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{{short description|Locomotive powered by a diesel engine}}
{{more citations needed|date=December 2019}}
[[File:ЧМЭ3-2908,
[[Image:Dawlish Warren 1970s - 5.jpg|thumb|right|The [[InterCity 125]]
[[File:Three-loco-styles.jpg|thumb|These locomotives operated by [[Pacific National]]
A '''diesel locomotive''' is a type of [[railway]] [[locomotive]] in which the [[prime mover (locomotive)|
Early [[internal combustion engine|internal combustion]] locomotives and railcars used [[kerosene]] and [[gasoline]] as their fuel. [[Rudolf Diesel]] patented his first [[compression-ignition engine]]<ref>{{cite patent |inventor=Rudolf Diesel |country=U.S. |number=608,845 |fdate=15 July 1895 |issue-date=9 August 1898 |url=http://www.google.com/patents?vid=USPAT608845&id=vQVgAAAAEBAJ&dq=608845 |title=Internal-combustion engine}}</ref> in 1898, and steady improvements to the design of diesel engines reduced their physical size and improved their [[power-to-weight
The first successful diesel engines used [[diesel–electric transmission]]s, and by 1925 a small number of diesel locomotives of {{convert|600|hp|kW|abbr=on}} were in service in the United States. In 1930, Armstrong Whitworth of the United Kingdom delivered two {{convert|1200|hp|kW|abbr=on}} locomotives using [[Sulzer (manufacturer)|Sulzer]]-designed engines to [[Buenos Aires Great Southern Railway]] of Argentina. In 1933, diesel–electric technology developed by [[Maybach]] was used to propel the [[DRG Class SVT 877]], a high-speed intercity two-car set, and went into series production with other streamlined car sets in Germany starting in 1935. In the United States, diesel–electric propulsion was brought to high-speed mainline passenger service in late 1934, largely through the research and development efforts of [[General Motors]] dating back to the late 1920s and advances in lightweight car body design by the [[Budd Company]].
The economic recovery from World War II
==History==
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[[File:Acsev56.jpg|thumb|Petrol–electric [[Weitzer railmotor]], first 1903, series 1906]]
The earliest recorded example of the use of an internal combustion engine in a railway locomotive is the prototype designed by [[William Dent Priestman]], which was examined by [[William Thomson, 1st Baron Kelvin]] in 1888 who described it as a "[[William Dent Priestman#The Priestman Oil Engine|Priestman oil engine]] mounted upon a truck which is worked on a temporary line of rails to show the adaptation of a petroleum engine for locomotive purposes."<ref>{{citation| magazine = The Engineer| date = 24 April 1956| page = 254| title = Motive power for British Railways| url = http://www.gracesguide.co.uk/images/5/56/Er19560824.pdf| volume = 202| access-date = 28 February 2014| archive-url = https://web.archive.org/web/20140304150727/http://www.gracesguide.co.uk/images/5/56/Er19560824.pdf| archive-date = 4 March 2014| url-status = dead}}</ref><ref>{{citation|journal = The Electrical Review| volume =22|page = 474| date= 4 May 1888|quote = A small double cylinder engine has been mounted upon a truck, which is worked on a temporary line of rails, in order to show the adaptation of a petroleum engine for locomotive purposes, on tramways}}</ref> In 1894, a {{convert|20|hp|kW|abbr=on}} two-axle machine built by [[Priestman Brothers]] was used on the [[Hull Docks]].<ref>{{citation|journal = Diesel Railway Traction|volume = 17|year= 1963 |page=25| quote=In one sense a dock authority was the earliest user of an oil-engined locomotive, for it was at the Hull docks of the North Eastern Railway that the Priestman locomotive put in its short period of service in 1894}}</ref><ref>{{citation| title = railway Locomotives| page
[[Rudolf Diesel]] considered using his engine for powering locomotives in his 1893 book ''Theorie und Konstruktion eines rationellen Wärmemotors zum Ersatz der Dampfmaschine und der heute bekannten Verbrennungsmotoren'' (''[[Theory and Construction of a Rational Heat Motor]]'').<ref>{{Citation
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| language = de
| isbn = 978-3-642-64941-7
| pages = 89–91}}</ref> However, the
In 1906, Rudolf Diesel, [[Adolf Klose]] and the steam and diesel engine manufacturer Gebrüder Sulzer founded Diesel-Sulzer-Klose GmbH to manufacture diesel-powered locomotives. Sulzer had been manufacturing diesel engines since 1898. The Prussian State Railways ordered a diesel locomotive from the company in 1909, and after test runs between [[Winterthur–Romanshorn railway|Winterthur and Romanshorn]], Switzerland, the diesel–mechanical locomotive was delivered in Berlin in September 1912. The world's first diesel-powered locomotive was operated in the summer of 1912 on the same line from Winterthur
Small numbers of prototype diesel locomotives were produced in a number of countries through the mid-1920s.
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{{See also|List of locomotives in China#Diesel locomotives}}
One of the first domestically
==== India ====
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====Japan====
In Japan, starting in the 1920s, some petrol–electric railcars were produced. The first diesel–electric traction and the first air-streamed vehicles on Japanese rails were the two DMU3s of class Kiha 43000 (キハ43000系).<ref>{{cite web|url=http://rail.hobidas.com/photo/archives/2005/07/50.html|title=DD50 5 DD50 2｜随時アップ：消えた車輌写真館｜鉄道ホビダス|website=rail.hobidas.com}}</ref> Japan's first series of diesel locomotives was class DD50 (国鉄DD50形), twin locomotives, developed since 1950 and in service since 1953.<ref>{{cite web|url=http://blogs.yahoo.co.jp/h53001126/4568133.html|title=キハ４３０００の資料 – しるねこの微妙な生活／浮気心あれば水心!?|access-date=2013-01-09|archive-date=2016-06-25|archive-url=https://web.archive.org/web/20160625140247/http://blogs.yahoo.co.jp/h53001126/4568133.html|url-status=dead}}</ref>
== Creation ==
A diesel locomotive is a type of railway locomotive when it's the diesel engine powered that turn the wheels, diesel locomotives than steam locomotives.
===Early diesel locomotives and railcars in Europe===
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[[File:Limousin2010RVT01.jpg|thumb|[[Switzerland|Swiss]] and German co-production: world's first functional diesel–electric railcar, 1914]]
In 1914, the world's first functional diesel–electric railcars were produced for the ''Königlich-Sächsische Staatseisenbahnen'' ([[Royal Saxon State Railways]]) by [[Waggonfabrik Rastatt]] with electric equipment from [[Brown, Boveri & Cie]] and diesel engines from [[Switzerland|Swiss]] [[Sulzer (manufacturer)|Sulzer AG]]. They were classified as
[[Fiat]] claims to have built the first Italian diesel–electric locomotive in 1922, but little detail is available. Several Fiat-[[Tecnomasio|TIBB]] Bo'Bo' diesel–locomotives were built for service on the {{Track gauge|950 mm}} narrow gauge Ferrovie Calabro Lucane and the [[Società per le Strade Ferrate del Mediterraneo|Società per le Strade Ferrate del Mediterrano]] in southern Italy in 1926, following trials in 1924–25.<ref>{{cite web|url=http://www.ferrovie.it/forum/viewtopic.php?f=22&t=13653|title=vecchia loco ferrovie della Calabria – Ferrovie.it|website=www.ferrovie.it}}</ref> The six-cylinder two-stroke motor produced {{Convert|440|hp|kW}} at 500{{nbsp}}rpm, driving four DC motors, one for each axle. These {{Convert|44|tonnes|ton}} locomotives with {{Convert|45|km/h|abbr=on}} top speed proved quite successful.<ref>{{Cite book|last=Messerschmitt|first=Wolfgang|title=Geschichte der italienischen Elektro- und Diesellokomotiven|publisher=Orell Füesli Verlag|year=1969|location=Zürich|pages=101–102|language=de|trans-title=History of Italy's electric and Diesel locomotives}}</ref>
In 1924, two diesel–electric locomotives were taken in service by the [[Rail transport in the Soviet Union|Soviet railways]], almost at the same time:
[[File:Teplovoz Eel2 (2).jpg|thumb|left|
* The engine Э<sup>эл</sup>2 ([[Russian locomotive class E el-2|E<sup>el</sup>2]] original number Юэ 001/Yu-e 001) started on October 22. It had been designed by a team led by [[Yuri Lomonosov]] and built 1923–1924 by [[Maschinenfabrik Esslingen]] in Germany. It had five driving axles (1'E1'). After several test rides, it hauled trains for almost three decades from 1925 to 1954.<ref>{{cite web|url=http://izmerov.narod.ru/first/thefirst3.html|title=The first russian diesel locos|website=izmerov.narod.ru}}</ref>
* The engine Щэл1 ([[Soviet locomotive class shch-el-1|Shch-el 1]], original number ''Юэ2/Yu-e 2)'', started on November 9. It had been developed by [[Yakov Modestovich Gakkel]]
In 1935, [[Krauss-Maffei]], [[MAN AG|MAN]] and [[Voith]] built the first diesel–hydraulic locomotive, called [[DRG Class V 140|V 140]], in Germany. Diesel–hydraulics became the mainstream in diesel locomotives in Germany since the German railways (DRG) were pleased with the performance of that engine. Serial production of diesel locomotives in Germany began after World War II.
====Switchers====
{{Main article|Switcher locomotive}}
[[File:Rangeerlocomotor NS 228.jpg|thumb|Shunter of {{lang|nl|[[Nederlandse Spoorwegen]]|italic=no}} from 1934, in modern livery]]
In many railway stations and industrial compounds, steam shunters had to be kept hot during many breaks between scattered short tasks. Therefore, diesel traction became economical for [[Shunting (rail)|shunting]] before it became economical for hauling trains. The construction of diesel shunters began in 1920 in France, in 1925 in Denmark, in 1926 in the Netherlands, and in 1927 in Germany. After a few years of testing, hundreds of units were produced within a decade.
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* In Germany, the [[Flying Hamburger]] was built in 1932. After a test ride in December 1932, this two-coach diesel railcar (in English terminology a DMU2) started service at [[Deutsche Reichsbahn]] (DRG) in February 1933. It became the prototype of [[DRG Class SVT 137]] with 33 more highspeed DMUs, built for DRG till 1938, 13 DMU 2 ("Hamburg" series), 18 DMU 3 ("Leipzig" and "Köln" series), and two DMU 4 ("Berlin" series).
* French [[SNCF]] classes XF 1000 and XF 1100 comprised 11 high-speed DMUs, also called TAR, built 1934–1939.
* In Hungary, [[Ganz Works]] built the {{Interlanguage link|Arpád railmotor|hu|Aamot|de|MÁV-Baureihe Árpád}}, a kind of a luxurious railbus in a series of seven items since 1934
====Further developments====
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[[General Electric]] (GE) entered the [[railcar]] market in the early twentieth century, as [[Thomas Edison]] possessed a patent on the electric locomotive, his design actually being a type of electrically propelled railcar.<ref>Edison, Thomas A. U.S. Patent No. 493,425, filed January 19, 1891, and issued March 14, 1891 ''Accessed via the Edison Papers at: [http://edison.rutgers.edu/patents/00493425.PDF US Patent #493,425] on February 8, 2007.''</ref> GE built its first electric locomotive prototype in 1895. However, high electrification costs caused GE to turn its attention to internal combustion power to provide electricity for electric railcars. Problems related to co-ordinating the prime mover and [[traction motor|electric motor]] were immediately encountered, primarily due to limitations of the [[Ward Leonard control|Ward Leonard]] current control system that had been chosen.{{Citation needed|date=February 2016}} [[GE Rail]] was formed in 1907 and 112 years later, in 2019, was purchased by and merged with [[Wabtec]].
A significant breakthrough occurred in 1914, when [[Hermann Lemp]], a GE electrical engineer, developed and patented a reliable control system that controlled the engine and traction motor with a single lever; subsequent improvements were also patented by Lemp.<ref>Lemp, Hermann. U.S. Patent No. 1,154,785, filed April 8, 1914, and issued September 28, 1915. ''Accessed via Google Patent Search at: [
In 1917–1918, GE produced three experimental diesel–electric locomotives using Lemp's control design, the first known to be built in the United States.<ref name="SDSG">{{harvnb|Pinkepank|1973|pp=139–141}}</ref> Following this development, the 1923 [[Kaufman Act]] banned steam locomotives from New York City, because of severe pollution problems. The response to this law was to electrify high-traffic rail lines. However, electrification was uneconomical to apply to lower-traffic areas.
The first regular use of diesel–electric locomotives was in [[Switcher locomotive|switching]] (shunter) applications, which were more forgiving than mainline applications of the limitations of contemporary diesel technology and where the idling economy of diesel relative to steam would be most beneficial. GE entered a collaboration with the [[American Locomotive Company]] (ALCO) and [[Ingersoll-Rand]] (the "AGEIR" consortium) in 1924 to produce a prototype {{convert|300|hp|kW|abbr=on}} "boxcab" locomotive delivered in July 1925. This locomotive demonstrated that the diesel–electric power unit could provide many of the benefits of an [[electric locomotive]] without the railroad having to bear the sizeable expense of electrification.{{sfn|Churella|1998|pp=25-27}} The unit successfully demonstrated, in switching and local freight and passenger service, on ten railroads and three industrial lines.<ref>Evolution of the American Diesel Locomotive, J Parker Lamb 2007, Indiana University Press, {{ISBN|978-0-253-34863-0}}, p.29</ref> Westinghouse Electric and Baldwin collaborated to build switching locomotives starting in 1929. However, the [[Great Depression]] curtailed demand for Westinghouse's electrical equipment, and they stopped building locomotives internally, opting to supply electrical parts instead.{{sfn|Churella|1998|pp=28-30}}
In June 1925, [[Baldwin Locomotive Works]] outshopped a prototype diesel–electric locomotive for "special uses" (such as for runs where water for steam locomotives was scarce) using electrical equipment from [[Westinghouse Electric Corporation (1886)|Westinghouse Electric Company]].<ref>{{Citation |title=Railroads To Try Diesel Locomotive |newspaper=Special to the New York Times |date=February 18, 1925 |page=1}}</ref> Its twin-engine design was not successful, and the unit was scrapped after a short testing and demonstration period.{{sfn|Pinkepank|1973|p=283}} Industry sources were beginning to suggest "the outstanding advantages of this new form of motive power".{{sfn|Churella|1998|p=27}} In 1929, the [[Canadian National Railways]] became the first North American railway to use diesels in mainline service with two units, 9000 and 9001, from Westinghouse.{{sfn|Pinkepank|1973|p=409}} However, these early diesels proved expensive and unreliable, with their high cost of acquisition relative to steam unable to be realized in operating cost savings as they were frequently out of service. It would be another five years before diesel–electric propulsion would be successfully used in mainline service, and nearly ten years before fully replacing steam became a real prospect with existing diesel technology.
Before diesel power could make inroads into mainline service, the limitations of diesel engines circa 1930 – low power-to-weight ratios and narrow output range – had to be overcome. A major effort to overcome those limitations was launched by [[General Motors]] after they moved into the diesel field with their acquisition of the [[Winton Engine Company]], a major manufacturer of diesel engines for marine and stationary applications, in 1930. Supported by the General Motors Research Division, GM's [[Cleveland Diesel Engine Division|Winton Engine Corporation]] sought to develop diesel engines suitable for high-speed mobile use. The first milestone in that effort was delivery in early 1934 of the Winton 201A, a [[two-stroke]], [[Roots-type supercharger|mechanically
Diesel–electric railroad locomotion entered mainline service when the [[Burlington Route]] and [[Union Pacific]] used custom-built diesel "[[streamliner]]s" to haul passengers, starting in late 1934.<ref name="Stover 212"/><ref>[https://books.google.com/books?id=79oDAAAAMBAJ&dq=Popular+Science+1933+plane+%22Popular+Mechanics%22&pg=PA165 "Diesel Streamliners Now Link Coast-to-Coast"] ''Popular Mechanics'', August 1937</ref> Burlington's ''[[Burlington Zephyr|Zephyr]]'' trainsets evolved from articulated three-car sets with 600 hp power cars in 1934 and early 1935, to the ''Denver Zephyr'' semi-articulated ten car trainsets pulled by cab-booster power sets introduced in late 1936. Union Pacific started diesel streamliner service between Chicago and Portland Oregon in June 1935, and in the following year would add [[Los Angeles|Los Angeles, CA]], [[Oakland, California|Oakland, CA]], and [[Denver|Denver, CO]] to the destinations of diesel streamliners out of Chicago. The Burlington and Union Pacific streamliners were built by the [[Budd Company]] and the [[Pullman-Standard|Pullman-Standard Company]], respectively, using the new Winton engines and power train systems designed by GM's [[Electro-Motive Corporation]]. EMC's experimental [[EMC 1800 hp B-B|1800 hp B-B]] locomotives of 1935 demonstrated the multiple-unit control systems used for the cab/booster sets and the twin-engine format used with the later ''Zephyr'' power units. Both of those features would be used in EMC's later production model locomotives. The lightweight diesel streamliners of the mid-1930s demonstrated the advantages of diesel for passenger service with breakthrough schedule times, but diesel locomotive power would not fully come of age until regular series production of mainline diesel locomotives commenced and it was shown suitable for full-size passenger and freight service.
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In the early postwar era, EMD dominated the market for mainline locomotives with their E and F series locomotives. ALCO-GE in the late 1940s produced switchers and road-switchers that were successful in the short-haul market. However, EMD launched their [[EMD GP7|GP series]] road-switcher locomotives in 1949, which displaced all other locomotives in the freight market including their own F series locomotives. GE subsequently dissolved its partnership with ALCO and would emerge as EMD's main competitor in the early 1960s, eventually taking the top position in the locomotive market from EMD.
Early diesel–electric locomotives in the United States used direct current (DC) traction motors
===Early diesel locomotives and railcars in Oceania===
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The [[Trans-Australian Railway]] built 1912 to 1917 by Commonwealth Railways (CR) passes through 2,000 km of waterless (or salt watered) desert terrain unsuitable for steam locomotives. The original engineer [[Henry Deane (engineer)|Henry Deane]] envisaged [[Diesel engine|diesel operation]] to overcome such problems.<ref name=burk>Burke, A 1991., ''Rails through the Wilderness''; New South Wales University Press</ref> Some have suggested that the CR worked with the South Australian Railways to trial diesel traction.<ref>Holden, R 2006 No. 259 : the curious story of a forgotten locomotive, Railmac Publications</ref> However, the technology was not developed enough to be reliable.
As in Europe, the usage of internal combustion engines advanced more readily in self-propelled railcars than in locomotives
* Some Australian railway companies bought [[McKeen railmotor]]s.
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==Transmission types==
===Diesel–mechanical===
[[File:DieselMechanicalLocomotiveSchematic.svg|thumb|Schematic illustration of a
A diesel–mechanical locomotive uses a [[Transmission (mechanics)|mechanical transmission]] in a fashion similar to that employed in most road vehicles. This type of transmission is generally limited to low-powered, low-speed [[shunting (rail)|shunting]] (switching) locomotives, lightweight [[multiple unit]]s and self-propelled [[railcar]]s.
[[File:D2069 at Doncaster Works.JPG|thumb|left|A [[British Rail Class 03]] diesel–mechanical [[shunter]] with a [[Jackshaft (locomotive)|jackshaft]] under the cab.]]
The mechanical transmissions used for railroad propulsion are generally more complex and much more robust than standard-road versions. There is usually a [[fluid coupling]] interposed between the engine and gearbox, and the gearbox is often of the [[epicyclic gearing|epicyclic (planetary)]] type to permit shifting while under load. Various systems have been devised to minimise the break in transmission during gear changing
Diesel–mechanical propulsion is limited by the difficulty of building a reasonably sized transmission capable of coping with the power and [[torque]] required to move a heavy train. A number of attempts to use diesel–mechanical propulsion in high power applications have been made (e.g., the {{convert|1500|kW|hp|abbr=on}} [[British Rail 10100]] locomotive),
{{clear}}
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[[File:DieselElectricLocomotiveSchematic.svg|thumb|right|Schematic diagram of a diesel–electric locomotive]]
[[File:UnionPacific6922.jpg|thumb|[[EMD DDA40X]], the most powerful single-unit diesel-electric locomotive in the world with two diesel engines, rated at {{convert|6600|hp|kW|-1|abbr=on}}<ref name="DD40AX">{{Cite book |title=The field guide to trains : locomotives and rolling stock |last=Solomon |first=Brian |isbn=9780760349977 |location=Minneapolis, Minnesota |page=189 |chapter=EMD DDA40X |date=15 June 2016 |oclc=928614280 |chapter-url=https://books.google.com/books?id=tigVDAAAQBAJ&pg=PA189}}</ref>]]
[[File:ТЭП80-0002, Россия, Тверская область, станция Калинин (Trainpix 208953).jpg|right|thumb|Russian diesel locomotive [[TEP80]], the fastest diesel-electric locomotive in the world that reached {{convert|271|km/h|mph|abbr=on}} on 5 October 1993.<ref>{{YouTube|id=wwYXjxXFha0|title = Рекордные испытания ТЭП80-0002 05.10.1993.TEP80 world speed record 271 km/h}}</ref>]]
In a '''diesel–electric locomotive''', the diesel engine drives either an electrical [[electric generator|DC generator]] (generally, less than {{convert|3000|hp||abbr=on}} net for traction), or an electrical [[alternator|AC alternator-rectifier]] (generally 3,000{{nbsp}}hp net or more for traction), the output of which provides power to the [[traction motor]]s that drive the locomotive. There is no mechanical connection between the diesel engine and the wheels.
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[[File:Metra Locomotives F40PH-2 & MP36PH-3S.jpg|thumb|left|The [[EMD F40PH]] (left) and [[MPI MPXpress]]-series MP36PH-3S (right) [[locomotive]]s [[Railway coupling|coupled]] together by [[Metra]] use [[diesel–electric transmission]].]]
[[File:Nákladové nádraží Žižkov, lokomotiva 742.330.jpg|thumb|Czech [[ČSD Class T 466.2|Class 742 and 743]] shunting locomotive]]▼
Originally, the traction motors and generator were [[direct current|DC]] machines. Following the development of high
▲[[File:Nákladové nádraží Žižkov, lokomotiva 742.330.jpg|thumb|Czech [[ČSD Class T 466.2|Class 742 and 743]] locomotive]]
▲Originally, the traction motors and generator were [[direct current|DC]] machines. Following the development of high-capacity [[silicon rectifiers]] in the 1960s, the DC generator was replaced by an [[alternator]] using a [[diode bridge]] to convert its output to DC. This advance greatly improved locomotive reliability and decreased generator maintenance costs by elimination of the [[commutator (electric)|commutator]] and [[brush (electric)|brushes]] in the generator. Elimination of the brushes and commutator, in turn, eliminated the possibility of a particularly destructive type of event referred to as a flashover (also known as an [[arc fault]]), which could result in immediate generator failure and, in some cases, start an engine room fire.
Current North American practice is for four axles for high-speed passenger or "time" freight, or for six axles for lower-speed or "manifest" freight. The most modern units on "time" freight service tend to have six axles underneath the frame. Unlike those in "manifest" service, "time" freight units will have only four of the axles connected to traction motors, with the other two as idler axles for weight distribution.
In the late 1980s, the development of high-power [[Variable-frequency drive|variable-voltage/variable-frequency]] (VVVF) drives, or "traction inverters", allowed the use of polyphase AC traction motors, thereby also eliminating the motor commutator and brushes. The result is a more efficient and reliable drive that requires relatively little maintenance and is better able to cope with overload conditions that often destroyed the older types of motors.
[[File:CSX locomotive cab.jpg|thumb|right|Engineer's controls in a diesel–electric locomotive cab. The lever near bottom-centre is the throttle and the lever visible at bottom left is the automatic brake valve control.]]▼
====Diesel–electric control====
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====Throttle operation====
▲[[File:CSX locomotive cab.jpg|thumb|right|Engineer's controls in a [[hood unit|hood]]-styled diesel–electric locomotive cab. The lever near bottom-centre is the throttle and the lever visible at bottom left is the automatic brake valve control.]]
[[File:116U-rabmash.jpg|thumb|Cab of the [[boxcab]]-styled Russian locomotive [[2TE116]]U. "11" indicates the throttle.]]
The prime mover's [[Power (physics)|power]] output is primarily determined by its rotational speed ([[revolutions per minute|RPM]]) and fuel rate, which are regulated by a [[governor (device)|governor]] or similar mechanism. The governor is designed to react to both the throttle setting, as determined by the engine driver and the speed at which the prime mover is running (see [[Control theory]]).
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In older locomotives, the throttle mechanism was [[ratchet (device)|ratcheted]] so that it was not possible to advance more than one power position at a time. The engine driver could not, for example, pull the throttle from notch 2 to notch 4 without stopping at notch 3. This feature was intended to prevent rough train handling due to abrupt power increases caused by rapid throttle motion ("throttle stripping", an operating rules violation on many railroads). Modern locomotives no longer have this restriction, as their control systems are able to smoothly modulate power and avoid sudden changes in [[train]] loading regardless of how the engine driver operates the controls.
[[File:Cabview & Engine Room M61 459.022 - cab and engine room.webm|thumb|thumbtime=1:00|Overview of a driver's cab and an engine room of the Hungarian [[cab unit|cab-styled]] [[MAV M61|M61]] diesel-electric locomotive. Changes in diesel engine sounds can be heard during switching the throttle.]]
When the throttle is in the idle position, the prime mover receives minimal fuel, causing it to idle at low RPM. In addition, the traction motors are not connected to the main generator and the generator's field windings are not excited (energized) – the generator does not produce electricity without excitation. Therefore, the locomotive will be in "neutral". Conceptually, this is the same as placing an automobile's transmission into neutral while the engine is running.
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As the throttle is moved to higher power notches, the fuel rate to the prime mover will increase, resulting in a corresponding increase in RPM and horsepower output. At the same time, main generator field excitation will be proportionally increased to absorb the higher power. This will translate into increased electrical output to the traction motors, with a corresponding increase in tractive force. Eventually, depending on the requirements of the train's schedule, the engine driver will have moved the throttle to the position of maximum power and will maintain it there until the train has accelerated to the desired speed.
[[File:EMD diesel locomotives of the USA in operation with engine sounds.webm|thumb|thumbtime=8:25|[[Electro Motive Diesel|EMD]] and [[General Electric|GE]] mainline diesel-electric locomotives of the USA in operation with freight trains. Sounds of diesel engines during idle and power up]]
The propulsion system is designed to produce maximum traction motor torque at start-up, which explains why modern locomotives are capable of starting trains weighing in excess of 15,000 tons, even on ascending grades.
Current technology allows a locomotive to develop as much as 30% of its loaded driver weight in tractive force, amounting to {{convert|120000|lbf|kN}} of [[tractive force]] for a large, six-axle freight (goods) unit.
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====Propulsion system operation====
[[File:3000hp curve ver2.jpg|thumb|350px|Typical main generator constant power curve at "notch 8"]]
[[File:Zamracena engine.JPG|thumb|Diesel engine and main DC generator of a Czech Class 751 locomotive]]
[[File:116U-left-corridore-diesel.jpg|thumb|Left corridor of power compartment of Russian locomotive [[2TE116]]U, 3 – alternator, 4 – rectifier, 6 – diesel]]
[[File:2TE116-691 with freight train, Izmail - Artsiz, 2012.webm|right|thumb|thumbtime=10|Soviet [[2TE116]] diesel-electric locomotive in motion with a freight train. Sounds of diesel engines at full power]]
A locomotive's control system is designed so that the main generator [[electrical power]] output is matched to any given engine speed. Given the innate characteristics of traction motors, as well as the way in which the motors are connected to the main generator, the generator will produce high current and low voltage at low locomotive speeds, gradually changing to low current and high voltage as the locomotive accelerates. Therefore, the net power produced by the locomotive will remain constant for any given throttle setting (''see power curve graph for notch 8'').
In older designs, the prime mover's governor and a companion device, the load regulator, play a central role in the control system. The governor has two external inputs: requested engine speed, determined by the engine driver's throttle setting, and actual engine speed ([[feedback]]). The governor has two external control outputs: [[fuel injector]] setting, which determines the engine fuel rate, and current regulator position, which affects main generator excitation. The governor also incorporates a separate overspeed protective mechanism that will immediately cut off the fuel supply to the injectors and sound an alarm in the [[Cab (locomotive)|cab]] in the event the prime mover exceeds a defined RPM. Not all of these inputs and outputs are necessarily electrical.
[[File:EMD 567.jpg|thumb|An [[EMD 567|EMD 12-567B]] 12-cylinder 2-stroke diesel engine (foreground; square "hand holes"), stored pending rebuild, and missing some components, with a 16-567C or D 16-cylinder engine (background; round "hand holes").]]
As the load on the engine changes, its rotational speed will also change. This is detected by the governor through a change in the engine speed feedback signal. The net effect is to adjust both the fuel rate and the load regulator position so that engine RPM and [[torque]] (and therefore power output) will remain constant for any given throttle setting, regardless of actual road speed.
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At standstill, main generator output is initially low voltage/high current, often in excess of 1000 [[ampere]]s per motor at full power. When the locomotive is at or near standstill, current flow will be limited only by the DC resistance of the motor windings and interconnecting circuitry, as well as the capacity of the main generator itself. Torque in a [[Traction motor|series-wound motor]] is approximately proportional to the square of the current. Hence, the traction motors will produce their highest torque, causing the locomotive to develop maximum [[tractive effort]], enabling it to overcome the inertia of the train. This effect is analogous to what happens in an automobile [[automatic transmission]] at start-up, where it is in first gear and thereby producing maximum torque multiplication.
As the locomotive accelerates, the now-rotating motor armatures will start to generate a [[counter-electromotive force]] (back EMF, meaning the motors are also trying to act as generators), which will oppose the output of the main generator and cause traction motor current to decrease. Main generator voltage will correspondingly increase in an attempt to maintain motor power
Transition methods include:
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A common option on diesel–electric locomotives is [[Dynamic braking|dynamic (rheostatic) braking]].
Dynamic braking takes advantage of the fact that the [[traction motor]] armatures are always rotating when the locomotive is in motion and that a motor can be made to act as a [[electrical generator|generator]] by separately exciting the field winding. When dynamic braking is
* The field winding of each traction motor is connected across the main generator.
* The armature of each traction motor is connected across a forced-air-cooled [[resistor#Wire wound|resistance grid]] (the dynamic braking grid) in the roof of the locomotive's hood.
* The prime mover RPM is increased, and the main generator field is excited, causing a corresponding excitation of the traction motor fields.
The aggregate effect of the above is to cause each traction motor to generate electric power and dissipate it as heat in the dynamic braking grid. A fan connected across the grid provides forced-air cooling. Consequently, the fan is powered by the output of the traction motors and will tend to run faster and produce more airflow as more energy is applied to the grid.
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Ultimately, the source of the energy dissipated in the dynamic braking grid is the motion of the locomotive as imparted to the traction motor armatures. Therefore, the traction motors impose drag and the locomotive acts as a brake. As speed decreases, the braking effect decays and usually becomes ineffective below approximately 16 km/h (10 mph), depending on the gear ratio between the traction motors and [[axle]]s.
Dynamic braking is particularly beneficial when operating in mountainous regions
====Electro-diesel====
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===Diesel–hydraulic===
<!-- The material on torque converters is confusing and somewhat inaccurate. The editor should examine the torque converter article for correct terminology. -->
[[File:Vaxellok.jpg|thumb|Schematic diagram of a diesel–hydraulic shunting locomotive with hydromechanical transmission]]
[[File:JNR DD51-1 at Usui Pass Railway Heritage Park.jpg|thumb|right|[[JNR Class DD51|JNR DD51]] 1 diesel-hydraulic]]▼
Diesel–hydraulic locomotives use one or more [[torque converter]]s, in combination with fixed ratio gears. Drive shafts and gears form the final drive to convey the power from the torque converters to the wheels, and to effect reverse. The difference between [[Hydraulics|hydraulic]] and mechanical systems is where the speed and torque is adjusted. In the mechanical transmission system that has multiple ratios such as in a gear box, if there is a hydraulic section, it is only to allow the engine to run when the train is too slow or stopped. In the hydraulic system, hydraulics are the primary system for adapting engine speed and torque to the train's situation, with gear selection for only limited use, such as reverse gear.
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====Hydrokinetic transmission====
{{see also|Torque converter|Fluid coupling}}
[[File:TGM6-diesel-UGP.jpg|thumb|An equipment of a Russian [[Lyudinovsky_Locomotive_Plant|TGM6]] diesel-hydraulic locomotive:<br>1 — diesel, 2 — oil filter, 3 — turning gear, 4 — water-to-fuel heater, 5 — auxiliary electric generator, 6 — hydrokinetic transmission, 7 — first gear valve (with manual shift handle), 8 — automatic transmission oil filter]]
[[File:Db-220002-01-c.jpg|thumb|right|[[DB Class V 200|DB class V 200]] diesel–hydraulic]]▼
Hydrokinetic transmission (also called hydrodynamic transmission) uses a [[torque converter]]. A torque converter consists of three main parts, two of which rotate, and one (the [[stator]]) that has a lock preventing backwards rotation and adding output torque by redirecting the oil flow at low output RPM. All three main parts are sealed in an oil-filled housing. To match engine speed to load speed over the entire speed range of a locomotive some additional method is required to give sufficient range. One method is to follow the torque converter with a mechanical gearbox which switches ratios automatically, similar to an automatic transmission in an automobile. Another method is to provide several torque converters each with a range of variability covering part of the total required; all the torque converters are mechanically connected all the time, and the appropriate one for the speed range required is selected by filling it with oil and draining the others. The filling and draining is carried out with the transmission under load, and results in very smooth range changes with no break in the transmitted power.
<gallery widths="200px" heights="150px"">
Williton Class 52 engine and transmission.jpg|Diesel prime mover (left) and hydraulic transmission (right) of the [[British Rail Class 52]] diesel locomotive
File:SAR Class 61-000 61-006 (D750) 1.jpg|[[South African Class 61-000]] diesel-hydraulic locomotive under construction
</gallery>
[[File:SGL V500.17-III.JPG|thumb|right|[[Voith Maxima|Voith Maxima 40CC]], the most powerful single-engined diesel-hydraulic locomotive in the world, rated at {{convert|3,600|kW|hp|abbr=on}}<ref name="G1975de">{{cite web |url=http://voithturbo.com/sys/php/docdb_stream.php?pk=3508|title=Voith Maxima product folder |date=August 2010|publisher=Voith Turbo Lokomotivtechnik|access-date=2011-01-18}}</ref>]]
[[File:Western Warship and Hymek.jpg|thumb|right|British Rail diesel–hydraulic locomotives: [[British Rail Class 52|Class 52 "Western"]], [[British Rail Class 42|Class 42 "Warship"]] and [[British Rail Class 35|Class 35 "Hymek"]]]]▼
Diesel-hydraulic locomotives are less efficient than diesel–electrics. The first-generation BR diesel hydraulics were significantly less efficient (c. 65%) than diesel electrics (c. 80%),{{citation needed|date=February 2014}} Moreover, initial versions were found in many countries to be mechanically more complicated and more likely to break down.{{citation needed|date=February 2014}} Hydraulic transmission for locomotives was developed in Germany.{{citation needed|date=February 2014}} There is still debate over the relative merits of hydraulic vs. electrical transmission systems: advantages claimed for hydraulic systems include lower weight, high reliability, and lower capital cost.{{citation needed|date=February 2014}}
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In Germany and Finland, diesel–hydraulic systems have achieved high reliability in operation.{{citation needed|date=February 2014}} In the UK the diesel–hydraulic principle gained a poor reputation due to the poor durability and reliability of the Maybach [[Mekydro]] hydraulic transmission.{{citation needed|date=February 2014}} Argument continues over the relative reliability of hydraulic systems, with questions over whether data has been manipulated to favour local suppliers over non-German ones.{{Citation needed|date=October 2008}}
===== Multiple units =====▼
Diesel–hydraulic drive is common in multiple units, with various transmission designs used including [[Voith]] torque converters, and [[fluid coupling]]s in combination with mechanical gearing.▼
The majority of [[British Rail]]'s second generation passenger DMU stock used hydraulic transmission. In the 21st century, designs using hydraulic transmission include [[Bombardier Transportation|Bombardier]]{{'s}} [[Bombardier Turbostar|Turbostar]], [[Bombardier Talent|Talent]], [[RegioSwinger]] families; diesel engined versions of the [[Siemens Desiro]] platform, and the [[Stadler Regio-Shuttle]].▼
[[File:VR Dv12 locomotive in Tampere Aug2008 001.jpg|thumb|right|A [[VR Class Dv12]] diesel–hydraulic locomotive]]▼
[[File:DH GMD 6031 VFRGS-RF Guido Mota.jpg|thumb|right|A [[GMD GMDH-1]] diesel–hydraulic locomotive]]▼
Diesel–hydraulic locomotives have a smaller market share than those with diesel–electric transmission – the main worldwide user of main-line hydraulic transmissions was the [[Federal Republic of Germany]], with designs including the 1950s [[DB class V 200]], and the 1960 and 1970s [[DB Class V 160 family]]. [[British Rail]] introduced a number of diesel-hydraulic designs during its [[1955 Modernisation Plan]], initially license-built versions of German designs (see [[:Category:Diesel-hydraulic locomotives of Great Britain|Category:Diesel–hydraulic locomotives of Great Britain]]). In Spain, [[Renfe]] used high power to weight ratio twin-engine German designs to haul high speed trains from the 1960s to 1990s. (See [[Renfe Class 340|Renfe Classes 340]], [[Renfe Class 350|350]], [[Renfe Class 352|352]], [[Renfe Class 353|353]], [[Renfe Class 354|354]])
Other main-line locomotives of the post-war period included the 1950s [[GMD GMDH-1]] experimental locomotives; the [[Henschel & Son]] built [[South African Class 61-000]]; in the 1960s [[Southern Pacific Transportation Company|Southern Pacific]] bought 18 Krauss-Maffei [[KM ML-4000]] diesel–hydraulic locomotives. The [[Denver & Rio Grande Western Railroad]] also bought three, all of which were later sold to SP.<ref>{{cite book|last= Marre|first= Louis A.|title=Diesel Locomotives: The First Fifty Years|publisher=Kalmbach|year = 1995|location = Waukesha, Wis., USA|pages = 384–385|isbn=978-0-89024-258-2}}</ref>
In Finland, over 200 Finnish-built [[VR Class Dv12|VR class Dv12]] and Dr14 diesel–hydraulics with [[Voith]] transmissions have been continuously used since the early 1960s. All units of Dr14 class and most units of Dv12 class are still in service. VR has abandoned some weak-conditioned units of 2700 series Dv12s.<ref>[https://web.archive.org/web/20091015151807/http://www.iltasanomat.fi/uutiset/kotimaa/uutinen.asp?id=1740927 Suruliputus saatteli veturit viimeiselle matkalle] {{in lang|fi}}</ref>
In the 21st century series production standard gauge diesel–hydraulic designs include the [[Voith Gravita]], ordered by [[Deutsche Bahn]], and the [[Vossloh G2000 BB]], [[MaK / Vossloh G1206|G1206]] and [[Vossloh G1700 BB|G1700]] designs, all manufactured in Germany for freight use.
<gallery heights=150px widths=220px>
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File:ТГМ23Б-2954, Литва, Паневежский уезд, подъездной путь от станции Рокишкис (Trainpix 142683).jpg|A Soviet diesel-hydraulic locomotive [[TGM23]]
</gallery>
▲Diesel–hydraulic drive is common in multiple units, with various transmission designs used including [[Voith]] torque converters, and [[fluid coupling]]s in combination with mechanical gearing.
▲The majority of [[British Rail]]'s second generation passenger DMU stock used hydraulic transmission. In the 21st century, designs using hydraulic transmission include [[Bombardier Transportation|Bombardier]]{{'s}} [[Bombardier Turbostar|Turbostar]], [[Bombardier Talent|Talent]], [[RegioSwinger]] families; diesel engined versions of the [[Siemens Desiro]] platform, and the [[Stadler Regio-Shuttle]].
===Diesel–steam===
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===Cow-calf===
{{Main|Cow-calf}}
[[File:Baltimore and Ohio 9624 (TR4) Cow and Calf at Riverside Yard, Baltimore (22341847029).jpg|thumb|right|280px|EMD TR4 cow-calf-locomotive]]
In North American railroading, a [[cow-calf]] set is a pair of switcher-type locomotives: one (the cow) equipped with a driving cab, the other (the calf) without a cab, and controlled from the cow through cables. Cow-calf sets are used in heavy switching and [[hump yard]] service. Some are radio controlled without an operating engineer present in the cab. This arrangement is also known as [[master/slave (technology)|master–slave]]. Where two connected units were present, [[Electro-Motive Diesel|EMD]] called these TR-2s (approximately {{convert|2,000|HP|abbr=on|disp=or}}); where three units, TR-3s (approximately {{convert|3,000|HP|abbr=on|disp=or}}).
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==Environmental impact==
{{See also|Diesel exhaust}}
[[File:Air pollution by diesel locomotive.jpg|thumb|right|Air pollution by Soviet [[TE10|2TE10M]] diesel locomotive]]
Although diesel locomotives generally emit less sulphur dioxide, a major [[Pollution|pollutant]] to the environment, and greenhouse gases than steam locomotives, they
For years, it was thought by American government scientists who measure [[air pollution]] that diesel locomotive engines were relatively clean and emitted far less health-threatening emissions than those of diesel trucks or other vehicles; however, the scientists discovered that because they used faulty estimates of the amount of fuel consumed by diesel locomotives, they grossly understated the amount of pollution generated annually. After revising their calculations, they concluded that the annual emissions of nitrogen oxide, a major ingredient in [[smog]] and [[acid rain]], and soot would be by 2030 nearly twice what they originally assumed.<ref>{{cite news | url = https://www.washingtonpost.com/wp-dyn/content/article/2006/08/13/AR2006081300530.html | title = Attention to Locomotives' Emissions Renewed | newspaper = [[The Washington Post]] | last = Eilperin | first = Juliet | date = 2006-08-14 | access-date = 2011-08-06 }}</ref><ref>{{cite news | url = http://articles.chicagotribune.com/2011-02-14/news/ct-met-metra-air-testing-20110213_1_scott-fruin-outbound-trains-oldest-trains | title = Metra finds 'alarming' pollution on some trains | work = Chicago Tribune | last = Hawthorne | first = Michael | date = February 14, 2011 | access-date = 2011-08-06 }}</ref> In Europe, where most major railways have been electrified, there is less concern.
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In 2008, the [[United States Environmental Protection Agency]] (EPA) mandated regulations requiring all new or refurbished diesel locomotives to meet [[Not-To-Exceed|Tier II]] pollution standards that slash the amount of allowable soot by 90% and require an 80% reduction in [[nitrogen oxide]] emissions. ''See'' [[List of low emissions locomotives]].
Other technologies that are being deployed to reduce diesel locomotive emissions and fuel consumption include "Genset" switching locomotives and hybrid [[Green Goat]] designs. Genset locomotives use multiple smaller high-speed diesel engines and generators (generator sets), rather than a single medium-speed diesel engine and a single generator.<ref>{{cite web| url=http://www.northeastdiesel.org/pdf/low-emissions-switcher-012206.pdf| title=Multi-Engine GenSet Ultra Low Emissions Road-Switcher Locomotive| publisher=National Railway Equipment Company| access-date=2012-06-03| archive-url=https://web.archive.org/web/20120210130641/http://www.northeastdiesel.org/pdf/low-emissions-switcher-012206.pdf| archive-date=2012-02-10| url-status=dead}}</ref> Because of the cost of developing clean engines, these smaller high-speed engines are based on already developed truck engines. Green Goats are a type of [[Hybrid train|hybrid]] switching locomotive utilizing a small diesel engine and a large bank of rechargeable batteries.<ref>{{cite web | url = http://www.railpower.com/products_hl.html | access-date = 2012-06-03 | title = Railpower Technologies Products| archive-url = https://web.archive.org/web/20080114062221/http://www.railpower.com/products_hl.html| archive-date = January 14, 2008}}</ref><ref>[http://www.trainweb.org/gensets/railpower.html RJ Corman Railpower Genset & Hybrid Switchers]. Trainweb.org. Retrieved on 2013-08-16.</ref> Switching locomotives are of particular concern as they typically operate in a limited area, often in or near urban centers, and spend much of their time idling. Both designs reduce pollution below EPA Tier II standards and cut or eliminate emissions during idle.
==Advantages over steam==
As diesel locomotives advanced, the cost of manufacturing and operating them dropped, and they became cheaper to own and operate than steam locomotives. In North America, [[steam locomotive]]s were custom-made for specific railway routes, so economies of scale were difficult to achieve.{{sfn|Churella|1998|p=10}} Though more complex to produce with exacting manufacturing tolerances ({{convert|1/10000|in|adj=on|disp=or}} for diesel, compared with {{convert|1/100|in|adj=on}} for steam), diesel locomotive parts were easier to mass-produce. [[Baldwin Locomotive Works]] offered almost 500 steam models in its heyday, while [[Electro-Motive Diesel|EMD]] offered fewer than ten diesel varieties.{{sfn|Churella|1998|p=19}} In the United Kingdom, [[British Railways]] built steam locomotives to standard designs from 1951 onwards. These included standard, interchangeable parts, making them cheaper to produce than the diesel locomotives then available. The capital cost per [[Tractive force|drawbar horse power]] was £13 6s (steam), £65 (diesel), £69 7s (turbine) and £17 13s (electric).<ref>{{cite journal |journal=Railway Magazine |date=January 1951 |pages=60–61 |title=Standardisation and Comparative Costs of Motive Power on B.R.}}</ref>
Diesel locomotives offer significant operating advantages over steam locomotives.<ref>[http://www.sdrm.org/faqs/hostling.html http://www.sdrm.org/faqs/hostling.html] {{Webarchive|url=https://web.archive.org/web/20110130055335/http://www.sdrm.org/faqs/hostling.html |date=2011-01-30 }}, Phil Jern "How to Boot a Steam Locomotive" (1990) San Diego Railroad Museum.</ref> They can safely be operated by one person, making them ideal for switching/shunting duties in yards (although for safety reasons many main-line diesel locomotives continue to have two-person crews: an engineer and a conductor/switchman) and the operating environment is much more attractive, being quieter, fully weatherproof and without the dirt and heat that is an inevitable part of operating a steam locomotive. Diesel locomotives can be worked [[multiple working|in multiple]] with a single crew controlling multiple locomotives in a single train – something not practical with steam locomotives. This brought greater efficiencies to the operator, as individual locomotives could be relatively low-powered for use as a single unit on light duties but marshaled together to provide the power needed on a heavy train. With steam traction, a single very powerful and expensive locomotive was required for the heaviest trains, or the operator resorted to [[double heading]] with multiple locomotives and crews, a method which was also expensive and brought with it its own operating difficulties.
Diesel engines can be started and stopped almost instantly, meaning that a diesel locomotive has the potential to incur no fuel costs when not being used. However, it is still the practice of large North American railroads to use straight water as a coolant in diesel engines instead of coolants that incorporate anti-freezing properties; this results in diesel locomotives being left idling when parked in cold climates instead of being completely shut down. A diesel engine can be left idling unattended for hours or even days, especially since practically every diesel engine used in locomotives has systems that automatically shut the engine down if problems such as a loss of oil pressure or coolant loss occur. Automatic start/stop systems are available which monitor coolant and engine temperatures. When the unit is close to having its coolant freeze, the system restarts the diesel engine to warm the coolant and other systems.<ref>[http://www.ztr.com/smartstart.php SmartStart® IIe – Automatic Engine Start/Stop System] {{Webarchive|url=https://web.archive.org/web/20120721124807/http://www.ztr.com/smartstart.php |date=2012-07-21 }}. Ztr.com. Retrieved on 2013-08-16.</ref>
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However, one study published in 1959 suggested that many of the comparisons between diesel and steam locomotives were made unfairly, mostly because diesels were a newer technology. After painstaking analysis of financial records and technological progress, the author found that if research had continued on steam technology instead of diesel, there would be negligible financial benefit in converting to diesel locomotion.<ref>Brown, H. F. (1959). Economic results of diesel–electric motive power on the railways in the United States. ''Proceedings of the Institution of Mechanical Engineers, 175''(1), 257-317. doi:10.1243/PIME_PROC_1961_175_025_02</ref>
By the mid-1960s, diesel locomotives had effectively replaced steam locomotives where electric traction was not in use.<ref name="Stover 213"/> Attempts to develop [[advanced steam technology]] continue in the 21st century
==See also==
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* [[Alternative fuel vehicle|Alternative fuels for diesel engines]]
* [[Diesel multiple unit]]
* [[Gas turbine locomotive]]
* [[Heilmann locomotive]]
* [[Hybrid electric vehicle]]
* [[Non-road engine]]
{{div col end}}
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* [https://web.archive.org/web/20150901062917/http://www.railway-technical.com/diesel.shtml Diesel locomotive]
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