Adiesel locomotiveis a type ofrailwaylocomotivein which theprime moveris adiesel engine. Several types of diesel locomotive have been developed, differing mainly in the means by which mechanical power is conveyed to the driving wheels (drivers).

TheInterCity 125, the current confirmed record holder as thefastest diesel-powered trainat 148mph (238km/h); is made up of twopower cars, one at each end of a fixed formation of carriages; capable of 125mph (201km/h) in regular service.

Twin-section diesel locomotive2M62M-1198(rebuilt withCATengines), near Kyviks,Lithuania.Contents[hide] 1Overview 2History 2.1Adaptation of the diesel engine for rail use 2.2Advance of diesel traction in USA 2.3Early diesel locomotives and railcars in Europe 2.4Early diesel locomotives and railcars in Asia 2.5Early diesel locomotives and railcars in Australia 3Diesels advantages over steam 4Transmission types 4.1Diesel-mechanical 4.2Diesel-electric 4.3Diesel-hydraulic 4.4Diesel-steam 4.5Diesel-pneumatic 5Multiple-unit operation 5.1Cab arrangements 5.2Cow-calf 6Flameproof diesel locomotive 7Lights 8Environmental impact 8.1Mitigation 9See also 10References 10.1Sources 11External linksOverview[edit]This sectiondoes notciteanyreferences or sources.Please help improve this section byadding citations to reliable sources. Unsourced material may be challenged andremoved.(April 2013)

Earlyinternal combustion engine-powered locomotives and railmotors usedgasolineas their fuel. Soon after Dr.Rudolf Dieselpatented his firstcompression ignition engine[1]in 1892, it was considered for railway propulsion. Progress was slow, however, as several problems had to be overcome.

Petrol-electricWeitzer railmotor, first 1903, series 1906Power transmission was a primary concern. As opposed to steam and electric engines, internal combustion engines work efficiently only within a limited range of turning frequencies. In light vehicles, this could be overcome by aclutch. In heavy railway vehicles, mechanical transmission never worked well or else wore out too soon. Experience with early gasoline powered locomotives and railcars was valuable for the development of diesel traction. One step towardsdiesel-electrictransmission was petrol-electric vehicle, such as theWeitzer railmotor(1903 ff.)[2]Steady improvements in diesel design (many developed bySulzer Ltd.ofSwitzerland, with whom Dr. Diesel was associated for a time) gradually reduced its physical size and improved its power-to-weight ratio to a point where one could be mounted in a locomotive. Once the concept of diesel-electric drive was accepted, the pace of development quickened, and by 1925 a small number of diesel locomotives of 600 horsepower were in service in the United States. In 1930, Armstrong Whitworth of the United Kingdom delivered two 1,200hp locomotives using engines of Sulzer design toBuenos Aires Great Southern Railwayof Argentina.By the mid-1950s, with economic recovery from the Second World War, production of diesel locomotives had begun in many countries and the diesel locomotive was on its way to becoming the dominant type of locomotive. It offered greater flexibility and performance than thesteam locomotive, as well as substantially lower operating and maintenance costs, other than where electric traction was in use due to policy decisions. Currently, almost all diesel locomotives are diesel-electric, although the diesel-hydraulic type was widely used between the 1950s and 1970s.The Soviet diesel locomotiveTEP80-0002lays claim to the world speed record for a diesel railed vehicle, having reached 271km/h (168mph) on 5 October 1993.History[edit]Adaptation of the diesel engine for rail use[edit]

A WDM-3A diesel locomotive of Indian Railways, used to haul both passenger and freight.

A string of four diesel locomotives haul a long freight train in the U.S. state ofWashington.Earliest recorded examples of an internal combustion engine for railway use included a prototype designed byWilliam Dent Priestman, which was examined bySir William Thomsonin 1888 who described it as a"[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.".[3][4]In 1894, a 20 h.p. two axle machine built byPriestman Brotherswas used on theHull Docks.[5][6]In 1896 an oil-engined railway locomotive was built for theRoyal Arsenal,Woolwich,England, in 1896, using an engine designed byHerbert Akroyd Stuart.[7][unreliable source?]It was not, strictly, a diesel because it used ahot bulb engine(also known as a semi-diesel) but it was the precursor of the diesel.Following the expiration of Dr.Rudolf Diesels patent in 1912, his engine design was successfully applied to marine propulsion and stationary applications. However, the massiveness and poor power-to-weight ratio of these early engines made them unsuitable for propelling land-based vehicles. Therefore, the engine's potential as a railroad prime mover was not initially recognized.[8]This changed as development reduced the size and weight of the engine.The worlds first diesel-powered locomotive was operated in the summer of 1912 on theWinterthur-Romanshorn Railroadin Switzerland, but was not a commercial success.[9]In 1906,Rudolf Diesel,Adolf Kloseand the steam and Diesel engine manufacturer Gebrder 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 and Romanshorn the Diesel-mechanical locomotive was delivered in Berlin in September 1912. During further test runs in 1913 several problems were found. After the First World War broke out in 1914, all further trials were stopped. The locomotive weight was 95 tonnes and the power was 883kW with a maximum speed of 100km/h.[10]Small numbers of prototype diesel locomotives were produced in a number of countries through the mid-1920s.Advance of diesel traction in USA[edit]Early American developments[edit]Adolphus Buschpurchased the American manufacturing rights for the Diesel engine in 1898 but never applied this new form of power to transportation. Only limited success was achieved in the early twentieth century with direct-driven gasoline and Diesel powered railcars.[11]General Electric(GE) entered therailcarmarket in the early twentieth century, asThomas Edisonpossessed a patent on the electric locomotive, his design actually being a type of electrically propelled railcar.[12]GE built its first electric locomotive prototype in 1895. However, high electrification costs caused GE to turn its attention to Diesel power to provide electricity for electric railcars. Problems related to co-coordinating the Diesel engine andelectric motorwere immediately encountered, primarily due to limitations of theWard Leonardelectric elevator drive system that had been chosen.A significant breakthrough occurred in 1914, whenHermann Lemp, aGEelectrical engineer, developed and patented a reliabledirect currentelectrical control system (subsequent improvements were also patented by Lemp).[13]Lemp's design used a single lever to control both engine and generator in a coordinated fashion, and was theprototypefor all diesel-electric locomotive control systems.In 191718, GE produced three experimental diesel-electric locomotives using Lemp's control design, the first known to be built in the United States.[14]Following this development, the 1923Kaufman Actbanned steam locomotives fromNew York Citybecause 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 switching (shunter) applications. General Electric produced several small switching locomotives in the 1930s (the famous "44-tonner" switcher was introduced in 1940) Westinghouse Electric and Baldwin collaborated to build switching locomotives starting in 1929. However, theGreat Depressioncurtailed demand for Westinghouses electrical equipment, and they stopped building locomotives internally, opting to supply electrical parts instead.[15]First American series production locomotives[edit]General Electric continued to be interested in developing a practical diesel railway locomotive, and approachedIngersoll-Randin 1924. The resulting 300 horsepower locomotive was fitted with anelectrical generatorandtraction motorssupplied byGE, as well as a form of Lemp's control system, and was delivered in July 1925. This locomotive demonstrated that the diesel-electric power unit could provide many of the benefits of anelectric locomotivewithout the railroad having to bear the sizeable expense of electrification.[16]The unit successfully demonstratedin switching, road freight and passenger serviceon a bakers dozen of railroads, and became the prototype for 33 units of 600 horsepowerAGEIR boxcabswitching locomotivesbuilt by a consortium of GE, I-R and theAmerican Locomotive Companyfor several New York City railroads.[17]In June 1925,Baldwin Locomotive Worksoutshopped a prototype diesel-electric locomotive for "special uses" (such as for runs where water for steam locomotives was scarce) using electrical equipment fromWestinghouse Electric Company.[18]Its twin-engine design was not successful, and the unit was scrapped after a short testing and demonstration period.[19]Industry sources were beginning to suggest the outstanding advantages of this new form of motive power.[20]In 1929, theCanadian National Railwaysbecame the first North American railway to use diesels in mainline service with two units, 9000 and 9001, from Westinghouse.[21]Diesel-electric railroad locomotion entered the American mainstream when theBurlington RailroadandUnion Pacificused Diesel "streamliners" to haul passengers, both since 1934.[11][22]Following the successful 1939 tour of General Motors'EMD'sFTdemonstrator freight locomotive set, the transition from steam to Diesel power began, the pace substantially quickening in the years following the close ofWorld War II.Fairbanks-Morsedeveloped a uniqueopposed-piston enginethat was used in their locomotives, as well as in submarines.[23]Early diesel-electric locomotives in the United States used direct current (DC) traction motors, but alternating current (AC) motors came into widespread use in the 1990s, starting with theElectro-Motive SD70MACin 1993 and followed by theGeneral Electric's AC4400CWin 1994 andAC6000CWin 1995.[24]Early diesel locomotives and railcars in Europe[edit]

Swiss&Germanco-production: world's first functional diesel-electric railcar 1914First functional diesel vehicles[edit]In 1914, world's first functional diesel-electric railcars were produced for theKniglich-Schsische Staatseisenbahnen(Royal Saxon State Railways) byWaggonfabrik Rastattwith electric equipment fromBrown, Boveri & Cieand diesel engines fromSwissSulzer AG. They were classified asDET 1 and DET 2(de.wiki). Due to shortage of petrol products duringWorld War I, they remained unused for regular service in Germany. In 1922, they were sold to SwissCompagnie du Chemin de fer Rgional du Val-de-Travers(fr.wiki), where they were used in regular service up to theelectrificationof the line in 1944. Afterwards, the company kept them in service as boosters till 1965.Fiatclaims a first Italian diesel-electric locomotive built in 1922, but little detail is available. A Fiat-TIBB diesel-locomotive "A", of 440CV, is reported to have entered service on the Ferrovie Calabro Lucane in southern Italy in 1926, following trials in 1924-5.[25]

World's first useful diesel locomotive for long distancesSD Eel2, 1924 inKievIn 1924, two diesel-electric locomotives were taken in service by theSoviet railways, almost at one time: The engine 2 (Eel2original number 001/Yu-e 001) started on October 22. It had been designed by a team led byYuri Lomonosovand built 19231924 byMaschinenfabrik Esslingenin Germany. It had 5 driving axles (1'E1'). After several test rides, it hauled trains for almost three decades from 1925 to 1954.[26]Though proved to be world's first functional diesel locomotive, it didn't become a series. But it became a model for several classes of Soviet diesel locomotives. (see alsoCategory:Diesel locomotives of Russia) The engine 1 (Shch-el 1, original number2/Yu-e 2), started on November 9. It had been developed byYakov Modestovich Gakkel(ru.wiki) and built byBaltic ShipyardinSaint Petersburg. It had ten driving axles in threebogies(1' Co' Do' Co' 1'). From 1925 to 1927, it hauled trains betweenMoscowandKurskand inCaucasusregion. Due to technical problems, afterwards it was out of service. Since 1934, it was used as a stationary electric generator.In 1935,Krauss-Maffei,MANandVoithbuilt the first diesel-hydraulic locomotive, calledV 140, in Germany. The German railways (DRG) being very pleased with the performance of that engine, diesel-hydraulics became the mainstream in diesel locomotives in Germany. Serial production of diesel locomotives in Germany began after World War II.Switchers[edit]

Shunter ofNederlandse Spoorwegenfrom 1934, in modern liveryIn many railway stations and industrial compounds, steam shunters had to be kept hot during lots of lazy breaks between scattered short tasks. Therefore, diesel traction became economic for shunting, before it became economic 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 few years of testing, hundreds of units were produced within a decade.Diesel railcars for regional traffic[edit]

Renault VH,France, 1933/34Diesel-powered or "oil-engined" railcars, generally diesel-mechanical, were developed by various European manufacturers in the 1930s, e.g. byWilliam Beardmore and Companyfor theCanadian National Railways(theBeardmore Tornadoengine was subsequently used in theR101airship). Some of those series for regional traffic were begun with gasoline motors and then continued with diesel motors, such as Hungarian BCmot(The class code doesn't tell anything but "railmotor with 2nd and 3rd class seats".), 128 cars built 1926 1937, or GermanWismar railbuses(57 cars 1932 1941). In France, the first diesel railcar wasRenault VH, 115 units produced 1933/34. In Italy, after 6 Gasoline cars since 1931, Fiat andBredabuilt a lot of diesel railmotors, more than 110 from 1933 to 1938 and 390 from 1940 to 1953,Class 772known asLittorina, and Class ALn 900.High speed railcars[edit]In the 1930es, streamlined highspeed diesel railcars were developed in several countries: In Germany, theFlying Hamburgerwas built in 1932. After a test ride in December 1932, this two coach diesel railcar (in English terminology a DMU2) started service atDeutsche Reichsbahn(DRG) in February 1933. It became the prototype ofDRG Class SVT 137with 33 more highspeed DMUs, built for DRG till 1938, 13 DMU 2 ("Hamburg" series), 18 DMU 3 ("Leipzig" and "Kln" series), and 2 DMU 4 ("Berlin" series). FrenchSNCFclasses XF 1000 and XF 1100 comprised 11 high speed DMUs, also called TAR, built 19341939. In Hungary,Ganz WorksbuiltArpd railmotor(see hu.wikiandde.wiki), a kind of a luxurious railbus in a series of 7 items since 1934, and started to buildHargitaDMU amazingly in 1944 (see hu.wiki)Diesel overcomes steam[edit]

British Rail Class D16/1, since 1948In 1945, a batch of 30 Baldwin diesel-electric locomotives,Baldwin 0-6-6-0 1000, was delivered from the United States to the railways of the Soviet Union.In 1948, the London Midland & Scottish Railway introduced the first of a pair of 1,600hp Co-Co diesel-electric locomotives (laterBritish Rail Class D16/1) for regular use in the United Kingdom, although British manufacturers such as Armstrong Whitworth had been exporting diesel locomotives since 1930. Fleet deliveries to British Railways, of other designs such as Class 20 and Class 31, began in 1957.Series production of diesel locomotives inItalybegan in the mid-1950s. Generally, diesel traction in Italy was of less importance than in other countries, as it was amongst the most advanced countries in electrification of the main lines and, as a result of Italian geography, even on many domestic connections freight transport over sea is cheaper than rail transport.Early diesel locomotives and railcars in Asia[edit]Japan[edit]In Japan, since 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 (43000)[27]Japan's first series of diesel locomotives was class DD50 (DD50), twin locomotives, developed since 1950 and in service since 1953.[28]China[edit]One of the first home developed diesel vehicles of China was the DMUDongfeng(), produced in 1958 byCSR Sifang. Series production of China's first diesel locomotive class, the DFH 1, began in 1964 following construction of a prototype in 1959.Early diesel locomotives and railcars in Australia[edit]TheTrans-Australian Railwaybuilt 1912 to 1917 by Commonwealth Railways (CR) passes through 2000km of waterless (or salt watered) desert terrain unsuitable for steam locomotives. The original engineerHenry Deaneenvisageddiesel operationto overcome such problems.[29]Some have suggested that the CR worked with the South Australian Railways to trial diesel traction.[30]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 boughtMcKeen railcars. In the 1920s and 1930s, more reliable Gasoline railmotors were built by Australian industries. Australia's first diesel railcars wereNSWGR 400 & 500 Classin 1938. High speed vehicles for those days' possibilities on3ft6in(1,067mm) were the 10Vulcan railcarsof 1940 for New Zealand.Diesels advantages over steam[edit]Diesel engines slowly eclipsed those powered by steam as the manufacturing and operational efficiencies of the former made them cheaper to own and operate. While initial costs of diesel engines were high,steam locomotiveswere custom-made for specific railway routes and lines and, as such, economies of scale were difficult to achieve.[31]Though more complex to produce with exacting manufacturing tolerances (110000-inch (0.0025mm) for diesel, compared with1100-inch (0.25mm) for steam), diesel locomotive parts were more conducive to mass production. While the steam engine manufacturerBaldwinoffered almost five hundred steam models in its heyday,EMDoffered fewer than ten diesel varieties.[32]Diesel locomotives offer significant operating advantages over steam locomotives.[33]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 2-man crews: an engineer and a conductor/switchman) and the operating environment is much more attractive, being much quieter, fully weatherproof and without the dirt and heat that is an inevitable part of operating a steam locomotive. Diesel locomotives can be workedin multiplewith a single crew controlling multiple locomotives throughout a single trainsomething 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 still under the control of a single crew. With steam traction a single very powerful and expensive locomotive was required for the heaviest trains or the operator resorted todouble headingwith 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 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. Still, 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. In recent years, automatic start/stop systems such as SmartStart have been adopted, which monitor coolant and engine temperatures. When these temperatures show that the unit is close to having its coolant freeze, the system restarts the diesel engine to warm the coolant and other systems.[34]Steam locomotives, by comparison, require intensive maintenance, lubrication, and cleaning before, during, and after use. Preparing and firing a steam locomotive for use from cold can take many hours, although it may be kept in readiness between uses with a smallfireto maintain a slight heat in theboiler, but this requires regularstokingand frequent attention to maintain the level of water in the boiler. This may be necessary to prevent the water in the boiler freezing in cold climates, so long as the water supply itself is not frozen.Moreover, maintenance and operational costs of steam locomotives were much higher than diesel counterparts even though it took diesel locomotives almost 50 years to reach the same power output that steam locomotives could achieve at their technological height.[citation needed]Annual maintenance costs for steam locomotives accounted for 25% of the initial purchase price. Spare parts were cast from wooden masters for specific locomotives. The sheer number of unique steam locomotives meant that there was no feasible way for spare-part inventories to be maintained.[35]With diesel locomotives spare parts could be mass-produced and held in stock ready for use and many parts and sub-assemblies could be standardised across an operator's fleet using different models of locomotive from the same builder. Parts could be interchanged between diesel locomotives of the same or similar design, reducing down-time; for example, a locomotive's faulty prime mover may be removed and quickly replaced with another spare unit, allowing the locomotive to return to service whilst the original prime mover is repaired (and which can in turn be held in reserve to be fitted to another locomotive). Repair or overhaul of the main workings of a steam locomotive required the locomotive to be out of service for as long as it took for the work to be carried out in full.Steam engines also required large quantities of coal and water, which were expensive variable operating costs.[36]Further, thethermal efficiencyof steam was considerably less than that of diesel engines. Diesels theoretical studies demonstrated potential thermal efficiencies for a compression ignition engine of 36% (compared with 610% for steam), and an 1897 one-cylinder prototype operated at a remarkable 26% efficiency.[37]However, one study published in 1959 suggested that many of the comparisons between diesel and steam locomotives were made unfairly mostly because diesels were newer. 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.[38]By the mid-1960s, diesel locomotives had effectively replacedsteam locomotiveswhere electric traction was not in use.[36]Attempts to developAdvanced steam technologycontinue in the 21st century but have not made a significant impact.Transmission types[edit]Unlike steam engines, internal combustion engines require a transmission to power the wheels. The engine must be allowed to continue to run when the locomotive is stopped.Diesel-mechanical[edit]

ABritish Rail Class 03diesel-mechanicalshunter(switcher) with ajackshaftunder the cab.A diesel-mechanical locomotive uses amechanical transmissionin a fashion similar to that employed in most road vehicles. This type of transmission is generally limited to low-powered, low speedshunting (switching)locomotives, lightweightmultiple unitsand self-propelledrailcars.

Schematic illustration of a diesel mechanical locomotiveThe mechanical transmissions used for railroad propulsion are generally more complex and much more robust than standard-road versions. There is usually afluid couplinginterposed between the engine and gearbox, and the gearbox is often of theepicyclic (planetary)type to permit shifting while under load. Various systems have been devised to minimise the break in transmission during gear changing; e.g., the S.S.S. (synchro-self-shifting) gearbox used byHudswell Clarke.Diesel-mechanical propulsion is limited by the difficulty of building a reasonably sized transmission capable of coping with the power andtorquerequired to move a heavy train. A number of attempts to use diesel-mechanical propulsion in high power applications have been made (e.g., the 1,500kW (2000 horsepower)British Rail 10100locomotive), although none have proved successful in the end.Diesel-electric[edit]For locomotives powered by both external electricity and diesel fuel, seeelectro-dieselbelow. For locomotives powered by a combination of diesel or fuel cells and batteries orultracapacitors, seehybrid locomotive.

Schematic diagram of diesel electric locomotiveIn adiesel-electriclocomotive, the diesel engine drives either an electricalDC generator(generally, less than 3,000 horsepower (2,200kW) net for traction), or an electricalAC alternator-rectifier(generally 3,000 horsepower (2,200kW) net or more for traction), the output of which provides power to thetraction motorswhich drive the locomotive. There is no mechanical connection between the diesel engine and the wheels.The important components of diesel-electric propulsion are the diesel engine (also known as theprime mover), the main generator/alternator-rectifier,traction motors(usually with four or six axles), and a control system consisting of the enginegovernorand electrical and/or electronic components, includingswitchgear,rectifiersand other components, which control or modify the electrical supply to the traction motors. In the most elementary case, the generator may be directly connected to the motors with only very simple switchgear.

TheEMD F40PH(left) andMPI MPXpress-series MP36PH-3S (right)locomotivescoupledtogether byMetrausediesel-electric transmission.

Soviet 2TE10U locomotiveOriginally, the traction motors and generator wereDCmachines. Following the development of high-capacitysilicon rectifiersin the 1960s, the DC generator was replaced by analternatorusing adiode bridgeto convert its output to DC. This advance greatly improved locomotive reliability and decreased generator maintenance costs by elimination of thecommutatorandbrushesin the generator. Elimination of the brushes and commutator, in turn, disposed of the possibility of a particularly destructive type of event referred to as aflashover, 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.In the late 1980s, the development of high-powervariable-frequency/variable-voltage(VVVF) drives, or "traction inverters," has allowed the use of polyphase AC traction motors, thus 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.

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[edit]

MLWmodel S-3 produced in 1957 for theCPRadhering to designs byALCO.A diesel-electric locomotive's power output is independent of road speed, as long as the units generator current and voltage limits are not exceeded. Therefore, the unit's ability to developtractive effort(also referred to asdrawbar pullortractive force, which is what actually propels the train) will tend to inversely vary with speed within these limits. (See power curve below). Maintaining acceptable operating parameters was one of the principal design considerations that had to be solved in early diesel-electric locomotive development and, ultimately, led to the complex control systems in place on modern units.Throttle operation[edit]

AnEMD 12-567BRoots-blown 12-cylinder diesel engine (square "hand holes"), stored pending rebuild, and missing some components, most notably the two Roots blowers, with a 16-567C or D 16-cylinder engine (round "hand holes") behind it, also missing some components. EMD 645 and EMD 710 engines appear identically to the 567 C or D engines, and are the same size externally, although the displacement is quite different.[relevant?discuss]The prime mover'spoweroutput is primarily determined by its rotational speed (RPM) and fuel rate, which are regulated by agovernoror 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.[39]Locomotive power output, and thus speed, is typically controlled by the engine driver using a stepped or "notched"throttlethat producesbinary-like electrical signals corresponding to throttle position. This basic design lends itself well tomultiple unit(MU) operation by producing discrete conditions that assure that all units in aconsistrespond in the same way to throttle position. Binary encoding also helps to minimize the number oftrainlines(electrical connections) that are required to pass signals from unit to unit. For example, only four trainlines are required to encode all possible throttle positions.North American locomotives, such as those built byEMDorGeneral Electric, have nine throttle positions, one idle and eight power (as well as an emergency stop position that shuts down the prime mover). ManyUK-built locomotives have a ten-position throttle. The power positions are often referred to by locomotive crews as "run 3" or "notch 3", depending upon the throttle setting.In older locomotives, the throttle mechanism wasratchetedso 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 intrainloading regardless of how the engine driver operates the controls.When the throttle is in the idle position, the prime mover will be receiving minimal fuel, causing it to idle at low RPM. In addition, the traction motors will not be connected to the main generator and the generator's field windings will not be excited (energized) the generator will not produce electricity with no 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.To set the locomotive in motion, thereverser control handleis placed into the correct position (forward or reverse), thebrakeis released and the throttle is moved to the run 1 position (the first power notch). An experienced engine driver can accomplish these steps in a coordinated fashion that will result in a nearly imperceptible start. The positioning of the reverser and movement of the throttle together is conceptually like shifting an automobile's automatic transmission into gear while the engine is idlingPlacing the throttle into the first power position will cause the traction motors to be connected to the main generator and the latter's field coils to be excited. With excitation applied, the main generator will deliver electricity to the traction motors, resulting in motion. If the locomotive is running "light" (that is, not coupled to the rest of a train) and is not on an ascending grade, it will easily accelerate. On the other hand, if a long train is being started, the locomotive may stall as soon as some of the slack has been taken up, as the drag imposed by the train will exceed the tractive force being developed. An experienced engine driver will be able to recognize an incipient stall and will gradually advance the throttle as required to maintain the pace of acceleration.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.As will be seen in the following discussion, 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 percent of its loaded driver weight intractive force, amounting to some 120,000 pounds-force (530kN) ofdrawbar pullfor a large, six-axle freight (goods) unit. In fact, aconsistof such units can produce more than enough drawbar pull at start-up to damage or derail cars (if on a curve) or break couplers (the latter being referred to in North American railroad slang as "jerking a lung"). Therefore, it is incumbent upon the engine driver to carefully monitor the amount of power being applied at start-up to avoid damage. In particular, "jerking a lung" could be a calamitous matter if it were to occur on an ascending grade, except that the safety inherent in the correct operation ofautomatic train brakesinstalled in wagons today, prevents runaway trains by automatically applying the wagon brakes when train line air pressure drops.Propulsion system operation[edit]As previously explained, the locomotive's control system is designed so that the main generatorelectrical poweroutput 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).

Typical main generator constant power curve at "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 injectorsetting, which determines the engine fuel rate, and load 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 theinjectorsand sound an alarm in thecabin the event the prime mover exceeds a defined RPM. Not all of these inputs and outputs are necessarily electrical.The load regulator is essentially a largepotentiometerthat controls the main generator power output by varying its field excitation and hence the degree of loading applied to the engine. The load regulator's job is relatively complex, because although the prime mover's power output is proportional to RPM and fuel rate, the main generator's output is not (which characteristic was not correctly handled by theWard Leonardelevator- and hoist-type drive system that was initially tried in early locomotives). Instead, a quite complex electro-hydraulicWoodwardgovernor was employed. Today, this important function would be performed by the Engine control unit, itself being a part of the Locomotive control unit.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 andtorque(and thus power output) will remain constant for any given throttle setting, regardless of actual road speed.In newer designs controlled by a traction computer, each engine speed step is allotted an appropriate power output, or kW reference, in software. The computer compares this value with actual main generator power output, or kW feedback, calculated from traction motor current and main generator voltage feedback values. The computer adjusts the feedback value to match the reference value by controlling the excitation of the main generator, as described above. The governor still has control of engine speed, but the load regulator no longer plays a central role in this type of control system. However, the load regulator is retained as a back-up in case of engine overload. Modern locomotives fitted withelectronic fuel injection(EFI) may have no mechanical governor; however a virtual load regulator and governor are retained with computer modules.Traction motor performance is controlled either by varying the DC voltage output of the main generator, for DC motors, or by varying the frequency and voltage output of theVVVFfor AC motors. With DC motors, various connection combinations are utilized to adapt the drive to varying operating conditions.At standstill, main generator output is initially low voltage/high current, often in excess of 1000amperesper 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 aseries-wound motoris approximately proportional to the square of the current. Hence, the traction motors will produce their highest torque, causing the locomotive to develop maximumtractive effort, enabling it to overcome the inertia of the train. This effect is analogous to what happens in an automobileautomatic transmissionat start-up, where it is in first gear and thus producing maximum torque multiplication.As the locomotive accelerates, the now-rotating motor armatures will start to generate acounter-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, but will eventually reach a plateau. At this point, the locomotive will essentially cease to accelerate, unless on a downgrade. Since this plateau will usually be reached at a speed substantially less than the maximum that may be desired, something must be done to change the drive characteristics to allow continued acceleration. This change is referred to as "transition," a process that is analogous to shifting gears in an automobile.Transition methods include: Series / Parallel or "motor transition". Initially, pairs of motors are connected in series across the main generator. At higher speed, motors are reconnected in parallel across the main generator. "Field shunting", "field diverting", or "weak fielding". Resistance is connected in parallel with the motor field. This has the effect of increasing thearmaturecurrent, producing a corresponding increase in motor torque and speed.Both methods may also be combined, to increase the operating speed range. Generator transition Reconnecting the two separate internal main generatorstator windingsfrom parallel to series to increase the output voltage.In older locomotives, it was necessary for the engine driver to manually execute transition by use of a separate control. As an aid to performing transition at the right time, theload meter(an indicator that informs the engine driver on how much current is being drawn by the traction motors) was calibrated to indicate at which points forward or backward transition should take place. Automatic transition was subsequently developed to produce better operating efficiency, and to protect the main generator and traction motors from overloading from improper transition.Modern locomotives incorporate tractionalternators, AC to DC, with the capability to deliver 1,200 volts (earlier tractiongenerators, DC to DC, had the capability to deliver only 600 volts). This improvement was accomplished largely through improvements in silicon diode technology. With the capability to deliver 1,200 volts to the traction motors, the necessity for "transition" was eliminated.Dynamic braking[edit]Main article:Dynamic brakeA common option on diesel-electric locomotives isdynamic (rheostatic) braking.Dynamic braking takes advantage of the fact that thetraction motorarmatures are always rotating when the locomotive is in motion and that a motor can be made to act as ageneratorby separately exciting the field winding. When dynamic braking is utilized, the traction control circuits are configured as follows: 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-cooledresistance 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.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 16km/h (10mph), depending on the gear ratio between the traction motors andaxles.Dynamic braking is particularly beneficial when operating in mountainous regions; where there is always the danger of a runaway due to overheated friction brakes during descent (see also comments in theair brakearticle regarding loss of braking due to improper train handling). In such cases, dynamic brakes are usually applied in conjunction with theair brakes, the combined effect being referred to asblended braking. The use of blended braking can also assist in keeping the slack in a long train stretched as it crests a grade, helping to prevent a "run-in", an abrupt bunching of train slack that can cause a derailment. Blended braking is also commonly used withcommuter trainsto reduce wear and tear on the mechanical brakes that is a natural result of the numerous stops such trains typically make during a run.Electro-diesel[edit]

Metro-North's GE GenesisP32AC-DMelectro-diesel locomotive can also operate off ofthird-railelectrification.Main article:Electro-diesel locomotiveThese special locomotives can operate as anelectric locomotiveor as a diesel locomotive. TheLong Island Rail Road,Metro-North RailroadandNew Jersey Transit Rail Operationsoperate dual-mode diesel-electric/third-rail (catenary on NJTransit) locomotives between non-electrified territory andNew York Citybecause of a local law banning diesel-powered locomotives inManhattantunnels. For the same reason,Amtrakoperates a fleet of dual-mode locomotives in the New York area.British Railoperated dual diesel-electric/electric locomotives designed to run primarily as electric locomotives with reduced power available when running on diesel power. This allowed railway yards to remain un-electrified, as the third rail power system is extremely hazardous in a yard area.Diesel-hydraulic[edit]Diesel-hydraulic locomotives use one or moretorque converters, in combination with gears, with a mechanical final drive to convey the power from the diesel engine to the wheels.Hydrostatic transmission systems are also used in some rail applications, primarily low speed shunting[citation needed]and rail-maintenance vehicles.Hydrokinetic transmission[edit]See also:Torque converterandFluid coupling

DBclassV 200diesel-hydraulic

A Henschel (Germany) diesel-hydraulic locomotive inMedan,North SumatraHydrokinetic transmission (also called hydrodynamic transmission) uses atorque converter. A torque converter consists of three main parts, two of which rotate, and one (thestator) 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 on a car. 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.Passenger Multiple units[edit]Diesel-hydraulic drive is common in multiple units, with various transmission designs used includingVoithtorque converters, andfluid couplingsin combination with mechanical gearing.The majority ofBritish Rail's second generation passenger DMU stock used hydraulic transmission.In the 21st century designs using hydraulic transmission includeBombardier'sTurbostar,Talent,RegioSwingerfamilies; diesel engined versions ofSiemens'sDesiroplatform, and theStadler Regio-Shuttle.Locomotives[edit]

British Rail diesel-hydraulic locomotives:Class 52 "Western",Class 42 "Warship"andClass 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] moreover initial versions were found in many countries to be mechanically more complicated and more likely to break down.[citation needed]Hydraulic transmission for locomotives was developed in Germany.[citation needed]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]By the 21st century, for diesel locomotive traction worldwide the majority of countries used diesel-electric designs, with diesel hydraulic designs not found in use outside Germany and Japan, and some neighbouring states, where it is used in designs for freight work.In Germany and Finland, diesel-hydraulic systems have achieved high reliability in operation.[citation needed]In the UK the diesel-hydraulic principle gained a poor reputation due to the poor durability and reliability of the MaybachMekydrohydraulic transmission.[citation needed]Argument continues over the relative reliability of hydraulic systems, with questions over whether data has been manipulated favour local suppliers over non-German ones.[citation needed]Examples[edit]See also:Category:Diesel-hydraulic locomotives

AVRClass Dv12diesel-hydraulic locomotive

AGMDGMDH-1diesel-hydraulic locomotiveDiesel-hydraulic locomotives have a smaller market share than those with diesel electric transmission - the main worldwide user of main-line hydraulic transmissions was theFederal Republic of Germany, with designs including the 1950sDB class V 200, and the 1960/70'sDB Class V 160 family.British Railintroduced a number of diesel hydraulic designs during it1955 Modernisation Plan, initially license built versions of German designs (seeCategory:Diesel-hydraulic locomotives of Great Britain). In SpainRENFEused high power to weight ratio twin engined German designs to haul high speed trains from the 1960s to 1990s. (seeRENFE Classes 340,350,352,353,354)Other main-line locomotives of the post war period included the 1950sGMD GMDH-1experimental locomotives; theHenschel & SonbuiltSouth African Class 61-000; in the 1960sSouthern Pacificbought 18 Krauss-MaffeiKM ML-4000diesel-hydraulic locomotives. TheDenver & Rio Grande Westernalso bought three, all of which were later sold to SP.[40]In Finland, over 200 Finnish-built VR classDv12and Dr14 diesel-hydraulics withVoithtransmissions 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.[41]In the 21st century series production standard gauge diesel-hydraulic designs include theVoith Gravita, ordered byDeutsche Bahn, and theVossloh G2000,G1206andG1700designs, all manufactured in Germany for freight use.Hydrostatic transmission[edit]Hydraulic drive systems using a hydrostatichydraulic drive systemhave been applied to rail use. Modern examples included 350 to 750hp (260 to 560kW) shunting locomotives byCMI Group(Belgium),[42]4 to 12 tonne 35 to 58kW (47 to 78hp) narrow gauge industrial locomoitves byAtlas Copcosubsidiary GIA.[43]Hydrostatic drives are also utilised in railway maintenance machines (tampers, rail grinders).[44]Application of hydrostatic transmissions are generally limited to small shunting locomotives and rail maintenance equipment, as well as being used for non-tractive applications in diesel engines such as drives for traction motor fans.[citation needed]Diesel-steam[edit]Main article:Steam diesel hybrid locomotiveSteam-diesel hybrid locomotives can use steam generated from a boiler or diesel to power a piston engine. TheCristiani Compressed Steam Systemused a diesel engine to power a compressor to drive and recirculate steam produced by a boiler; effectively using steam as the power transmission medium, with the diesel engine being theprime mover[45]Diesel-pneumatic[edit]The diesel-pneumatic locomotive was of interest in the 1930s because it offered the possibility of converting existing steam locomotives to diesel operation. The frame and cylinders of the steam locomotive would be retained and the boiler would be replaced by a diesel engine driving anair compressor. The problem was lowthermal efficiencybecause of the large amount of energy wasted as heat in the air compressor. Attempts were made to compensate for this by using the diesel exhaust to re-heat the compressed air but these had limited success. A German proposal of 1929 did result in a prototype[46]but a similar British proposal of 1932, to use anLNER Class R1locomotive, never got beyond the design stage.Multiple-unit operation[edit]

Diesel-electric locomotive built by EMD for service in the UK and continental Europe.Most Diesel locomotives are capable ofmultiple unit operation (MU)as a means of increasinghorsepowerandtractive effortwhen hauling heavy trains. AllNorth Americanlocomotives, including export models, use a standardizedAARelectrical control system interconnected by a 27-pinjumper cablebetween the units. For UK-built locomotives, a number of incompatible control systems are used, but the most common is the Blue Star system, which is electro-pneumatic and fitted to most early diesel classes. A small number of types, typically higher-powered locomotives intended for passenger only work, do not have multiple control systems. In all cases, the electrical control connections made common to all units in aconsistare referred to astrainlines. The result is that all locomotives in aconsistbehave as one in response to the engine driver's control movements.The ability to couple Diesel-electric locomotives in an MU fashion was first introduced in theEMD FTfour-unit demonstrator that toured theUSAin 1939. At the time, American railroad work rules required that each operating locomotive in a train had to have on board a full crew.EMDcircumvented that requirement by coupling the individual units of the demonstrator withdrawbarsinstead of conventionalknuckle couplersand declaring the combination to be a single locomotive. Electrical interconnections were made so one engine driver could operate the entire consist from the head-end unit. Later on, work rules were amended and the semi-permanent coupling of units with drawbars was eliminated in favour of couplers, as servicing had proved to be somewhat cumbersome owing to the total length of the consist (about 200 feet or nearly 61 meters).In mountainous regions, it is common to interposehelper locomotivesin the middle of the train, both to provide the extra power needed to ascend a grade and to limit the amount ofstressapplied to thedraft gearof the car coupled to the head-end power. The helper units in suchdistributed powerconfigurations are controlled from the lead unit's cab through coded radio signals. Although this is technically not an MU configuration, the behaviour is the same as with physically interconnected units.Cab arrangements[edit]Cab arrangements vary by builder and operator. Practice in the U.S. has traditionally been for a cab at one end of the locomotive with limited visibility if the locomotive is not operated cab forward. This is not usually a problem as U.S. locomotives are usually operated in pairs, or threes, and arranged so that a cab is at each end of each set. European practice is usually for a cab at each end of the locomotive as trains are usually light enough to operate with one locomotive. Early U.S. practice was to add power units without cabs (booster orB units) and the arrangement was often A-B, A-B-A, or A-B-B-A where A was a unit with a cab. Center cabs were sometimes used for switch locomotives.Cow-calf[edit]Main article:Cow-calfIn North American railroading, acow-calfset 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 andhump yardservice. Some are radio controlled without an operating engineer present in the cab. This arrangement is also known asmaster-slave. Where two connected units were present,EMDcalled these TR-2s (approximately 2,000 HP); where three units, TR-3s (approximately 3,000 HP).Cow-calves have largely disappeared as these engine combinations exceeded their economic lifetimes many years ago.Present North American practice is to pair two 3,000 HPGP40-2orSD40-2road switchers, often nearly worn-out and very soon ready for rebuilding or scrapping, and to utilize these for so-called "transfer" uses, for which the TR-2, TR-3 and TR-4 engines were originally intended, hence the designation TR, for "transfer".Occasionally, the second unit may have its prime-mover and traction alternator removed and replaced by concrete and/or steel ballast and the power for traction obtained from the master unit. As a 16-cylinder prime-mover generally weighs in the 36,000 pound range, and a 3,000 HP traction alternator generally weighs in the 18,000 pound range, this would mean that 54,000 pounds would be needed for ballast.A pair of fully capable "Dash 2" units would be rated 6,000 HP. A "Dash 2" pair where only one had a prime-mover/alternator would be rated 3,000 HP, with all power provided by master, but the combination benefits from the tractive effort provided by the slave as engines in transfer service are seldom called upon to provide 3,000 HP much less 6,000 HP on a continuous basis.Flameproof diesel locomotive[edit]A standard diesel locomotive presents a very low fire risk but flame proofing can reduce the risk even further. This involves fitting a water-filled box to the exhaust pipe to quench any red-hot carbon particles that may be emitted. Other precautions may include a fully insulated electrical system (neither side earthed to the frame) and all electric wiring enclosed in conduit.The flameproof diesel locomotive has replaced thefireless steam locomotivein areas of high fire risk such asoil refineriesandammunition dumps. Preserved examples of flameproof diesel locomotives include: Francis Baily of Thatcham(ex-RAF Welford) atSouthall Railway Centre Naworth(ex-National Coal Board) at theSouth Tynedale Railway[47]Latest development of the "Flameproof Diesel Vehicle Applied New Exhaust Gas Dry Type Treatment System does not need the water supply.[48]Lights[edit]ACanadian National Railwaytrain showing the placement of the headlight and ditch lights on the locomotive.The lights fitted to diesel locomotives vary from country to country. North American locomotives are fitted with two headlights for redundancy and a pair of ditch lights. The latter are fitted low down at the front and are designed to make the locomotive easily visible as it approaches agrade crossing. Older locomotives may be fitted with a Gyralite orMars Lightinstead of the ditch lights.Environmental impact[edit]See also:Diesel exhaustAlthough diesel locomotives generally emit less sulphur dioxide, a majorpollutantto the environment, and greenhouse gases than steam locomotives, they are not completely clean in that respect.[49]Furthermore, like other diesel powered vehicles, they emitnitrogen oxidesandfine particles, which are a risk to public health. In fact, in this last respect diesel locomotives may perform worse than steam locomotives.For years, it was thought by American government scientists who measureair pollutionthat 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 (In Europe, where most major railways have been electrified, there is less concern). After revising their calculations, they concluded that the annual emissions of nitrogen oxide, a major ingredient insmogandacid rain, and soot would be by 2030 nearly twice what they originally assumed.[50][51]This would mean that diesel locomotives would be releasing more than 800,000 tons of nitrogen oxide and 25,000 tons of soot every year within a quarter of a century, in contrast to the EPA's previous projections of 480,000 tons ofnitrogen dioxideand 12,000 tons of soot. Since this was discovered, to reduce the effects of the diesel locomotive onhumans(who are breathing the noxious emissions) and onplantsandanimals, it is considered practical to install traps in the diesel engines to reduce pollution levels[52]and other forms (e.g., use ofbiodiesel).Diesel locomotive pollution has been of particular concern in the city ofChicago. TheChicago Tribunereported levels of diesel soot inside locomotives leaving Chicago at levels hundreds of times above what is normally found on streets outside.[53]Residents of several neighborhoods are most likely exposed to diesel emissions at levels several times higher than the national average for urban areas.[54]Mitigation[edit]In 2008, theUnited States Environmental Protection Agency(EPA) mandated regulations requiring all new or refurbished diesel locomotives to meetTier IIpollution standards that slash the amount of allowable soot by 90% and require an 80% reduction innitrogen oxideemissions.SeeList of low emissions locomotives.Other technologies that are being deployed to reduce locomotive emissions and fuel consumption include "Genset" switching locomotives and hybridGreen Goatdesigns. Genset locomotives use multiple high-speed diesel engines and generators (generator sets), rather than a single medium-speed diesel engine and a single generator.[55]Green Goats are a type ofhybridswitching locomotive utilizing a small diesel engine and a large bank of rechargeable batteries.[56][57]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.See also[edit] Diesel multiple unit Diesel-electric transmission Diesel engine Electric locomotive Electrification Electro-diesel locomotive Hybrid electric vehicle Hybrid locomotive Non-road engineReferences[edit]1. Jump up^Diesel, Rudolf. U.S. Patent No. 608,845, filed July 15, 1895, and issued August 9, 1898Accessed via Google Patent Search at:US Patent #608,845on February 8, 2007.2. Jump up^References for Weitzer railmotor: Arnold Heller:Der Automobilmotor im Eisenbahnbetriebe, Leipzig 1906, reprinted by Salzwasserverlag 2011,ISBN 978-3-86444-240-7 Rll:Enzyklopdie des EisenbahnwesensElektrische Eisenbahnen, there go toVII. Automobile Triebwagenzu b) Benzin-, Benzol- oder Gasolin-elektrischen Triebwagen http://www.us.archive.org/about/terms.phpSearch:Self-Contained Railway Motor Cars and Locomotives GO! Raymond S Zeitler, American School (Chicago, Ill.):Self-Contained Railway Motor Cars and Locomotives, sectionSELF-CONTAINED RAILWAY CARS 5759 Rll:Arader und Csander Eisenbahnen Vereinigte Aktien-Gesellschaft Museal railcars of BHV and their history3. Jump up^"Motive power for British Railways"(PDF),The Engineer202, 24 April 1956: 2544. Jump up^The Electrical Review22, 4 May 1888: 474,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 tramwaysMissing or empty|title=(help)5. Jump up^Diesel Railway Traction(Railway Gazette)17, 1963: 25,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 1894Missing or empty|title=(help)6. Jump up^Day, John R.; Cooper, Basil Knowlman (1960),railway Locomotives, Frederick Muller, p.42,The diesel has quite a long history, and the first one ran as far back as 1894. This was a tiny 30-h.p. two-axle standard-gauge locomotive with a two- cylinder engine designed by William Dent Priestman7. Jump up^Doherty, J.M. (1962),Diesel Locomotive Practice, Odhams Press8. Jump up^Churella 1998, p.15.9. Jump up^Churella 1998, p.12.10. Jump up^Glatte, Wolfgang (1993).Deutsches Lok-Archiv: Diesellokomotiven 4. Auflage. Berlin: Transpress.ISBN3-344-70767-1.11. ^Jump up to:abStover, John F. (1997).American Railroads.Chicago, Illinois: TheUniversity of Chicago Press. p.212.ISBN978-0-226-77658-3.12. Jump up^Edison, Thomas A. U.S. Patent No. 493,425, filed January 19, 1891, and issued March 14, 1891Accessed via the Edison Papers at:US Patent #493,425on February 8, 2007.13. Jump up^Lemp, Hermann. U.S. Patent No. 1,154,785, filed April 8, 1914, and issued September 28, 1915.Accessed via Google Patent Search at:US Patent #1,154,785on February 8, 2007.14. Jump up^Pinkepank 1973, pp.13914115. Jump up^Churella 1998, pp.28-30.16. Jump up^Churella 1998, pp.25-27.17. Jump up^Pinkepank 1973, p.209211.18. Jump up^"Railroads To Try Diesel Locomotive",Special to the New York Times, February 18, 1925: 119. Jump up^Pinkepank 1973, p.283.20. Jump up^Churella 1998, p.27.21. Jump up^Pinkepank 1973, p.409.22. Jump up^"Diesel Streamliners Now Link Coast-to-Coast"Popular Mechanics, August 193723. Jump up^Wendel, C.H. (1987).Power in the Past, Vol. 2; A History of Fairbanks-Morse and Co., Stemgas Publishing Company, 1982.24. Jump up^Solomon, Brian,Locomotive, 2001, pp 120, 13025. Jump up^http://www.ferrovie.it/forum/viewtopic.php?f=22&t=1365326. Jump up^Russian page on -227. Jump up^short Japanese presentation of Kiha 43000 (43000) with a photo28. Jump up^short Japanese presentation of DD50 (DD50) with a photo29. Jump up^Burke, A 1991.,Rails through the Wilderness; New South Wales University Press30. Jump up^Holden, R 2006 No. 259: the curious story of a forgotten locomotive, Railmac Publications31. Jump up^Churella 1998, p.10.32. Jump up^Churella 1998, p.19.33. Jump up^http://www.sdrm.org/faqs/hostling.html, Phil Jern "How to Boot a Steam Locomotive" (1990) San Diego Railroad Museum.34. Jump up^SmartStart IIe - Automatic Engine Start/Stop System. Ztr.com. Retrieved on 2013-08-16.35. Jump up^Churella 1998, pp.12-17.36. ^Jump up to:abStover, 21337. Jump up^Churella 1998, p.14.38. Jump up^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_0239. Jump up^Control theory40. Jump up^Marre, Louis A. (1995).Diesel Locomotives: The First Fifty Years. Waukesha, Wis., USA: Kalmbach. pp.384385.ISBN0-89024-258-5.41. Jump up^Suruliputus saatteli veturit viimeiselle matkalle(Finnish)42. Jump up^"Shunting locomotives",www.cmigroupe.com, retrieved Feb 201443. Jump up^"Locomotives",www.gia.se, retrieved Feb 201444. Jump up^Solomon, Brian (2001),Railway Maintenance Equipment: The Men and Machines That Keep the Railroads Running, Voyager Press, pp.78, 96,ISBN076030975245. Jump up^The Paragon-Cristiani Compressed Steam Systemdslef.dsl.pipex.com46. Jump up^"A German Diesel-Pneumatic Locomotive". Douglas-self.com. Retrieved2011-08-20.47. Jump up^[1][dead link]48. Jump up^"Development of the Flameproof Diesel Vehicle Applied New Exhaust Gas Dry Type Treatment System". Sciencelinks.jp. 2009-03-18. Retrieved2011-08-20.49. Jump up^King, Joe (2008-09-22)."Engineering gets $1 million grant to make locomotives leaner, greener". Northern Illinois University. Retrieved2011-08-06.50. Jump up^Eilperin, Juliet (2006-08-14)."Attention to Locomotives' Emissions Renewed".Washington Post. Retrieved2011-08-06.51. Jump up^Hawthorne, Michael (February 14, 2011)."Metra finds 'alarming' pollution on some trains".Chicago Tribune. Retrieved2011-08-06.52. Jump up^Wilkins, Davell (2011-04-13)."Study: Installed Traps In Diesel Engines Reduce Pollution Levels".Top News. Retrieved2011-08-06.53. Jump up^"Pollution on Metra Trains Worse Than Thought: Report".Fox Chicago News. 2011-02-14. Retrieved2011-08-06.54. Jump up^Lydersen, Kari (April 21, 2011)."Black Carbon Testing Finds High Levels".The New York Times. RetrievedAugust 6,2011.55. Jump up^"Multi-Engine GenSet Ultra Low Emissions Road-Switcher Locomotive"(PDF). National Railway Equipment Company. Retrieved2012-06-03.56. Jump up^"Railpower Technologies Products". Archived fromthe originalon January 14, 2008. Retrieved2012-06-03.57. Jump up^RJ Corman Railpower Genset & Hybrid Switchers. Trainweb.org. Retrieved on 2013-08-16.Sources[edit] Churella, Albert J. (1998).From Steam to Diesel: Managerial Customs and Organizational Capabilities in the Twentieth-Century American Locomotive Industry.Princeton, New Jersey:Princeton University Press.ISBN0-691-02776-5. Pinkepank, Jerry A. (1973).The Second Diesel Spotters Guide. Milwaukee WI: Kalmbach Books.ISBN0-89024-026-4.External links[edit]Wikimedia Commons has media related toDiesel locomotives.

US Government test of GP38-2 locomotive with biodiesel fuel. A 1926 articleThe Diesel Engine in Railway Transportationon Diesel locomotives Diesel locomotive[hide] v t eRailway brakes

Types Counter-pressure brake Countersteam brake Dynamic brake Eddy current brake Electromagnetic brake Exhaust brake Heberlein brake Hand brake Kunze-Knorr brake Railway air brake Railway disc brake Regenerative brake Steam brake Track brake Vacuum brake

Manufacturers Faiveley Transport Knorr-Bremse(New York Air Brake) Westinghouse Air Brake Company Westinghouse Brake and Signal Company Ltd

Other aspects Brake van Diesel brake tender Diesel electric locomotive dynamic braking Electronically controlled pneumatic brakes Electro-pneumatic brake system on British railway trains Emergency brake (train) Retarder Dowty retarders

Related topics Air brake Bicycle brake Brake Dead man's switch Drum brake Engine braking Hydraulic brake Pneumatics Railroad Safety Appliance Act(United States) Vehicle brake

Authority control GND:4012210-4

Categories: Diesel locomotives Diesel-electric vehicles