A diesel–electric transmission , or diesel–electric powertrain , is a transmission system powered by diesel engines for vehicles in road , rail , and marine transport . Diesel–electric transmission is similar to petrol–electric transmission , which is powered by petrol engines .
131-421: Diesel–electric transmission is used on railways by diesel–electric locomotives and diesel–electric multiple units , as electric motors are able to supply full torque from 0 RPM . Diesel–electric systems are also used in marine transport , including submarines, and on some other land vehicles. The defining characteristic of diesel–electric transmission is that it avoids the need for a gearbox , by converting
262-471: A consist 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 , have eight throttle positions or "notches" as well as
393-467: A weed hatch over the propeller, and once the narrowboat is stationary, the hatch may be opened to give access to the propeller, enabling debris to be cleared. Yachts and river boats rarely have weed hatches; instead they may fit a rope cutter that fits around the prop shaft and rotates with the propeller. These cutters clear the debris and obviate the need for divers to attend manually to the fouling. Several forms of rope cutters are available: A cleaver
524-429: 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
655-576: A New Generation of Vehicles was a cooperative research program between the U.S. government and "The Big Three" automobile manufacturers ( DaimlerChrysler , Ford and General Motors ) that developed diesel hybrid cars. Diesel–electric propulsion has been tried on some military vehicles , such as tanks . The German armored vehicles VK 45.01 (P) , Elefant , and Panzer VIII Maus of the Second World War were petrol-electric or diesel-electric propelled. The prototype TOG1 and TOG2 super heavy tanks of
786-609: A Rational Heat Motor ). However, the large size 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 was not initially recognized. This changed as research and development reduced the size and weight of the engine. In 1906, Rudolf Diesel, Adolf Klose and the steam and diesel engine manufacturer Gebrüder Sulzer founded Diesel-Sulzer-Klose GmbH to manufacture diesel-powered locomotives. Sulzer had been manufacturing diesel engines since 1898. The Prussian State Railways ordered
917-419: A better match of angle of attack to the wake velocity over the blades. A warped helicoid is described by specifying the shape of the radial reference line and the pitch angle in terms of radial distance. The traditional propeller drawing includes four parts: a side elevation, which defines the rake, the variation of blade thickness from root to tip, a longitudinal section through the hub, and a projected outline of
1048-434: A blade onto a longitudinal centreline plane. The expanded blade view shows the section shapes at their various radii, with their pitch faces drawn parallel to the base line, and thickness parallel to the axis. The outline indicated by a line connecting the leading and trailing tips of the sections depicts the expanded blade outline. The pitch diagram shows variation of pitch with radius from root to tip. The transverse view shows
1179-436: A combination: Queen Mary 2 has a set of diesel engines in the bottom of the ship plus two gas turbines mounted near the main funnel; all are used for generating electrical power, including those used to drive the propellers . This provides a relatively simple way to use the high-speed, low-torque output of a turbine to drive a low-speed propeller, without the need for excessive reduction gearing. Most early submarines used
1310-583: 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 in 1914 prevented all further trials. The locomotive weight
1441-499: A diesel-driven charging circuit. ALCO acquired the McIntosh & Seymour Engine Company in 1929 and entered series production of 300 hp (220 kW) and 600 hp (450 kW) 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
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#17328837191231572-503: A direct mechanical connection between the combustion engine and propeller, switching between diesel engines for surface running and electric motors for submerged propulsion. This was effectively a "parallel" type of hybrid, since the motor and engine were coupled to the same shaft. On the surface, the motor (driven by the engine) was used as a generator to recharge the batteries and supply other electric loads. The engine would be disconnected for submerged operation, with batteries powering
1703-660: A direct-drive diesel locomotive would require an impractical number of gears to keep the engine within its powerband; coupling the diesel to a generator eliminates this problem. An alternative is to use a torque converter or fluid coupling in a direct drive system to replace the gearbox. Diesel electric based buses have also been produced, including hybrid systems able to run on and store electrical power in batteries. The two main providers of hybrid systems for diesel–electric transit buses include Allison Transmission and BAE Systems . New Flyer Industries , Gillig Corporation , and North American Bus Industries are major customers for
1834-508: A ducted propeller. The cylindrical duct acts as the stator, while the tips of the blades act as the rotor. They typically provide high torque and operate at low RPMs, producing less noise. The system does not require a shaft, reducing weight. Units can be placed at various locations around the hull and operated independently, e.g., to aid in maneuvering. The absence of a shaft allows alternative rear hull designs. Twisted- toroid (ring-shaped) propellers, first invented over 120 years ago, replace
1965-465: A flashover (also known as an arc fault ), which could result in immediate generator failure and, in some cases, start an engine room fire. Current North American practice is for four axles for high-speed passenger or "time" freight, or for six axles for lower-speed or "manifest" freight. The most modern units on "time" freight service tend to have six axles underneath the frame. Unlike those in "manifest" service, "time" freight units will have only four of
2096-560: 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 , mechanically aspirated , uniflow-scavenged , unit-injected diesel engine that could deliver
2227-457: A manually-driven ship and successfully used it on a steamboat in 1829. His 48-ton ship Civetta reached 6 knots. This was the first successful Archimedes screw-propelled ship. His experiments were banned by police after a steam engine accident. Ressel, a forestry inspector, held an Austro-Hungarian patent for his propeller. The screw propeller was an improvement over paddlewheels as it wasn't affected by ship motions or draft changes. John Patch ,
2358-400: A marine screw propeller is based on a helicoidal surface. This may form the face of the blade, or the faces of the blades may be described by offsets from this surface. The back of the blade is described by offsets from the helicoid surface in the same way that an aerofoil may be described by offsets from the chord line. The pitch surface may be a true helicoid or one having a warp to provide
2489-668: A mariner in Yarmouth, Nova Scotia developed a two-bladed, fan-shaped propeller in 1832 and publicly demonstrated it in 1833, propelling a row boat across Yarmouth Harbour and a small coastal schooner at Saint John, New Brunswick , but his patent application in the United States was rejected until 1849 because he was not an American citizen. His efficient design drew praise in American scientific circles but by then he faced multiple competitors. Despite experimentation with screw propulsion before
2620-401: 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. Propeller A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft ) is a device with a rotating hub and radiating blades that are set at
2751-453: A pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on
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#17328837191232882-501: A propeller's forward thrust as being a reaction proportionate to the mass of fluid sent backward per time and the speed the propeller adds to that mass, and in practice there is more loss associated with producing a fast jet than with creating a heavier, slower jet. (The same applies in aircraft, in which larger-diameter turbofan engines tend to be more efficient than earlier, smaller-diameter turbofans, and even smaller turbojets , which eject less mass at greater speeds.) The geometry of
3013-475: A propeller. Robert Hooke in 1681 designed a horizontal watermill which was remarkably similar to the Kirsten-Boeing vertical axis propeller designed almost two and a half centuries later in 1928; two years later Hooke modified the design to provide motive power for ships through water. In 1693 a Frenchman by the name of Du Quet invented a screw propeller which was tried in 1693 but later abandoned. In 1752,
3144-421: 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 . 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,
3275-477: A real prospect with existing diesel technology. Before diesel power could make inroads into mainline service, the limitations of diesel engines circa 1930 – low power-to-weight ratios and narrow output range – had to be overcome. A major effort to overcome those limitations was launched by General Motors after they moved into the diesel field with their acquisition of the Winton Engine Company ,
3406-681: A revised patent in keeping with this accidental discovery. In the meantime, Ericsson built a 45-foot (14 m) screw-propelled steamboat, Francis B. Ogden in 1837, and demonstrated his boat on the River Thames to senior members of the British Admiralty , including Surveyor of the Navy Sir William Symonds . In spite of the boat achieving a speed of 10 miles an hour, comparable with that of existing paddle steamers , Symonds and his entourage were unimpressed. The Admiralty maintained
3537-464: A rotary steam engine coupled to a four-bladed propeller. The craft achieved a speed of 4 mph (6.4 km/h), but Stevens abandoned propellers due to the inherent danger in using the high-pressure steam engines. His subsequent vessels were paddle-wheeled boats. By 1827, Czech inventor Josef Ressel had invented a screw propeller with multiple blades on a conical base. He tested it in February 1826 on
3668-416: A rubber bushing can be replaced or repaired depends upon the propeller; some cannot. Some can, but need special equipment to insert the oversized bushing for an interference fit . Others can be replaced easily. The "special equipment" usually consists of a funnel, a press and rubber lubricant (soap). If one does not have access to a lathe, an improvised funnel can be made from steel tube and car body filler; as
3799-411: A similar propeller attached to a rod angled down temporarily deployed from the deck above the waterline and thus requiring no water seal, and intended only to assist becalmed sailing vessels. He tested it on the transport ship Doncaster at Gibraltar and Malta, achieving a speed of 1.5 mph (2.4 km/h). In 1802, American lawyer and inventor John Stevens built a 25-foot (7.6 m) boat with
3930-651: A small model boat to test his invention, which was demonstrated first on a pond at his Hendon farm, and later at the Royal Adelaide Gallery of Practical Science in London , where it was seen by the Secretary of the Navy, Sir William Barrow. Having secured the patronage of a London banker named Wright, Smith then built a 30-foot (9.1 m), 6- horsepower (4.5 kW) canal boat of six tons burthen called Francis Smith , which
4061-502: A strategic need for rail engines without plumes of smoke above them. Diesel technology was not yet sufficiently developed but a few precursor attempts were made, especially for petrol–electric transmissions by the French (Crochat-Collardeau, patent dated 1912 also used for tanks and trucks) and British ( Dick, Kerr & Co and British Westinghouse ). About 300 of these locomotives, only 96 being standard gauge, were in use at various points in
Diesel–electric powertrain - Misplaced Pages Continue
4192-508: Is a type of railway locomotive in which the power source is a diesel engine . Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is conveyed to the driving wheels . The most common are diesel–electric locomotives and diesel–hydraulic. Early internal combustion locomotives and railcars used kerosene and gasoline as their fuel. Rudolf Diesel patented his first compression-ignition engine in 1898, and steady improvements to
4323-445: Is a type of propeller design especially used for boat racing. Its leading edge is formed round, while the trailing edge is cut straight. It provides little bow lift, so that it can be used on boats that do not need much bow lift, for instance hydroplanes , that naturally have enough hydrodynamic bow lift. To compensate for the lack of bow lift, a hydrofoil may be installed on the lower unit. Hydrofoils reduce bow lift and help to get
4454-479: Is an opportunity to only change the pitch or the damaged blades. Being able to adjust pitch will allow for boaters to have better performance while in different altitudes, water sports, or cruising. Voith Schneider propellers use four untwisted straight blades turning around a vertical axis instead of helical blades and can provide thrust in any direction at any time, at the cost of higher mechanical complexity. A rim-driven thruster integrates an electric motor into
4585-421: Is because clutches would need to be very large at these power levels and would not fit in a standard 2.5 m (8 ft 2 in)-wide locomotive frame, or would wear too quickly to be useful. The first successful diesel engines used diesel–electric transmissions , and by 1925 a small number of diesel locomotives of 600 hp (450 kW) were in service in the United States. In 1930, Armstrong Whitworth of
4716-533: Is better able to cope with overload conditions that often destroyed the older types of motors. 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 (also referred to as drawbar pull or tractive force , which is what actually propels the train) will tend to inversely vary with speed within these limits. (See power curve below). Maintaining acceptable operating parameters
4847-502: Is generally limited to low-powered, low-speed shunting (switching) locomotives, lightweight multiple units and self-propelled railcars . The mechanical transmissions used for railroad propulsion are generally more complex and much more robust than standard-road versions. There is usually a fluid coupling interposed between the engine and gearbox, and the gearbox is often of the epicyclic (planetary) type to permit shifting while under load. Various systems have been devised to minimise
4978-422: Is identical to petrol–electric transmission , which is used on vehicles powered by petrol engines, and to turbine–electric powertrain , which is used for gas turbines . Diesel–electric transmissions are a type of continuously variable transmission . The absence of a gearbox eliminates the need for gear changes, which prevents uneven acceleration caused by the disengagement of a clutch . With auxiliary batteries
5109-531: Is modelled as an infinitely thin disc, inducing a constant velocity along the axis of rotation and creating a flow around the propeller. A screw turning through a solid will have zero "slip"; but as a propeller screw operates in a fluid (either air or water), there will be some losses. The most efficient propellers are large-diameter, slow-turning screws, such as on large ships; the least efficient are small-diameter and fast-turning (such as on an outboard motor). Using Newton's laws of motion, one may usefully think of
5240-626: Is paired with electric motors for this reason. Petrol engine produces most torque at high rpm, supplemented by electric motors' low rpm torque. The first diesel motorship was also the first diesel–electric ship, the Russian tanker Vandal from Branobel , which was launched in 1903. Steam turbine–electric propulsion has been in use since the 1920s ( Tennessee -class battleships ), using diesel–electric powerplants in surface ships has increased lately. The Finnish coastal defence ships Ilmarinen and Väinämöinen laid down in 1928–1929, were among
5371-414: 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 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
Diesel–electric powertrain - Misplaced Pages Continue
5502-482: Is the tangential offset of the line of maximum thickness to a radius The propeller characteristics are commonly expressed as dimensionless ratios: Cavitation is the formation of vapor bubbles in water near a moving propeller blade in regions of very low pressure. It can occur if an attempt is made to transmit too much power through the screw, or if the propeller is operating at a very high speed. Cavitation can waste power, create vibration and wear, and cause damage to
5633-576: The Academie des Sciences in Paris granted Burnelli a prize for a design of a propeller-wheel. At about the same time, the French mathematician Alexis-Jean-Pierre Paucton suggested a water propulsion system based on the Archimedean screw. In 1771, steam-engine inventor James Watt in a private letter suggested using "spiral oars" to propel boats, although he did not use them with his steam engines, or ever implement
5764-637: The Burlington Route and Union Pacific used custom-built diesel " streamliners " to haul passengers, starting in late 1934. Burlington's Zephyr trainsets evolved from articulated three-car sets with 600 hp power cars in 1934 and early 1935, to the Denver Zephyr semi-articulated ten car trainsets pulled by cab-booster power sets introduced in late 1936. Union Pacific started diesel streamliner service between Chicago and Portland Oregon in June 1935, and in
5895-717: The Busch-Sulzer 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 (GE) entered the railcar market in the early twentieth century, as Thomas Edison possessed a patent on the electric locomotive, his design actually being a type of electrically propelled railcar. 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
6026-600: The Canadian National Railways 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
6157-490: The DFH1 , began in 1964 following the construction of a prototype in 1959. 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. In 1914,
6288-484: 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 440 horsepower (330 kW) at 500 rpm, driving four DC motors, one for each axle. These 44 tonnes (43 long tons; 49 short tons) locomotives with 45 km/h (28 mph) top speed proved quite successful. In 1924, two diesel–electric locomotives were taken in service by
6419-981: The Soviet railways , almost at the same time: In 1935, Krauss-Maffei , MAN and Voith 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. 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
6550-406: The electrification of the line in 1944. Afterwards, the company kept them in service as boosters until 1965. Fiat 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 950 mm ( 3 ft 1 + 3 ⁄ 8 in ) narrow gauge Ferrovie Calabro Lucane and
6681-404: The mechanical force of the diesel engine into electrical energy (through an alternator ), and using the electrical energy to drive traction motors , which propel the vehicle mechanically. The traction motors may be powered directly or via rechargeable batteries , making the vehicle a type of hybrid electric vehicle . This method of transmission is sometimes termed electric transmission, as it
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#17328837191236812-417: The vapor pressure of the water, resulting in the formation of a vapor pocket. Under such conditions, the change in pressure between the downstream surface of the blade (the "pressure side") and the suction side is limited, and eventually reduced as the extent of cavitation is increased. When most of the blade surface is covered by cavitation, the pressure difference between the pressure side and suction side of
6943-432: The 1,500 kW (2,000 hp) British Rail 10100 locomotive), though only few have proven successful (such as the 1,342 kW (1,800 hp) DSB Class MF ). In a diesel–electric locomotive , the diesel engine drives either an electrical DC generator (generally, less than 3,000 hp (2,200 kW) net for traction), or an electrical AC alternator-rectifier (generally 3,000 hp net or more for traction),
7074-498: The 1830s, few of these inventions were pursued to the testing stage, and those that were proved unsatisfactory for one reason or another. In 1835, two inventors in Britain, John Ericsson and Francis Pettit Smith , began working separately on the problem. Smith was first to take out a screw propeller patent on 31 May, while Ericsson, a gifted Swedish engineer then working in Britain, filed his patent six weeks later. Smith quickly built
7205-414: The 1880s. The Wright brothers pioneered the twisted aerofoil shape of modern aircraft propellers. They realized an air propeller was similar to a wing. They verified this using wind tunnel experiments. They introduced a twist in their blades to keep the angle of attack constant. Their blades were only 5% less efficient than those used 100 years later. Understanding of low-speed propeller aerodynamics
7336-440: The 1930s, the system was adapted for streamliners , the fastest trains of their day. Diesel–electric powerplants became popular because they greatly simplified the way motive power was transmitted to the wheels and because they were both more efficient and had greatly reduced maintenance requirements. Direct-drive transmissions can become very complex, considering that a typical locomotive has four or more axles . Additionally,
7467-456: The 1960s, the DC generator was replaced by an alternator using a diode bridge to convert its output to DC. This advance greatly improved locomotive reliability and decreased generator maintenance costs by elimination of the commutator and brushes in the generator. Elimination of the brushes and commutator, in turn, eliminated the possibility of a particularly destructive type of event referred to as
7598-513: The 1990s, starting with the Electro-Motive SD70MAC in 1993 and followed by General Electric's AC4400CW in 1994 and AC6000CW in 1995. The Trans-Australian Railway built 1912 to 1917 by Commonwealth Railways (CR) passes through 2,000 km of waterless (or salt watered) desert terrain unsuitable for steam locomotives. The original engineer Henry Deane envisaged diesel operation to overcome such problems. Some have suggested that
7729-727: The Allison EP hybrid systems, while Orion Bus Industries and Nova Bus are major customer for the BAE HybriDrive system. Mercedes-Benz makes their own diesel–electric drive system, which is used in their Citaro . The only bus that runs on single diesel–electric transmission is the Mercedes Benz Cito low floor concept bus which was introduced in 1998. Examples include: In the automobile industry, diesel engines in combination with electric transmissions and battery power are being developed for future vehicle drive systems. Partnership for
7860-582: 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: A diesel–mechanical locomotive uses a mechanical transmission in a fashion similar to that employed in most road vehicles. This type of transmission
7991-877: The Netherlands, and in 1927 in Germany. After a few years of testing, hundreds of units were produced within a decade. 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 for the Canadian National Railways (the Beardmore Tornado engine was subsequently used in the R101 airship). Some of those series for regional traffic were begun with gasoline motors and then continued with diesel motors, such as Hungarian BC (The class code doesn't tell anything but "railmotor with 2nd and 3rd class seats".), 128 cars built 1926–1937, or German Wismar railbuses (57 cars 1932–1941). In France,
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#17328837191238122-452: The Royal Navy's view that screw propellers would prove unsuitable for seagoing service, Smith determined to prove this assumption wrong. In September 1837, he took his small vessel (now fitted with an iron propeller of a single turn) to sea, steaming from Blackwall, London to Hythe, Kent , with stops at Ramsgate , Dover and Folkestone . On the way back to London on the 25th, Smith's craft
8253-543: The Second World War used twin generators driven by V12 diesel engines. More recent prototypes include the SEP modular armoured vehicle and T95e . Future tanks may use diesel–electric drives to improve fuel efficiency while reducing the size, weight and noise of the power plant. Attempts with diesel–electric drives on wheeled military vehicles include the unsuccessful ACEC Cobra , MGV , and XM1219 armed robotic vehicle . Diesel locomotive#Diesel–electric A diesel locomotive
8384-498: The US made much use of diesel–electric transmission before 1945. After World War II, by contrast, it gradually became the dominant mode of propulsion for conventional submarines. However, its adoption was not always swift. Notably, the Soviet Navy did not introduce diesel–electric transmission on its conventional submarines until 1980 with its Paltus class . During World War I , there was
8515-552: The United Kingdom delivered two 1,200 hp (890 kW) locomotives using Sulzer -designed engines to Buenos Aires Great Southern Railway of Argentina. In 1933, diesel–electric technology developed by Maybach was used to propel the DRG Class SVT 877 , a high-speed intercity two-car set, and went into series production with other streamlined car sets in Germany starting in 1935. In the United States, diesel–electric propulsion
8646-490: 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 road locomotives, but most in
8777-528: The absence of lengthwise twist made them less efficient than the Wright propellers. Even so, this may have been the first use of aluminium in the construction of an airscrew. In the nineteenth century, several theories concerning propellers were proposed. The momentum theory or disk actuator theory – a theory describing a mathematical model of an ideal propeller – was developed by W.J.M. Rankine (1865), A.G. Greenhill (1888) and R.E. Froude (1889). The propeller
8908-510: The adoption of screw propulsion by the Royal Navy , in addition to her influence on commercial vessels. Trials with Smith's Archimedes led to a tug-of-war competition in 1845 between HMS Rattler and HMS Alecto with the screw-driven Rattler pulling the paddle steamer Alecto backward at 2.5 knots (4.6 km/h). The Archimedes also influenced the design of Isambard Kingdom Brunel 's SS Great Britain in 1843, then
9039-433: 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
9170-706: The benefits of an electric locomotive 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 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 outshopped
9301-419: The blade drops considerably, as does the thrust produced by the propeller. This condition is called "thrust breakdown". Operating the propeller under these conditions wastes energy, generates considerable noise, and as the vapor bubbles collapse it rapidly erodes the screw's surface due to localized shock waves against the blade surface. Tip vortex cavitation is caused by the extremely low pressures formed at
9432-400: The blades with a-circular rings. They are significantly quieter (particularly at audible frequencies) and more efficient than traditional propellers for both air and water applications. The design distributes vortices generated by the propeller across the entire shape, causing them to dissipate faster in the atmosphere. For smaller engines, such as outboards, where the propeller is exposed to
9563-420: The break in transmission during gear changing, such as the S.S.S. (synchro-self-shifting) gearbox used by Hudswell Clarke . Diesel–mechanical propulsion is limited by the difficulty of building a reasonably sized transmission capable of coping with the power and torque required to move a heavy train. A number of attempts to use diesel–mechanical propulsion in high power applications have been made (for example,
9694-453: The bushing in the hub is overcome and the rotating propeller slips on the shaft, preventing overloading of the engine's components. After such an event the rubber bushing may be damaged. If so, it may continue to transmit reduced power at low revolutions, but may provide no power, due to reduced friction, at high revolutions. Also, the rubber bushing may perish over time leading to its failure under loads below its designed failure load. Whether
9825-487: The conflict. In the 1920s, diesel–electric technology first saw limited use in switcher locomotives (UK: shunter locomotives ), locomotives used for moving trains around in railroad yards and assembling and disassembling them. An early company offering "Oil-Electric" locomotives was the American Locomotive Company (ALCO). The ALCO HH series of diesel–electric switcher entered series production in 1931. In
9956-600: The core of the tip vortex. The tip vortex is caused by fluid wrapping around the tip of the propeller; from the pressure side to the suction side. This video demonstrates tip vortex cavitation. Tip vortex cavitation typically occurs before suction side surface cavitation and is less damaging to the blade, since this type of cavitation doesn't collapse on the blade, but some distance downstream. Variable-pitch propellers may be either controllable ( controllable-pitch propellers ) or automatically feathering ( folding propellers ). Variable-pitch propellers have significant advantages over
10087-422: 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 , 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
10218-474: The diesel engine and the propeller that was initially common, the advantages were eventually found to be more important. One of several significant advantages is that it mechanically isolates the noisy engine compartment from the outer pressure hull and reduces the acoustic signature of the submarine when surfaced. Some nuclear submarines also use a similar turbo-electric propulsion system, with propulsion turbo generators driven by reactor plant steam. Among
10349-457: The electric motor and supplying all other power as well. In a true diesel–electric transmission arrangement, by contrast, the propeller or propellers are always driven directly or through reduction gears by one or more electric motors , while one or more diesel generators provide electric energy for charging the batteries and driving the motors. While this solution comes with a few disadvantages compared to direct mechanical connection between
10480-443: The engine governor and electrical or electronic components, including switchgear , rectifiers 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. Originally, the traction motors and generator were DC machines. Following the development of high-capacity silicon rectifiers in
10611-419: 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 for all internal combustion–electric drive control systems. In 1917–1918, GE produced three experimental diesel–electric locomotives using Lemp's control design,
10742-409: The engine at normal loads. The pin is designed to shear when the propeller is put under a load that could damage the engine. After the pin is sheared the engine is unable to provide propulsive power to the boat until a new shear pin is fitted. In larger and more modern engines, a rubber bushing transmits the torque of the drive shaft to the propeller's hub. Under a damaging load the friction of
10873-423: 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
11004-399: The filler is only subject to compressive forces it is able to do a good job. Often, the bushing can be drawn into place with nothing more complex than a couple of nuts, washers and a threaded rod. A more serious problem with this type of propeller is a "frozen-on" spline bushing, which makes propeller removal impossible. In such cases the propeller must be heated in order to deliberately destroy
11135-456: The first diesel railcar was Renault VH , 115 units produced 1933/34. In Italy, after six Gasoline cars since 1931, Fiat and Breda 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. In the 1930s, streamlined highspeed diesel railcars were developed in several countries: In 1945, a batch of 30 Baldwin diesel–electric locomotives, Baldwin 0-6-6-0 1000 ,
11266-480: The first known to be built in the United States. Following this development, the 1923 Kaufman Act banned steam locomotives from New York City, because of severe pollution problems. The response to this law was to electrify high-traffic rail lines. However, electrification was uneconomical to apply to lower-traffic areas. The first regular use of diesel–electric locomotives was in switching (shunter) applications, which were more forgiving than mainline applications of
11397-581: The first surface ships to use diesel–electric transmission. Later, the technology was used in diesel powered icebreakers . In World War II, the United States Navy built diesel–electric surface warships. Due to machinery shortages destroyer escorts of the Evarts and Cannon classes were diesel–electric, with half their designed horsepower (The Buckley and Rudderow classes were full-power steam turbine–electric). The Wind -class icebreakers , on
11528-535: The fixed-pitch variety, namely: An advanced type of propeller used on the American Los Angeles-class submarine as well as the German Type 212 submarine is called a skewback propeller . As in the scimitar blades used on some aircraft, the blade tips of a skewback propeller are swept back against the direction of rotation. In addition, the blades are tilted rearward along the longitudinal axis, giving
11659-415: The fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft with an approximately horizontal axis. The principle employed in using a screw propeller is derived from stern sculling . In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the water at the effective angle. The innovation introduced with
11790-553: The following year would add Los Angeles, CA , Oakland, CA , and Denver, CO to the destinations of diesel streamliners out of Chicago. The Burlington and Union Pacific streamliners were built by the Budd Company and the Pullman-Standard Company , respectively, using the new Winton engines and power train systems designed by GM's Electro-Motive Corporation . EMC's experimental 1800 hp B-B locomotives of 1935 demonstrated
11921-406: 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
12052-530: The idea. One of the first practical and applied uses of a propeller was on a submarine dubbed Turtle which was designed in New Haven, Connecticut , in 1775 by Yale student and inventor David Bushnell , with the help of clock maker, engraver, and brass foundryman Isaac Doolittle . Bushnell's brother Ezra Bushnell and ship's carpenter and clock maker Phineas Pratt constructed the hull in Saybrook, Connecticut . On
12183-486: The limitations of contemporary diesel technology and where the idling economy of diesel relative to steam would be most beneficial. GE entered a collaboration with the American Locomotive Company (ALCO) and Ingersoll-Rand (the "AGEIR" consortium) in 1924 to produce a prototype 300 hp (220 kW) "boxcab" locomotive delivered in July 1925. This locomotive demonstrated that the diesel–electric power unit could provide many of
12314-431: 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
12445-440: The mid-1910s, the technology was immediately reintroduced when Sweden began to design its own submarines again in the mid-1930s. From that point onwards, diesel–electric transmission has been consistently used for all new classes of Swedish submarines, albeit supplemented by air-independent propulsion (AIP) as provided by Stirling engines beginning with HMS Näcken in 1988. Another early adopter of diesel–electric transmission
12576-521: 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. Adolphus Busch purchased the American manufacturing rights for the diesel engine in 1898 but never applied this new form of power to transportation. He founded
12707-412: The motors can run on electric alone, for example when the noise or exhaust from the engine disrupts a clean air zone . Disadvantages of a diesel electric transmission are the potential complexity, cost, and decreased efficiency due to energy conversion. Diesel engines and electric motors are both known for having high torque at low rpm, this may leave high rpm with little torque. Typically a petrol engine
12838-543: 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
12969-495: The night of September 6, 1776, Sergeant Ezra Lee piloted Turtle in an attack on HMS Eagle in New York Harbor . Turtle also has the distinction of being the first submarine used in battle. Bushnell later described the propeller in an October 1787 letter to Thomas Jefferson : "An oar formed upon the principle of the screw was fixed in the forepart of the vessel its axis entered the vessel and being turned one way rowed
13100-542: The other hand, were designed for diesel–electric propulsion because of its flexibility and resistance to damage. Some modern diesel–electric ships, including cruise ships and icebreakers, use electric motors in pods called azimuth thrusters underneath to allow for 360° rotation, making the ships far more maneuverable. An example of this is Symphony of the Seas , the largest passenger ship as of 2019. Gas turbines are also used for electrical power generation and some ships use
13231-402: The output of which provides power to the traction motors 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 ), the main generator/alternator-rectifier, traction motors (usually with four or six axles), and a control system consisting of
13362-580: 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 of American railroads. In 1941, ALCO-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;
13493-731: The pioneering users of true diesel–electric transmission was the Swedish Navy with its first submarine, HMS Hajen (later renamed Ub no 1 ), launched in 1904 and originally equipped with a semi-diesel engine (a hot-bulb engine primarily meant to be fueled by kerosene), later replaced by a true diesel. From 1909 to 1916, the Swedish Navy launched another seven submarines in three different classes ( 2nd class , Laxen class , and Braxen class ), all using diesel–electric transmission. While Sweden temporarily abandoned diesel–electric transmission as it started to buy submarine designs from abroad in
13624-478: The prime mover and electric motor were immediately encountered, primarily due to limitations of the Ward Leonard current control system that had been chosen. GE Rail was formed in 1907 and 112 years later, in 2019, was purchased by and merged with Wabtec . A significant breakthrough occurred in 1914, when Hermann Lemp , a GE electrical engineer, developed and patented a reliable control system that controlled
13755-447: The propeller an overall cup-shaped appearance. This design preserves thrust efficiency while reducing cavitation, and thus makes for a quiet, stealthy design. A small number of ships use propellers with winglets similar to those on some airplane wings, reducing tip vortices and improving efficiency. A modular propeller provides more control over the boat's performance. There is no need to change an entire propeller when there
13886-406: The propeller. It can occur in many ways on a propeller. The two most common types of propeller cavitation are suction side surface cavitation and tip vortex cavitation. Suction side surface cavitation forms when the propeller is operating at high rotational speeds or under heavy load (high blade lift coefficient ). The pressure on the upstream surface of the blade (the "suction side") can drop below
14017-450: 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
14148-403: The risk of collision with heavy objects, the propeller often includes a device that is designed to fail when overloaded; the device or the whole propeller is sacrificed so that the more expensive transmission and engine are not damaged. Typically in smaller (less than 10 hp or 7.5 kW) and older engines, a narrow shear pin through the drive shaft and propeller hub transmits the power of
14279-404: The rubber insert. Once the propeller is removed, the splined tube can be cut away with a grinder and a new spline bushing is then required. To prevent a recurrence of the problem, the splines can be coated with anti-seize anti-corrosion compound. In some modern propellers, a hard polymer insert called a drive sleeve replaces the rubber bushing. The splined or other non-circular cross section of
14410-471: The screw propeller was the extension of that arc through more than 360° by attaching the blade to a rotating shaft. Propellers can have a single blade , but in practice there is nearly always more than one so as to balance the forces involved. The origin of the screw propeller starts at least as early as Archimedes (c. 287 – c. 212 BC), who used a screw to lift water for irrigation and bailing boats, so famously that it became known as Archimedes' screw . It
14541-599: The sleeve inserted between the shaft and propeller hub transmits the engine torque to the propeller, rather than friction. The polymer is weaker than the components of the propeller and engine so it fails before they do when the propeller is overloaded. This fails completely under excessive load, but can easily be replaced. Whereas the propeller on a large ship will be immersed in deep water and free of obstacles and flotsam , yachts , barges and river boats often suffer propeller fouling by debris such as weed, ropes, cables, nets and plastics. British narrowboats invariably have
14672-405: The success of the custom streamliners, sought to expand the market for diesel power by producing standardized locomotives under their Electro-Motive Corporation . In 1936, EMC's new factory started production of switch engines. In 1937, the factory started producing their new E series streamlined passenger locomotives, which would be upgraded with more reliable purpose-built engines in 1938. Seeing
14803-432: The throttle from notch 2 to notch 4 without stopping at notch 3. This feature was intended to prevent rough train handling due to abrupt power increases caused by rapid throttle motion ("throttle stripping", an operating rules violation on many railroads). Modern locomotives no longer have this restriction, as their control systems are able to smoothly modulate power and avoid sudden changes in train loading regardless of how
14934-479: The throttle setting, as determined by the engine driver and the speed at which the prime mover is running (see Control theory ). Locomotive power output, and therefore speed, is typically controlled by the engine driver using a stepped or "notched" throttle that produces binary -like electrical signals corresponding to throttle position. This basic design lends itself well to multiple unit (MU) operation by producing discrete conditions that assure that all units in
15065-452: The transverse projection of a blade and the developed outline of the blade. The blades are the foil section plates that develop thrust when the propeller is rotated The hub is the central part of the propeller, which connects the blades together and fixes the propeller to the shaft. This is called the boss in the UK. Rake is the angle of the blade to a radius perpendicular to the shaft. Skew
15196-451: The use of an internal combustion engine in a railway locomotive is the prototype designed by William Dent Priestman , which was examined by William Thomson, 1st Baron Kelvin in 1888 who described it as a " Priestman oil engine mounted upon a truck which is worked on a temporary line of rails to show the adaptation of a petroleum engine for locomotive purposes." In 1894, a 20 hp (15 kW) two-axle machine built by Priestman Brothers
15327-471: The vessel forward but being turned the other way rowed it backward. It was made to be turned by the hand or foot." The brass propeller, like all the brass and moving parts on Turtle , was crafted by Issac Doolittle of New Haven. In 1785, Joseph Bramah of England proposed a propeller solution of a rod going through the underwater aft of a boat attached to a bladed propeller, though he never built it. In February 1800, Edward Shorter of London proposed using
15458-466: The view that screw propulsion would be ineffective in ocean-going service, while Symonds himself believed that screw propelled ships could not be steered efficiently. Following this rejection, Ericsson built a second, larger screw-propelled boat, Robert F. Stockton , and had her sailed in 1839 to the United States, where he was soon to gain fame as the designer of the U.S. Navy 's first screw-propelled warship, USS Princeton . Apparently aware of
15589-657: The world's first functional diesel–electric railcars were produced for the Königlich-Sächsische Staatseisenbahnen ( Royal Saxon State Railways ) by Waggonfabrik Rastatt with electric equipment from Brown, Boveri & Cie and diesel engines from Swiss Sulzer AG . They were classified as DET 1 and DET 2 ( de.wiki ). 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
15720-605: The world's largest ship and the first screw-propelled steamship to cross the Atlantic Ocean in August 1845. HMS Terror and HMS Erebus were both heavily modified to become the first Royal Navy ships to have steam-powered engines and screw propellers. Both participated in Franklin's lost expedition , last seen in July 1845 near Baffin Bay . Screw propeller design stabilized in
15851-467: Was 95 tonnes and the power was 883 kW (1,184 hp) with a maximum speed of 100 km/h (62 mph). Small numbers of prototype diesel locomotives were produced in a number of countries through the mid-1920s. One of the first domestically developed Diesel vehicles of China was the Dongfeng DMU (东风), produced in 1958 by CSR Sifang . Series production of China's first Diesel locomotive class,
15982-527: Was brought to high-speed mainline passenger service in late 1934, largely through the research and development efforts of General Motors dating back to the late 1920s and advances in lightweight car body design by the Budd Company . The economic recovery from World War II hastened the widespread adoption of diesel locomotives in many countries. They offered greater flexibility and performance than steam locomotives , as well as substantially lower operating and maintenance costs. The earliest recorded example of
16113-441: Was complete by the 1920s, although increased power and smaller diameters added design constraints. Alberto Santos Dumont , another early pioneer, applied the knowledge he gained from experiences with airships to make a propeller with a steel shaft and aluminium blades for his 14 bis biplane . Some of his designs used a bent aluminium sheet for blades, thus creating an airfoil shape. They were heavily undercambered , and this plus
16244-630: Was delivered from the United States to the railways of the Soviet Union. In 1947, the London, Midland and Scottish Railway (LMS) introduced the first of a pair of 1,600 hp (1,200 kW) Co-Co diesel–electric locomotives (later British Rail Class D16/1 ) for regular use in the United Kingdom, although British manufacturers such as Armstrong Whitworth had been exporting diesel locomotives since 1930. Fleet deliveries to British Railways, of other designs such as Class 20 and Class 31, began in 1957. Series production of diesel locomotives in Italy began in
16375-476: Was fitted with his wooden propeller and demonstrated on the Paddington Canal from November 1836 to September 1837. By a fortuitous accident, the wooden propeller of two turns was damaged during a voyage in February 1837, and to Smith's surprise the broken propeller, which now consisted of only a single turn, doubled the boat's previous speed, from about four miles an hour to eight. Smith would subsequently file
16506-435: Was observed making headway in stormy seas by officers of the Royal Navy. This revived Admiralty's interest and Smith was encouraged to build a full size ship to more conclusively demonstrate the technology. SS Archimedes was built in 1838 by Henry Wimshurst of London, as the world's first steamship to be driven by a screw propeller . The Archimedes had considerable influence on ship development, encouraging
16637-400: 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. The prime mover's power output is primarily determined by its rotational speed ( RPM ) and fuel rate, which are regulated by a governor or similar mechanism. The governor is designed to react to both
16768-550: Was probably an application of spiral movement in space (spirals were a special study of Archimedes) to a hollow segmented water-wheel used for irrigation by Egyptians for centuries. A flying toy, the bamboo-copter , was enjoyed in China beginning around 320 AD. Later, Leonardo da Vinci adopted the screw principle to drive his theoretical helicopter, sketches of which involved a large canvas screw overhead. In 1661, Toogood and Hays proposed using screws for waterjet propulsion, though not as
16899-490: Was shown suitable for full-size passenger and freight service. Following their 1925 prototype, the AGEIR consortium produced 25 more units of 300 hp (220 kW) "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
17030-744: Was the United States Navy , whose Bureau of Steam Engineering proposed its use in 1928. It was subsequently tried in the S-class submarines S-3 , S-6 , and S-7 before being put into production with the Porpoise class of the 1930s. From that point onwards, it continued to be used on most US conventional submarines. Apart from the British U-class and some submarines of the Imperial Japanese Navy that used separate diesel generators for low speed running, few navies other than those of Sweden and
17161-719: Was used on the Hull Docks . In 1896, an oil-engined railway locomotive was built for the Royal Arsenal in Woolwich , England, using an engine designed by Herbert Akroyd Stuart . It was not a diesel, because it used a hot-bulb engine (also known as a semi-diesel), but it was the precursor of the diesel. Rudolf Diesel considered using his engine for powering locomotives in his 1893 book Theorie und Konstruktion eines rationellen Wärmemotors zum Ersatz der Dampfmaschine und der heute bekannten Verbrennungsmotoren ( Theory and Construction of
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