrical resistance shares some conceptual parallels with the mechanical...
could develop in the supply or return circuits, especially at rail joints, and allow dangerous current leakage into the ground. An early example was at the Kennecott Copper Mine, Latouche, Alaska, where in 1917 the underground haulage ways were widened to enable working by two battery locomotives of 4½ tons.
In 1928, Kennecott Copper ordered four 700-series electric locomotives with on-board batteries. These locomotives weighed 85 tons and operated on 750-volt overhead trolley wire with considerable further range whilst running on batteries. The locomotives provided several decades of service using Nickel-iron battery
Nickel-iron battery
The nickel–iron battery is a storage battery having a nickel oxide-hydroxide cathode and an iron anode, with an electrolyte of potassium hydroxide. The active materials are held in nickel-plated steel tubes or perforated pockets...
(Edison) technology. The batteries were replaced with lead-acid batteries
Lead-acid battery
Lead–acid batteries, invented in 1859 by French physicist Gaston Planté, are the oldest type of rechargeable battery. Despite having a very low energy-to-weight ratio and a low energy-to-volume ratio, their ability to supply high surge currents means that the cells maintain a relatively large...
, and the locomotives were retired shortly afterward. All four locomotives were donated to museums, but one was scrapped. The others can be seen at the Boone and Scenic Valley Railroad
Boone and Scenic Valley Railroad
The Boone and Scenic Valley Railroad is a heritage railroad in Boone County, Iowa.-History:The railroad was started in 1983 by a group of volunteers primarily to preserve a scenic section of the former Fort Dodge, Des Moines and Southern Railroad. The original track was built in the 1890s and...
, Iowa, and at the Western Railway Museum
Western Railway Museum
The Western Railway Museum, in Solano County, California is located on Highway 12 between Rio Vista and Suisun. The museum is built along the former mainline of theSacramento Northern Railway...
in Rio Vista, California.
See also
- Railway electrification systemRailway electrification systemA railway electrification system supplies electrical energy to railway locomotives and multiple units as well as trams so that they can operate without having an on-board prime mover. There are several different electrification systems in use throughout the world...
- Hybrid train
- Air brake (rail)Air brake (rail)An air brake is a conveyance braking system actuated by compressed air. Modern trains rely upon a fail-safe air brake system that is based upon a design patented by George Westinghouse on March 5, 1872. The Westinghouse Air Brake Company was subsequently organized to manufacture and sell...
- Railway brakesBrake (railway)Brakes are used on the cars of railway trains to enable deceleration, control acceleration or to keep them standing when parked. While the basic principle is familiar from road vehicle usage, operational features are more complex because of the need to control multiple linked carriages and to be...
- BoxcabBoxcabA boxcab, in railroad terminology, is a locomotive in which the machinery and crew areas are enclosed in a box-like superstructure . It is a term mostly used in North America while in Victoria , such locomotives have been nicknamed "butterboxes"...
- Emily DavenportEmily DavenportEmily Goss Davenport was an inventor from Vermont, United States. Emily, with her husband Thomas Davenport, invented an electric motor and electric locomotive circa 1834....
- electric locomotive pioneer - Charles Grafton PageCharles Grafton PageCharles Grafton Page was an American electrical experimenter and inventor, physician, patent examiner, patent advocate, and professor of chemistry....
- electrical pioneer - Battery powered railcars