![Three-loco-styles](https://upload.wikimedia.org/wikipedia/commons/4/4a/Three-loco-styles.jpg)
A diesel locomotive is a type of
railway
Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...
locomotive
A locomotive or engine is a rail transport vehicle that provides the Power (physics), motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, Motor coach (rail), motor ...
in which the
prime mover
Prime mover may refer to:
Philosophy
*Unmoved mover, a concept in Aristotle's writings
Engineering
* Prime mover (engine), motor, a machine that converts various other forms of energy (chemical, electrical, fluid pressure/flow, etc) into energy o ...
is a
diesel engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...
. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conveyed to the
driving wheel
On a steam locomotive, a driving wheel is a powered wheel which is driven by the locomotive's pistons (or turbine, in the case of a steam turbine locomotive). On a conventional, non-articulated locomotive, the driving wheels are all coupled ...
s.
Early
internal combustion
An internal combustion engine (ICE or IC engine) is a heat engine in which the combustion of a fuel occurs with an oxidizer (usually air) in a combustion chamber that is an integral part of the working fluid flow circuit. In an internal combus ...
locomotives and railcars used
kerosene
Kerosene, paraffin, or lamp oil is a combustible hydrocarbon liquid which is derived from petroleum. It is widely used as a fuel in aviation as well as households. Its name derives from el, κηρός (''keros'') meaning "wax", and was regi ...
and
gasoline
Gasoline (; ) or petrol (; ) (see ) is a transparent, petroleum-derived flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines (also known as petrol engines). It consists mostly of organic co ...
as their fuel.
Rudolf Diesel
Rudolf Christian Karl Diesel (, ; 18 March 1858 – 29 September 1913) was a German inventor and Mechanical engineering, mechanical engineer who is famous for having invented the diesel engine, which burns diesel fuel; both are named after him.
...
patented his first
compression-ignition engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-cal ...
in 1898, and steady improvements to the design of diesel engines reduced their physical size and improved their power-to-weight ratios to a point where one could be mounted in a locomotive. Internal combustion engines only operate efficiently within a limited
power band
The power band of an internal combustion engine or electric motor is the range of operating speeds under which the engine or motor is able to output the most power, that is, the maximum energy per unit of time. This usually means that maximum a ...
, and while low power gasoline engines could be coupled to mechanical
transmissions, the more powerful diesel engines required the development of new forms of transmission. This is because clutches would need to be very large at these power levels and would not fit in a standard -wide locomotive frame, or wear too quickly to be useful.
The first successful diesel engines used
diesel–electric transmission
A diesel–electric transmission, or diesel–electric powertrain is a transmission system for vehicles powered by diesel engines in road, rail, and marine transport. Diesel–electric transmission is based on petrol–electric transmission, a v ...
s, and by 1925 a small number of diesel locomotives of were in service in the United States. In 1930, Armstrong Whitworth of the United Kingdom delivered two locomotives using
Sulzer-designed engines to
Buenos Aires Great Southern Railway
The Buenos Aires Great Southern Railway (BAGS) ( es, Ferrocarril del Sud) was one of the ''Big Four'' Indian gauge, broad gauge, , British-owned companies that built and operated railway networks in Argentina. The company was founded by Edward ...
of Argentina. In 1933, diesel–electric technology developed by
Maybach
Maybach (, ) is a Automotive industry in Germany, German luxury car brand that exists today as a part of Mercedes-Benz. The original company was founded in 1909 by Wilhelm Maybach and his son Karl Maybach, originally as a subsidiary of ''Lufts ...
was used to propel the
DRG Class SVT 877
The DRG Class SVT 877 Hamburg Flyer – sometimes also Flying Hamburger or in German ''Fliegender Hamburger'' – was Germany's first fast diesel train, and is credited with establishing the fastest regular railway connection in the world in its ti ...
, 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
The General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. It is the largest automaker in the United States and ...
dating back to the late 1920s and advances in lightweight car body design by the
Budd Company
The Budd Company was a 20th-century metal fabricator, a major supplier of body components to the automobile industry, and a manufacturer of stainless steel passenger rail cars, airframes, missile and space vehicles, and various defense products ...
.
The economic recovery from World War II caused the widespread adoption of diesel locomotives in many countries. They offered greater flexibility and performance than
steam locomotive
A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...
s, as well as substantially lower operating and maintenance costs.
History
Adaptation for rail use
![Acsev56](https://upload.wikimedia.org/wikipedia/commons/4/48/Acsev56.jpg)
The earliest recorded example of the use of an internal combustion engine in a railway locomotive is the prototype designed by
William Dent Priestman
William Dent Priestman (23 August 1847 7 September 1936), born near Kingston upon Hull was a Quaker and engineering pioneer, inventor of the Priestman Oil Engine, and co-founder with his brother Samuel of the Priestman Brothers engineering comp ...
, which was examined by
William Thomson, 1st Baron Kelvin
William Thomson, 1st Baron Kelvin, (26 June 182417 December 1907) was a British mathematician, mathematical physicist and engineer born in Belfast. Professor of Natural Philosophy at the University of Glasgow for 53 years, he did important ...
in 1888 who described it as a "
riestman oil enginemounted upon a truck which is worked on a temporary line of rails to show the adaptation of a petroleum engine for locomotive purposes." In 1894, a two-axle machine built by
Priestman Brothers
Priestman Brothers was an engineering company based in Kingston upon Hull, England that manufactured diggers, dredgers, cranes and other industrial machinery. In the later 1800s the company also produced the Priestman Oil Engine, an early desig ...
was used on the
Hull Docks
The Port of Hull is a port at the confluence of the River Hull and the Humber Estuary in Kingston upon Hull, in the East Riding of Yorkshire, England.
Seaborne trade at the port can be traced to at least the 13th century, originally cond ...
. In 1896, an oil-engined railway locomotive was built for the
Royal Arsenal
The Royal Arsenal, Woolwich is an establishment on the south bank of the River Thames in Woolwich in south-east London, England, that was used for the manufacture of armaments and ammunition, proofing, and explosives research for the Britis ...
in
Woolwich
Woolwich () is a district in southeast London, England, within the Royal Borough of Greenwich.
The district's location on the River Thames led to its status as an important naval, military and industrial area; a role that was maintained throu ...
, England, using an engine designed by
Herbert Akroyd Stuart
Herbert Akroyd-Stuart (28 January 1864 – 19 February 1927) was an English inventor who is noted for his invention of the hot bulb engine, or heavy oil engine.
Life
Akroyd-Stuart was born in Halifax, Yorkshire, but lived in Australia for a p ...
.
It was not a diesel, because it used a
hot bulb engine
Hot or the acronym HOT may refer to:
Food and drink
*Pungency, in food, a spicy or hot quality
*Hot, a wine tasting descriptor
Places
*Hot district, a district of Chiang Mai province, Thailand
**Hot subdistrict, a sub-district of Hot District ...
(also known as a semi-diesel), but it was the precursor of the diesel.
Rudolf Diesel
Rudolf Christian Karl Diesel (, ; 18 March 1858 – 29 September 1913) was a German inventor and Mechanical engineering, mechanical engineer who is famous for having invented the diesel engine, which burns diesel fuel; both are named after him.
...
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''. However, the massiveness and poor power-to-weight ratio of early diesel engines made them unsuitable for propelling land-based vehicles. Therefore, the engine's potential as a railroad
prime mover
Prime mover may refer to:
Philosophy
*Unmoved mover, a concept in Aristotle's writings
Engineering
* Prime mover (engine), motor, a machine that converts various other forms of energy (chemical, electrical, fluid pressure/flow, etc) into energy o ...
was not initially recognized. This changed as development reduced the size and weight of the engine.
In 1906, Rudolf Diesel,
Adolf Klose
Adolf Klose (21 May 1844 – 2 September 1923) was the chief engineer of the Royal Württemberg State Railways in southern Germany from June 1885 to 1896.
Klose was born in Bernstadt auf dem Eigen, in Saxony. Before his taking up his post in Stu ...
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 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, but was not a commercial success. During test runs in 1913 several problems were found. The outbreak of
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
in 1914 prevented all further trials. The locomotive weight was 95 tonnes and the power was with a maximum speed of .
Small numbers of prototype diesel locomotives were produced in a number of countries through the mid-1920s.
Early diesel locomotives and railcars in the United States
Early North American developments
Adolphus Busch
Adolphus Busch (10 July 1839 – 10 October 1913) was the German-born co-founder of Anheuser-Busch with his father-in-law, Eberhard Anheuser. He introduced numerous innovations, building the success of the company in the late 19th and early 20 ...
purchased the American manufacturing rights for the diesel engine in 1898 but never applied this new form of power to transportation. He founded the
Busch-Sulzer
The Busch-Sulzer Bros. Diesel Engine Company was founded by Adolphus Busch of the Anheuser-Busch brewing company in 1911 as a joint venture with Sulzer Brothers of Switzerland. The company manufactured diesel engines until 1946.
In 1897, Adolphu ...
company in 1911.
Only limited success was achieved in the early twentieth century with internal combustion engined railcars, due, in part, to difficulties with mechanical drive systems.
[
]
General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energ ...
(GE) entered the
railcar
A railcar (not to be confused with a railway car) is a self-propelled railway vehicle designed to transport passengers. The term "railcar" is usually used in reference to a train consisting of a single coach (carriage, car), with a drive ...
market in the early twentieth century, as
Thomas Edison
Thomas Alva Edison (February 11, 1847October 18, 1931) was an American inventor and businessman. He developed many devices in fields such as electric power generation, mass communication, sound recording, and motion pictures. These inventio ...
possessed a patent on the electric locomotive, his design actually being a type of electrically propelled railcar. 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
electric motor
An electric motor is an Electric machine, electrical machine that converts electrical energy into mechanical energy. Most electric motors operate through the interaction between the motor's magnetic field and electric current in a Electromagneti ...
were immediately encountered, primarily due to limitations of the
Ward Leonard current control system that had been chosen.
GE Rail
GE Transportation is a division of Wabtec. It was known as GE Rail and owned by General Electric until sold to Wabtec on February 25, 2019. The organization manufactures equipment for the railroad, marine, mining, drilling and energy generation ...
was formed in 1907 and 112 years later, in 2019, was purchased by and merged with
Wabtec
Wabtec Corporation (derived from Westinghouse Air Brake Technologies Corporation) is an American company formed by the merger of the Westinghouse Air Brake Company (WABCO) and MotivePower Industries Corporation in 1999. It is headquartered ...
.
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. Lemp's design solved the problem of overloading and damaging the traction motors with excessive electrical power at low speeds, and was the
prototype
A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and Software prototyping, software programming. A prototyp ...
for all internal combustion–electric drive control systems.
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.
Following this development, the 1923
Kaufman Act
The Kaufman Electrification Act of 1923, or Kaufman Act for short, was a law passed by the New York State Assembly, mandated electrification of all railroads in New York City by January 1, 1926. The bill was sponsored by recently elected Republic ...
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
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
The American Locomotive Company (often shortened to ALCO, ALCo or Alco) was an American manufacturer of locomotives, diesel generators, steel, and tanks that operated from 1901 to 1969. The company was formed by the merger of seven smaller locomo ...
(ALCO) and
Ingersoll-Rand
Ingersoll Rand is an American multinational company that provides flow creation and industrial products. The company was formed in February 2020 through the spinoff of the industrial segment of Ingersoll-Randplc (now known as Trane Technologies) ...
(the "AGEIR" consortium) in 1924 to produce a prototype "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
An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a battery or a supercapacitor. Locomotives with on-board fuelled prime movers, such as diesel engines or gas ...
without the railroad having to bear the sizeable expense of electrification. The unit successfully demonstrated, in switching and local freight and passenger service, on ten railroads and three industrial lines. Westinghouse Electric and Baldwin collaborated to build switching locomotives starting in 1929. However, the
Great Depression
The Great Depression (19291939) was an economic shock that impacted most countries across the world. It was a period of economic depression that became evident after a major fall in stock prices in the United States. The economic contagio ...
curtailed demand for Westinghouse's electrical equipment, and they stopped building locomotives internally, opting to supply electrical parts instead.
In June 1925,
Baldwin Locomotive Works
The Baldwin Locomotive Works (BLW) was an American manufacturer of railroad locomotives from 1825 to 1951. Originally located in Philadelphia, it moved to nearby Eddystone, Pennsylvania, in the early 20th century. The company was for decades t ...
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 Company
Westinghouse Electric Company LLC is an American nuclear power company formed in 1999 from the nuclear power division of the original Westinghouse Electric Corporation. It offers nuclear products and services to utilities internationally, includi ...
. Its twin-engine design was not successful, and the unit was scrapped after a short testing and demonstration period. Industry sources were beginning to suggest "the outstanding advantages of this new form of motive power". In 1929, the
Canadian National Railways
The Canadian National Railway Company (french: Compagnie des chemins de fer nationaux du Canada) is a Canadian Class I railroad, Class I freight railway headquartered in Montreal, Quebec, which serves Canada and the Midwestern United States, M ...
became the first North American railway to use diesels in mainline service with two units, 9000 and 9001, from Westinghouse. 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
The General Motors Company (GM) is an American Multinational corporation, multinational Automotive industry, automotive manufacturing company headquartered in Detroit, Michigan, United States. It is the largest automaker in the United States and ...
after they moved into the diesel field with their acquisition of the
Winton Engine Company
The Winton Motor Carriage Company was a pioneer United States automobile manufacturer based in Cleveland, Ohio. Winton was one of the first American companies to sell a motor car. In 1912 Winton became one of the first American manufacturers of ...
, a major manufacturer of diesel engines for marine and stationary applications, in 1930. Supported by the General Motors Research Division, GM's
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
A two-stroke (or two-stroke cycle) engine is a type of internal combustion engine that completes a Thermodynamic power cycle, power cycle with two strokes (up and down movements) of the piston during one power cycle, this power cycle being comple ...
,
mechanically-aspirated,
uniflow-scavenged,
unit-injected diesel engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...
that could deliver the required performance for a fast, lightweight passenger train. The second milestone, and the one that got American railroads moving towards diesel, was the 1938 delivery of GM's
Model 567 engine that was designed specifically for locomotive use, bringing a fivefold increase in life of some mechanical parts and showing its potential for meeting the rigors of freight service.
Diesel–electric railroad locomotion entered mainline service when the
Burlington Railroad
The Chicago, Burlington and Quincy Railroad was a railroad that operated in the Midwestern United States. Commonly referred to as the Burlington Route, the Burlington, or as the Q, it operated extensive trackage in the states of Colorado, Illin ...
and
Union Pacific
The Union Pacific Railroad , legally Union Pacific Railroad Company and often called simply Union Pacific, is a freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Paci ...
used custom-built diesel "
streamliner
A streamliner is a vehicle incorporating wikt:streamline, streamlining in a shape providing reduced air resistance. The term is applied to high-speed railway trainsets of the 1930s to 1950s, and to their successor "High-speed rail, bullet trai ...
s" to haul passengers, starting in late 1934.
Burlington's ''
Zephyr
In European tradition, a zephyr is a light wind or a west wind, named after Zephyrus, the Greek god or personification of the west wind.
Zephyr may also refer to:
Arts and media
Fiction Fiction media
* ''Zephyr'' (film), a 2010 Turkish ...
'' 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, CA
Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world' ...
,
Oakland, CA
Oakland is the largest city and the county seat of Alameda County, California, United States. A major West Coast port, Oakland is the largest city in the East Bay region of the San Francisco Bay Area, the third largest city overall in the Bay ...
, and
Denver, CO
Denver () is a consolidated city and county, the capital, and most populous city of the U.S. state of Colorado. Its population was 715,522 at the 2020 census, a 19.22% increase since 2010. It is the 19th-most populous city in the United ...
to the destinations of diesel streamliners out of Chicago. The Burlington and Union Pacific streamliners were built by the
Budd Company
The Budd Company was a 20th-century metal fabricator, a major supplier of body components to the automobile industry, and a manufacturer of stainless steel passenger rail cars, airframes, missile and space vehicles, and various defense products ...
and the
Pullman-Standard Company, respectively, using the new Winton engines and power train systems designed by GM's
Electro-Motive Corporation
Progress Rail Locomotives, doing business as Electro-Motive Diesel (EMD), is an American manufacturer of diesel-electric locomotives, locomotive products and diesel engines for the rail industry. The company is owned by Caterpillar through its sub ...
. EMC's experimental
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.
First American series production locomotives
Following their 1925 prototype, the AGEIR consortium produced 25 more units of "60 ton"
AGEIR boxcab switching locomotives between 1925 and 1928 for several New York City railroads, making them the first series-produced diesel locomotives. The consortium also produced seven twin-engine "100 ton" boxcabs and one hybrid trolley/battery unit with a diesel-driven charging circuit. ALCO acquired the
McIntosh & Seymour McIntosh & Seymour was an American manufacturer of steam and internal combustion engines during the late 19th and early 20th centuries.
The company was founded in 1886, and was based in Auburn, New York. It developed and sold a wide variety of stea ...
Engine Company in 1929 and entered series production of and single-cab switcher units in 1931. ALCO would be the pre-eminent builder of switch engines through the mid-1930s and would adapt the basic switcher design to produce versatile and highly successful, albeit relatively low powered, road locomotives.
GM, seeing the success of the custom streamliners, sought to expand the market for diesel power by producing standardized locomotives under their
Electro-Motive Corporation
Progress Rail Locomotives, doing business as Electro-Motive Diesel (EMD), is an American manufacturer of diesel-electric locomotives, locomotive products and diesel engines for the rail industry. The company is owned by Caterpillar through its sub ...
. In 1936, EMC's new factory started production of switch engines. In 1937, the factory started producing their new
E series E series may refer to:
* BMC E-series engine, a series of automobile engines
* Electronic E series of preferred numbers, a series of preferred values for electronic components such as resistors, capacitors, inductors, zener diodes
* Entwicklung seri ...
streamlined passenger locomotives, which would be upgraded with more reliable purpose-built engines in 1938. Seeing the performance and reliability of the new
567 model engine in passenger locomotives, EMC was eager to demonstrate diesel's viability in freight service.
Following the successful 1939 tour of
EMC's FT demonstrator freight locomotive set, the stage was set for
dieselization
Dieselisation (US: dieselization) is the process of equipping vehicles with a diesel engine or diesel engines. It can involve replacing an internal combustion engine powered by petrol (gasoline) fuel with an engine powered by diesel fuel, as o ...
of American railroads. In 1941,
ALCO-GE
Alco-GE was a partnership between the American Locomotive Company and General Electric that lasted from 1940 to 1953. Their main competitor was EMD.
Arrangement
Alco produced locomotive bodies and prime movers while GE supplied the electrical ge ...
introduced the
RS-1 road-switcher that occupied its own market niche while EMD's
F series locomotives were sought for mainline freight service. The US entry into World War II slowed conversion to diesel; the War Production Board put a halt to building new passenger equipment and gave naval uses priority for diesel engine production. During the
petroleum crisis of 1942–43, coal-fired steam had the advantage of not using fuel that was in critically short supply. EMD was later allowed to increase the production of its FT locomotives and ALCO-GE was allowed to produce a limited number of
DL-109
The ALCO DL-109 was one of six models of A1A-A1A Diesel locomotives built to haul passenger trains by the American Locomotive Company (ALCO) between December, 1939 and April, 1945 ("DL" stands for Diesel Locomotive). They were of a cab unit des ...
road locomotives, but most in the locomotive business were restricted to making switch engines and steam locomotives.
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
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, but alternating current (AC) motors came into widespread use in the 1990s, starting with the
Electro-Motive SD70MAC in 1993 and followed by
General Electric's AC4400CW in 1994 and
AC6000CW in 1995.
Early diesel locomotives and railcars in Europe
First functional diesel vehicles
![Limousin2010RVT01](https://upload.wikimedia.org/wikipedia/commons/0/01/Limousin2010RVT01.jpg)
In 1914, the world's first functional diesel–electric railcars were produced for the ''Königlich-Sächsische Staatseisenbahnen'' (
Royal Saxon State Railways
The Royal Saxon State Railways (german: Königlich Sächsische Staatseisenbahnen) were the state-owned railways operating in the Kingdom of Saxony from 1869 to 1918. From 1918 until their merger into the Deutsche Reichsbahn the title 'Royal' was d ...
) by
Waggonfabrik Rastatt
( en, Rastatt Coach Factory) is a German public-limited company based in Rastatt in the state of Baden-Württemberg in southwestern Germany. Its chief products are tramway vehicles and railway coaches and wagons. The firm was founded in and b ...
with electric equipment from
Brown, Boveri & Cie
Brown, Boveri & Cie. (Brown, Boveri & Company; BBC) was a Swiss group of electrical engineering companies.
It was founded in Zürich, in 1891 by Charles Eugene Lancelot Brown and Walter Boveri who worked at the Maschinenfabrik Oerlikon. In 1 ...
and diesel engines from
Swiss
Swiss may refer to:
* the adjectival form of Switzerland
* Swiss people
Places
* Swiss, Missouri
* Swiss, North Carolina
*Swiss, West Virginia
* Swiss, Wisconsin
Other uses
*Swiss-system tournament, in various games and sports
*Swiss Internation ...
Sulzer AG
Sulzer Ltd. is a Swiss industrial engineering and manufacturing firm, founded by Salomon Sulzer-Bernet in 1775 and established as Sulzer Brothers Ltd. (Gebrüder Sulzer) in 1834 in Winterthur, Switzerland. Today it is a publicly traded company w ...
. They were classified as
DET 1 and DET 2 (). Because of a shortage of petrol products during World War I, they remained unused for regular service in Germany. In 1922, they were sold to Swiss
Compagnie du Chemin de fer Régional du Val-de-Travers (), where they were used in regular service up to the
electrification
Electrification is the process of powering by electricity and, in many contexts, the introduction of such power by changing over from an earlier power source.
The broad meaning of the term, such as in the history of technology, economic histor ...
of the line in 1944. Afterwards, the company kept them in service as boosters until 1965.
Fiat
Fiat Automobiles S.p.A. (, , ; originally FIAT, it, Fabbrica Italiana Automobili di Torino, lit=Italian Automobiles Factory of Turin) is an Italian automobile manufacturer, formerly part of Fiat Chrysler Automobiles, and since 2021 a subsidiary ...
claims to have built the first Italian diesel–electric locomotive in 1922, but little detail is available. Several Fiat-
TIBB Bo'Bo' diesel–locomotives were built for service on the narrow gauge Ferrovie Calabro Lucane and the
Società per le Strade Ferrate del Mediterrano in southern Italy in 1926, following trials in 1924–25. The six-cylinder two-stroke motor produced at 500rpm, driving four DC motors, one for each axle. These locomotives with top speed proved quite successful.
In 1924, two diesel–electric locomotives were taken in service by the
Soviet railways
The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...
, almost at the same time:
![Teplovoz Eel2 (2)](https://upload.wikimedia.org/wikipedia/commons/d/d0/Teplovoz_Eel2_%282%29.jpg)
* The engine Э
эл2 (
Eel2 original number Юэ 001/Yu-e 001) started on October 22. It had been designed by a team led by
Yuri Lomonosov
Yury Vladimirovich Lomonosov (russian: Юрий Владимирович Ломоносов; 24 April 1876 – 19 November 1952) was a Russian railway engineer and a leading figure in the development of Russian Railways in the early 20th century ...
and built 1923–1924 by
Maschinenfabrik Esslingen
Maschinenfabrik Esslingen (ME), was a German engineering firm that manufactured locomotives, tramways, railway wagons, roll-blocks, technical equipment for the railways, (turntables and traversers), bridges, steel structures, pumps and boilers. ...
in Germany. It had five driving axles (1'E1'). After several test rides, it hauled trains for almost three decades from 1925 to 1954. Though proved to be world's first functional diesel locomotive, it did not become a series, but it became a model for several classes of Soviet diesel locomotives.
* The engine Щэл1 (
Shch-el 1, original number ''Юэ2/Yu-e 2)'', started on November 9. It had been developed by
Yakov Modestovich Gakkel
Yakov Modestovich Gakkel (; 30 April 1874 – 12 December 1945) was a Soviet and Russian scientist and engineer who made significant contributions to the development of aircraft and locomotives in the former Soviet Union.
Biography
His father ...
() and built by
Baltic Shipyard
The OJSC Baltic Shipyard (''Baltiysky Zavod'', formerly Shipyard 189 named after Grigoriy Ordzhonikidze) (russian: Балтийский завод имени С. Орджоникидзе) is one of the oldest shipyards in Russia and is part of ...
in
Saint Petersburg
Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...
. It had ten driving axles in three
bogie
A bogie ( ) (in some senses called a truck in North American English) is a chassis or framework that carries a wheelset, attached to a vehicle—a modular subassembly of wheels and axles. Bogies take various forms in various modes of transp ...
s (1' Co' Do' Co' 1'). From 1925 to 1927, it hauled trains between Moscow and
Kursk
Kursk ( rus, Курск, p=ˈkursk) is a city and the administrative center of Kursk Oblast, Russia, located at the confluence of the Kur, Tuskar, and Seym rivers. The area around Kursk was the site of a turning point in the Soviet–German stru ...
and in
Caucasus
The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range, have historically ...
region. Due to technical problems, afterwards, it was out of service. Since 1934, it was used as a stationary electric generator.
In 1935,
Krauss-Maffei
KraussMaffei is a German manufacturer of injection molding machines, machines for plastics extrusion technology, and reaction process machinery. It was acquired by ChemChina in 2016.
History Locomotives
KraussMaffei was formed in 1931 from a me ...
,
MAN
A man is an adult male human. Prior to adulthood, a male human is referred to as a boy (a male child or adolescent). Like most other male mammals, a man's genome usually inherits an X chromosome from the mother and a Y chromos ...
and
Voith
The Voith Group is a German manufacturer of machines for the pulp and paper industry, technical equipment for hydropower plants and drive and braking systems. The family-owned company, which operates worldwide and has its headquarters in Hei ...
built the first diesel–hydraulic locomotive, called
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
![Rangeerlocomotor NS 228](https://upload.wikimedia.org/wikipedia/commons/f/f6/Rangeerlocomotor_NS_228.jpg)
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 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.
Diesel railcars for regional traffic
![Autorail Renault VH2211 Mulhouse FRA 001](https://upload.wikimedia.org/wikipedia/commons/4/45/Autorail_Renault_VH2211_Mulhouse_FRA_001.jpg)
Diesel-powered or "oil-engined" railcars, generally diesel–mechanical, were developed by various European manufacturers in the 1930s, e.g. by
William Beardmore and Company
William Beardmore and Company was a British engineering and shipbuilding conglomerate based in Glasgow and the surrounding Clydeside area. It was active from 1886 to the mid-1930s and at its peak employed about 40,000 people. It was founded and ...
for the
Canadian National Railways
The Canadian National Railway Company (french: Compagnie des chemins de fer nationaux du Canada) is a Canadian Class I railroad, Class I freight railway headquartered in Montreal, Quebec, which serves Canada and the Midwestern United States, M ...
(the
Beardmore Tornado
The Beardmore Tornado was an eight-cylinder inline diesel aircraft engine built in 1927 by William Beardmore and Company of Glasgow, Scotland, and used in the British R101 airship when petrol engines were thought unsafe in the tropics. The mo ...
engine was subsequently used in the
R101
R101 was one of a pair of British rigid airships completed in 1929 as part of a British government programme to develop civil airships capable of service on long-distance routes within the British Empire. It was designed and built by an Air Mi ...
airship). Some of those series for regional traffic were begun with gasoline motors and then continued with diesel motors, such as Hungarian BC
mot (The class code doesn't tell anything but "railmotor with 2nd and 3rd class seats".), 128 cars built 1926–1937, or German
Wismar railbus
The 'Hanover version' of the Wismar railbus (''Wismarer Schienenbus'') was developed in the early 1930s as a light railbus for economical passenger services on branch lines in Germany.
History
As early as the 1920s, light branch lines (the so ...
es (57 cars 1932–1941). In France, the first diesel railcar was
Renault VH
Renault VH is the first standard-gauge railcar produced by Renault in large numbers, starting in 1933. One hundred units were manufactured in the Ile Seguin factories near Paris. The units ran on various SNCF lines until 1970.
Two examples have ...
, 115 units produced 1933/34.
In Italy, after six Gasoline cars since 1931, Fiat and
Breda
Breda () is a city and municipality in the southern part of the Netherlands, located in the province of North Brabant. The name derived from ''brede Aa'' ('wide Aa' or 'broad Aa') and refers to the confluence of the rivers Mark and Aa. Breda has ...
built a lot of diesel railmotors, more than 110 from 1933 to 1938 and 390 from 1940 to 1953,
Class 772 known as ''Littorina'', and Class ALn 900.
High-speed railcars
In the 1930s, streamlined highspeed diesel railcars were developed in several countries:
* In Germany, the
Flying Hamburger
The DRG Class SVT 877 Hamburg Flyer – sometimes also Flying Hamburger or in German ''Fliegender Hamburger'' – was Germany's first fast diesel train, and is credited with establishing the fastest regular railway connection in the world in its ti ...
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
The ''Deutsche Reichsbahn'', also known as the German National Railway, the German State Railway, German Reich Railway, and the German Imperial Railway, was the German national railway system created after the end of World War I from the regiona ...
(DRG) in February 1933. It became the prototype of
DRG Class SVT 137
The DRG Class SVT 137 was a class of streamlined diesel train sets of the Deutsche Reichsbahn-Gesellschaft and later of the Deutsche Bundesbahn (as class VT 04) and the Deutsche Reichsbahn. With a regular maximum speed of and average speeds of u ...
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
The Société nationale des chemins de fer français (; abbreviated as SNCF ; French for "National society of French railroads") is France's national state-owned railway company. Founded in 1938, it operates the country's national rail traffi ...
classes XF 1000 and XF 1100 comprised 11 high-speed DMUs, also called TAR, built 1934–1939.
* In Hungary,
Ganz Works
The Ganz Works or Ganz ( or , ''Ganz companies'', formerly ''Ganz and Partner Iron Mill and Machine Factory'') was a group of companies operating between 1845 and 1949 in Budapest, Hungary. It was named after Ábrahám Ganz, the founder and the ...
built the , a kind of a luxurious railbus in a series of seven items since 1934, and started to build the in 1944.
Further developments
![LMS 10000 at Derby](https://upload.wikimedia.org/wikipedia/commons/0/0e/LMS_10000_at_Derby.jpg)
In 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 1947, the
London, Midland and Scottish Railway
The London, Midland and Scottish Railway (LMSIt has been argued that the initials LMSR should be used to be consistent with LNER, GWR and SR. The London, Midland and Scottish Railway's corporate image used LMS, and this is what is generally u ...
(LMS) introduced the first of a pair of Co-Co diesel–electric locomotives (later
British Rail Class D16/1
LMS No. 10000 and 10001 were the first mainline diesel locomotives built in Great Britain. They were built in association with English Electric by the London, Midland and Scottish Railway at its Derby Works, using an English Electric 1,600 ...
) 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 in Italy began 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 the electrification of the main lines and as Italian geography makes freight transport by sea cheaper than rail transportation even on many domestic connections.
Early diesel locomotives and railcars in Asia
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). Japan's first series of diesel locomotives was class DD50 (国鉄DD50形), twin locomotives, developed since 1950 and in service since 1953.
China
One of the first domestically-developed Diesel vehicles of China was the DMU
Dongfeng Dongfeng is the romanization of several Chinese names of which most notably "East Wind" (); it may refer to:
People's Republic of China
* Dongfeng (missile) (), series of ballistic missiles of the People's Liberation Army
* Chinese series of dies ...
(东风), produced in 1958 by
CSR Sifang
CRRC Qingdao Sifang Co., Ltd. () is a Chinese rolling stock manufacturer based in Qingdao, Shandong province. Founded in 1900 during the German occupation, Qingdao Sifang is one of the oldest rolling stock manufacturers in China.
History
Qi ...
. Series production of China's first Diesel locomotive class, the DFH 1, began in 1964 following the construction of a prototype in 1959.
India
Early diesel locomotives and railcars in Australia
![McKeen railmotor at Wodonga](https://upload.wikimedia.org/wikipedia/commons/b/b3/McKeen_railmotor_at_Wodonga.jpg)
The
Trans-Australian Railway
The Trans-Australian Railway, opened in 1917, runs from Port Augusta in South Australia to Kalgoorlie in Western Australia, crossing the Nullarbor Plain in the process. As the only rail freight corridor between Western Australia and the easter ...
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 envisaged
diesel operation to overcome such problems.
[Burke, A 1991., ''Rails through the Wilderness''; New South Wales University Press] Some have suggested that the CR worked with the South Australian Railways to trial diesel traction. 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
The McKeen Railmotor was a 6-cylinder self-propelled railcar or railmotor. When McKeen Company of Omaha, Nebraska, U.S.A., first unveiled the car in 1905, the McKeen was among the first engines with a distillate-fueled motor. Revisions to the Mc ...
s.
* In the 1920s and 1930s, more reliable Gasoline railmotors were built by Australian industries.
* Australia's first diesel railcars were the NSWGR 100 Class (PH later DP) Silver City Comet cars in 1937.
* High-speed vehicles for those days' possibilities on were the ten
Vulcan railcars of 1940 for New Zealand.
Transmission types
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
![DieselMechanicalLocomotiveSchematic](https://upload.wikimedia.org/wikipedia/commons/6/61/DieselMechanicalLocomotiveSchematic.svg)
A diesel–mechanical locomotive uses a
mechanical transmission
Propulsion transmission is the mode of transmitting and controlling propulsion power of a machine. The term ''transmission'' properly refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive vehicles), differ ...
in a fashion similar to that employed in most road vehicles. This type of transmission is generally limited to low-powered, low speed
shunting (switching) locomotives, lightweight
multiple unit
A multiple-unit train or simply multiple unit (MU) is a self-propelled train composed of one or more carriages joined together, which when coupled to another multiple unit can be controlled by a single driver, with multiple-unit train contr ...
s and self-propelled
railcar
A railcar (not to be confused with a railway car) is a self-propelled railway vehicle designed to transport passengers. The term "railcar" is usually used in reference to a train consisting of a single coach (carriage, car), with a drive ...
s.
![D2069 at Doncaster Works](https://upload.wikimedia.org/wikipedia/commons/a/a8/D2069_at_Doncaster_Works.JPG)
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
A fluid coupling or hydraulic coupling is a hydrodynamic or 'hydrokinetic' device used to transmit rotating mechanical power. interposed between the engine and gearbox, and the gearbox is often of the
epicyclic (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 by
Hudswell Clarke
Hudswell, Clarke and Company Limited was an engineering and locomotive building company in Jack Lane, Hunslet, Leeds, West Yorkshire, England.
History
The company was founded as Hudswell and Clarke in 1860. In 1870 the name was changed to Hu ...
.
Diesel–mechanical propulsion is limited by the difficulty of building a reasonably sized transmission capable of coping with the power and
torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
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
British Rail 10100
British Railways 10100 was an unusual experimental diesel locomotive known informally as ''The Fell Diesel Locomotive'' (after Lt. Col. L. F. R. Fell, who was one of the designers). It was the joint production of Davey Paxman & Co, Shell Ref ...
locomotive), although none have proved successful in the end.
Diesel–electric
![DieselElectricLocomotiveSchematic](https://upload.wikimedia.org/wikipedia/commons/2/2b/DieselElectricLocomotiveSchematic.svg)
In a diesel–electric locomotive, the diesel engine drives either an electrical
DC generator
In electricity generation, a generator is a device that converts motive power (mechanical energy) or fuel-based power (chemical energy) into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, gas ...
(generally, less than net for traction), or an electrical
AC alternator-rectifier (generally 3,000hp net or more for traction), the output of which provides power to the
traction motor
A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric vehicle, electric or hydrogen vehicles, elevators or electric multiple unit.
Traction motors are used in electrically powered rail vehicles (ele ...
s that 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 the
prime mover
Prime mover may refer to:
Philosophy
*Unmoved mover, a concept in Aristotle's writings
Engineering
* Prime mover (engine), motor, a machine that converts various other forms of energy (chemical, electrical, fluid pressure/flow, etc) into energy o ...
), the main generator/alternator-rectifier, traction motors (usually with four or six axles), and a control system consisting of the engine
governor
A governor is an administrative leader and head of a polity or political region, ranking under the head of state and in some cases, such as governors-general, as the head of state's official representative. Depending on the type of political ...
and electrical or electronic components, including
switchgear
In an electric power system, a switchgear is composed of electrical disconnect switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Switchgear is used both to de-energize equipment to allow work to be ...
,
rectifiers
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The reverse operation (converting DC to AC) is performed by an inver ...
and 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.
![Metra Locomotives F40PH-2 & MP36PH-3S](https://upload.wikimedia.org/wikipedia/commons/3/3a/Metra_Locomotives_F40PH-2_%26_MP36PH-3S.jpg)
Originally, the traction motors and generator were
DC machines. Following the development of high-capacity
silicon rectifiers
A diode is a two-terminal electronic component that conducts current primarily in one direction (asymmetric conductance); it has low (ideally zero) resistance in one direction, and high (ideally infinite) resistance in the other.
A diode ...
in the 1960s, the DC generator was replaced by an
alternator
An alternator is an electrical generator that converts mechanical energy to electrical energy in the form of alternating current. For reasons of cost and simplicity, most alternators use a rotating magnetic field with a stationary armature.Go ...
using a
diode bridge
A diode bridge is a bridge rectifier circuit of four diodes that is used in the process of converting alternating current (AC) from the input terminals to direct current (DC, i.e. fixed polarity) on the output terminals. Its function is to co ...
to convert its output to DC. This advance greatly improved locomotive reliability and decreased generator maintenance costs by elimination of the
commutator
In mathematics, the commutator gives an indication of the extent to which a certain binary operation fails to be commutative. There are different definitions used in group theory and ring theory.
Group theory
The commutator of two elements, a ...
and
brushes
A brush is a common tool with bristles, wire or other filaments. It generally consists of a handle or block to which filaments are affixed in either a parallel or perpendicular orientation, depending on the way the brush is to be gripped durin ...
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 An arc fault is a high power discharge of electricity between two or more conductors. This discharge generates heat, which can break down the wire's insulation and trigger an electrical fire. Arc faults can range in current from a few amps up to t ...
), 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-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.
Diesel–electric control
![S3DieselElectricLocomotiveSRM](https://upload.wikimedia.org/wikipedia/commons/6/6f/S3DieselElectricLocomotiveSRM.jpg)
A diesel–electric locomotive's power output is independent of road speed, as long as the unit's generator current and voltage limits are not exceeded. Therefore, the unit's ability to develop
tractive effort
As used in mechanical engineering, the term tractive force can either refer to the total traction a vehicle exerts on a surface, or the amount of the total traction that is parallel to the direction of motion.
In railway engineering, the term tr ...
(also referred to as drawbar pull or
tractive force
As used in mechanical engineering, the term tractive force can either refer to the total traction a vehicle exerts on a surface, or the amount of the total traction that is parallel to the direction of motion.
In railway engineering, the term tr ...
, 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
![116U-rabmash](https://upload.wikimedia.org/wikipedia/commons/1/17/116U-rabmash.jpg)
The prime mover's
power
Power most often refers to:
* Power (physics), meaning "rate of doing work"
** Engine power, the power put out by an engine
** Electric power
* Power (social and political), the ability to influence people or events
** Abusive power
Power may a ...
output is primarily determined by its rotational speed (
RPM
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines.
Standards
ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...
) and fuel rate, which are regulated by a
governor
A governor is an administrative leader and head of a polity or political region, ranking under the head of state and in some cases, such as governors-general, as the head of state's official representative. Depending on the type of political ...
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
Control theory is a field of mathematics that deals with the control of dynamical systems in engineered processes and machines. The objective is to develop a model or algorithm governing the application of system inputs to drive the system to a ...
).
Locomotive power output, and therefore speed, is typically controlled by the engine driver using a stepped or "notched"
throttle
A throttle is the mechanism by which fluid flow is managed by constriction or obstruction.
An engine's power can be increased or decreased by the restriction of inlet gases (by the use of a throttle), but usually decreased. The term ''throttle'' ...
that produces
binary
Binary may refer to:
Science and technology Mathematics
* Binary number, a representation of numbers using only two digits (0 and 1)
* Binary function, a function that takes two arguments
* Binary operation, a mathematical operation that t ...
-like electrical signals corresponding to throttle position. This basic design lends itself well to
multiple unit
A multiple-unit train or simply multiple unit (MU) is a self-propelled train composed of one or more carriages joined together, which when coupled to another multiple unit can be controlled by a single driver, with multiple-unit train contr ...
(MU) operation by producing discrete conditions that assure that all units in a
consist
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and Passenger train, transport people or Rail freight transport, freight. Trains are typically pul ...
respond in the same way to throttle position. Binary encoding also helps to minimize the number of
trainlines (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 if there are up to 14 stages of throttling.
North American locomotives, such as those built by
EMD or
General Electric
General Electric Company (GE) is an American multinational conglomerate founded in 1892, and incorporated in New York state and headquartered in Boston. The company operated in sectors including healthcare, aviation, power, renewable energ ...
, have eight throttle positions or "notches" as well as a "reverser" to allow them to operate bi-directionally. Many UK-built locomotives have a ten-position throttle. The power positions are often referred to by locomotive crews depending upon the throttle setting, such as "run 3" or "notch 3".
In older locomotives, the throttle mechanism was
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
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and Passenger train, transport people or Rail freight transport, freight. Trains are typically pul ...
loading regardless of how the engine driver operates the controls.
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.
To set the locomotive in motion, the
reverser control handle is placed into the correct position (forward or reverse), the
brake
A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction.
Background ...
is 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 idling.
Placing 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.
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 of
tractive force
As used in mechanical engineering, the term tractive force can either refer to the total traction a vehicle exerts on a surface, or the amount of the total traction that is parallel to the direction of motion.
In railway engineering, the term tr ...
for a large, six-axle freight (goods) unit.
In fact, a
consist
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and Passenger train, transport people or Rail freight transport, freight. Trains are typically pul ...
of such units can produce more than enough
drawbar pull In automotive engineering, drawbar pull is the amount of horizontal force available to a vehicle at the drawbar for accelerating or pulling a load.
Drawbar pull is a function of velocity, and in general decreases as the speed of the vehicle increa ...
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
Slang is vocabulary (words, phrases, and linguistic usages) of an informal register, common in spoken conversation but avoided in formal writing. It also sometimes refers to the language generally exclusive to the members of particular in-gro ...
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 of
fail-safe
In engineering, a fail-safe is a design feature or practice that in the event of a specific type of failure, inherently responds in a way that will cause minimal or no harm to other equipment, to the environment or to people. Unlike inherent safe ...
automatic train brakes installed in wagons today, prevents runaway trains by automatically applying the wagon brakes when train line air pressure drops.
Propulsion system operation
![116U-left-corridore-diesel](https://upload.wikimedia.org/wikipedia/commons/f/fa/116U-left-corridore-diesel.jpg)
A locomotive's control system is designed so that the main generator
electrical power
Electric power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second. Standard prefixes apply to watts as with other SI units: thousands, millions and billions of ...
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
Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to ''feed back'' into itself. The notion of cause-and-effect has to be handled ...
). The governor has two external control outputs:
fuel injector
Fuel injection is the introduction of fuel in an internal combustion engine, most commonly automotive engines, by the means of an injector. This article focuses on fuel injection in reciprocating piston and Wankel rotary engines.
All comp ...
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 in the event the prime mover exceeds a defined RPM. Not all of these inputs and outputs are necessarily electrical.
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
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
(and therefore 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 with
electronic fuel injection
Manifold injection is a mixture formation system for internal combustion engines with external mixture formation. It is commonly used in engines with spark ignition that use petrol as fuel, such as the Otto engine, and the Wankel engine. In a mani ...
(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 the
VVVF
A variable-frequency drive (VFD) is a type of motor drive used in electro-mechanical drive systems to control AC motor speed and torque by varying motor input frequency and, depending on Topology (electrical circuits), topology, to control asso ...
for 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 1000
ampere
The ampere (, ; symbol: A), often shortened to amp,SI supports only the use of symbols and deprecates the use of abbreviations for units. is the unit of electric current in the International System of Units (SI). One ampere is equal to elect ...
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
series-wound motor
The universal motor is a type of electric motor that can operate on either AC or DC power and uses an electromagnet as its stator to create its magnetic field. It is a commutated series-wound motor where the stator's field coils are connected in ...
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
As used in mechanical engineering, the term tractive force can either refer to the total traction a vehicle exerts on a surface, or the amount of the total traction that is parallel to the direction of motion.
In railway engineering, the term tr ...
, enabling it to overcome the inertia of the train. This effect is analogous to what happens in an automobile
automatic transmission
An automatic transmission (sometimes abbreviated to auto or AT) is a multi-speed transmission used in internal combustion engine-based motor vehicles that does not require any input from the driver to change forward gears under normal driving c ...
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
Counter-electromotive force (counter EMF, CEMF, back EMF),Graf, "counterelectromotive force", Dictionary of Electronics is the electromotive force (EMF) manifesting as a voltage that opposes the change in current which induced it. CEMF is the EMF ...
(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 the
armature current, producing a corresponding increase in motor torque and speed.
Both methods may also be combined, to increase the operating speed range.
* Generator / rectifier transition
** Reconnecting the two separate internal main generator
stator windings of two rectifiers from 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, the
load meter (an indicator that shows the engine driver 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 traction ''inverters'', AC to DC, capable of delivering 1,200 volts (earlier traction ''generators'', DC to DC, were capable of delivering only 600 volts). This improvement was accomplished largely through improvements in silicon diode technology. With the capability of delivering 1,200 volts to the traction motors, the need for "transition" was eliminated.
Dynamic braking
A common option on diesel–electric locomotives is
dynamic (rheostatic) braking.
Dynamic braking takes advantage of the fact that the
traction motor
A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric vehicle, electric or hydrogen vehicles, elevators or electric multiple unit.
Traction motors are used in electrically powered rail vehicles (ele ...
armatures are always rotating when the locomotive is in motion and that a motor can be made to act as a
generator
Generator may refer to:
* Signal generator, electronic devices that generate repeating or non-repeating electronic signals
* Electric generator, a device that converts mechanical energy to electrical energy.
* Generator (circuit theory), an eleme ...
by 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-cooled
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.
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
An axle or axletree is a central shaft for a rotating wheel or gear. On wheeled vehicles, the axle may be fixed to the wheels, rotating with them, or fixed to the vehicle, with the wheels rotating around the axle. In the former case, bearing ...
s.
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. In such cases, dynamic brakes are usually applied in conjunction with the
air brakes, the combined effect being referred to as
blended 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 with
commuter train
Commuter rail, or suburban rail, is a passenger rail transport service that primarily operates within a metropolitan area, connecting commuters to a central city from adjacent suburbs or commuter towns. Generally commuter rail systems are consi ...
s to 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
![GE Genesis P32AC-DM 202 MNCRR Ossining](https://upload.wikimedia.org/wikipedia/commons/3/34/GE_Genesis_P32AC-DM_202_MNCRR_Ossining.jpg)
These special locomotives can operate as an
electric locomotive
An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a battery or a supercapacitor. Locomotives with on-board fuelled prime movers, such as diesel engines or gas ...
or as a diesel locomotive. The
Long Island Rail Road
The Long Island Rail Road , often abbreviated as the LIRR, is a commuter rail system in the southeastern part of the U.S. state of New York (state), New York, stretching from Manhattan to the eastern tip of Suffolk County, New York, Suffolk Co ...
,
Metro-North Railroad
Metro-North Railroad , trading as MTA Metro-North Railroad, is a suburban commuter rail service run by the Metropolitan Transportation Authority (MTA), a New York State public benefit corporations, public authority of the U.S. state of New Yor ...
and
New Jersey Transit Rail Operations
NJ Transit Rail Operations is the rail division of NJ Transit. It operates commuter rail service in New Jersey, with most service centered on transportation to and from New York City, Hoboken, and Newark. NJ Transit also operates rail service i ...
operate dual-mode diesel–electric/third-rail (
catenary
In physics and geometry, a catenary (, ) is the curve that an idealized hanging chain or cable assumes under its own weight when supported only at its ends in a uniform gravitational field.
The catenary curve has a U-like shape, superficia ...
on NJTransit) locomotives between non-electrified territory and New York City because of a local law banning diesel-powered locomotives in
Manhattan
Manhattan (), known regionally as the City, is the most densely populated and geographically smallest of the five boroughs of New York City. The borough is also coextensive with New York County, one of the original counties of the U.S. state ...
tunnels. For the same reason,
Amtrak
The National Railroad Passenger Corporation, Trade name, doing business as Amtrak () , is the national Passenger train, passenger railroad company of the United States. It operates inter-city rail service in 46 of the 48 contiguous United Stat ...
operates a fleet of dual-mode locomotives in the New York area.
British Rail
British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four British rai ...
operated 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 unelectrified, as the third rail power system is extremely hazardous in a yard area.
Diesel–hydraulic
![JNR DD51-1 at Usui Pass Railway Heritage Park](https://upload.wikimedia.org/wikipedia/commons/d/d7/JNR_DD51-1_at_Usui_Pass_Railway_Heritage_Park.jpg)
Diesel–hydraulic locomotives use one or more
torque converter
A torque converter is a type of fluid coupling that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the torque converter connects the power ...
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
hydraulic
Hydraulics (from Greek: Υδραυλική) is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counter ...
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.
Hydrostatic transmission
Hydraulic drive systems using a
hydrostatic
Fluid statics or hydrostatics is the branch of fluid mechanics that studies the condition of the equilibrium of a floating body and submerged body "fluids at hydrostatic equilibrium and the pressure in a fluid, or exerted by a fluid, on an imme ...
hydraulic drive system
Hydraulic machines use liquid fluid power to perform work. Heavy construction vehicles are a common example. In this type of machine, hydraulic fluid is pumped to various hydraulic motors and hydraulic cylinders throughout the machine and b ...
have been applied to rail use. Modern examples included shunting locomotives by
Cockerill (Belgium), 4 to 12 tonne narrow gauge industrial locomotives by
Atlas Copco
Atlas Copco (Copco from Compagnie Pneumatique Commerciale) is a Swedish multinational industrial company that was founded in 1873. It manufactures industrial tools and equipment.
The Atlas Copco Group is a global industrial group of companies h ...
subsidiary GIA. Hydrostatic drives are also utilised in railway maintenance machines (tampers, rail grinders).
Application of hydrostatic transmissions is 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.
Hydrokinetic transmission
![ID diesel loco BB 303-84-12 120920-0145 mdn](https://upload.wikimedia.org/wikipedia/commons/0/04/ID_diesel_loco_BB_303-84-12_120920-0145_mdn.JPG)
Hydrokinetic transmission (also called hydrodynamic transmission) uses a
torque converter
A torque converter is a type of fluid coupling that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the torque converter connects the power ...
. A torque converter consists of three main parts, two of which rotate, and one (the
stator
The stator is the stationary part of a rotary system, found in electric generators, electric motors, sirens, mud motors or biological rotors. Energy flows through a stator to or from the rotating component of the system. In an electric mot ...
) 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.
=Locomotives
=
![Western Warship and Hymek](https://upload.wikimedia.org/wikipedia/commons/c/c0/Western_Warship_and_Hymek.jpg)
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%), Moreover, initial versions were found in many countries to be mechanically more complicated and more likely to break down. Hydraulic transmission for locomotives was developed in Germany. 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.
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. In the UK the diesel–hydraulic principle gained a poor reputation due to the poor durability and reliability of the Maybach
Mekydro
A torque converter is a type of fluid coupling that transfers rotating power from a prime mover, like an internal combustion engine, to a rotating driven load. In a vehicle with an automatic transmission, the torque converter connects the power ...
hydraulic transmission. 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.
= Multiple units
=
Diesel–hydraulic drive is common in multiple units, with various transmission designs used including
Voith
The Voith Group is a German manufacturer of machines for the pulp and paper industry, technical equipment for hydropower plants and drive and braking systems. The family-owned company, which operates worldwide and has its headquarters in Hei ...
torque converters, and
fluid coupling
A fluid coupling or hydraulic coupling is a hydrodynamic or 'hydrokinetic' device used to transmit rotating mechanical power. s in combination with mechanical gearing.
The majority of
British Rail
British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four British rai ...
's second generation passenger DMU stock used hydraulic transmission. In the 21st century, designs using hydraulic transmission include
Bombardier Turbostar
The Bombardier Turbostar (sold as the ADtranz Turbostar until 2001) is a family of diesel multiple unit (DMU) passenger trains that was built by ADtranz and later Bombardier Transportation at Derby Litchurch Lane Works in the United Kingdom ...
,
Talent,
RegioSwinger families; diesel engined versions of the
Siemens Desiro
The Siemens Desiro (, , ) is a family of diesel or electric multiple unit passenger trains developed by Siemens Mobility, a division of the German Siemens AG conglomerate. The main variants are the Desiro Classic, Desiro ML, Desiro UK and the la ...
platform, and the
Stadler Regio-Shuttle
The Stadler Regio-Shuttle RS1 is the first widely used, new-generation, diesel railcar in Germany and Czech Republic for local railway services. Its most characteristic feature is the trapezium-shaped window frames. The Regio-Shuttle is classified ...
.
Examples
![DH GMD 6031 VFRGS-RF Guido Mota](https://upload.wikimedia.org/wikipedia/commons/e/e3/DH_GMD_6031_VFRGS-RF_Guido_Mota.jpg)
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
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated between ...
, with designs including the 1950s
DB class V 200
DB Class V 200 (also known as Class 220) was the first series production diesel-hydraulic express locomotive of the German Deutsche Bundesbahn and – as Am 4/4 – of the SBB-CFF-FFS in Switzerland.
History
DB Service
Five prototypes of ...
, and the 1960 and 1970s
DB Class V 160 family
The ''DB V 160 locomotive family'' comprises several classes of closely related 4-axle diesel-hydraulic locomotives built in the 1960s and 1970s for the Deutsche Bundesbahn which take the family name from the earliest built model: the 'DB Class V 1 ...
.
British Rail
British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four British rai ...
introduced a number of diesel-hydraulic designs during its
1955 Modernisation Plan
Events January
* January 3 – José Ramón Guizado becomes president of Panama.
* January 17 – , the first nuclear-powered submarine, puts to sea for the first time, from Groton, Connecticut.
* January 18– 20 – Battle of Yijian ...
, initially license-built versions of German designs (see
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 Classes 340,
350
__NOTOC__
Year 350 (Roman numerals, CCCL) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Sergius and Nigrinianus (or, less frequentl ...
,
352
Year 352 (Roman numerals, CCCLII) was a leap year starting on Wednesday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Decentius and Paulus (or, less frequently, year 110 ...
,
353
__NOTOC__
Year 353 ( CCCLIII) was a common year starting on Friday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Magnentius and Decentius (or, less frequently, year 110 ...
,
354
__NOTOC__
Year 354 ( CCCLIV) was a common year starting on Saturday (link will display the full calendar) of the Julian calendar. At the time, it was known as the Year of the Consulship of Constantius and Constantius (or, less frequently, yea ...
)
Other main-line locomotives of the post-war period included the 1950s
GMD GMDH-1
The GMD GMDH-1 was an experimental diesel-hydraulic, center-cab, switching locomotive built by General Motors Diesel of Canada. Four examples were built. The first two locomotives were each fitted with a pair of 6-cylinder Detroit Diesel serie ...
experimental locomotives; the
Henschel & Son
Henschel & Son (german: Henschel und Sohn) was a German company, located in Kassel, best known during the 20th century as a maker of transportation equipment, including locomotives, trucks, buses and trolleybuses, and armoured fighting vehic ...
built
South African Class 61-000
The South African Railways Class 61-000 of 1959 was a diesel-hydraulic locomotive.
Between May and July 1959, the South African Railways placed seven Henschel type DH-1420 diesel-hydraulic locomotives in service to also gain experience with ot ...
; in the 1960s
Southern Pacific
The Southern Pacific (or Espee from the railroad initials- SP) was an American Class I railroad network that existed from 1865 to 1996 and operated largely in the Western United States. The system was operated by various companies under the ...
bought 18 Krauss-Maffei
KM ML-4000
The Krauss-Maffei ML 4000 is a road switcher diesel-hydraulic locomotive, built between 1961 and 1969 by German manufacturer Krauss-Maffei in Munich, Germany. It generated from two Maybach V16 engines. 37 examples were built for two North Americ ...
diesel–hydraulic locomotives. The
Denver & Rio Grande Western Railroad
The Denver & Rio Grande Western Railroad , often shortened to ''Rio Grande'', D&RG or D&RGW, formerly the Denver & Rio Grande Railroad, was an American Class I railroad company. The railroad started as a narrow-gauge line running south from De ...
also bought three, all of which were later sold to SP.
In Finland, over 200 Finnish-built
VR class Dv12
The Dv12 (Sv12 and Sr12 until 1977) is the standard Finnish medium-weight diesel-hydraulic road switcher operated by VR. As all the main lines of Finnish railway network have been electrificied, the locomotive is designated mostly to unelectrifie ...
and Dr14 diesel–hydraulics with
Voith
The Voith Group is a German manufacturer of machines for the pulp and paper industry, technical equipment for hydropower plants and drive and braking systems. The family-owned company, which operates worldwide and has its headquarters in Hei ...
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.
In the 21st century series production standard gauge diesel–hydraulic designs include the
Voith Gravita
The Voith Gravita locomotives are a family of road switcher diesel-hydraulic locomotives built by Voith Turbo Lokomotivtechnik GmbH & Co. KG. Available in a range of configurations from 4 to 6 axles, they are designed for shunting and light and ...
, ordered by
Deutsche Bahn
The (; abbreviated as DB or DB AG) is the national railway company of Germany. Headquartered in the Bahntower in Berlin, it is a joint-stock company ( AG). The Federal Republic of Germany is its single shareholder.
describes itself as the se ...
, and the
Vossloh G2000 BB
The G 2000 BB is a four axle heavy shunting and mainline locomotive, designed by German company Vossloh and built at the former MaK plant in Kiel. At the time of its introduction in 2000 it was the most powerful hydraulic transmission locomoti ...
,
G1206
The Vossloh G1206 is a B'B' diesel hydraulic freight locomotive built in Kiel and used by several European railway operators including a SNCF specific variant the BB 461000 series.
The design was created in the mid-1990s by Maschinenbau Kiel ( ...
and
G1700 designs, all manufactured in Germany for freight use.
Diesel–steam
![Teploparovoz TP1](https://upload.wikimedia.org/wikipedia/commons/3/3d/Teploparovoz_TP1.jpg)
Steam-diesel hybrid locomotives can use steam generated from a boiler or diesel to power a piston engine. The ''Cristiani Compressed Steam System'' used 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 the
prime mover
Prime mover may refer to:
Philosophy
*Unmoved mover, a concept in Aristotle's writings
Engineering
* Prime mover (engine), motor, a machine that converts various other forms of energy (chemical, electrical, fluid pressure/flow, etc) into energy o ...
Diesel–pneumatic
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 an
air compressor
An air compressor is a pneumatic device that converts power (using an electric motor, diesel or gasoline engine, etc.) into potential energy stored in pressurized air (i.e., compressed air). By one of several methods, an air compressor forces ...
. The problem was low
thermal efficiency
In thermodynamics, the thermal efficiency (\eta_) is a dimensionless performance measure of a device that uses thermal energy, such as an internal combustion engine, steam turbine, steam engine, boiler, furnace, refrigerator, ACs etc.
For a he ...
because 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 but a similar British proposal of 1932, to use an
LNER Class R1
The Great Northern Railway (GNR) Class L1 (LNER Class R1) was a 0-8-2T side tank steam locomotive designed by Henry Ivatt. It was originally designed for suburban passenger traffic on the Metropolitan City Lines.
A prototype was built in 1 ...
locomotive, never got beyond the design stage.
Multiple-unit operation
![GM-EMD 2000](https://upload.wikimedia.org/wikipedia/commons/3/30/GM-EMD_2000.jpg)
Most diesel locomotives are capable of
multiple-unit operation
A multiple-unit train or simply multiple unit (MU) is a self-propelled train composed of one or more carriages joined together, which when coupled to another multiple unit can be controlled by a single driver, with multiple-unit train contro ...
(MU) as a means of increasing
horsepower
Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are the ...
and
tractive effort
As used in mechanical engineering, the term tractive force can either refer to the total traction a vehicle exerts on a surface, or the amount of the total traction that is parallel to the direction of motion.
In railway engineering, the term tr ...
when hauling heavy trains. All North American locomotives, including export models, use a standardized
AAR
AAR or Aar may refer to:
Geography
* Aar, a river in Switzerland, tributary of the Rhine
*Aar (Lahn), a tributary of Lahn river in Germany, descending from the Taunus mountains
* Aar (Dill), a tributary of Dill river in Germany, also in the bas ...
electrical control system interconnected by a 27-pin MU cable between 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 a
consist
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and Passenger train, transport people or Rail freight transport, freight. Trains are typically pul ...
are referred to as
trainlines.
The result is that all locomotives in a
consist
In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and Passenger train, transport people or Rail freight transport, freight. Trains are typically pul ...
behave 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 the
EMC EA/EB
The EMC EA/EB is an early passenger train-hauling diesel locomotive built from May 16, 1937, to 1938 by Electro-Motive Corporation of La Grange, Illinois for the Baltimore and Ohio Railroad. They were the first model in a long line of passenger die ...
of 1937. Electrical interconnections were made so one engine driver could operate the entire consist from the head-end unit.
In mountainous regions, it is common to interpose
helper locomotive
A bank engine (United Kingdom/Australia) (colloquially a banker), banking engine, helper engine or pusher engine (North America) is a railway locomotive that temporarily assists a train that requires additional power or traction to climb a grad ...
s in the middle of the train, both to provide the extra power needed to ascend a grade and to limit the amount of
stress
Stress may refer to:
Science and medicine
* Stress (biology), an organism's response to a stressor such as an environmental condition
* Stress (linguistics), relative emphasis or prominence given to a syllable in a word, or to a word in a phrase ...
applied to the
draft gear
A coupling (or a coupler) is a mechanism typically placed at each end of a railway vehicle that connects them together to form a train. A variety of coupler types have been developed over the course of railway history. Key issues in their desig ...
of the car coupled to the head-end power. The helper units in such
distributed power
In rail transport, distributed power (DP) is a generic term referring to the physical distribution—at intermediate points throughout the length of a train—of separate motive power groups. Such "groups" may be single units or multiple consist ...
configurations 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
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 or
B unit
B, or b, is the second letter of the Latin-script alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is '' bee'' (pronounced ), plural ''bees''. It re ...
s) and the arrangement was often A-B, A-A, A-B-A, A-B-B, or A-B-B-A where A was a unit with a cab. Center cabs were sometimes used for switch locomotives.
Cow-calf
In North American railroading, a
cow-calf
In rail transport, a cow-calf (also cow and calf) locomotive is a set of switcher-type diesel locomotives. The set usually is a pair; some 3-unit sets (with two calves, also known as herds) were built, but this was rare. A cow is equipped with a ...
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
A classification yard (American and Canadian English (Canadian National Railway use)), marshalling yard (British, Hong Kong, Indian, Australian, and Canadian English (Canadian Pacific Railway use)) or shunting yard (Central Europe) is a railway ya ...
service. Some are radio controlled without an operating engineer present in the cab. This arrangement is also known as
master-slave. Where two connected units were present,
EMD called these TR-2s (approximately ); where three units, TR-3s (approximately ).
Cow-calves have largely disappeared as these engine combinations exceeded their economic lifetimes many years ago.
Present North American practice is to pair two 3,000hp
GP40-2
The EMD GP40-2 is a 4-axle diesel locomotive built by General Motors Electro-Motive Division as part of its Dash 2 line between April 1972 and December 1986. The locomotive's power is provided by an EMD 645E3 16-cylinder engine which generates ...
or
SD40-2
The EMD SD40-2 is a AAR wheel arrangement#C-C, C-C diesel-electric locomotive built by Electro-Motive Diesel, EMD from 1972 to 1989.
The SD40-2 was introduced in January 1972 as part of EMD's ''EMD Dash 2, Dash 2'' series, competing against the ...
road 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 or steel ballast and the power for traction obtained from the master unit. As a 16-cylinder prime-mover generally weighs in the range, and a 3,000hp traction alternator generally weighs in the range, this would mean that would be needed for ballast.
A pair of fully capable "Dash 2" units would be rated . A "Dash 2" pair where only one had a prime-mover/alternator would be rated 3,000hp, 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 3,000hp much less 6,000hp on a continuous basis.
Fittings and appliances
Flameproofing
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 the
fireless steam locomotive
A fireless locomotive is a type of locomotive which uses reciprocating engines powered from a reservoir of compressed air or steam, which is filled at intervals from an external source. They offer advantages over conventional steam locomotives of ...
in areas of high fire risk such as
oil refineries
An oil refinery or petroleum refinery is an industrial process plant where petroleum (crude oil) is transformed and refined into useful products such as gasoline (petrol), diesel fuel, asphalt base, fuel oils, heating oil, kerosene, liquefie ...
and
ammunition dump
An ammunition dump, ammunition supply point (ASP), ammunition handling area (AHA) or ammunition depot is a military storage facility for live ammunition and explosives.
The storage of live ammunition and explosives is inherently hazardous. Th ...
s. Preserved examples of flameproof diesel locomotives include:
* ''Francis Baily of Thatcham'' (ex-
RAF Welford
Royal Air Force Welford or more simply RAF Welford is an active Royal Air Force station in Berkshire, England. The station is located approximately northwest of Newbury; about west-southwest of London
Opened in 1943, it was used during the Se ...
) at
Southall Railway Centre
Southall Railway Centre is a non-publicised railway heritage centre at Southall in west London, near to Southall railway station and the Grand Union Canal. Formerly of the Great Western Railway the site is now run partly by Locomotive Services ...
* ''Naworth'' (ex-
National Coal Board
The National Coal Board (NCB) was the statutory corporation created to run the nationalised coal mining industry in the United Kingdom. Set up under the Coal Industry Nationalisation Act 1946, it took over the United Kingdom's collieries on "v ...
) at the
South Tynedale Railway
The South Tynedale Railway is a preserved, Narrow gauge railway, narrow gauge heritage railway in Northern England and at 875ft is England's second highest narrow gauge railway after the Lynton and Barnstaple Railway in north Devon. The South ...
Latest development of the "Flameproof Diesel Vehicle Applied New Exhaust Gas Dry Type Treatment System" does not need the water supply.
Lights
The lights fitted to diesel locomotives vary from country to country. North American locomotives are fitted with two headlights (for safety in case one malfunctions) 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 a
grade crossing
A level crossing is an intersection where a railway line crosses a road, path, or (in rare situations) airport runway, at the same level, as opposed to the railway line crossing over or under using an overpass or tunnel. The term also ...
. Older locomotives may be fitted with a Gyralite or
Mars Light
Mars Lights are signal-safety lights used in the United States and built by Mars Signal Light Company for railroad locomotives and firefighting apparatus. Mars Lights used a variety of means to cause the light to oscillate vertically, horizontall ...
instead of the ditch lights.
Environmental impact
Although diesel locomotives generally emit less sulphur dioxide, a major
pollutant
A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oi ...
to the environment, and greenhouse gases than steam locomotives, they are not completely clean in that respect. Furthermore, like other diesel powered vehicles, they emit
nitrogen oxides Nitrogen oxide may refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds:
Charge-neutral
*Nitric oxide (NO), nitrogen(II) oxide, or nitrogen monoxide
*Nitrogen dioxide (), nitrogen(IV) oxide
*Nitrogen trioxide (), or ni ...
and
fine particles
Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The ter ...
, 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 measure
air pollution
Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different types ...
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
Smog, or smoke fog, is a type of intense air pollution. The word "smog" was coined in the early 20th century, and is a portmanteau of the words ''smoke'' and '' fog'' to refer to smoky fog due to its opacity, and odor. The word was then inte ...
and
acid rain
Acid rain is rain or any other form of precipitation that is unusually acidic, meaning that it has elevated levels of hydrogen ions (low pH). Most water, including drinking water, has a neutral pH that exists between 6.5 and 8.5, but acid ...
, and soot would be by 2030 nearly twice what they originally assumed. In Europe, where most major railways have been electrified, there is less concern.
This would mean that in the USA diesel locomotives would be releasing more than 800,000tons of nitrogen oxide and 25,000tons of soot every year within a quarter of a century, in contrast to the EPA's previous projections of 480,000tons of
nitrogen dioxide
Nitrogen dioxide is a chemical compound with the formula . It is one of several nitrogen oxides. is an intermediate in the industrial synthesis of nitric acid, millions of tons of which are produced each year for use primarily in the producti ...
and 12,000tons of soot. Since this was discovered, to reduce the effects of the diesel locomotive on humans (who are breathing the noxious emissions) and on plants and animals, it is considered practical to install traps in the diesel engines to reduce pollution levels and other methods of pollution control (e.g., use of
biodiesel
Biodiesel is a form of diesel fuel derived from plants or animals and consisting of long-chain fatty acid esters. It is typically made by chemically reacting lipids such as animal fat (tallow), soybean oil, or some other vegetable oil with ...
).
Diesel locomotive pollution has been of particular concern in the city of
Chicago
(''City in a Garden''); I Will
, image_map =
, map_caption = Interactive Map of Chicago
, coordinates =
, coordinates_footnotes =
, subdivision_type = Country
, subdivision_name ...
. The ''Chicago Tribune'' reported levels of diesel soot inside locomotives leaving Chicago at levels hundreds of times above what is normally found on streets outside. Residents of several neighborhoods are most likely exposed to diesel emissions at levels several times higher than the national average for urban areas.
Mitigation
In 2008, the
United States Environmental Protection Agency
The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
(EPA) mandated regulations requiring all new or refurbished diesel locomotives to meet
Tier II pollution standards that slash the amount of allowable soot by 90% and require an 80% reduction in
nitrogen oxide Nitrogen oxide may refer to a binary compound of oxygen and nitrogen, or a mixture of such compounds:
Charge-neutral
*Nitric oxide (NO), nitrogen(II) oxide, or nitrogen monoxide
*Nitrogen dioxide (), nitrogen(IV) oxide
* Nitrogen trioxide (), or n ...
emissions. ''See''
List of low emissions locomotives
The following is a list of diesel-electric locomotives that meet or exceed EPA Tier 2 locomotive emissions regulations, sorted by builder. This is a non-exhaustive list of locomotives in North America. Furthermore, green/clean energy is an always ...
.
Other technologies that are being deployed to reduce locomotive emissions and fuel consumption include "Genset" switching locomotives and hybrid
Green Goat
Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 Nanometre, nm. In subtractive color systems, used in painting and color printing, it is created by ...
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. 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
Hybrid may refer to:
Science
* Hybrid (biology), an offspring resulting from cross-breeding
** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species
** Hybridity, the property of a hybrid plant which is a union of two dif ...
switching locomotive utilizing a small diesel engine and a large bank of rechargeable batteries. 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
A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...
s were custom-made for specific railway routes, so economies of scale were difficult to achieve. Though more complex to produce with exacting manufacturing tolerances ( for diesel, compared with for steam), diesel locomotive parts were easier to mass-produce.
Baldwin Locomotive Works
The Baldwin Locomotive Works (BLW) was an American manufacturer of railroad locomotives from 1825 to 1951. Originally located in Philadelphia, it moved to nearby Eddystone, Pennsylvania, in the early 20th century. The company was for decades t ...
offered almost 500 steam models in its heyday, while
EMD offered fewer than ten diesel varieties. In the United Kingdom,
British Railways
British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most of the overground rail transport in Great Britain from 1948 to 1997. It was formed from the nationalisation of the Big Four British rai ...
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
drawbar horse power was £13 6s (steam), £65 (diesel), £69 7s (turbine) and £17 13s (electric).
Diesel locomotives offer significant operating advantages over steam locomotives. 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
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
In railroad terminology, double heading indicates the use of two locomotives at the front of a train, each operated individually by its own crew. The practice of triple-heading involves the use of three locomotives. The practice of multi-headi ...
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.
Steam locomotives 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. They can be kept in readiness between uses with a low fire, but this requires regular stoking and 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 is not frozen. After use a steam locomotive requires a lengthy disposal operation to perform cleaning, inspection, maintenance and refilling with water and fuel before it is ready for its next duty. By contrast, as early as 1939 EMD was promoting its
FT Series locomotive as needing no maintenance between 30-day inspections beyond refuelling and basic fluid level and safety checks which could be performed with the prime mover still running. Railways converting from steam to diesel operation in the 1940s and 1950s found that for a given period diesel locomotives were available for, on average, three or four times more revenue-earning hours than equivalent steam locomotives, allowing locomotive fleets to be cut drastically in size while maintaining operational capacity.
The maintenance and operational costs of steam locomotives were much higher than diesels. 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. With diesel locomotives spare parts could be mass-produced and held in stock ready for use and many parts and sub-assemblies could be standardized across an operator's fleet using different models of locomotive from the same builder. Modern diesel locomotive engines are designed to allow the power assemblies (systems of working parts and their block interfaces) to be replaced while keeping the main block in the locomotive, which greatly reduces the time that a locomotive is out of revenue-generating service when it requires maintenance.
Steam engines required large quantities of coal and water, which were expensive variable operating costs.
[Stover, 213] Further, the
thermal efficiency
In thermodynamics, the thermal efficiency (\eta_) is a dimensionless performance measure of a device that uses thermal energy, such as an internal combustion engine, steam turbine, steam engine, boiler, furnace, refrigerator, ACs etc.
For a he ...
of steam was considerably less than that of diesel engines. Diesel's theoretical studies demonstrated potential thermal efficiencies for a compression ignition engine of 36% (compared with 6–10% for steam), and an 1897 one-cylinder prototype operated at a remarkable 26% efficiency.
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.
[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]
By the mid-1960s, diesel locomotives had effectively replaced steam locomotives where electric traction was not in use.
Attempts to develop
advanced steam technology
Advanced steam technology (sometimes known as modern steam) reflects an approach to the technical development of the steam engine intended for a wider variety of applications than has recently been the case. Particular attention has been given t ...
continue in the 21st century, but have not had a significant effect.
See also
*
Alternative fuels for diesel engines
*
Diesel multiple unit
A diesel multiple unit or DMU is a multiple-unit train powered by on-board diesel engines. A DMU requires no separate locomotive, as the engines are incorporated into one or more of the carriages. Diesel-powered single-unit railcars are also ...
*
Diesel–electric transmission
A diesel–electric transmission, or diesel–electric powertrain is a transmission system for vehicles powered by diesel engines in road, rail, and marine transport. Diesel–electric transmission is based on petrol–electric transmission, a v ...
*
Diesel engine
The diesel engine, named after Rudolf Diesel, is an internal combustion engine in which ignition of the fuel is caused by the elevated temperature of the air in the cylinder due to mechanical compression; thus, the diesel engine is a so-call ...
*
Electric locomotive
An electric locomotive is a locomotive powered by electricity from overhead lines, a third rail or on-board energy storage such as a battery or a supercapacitor. Locomotives with on-board fuelled prime movers, such as diesel engines or gas ...
*
Electrification
Electrification is the process of powering by electricity and, in many contexts, the introduction of such power by changing over from an earlier power source.
The broad meaning of the term, such as in the history of technology, economic histor ...
*
Electro-diesel locomotive
An electro-diesel locomotive (also referred to as a dual-mode or bi-mode locomotive) is a type of locomotive that can be powered either from an electricity supply (like an electric locomotive) or by using the onboard diesel engine (like a diese ...
*
Gas turbine locomotive
A gas turbine locomotive is a type of railway locomotive in which the prime mover is a gas turbine. Several types of gas turbine locomotive have been developed, differing mainly in the means by which mechanical power is conveyed to the driving w ...
*
Heilmann locomotive
The Heilmann locomotives were a series of three experimental steam-electric locomotives produced in the 1890s for the French Chemins de Fer de l'Ouest (CF de l'Ouest). A prototype was built in 1894 and two larger locomotives were built in 1897. Th ...
*
Hybrid electric vehicle
A hybrid electric vehicle (HEV) is a type of hybrid vehicle that combines a conventional internal combustion engine (ICE) system with an electric propulsion system ( hybrid vehicle drivetrain). The presence of the electric powertrain is intende ...
*
Hybrid locomotive
*
Non-road engine
Non-road engines are engines that are used for other purposes than a motor vehicle that is used on a public roadway. The term is commonly used by regulators to classify the engines in order to control their emissions.
Non-road engines are use ...
References
Sources
*
*
External links
US Government test of GP38-2 locomotive with biodiesel fuel.*
ttps://web.archive.org/web/20150901062917/http://www.railway-technical.com/diesel.shtml Diesel locomotive
{{DEFAULTSORT:Diesel Locomotive
Locomotive
A locomotive or engine is a rail transport vehicle that provides the Power (physics), motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, Motor coach (rail), motor ...