A diesel–electric transmission, or diesel–electric powertrain, is used by a number of vehicle and ship types for providing locomotion.
A diesel–electric transmission system includes a diesel engine connected to an electrical generator, creating electricity that powers electric traction motors. No clutch is required. Before diesel engines came into widespread use, a similar system, using a petrol (gasoline) engine and called petrol–electric or gas–electric, was sometimes used.
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 at 0 RPM. Diesel–electric systems are also used in submarines and surface ships and some land vehicles.
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 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 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 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 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.
Early submarines used a direct mechanical connection between the 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 the electric motor and supplying all other power as well.
True diesel–electric transmissions for submarines were first proposed by the United States Navy's Bureau of Engineering in 1928—instead of driving the propeller directly while running on the surface, the submarine's diesel would instead drive a generator that could either charge the submarine's batteries or drive the electric motor. This meant that motor speed was independent of the diesel engine's speed, and the diesel could run at an optimum and non-critical speed, while one or more of the diesel engines could be shut down for maintenance while the submarine continued to run using battery power. The concept was pioneered in 1929 in the S-class submarines S-3, S-6, and S-7 to test the concept. The first production submarines with this system were the Porpoise-class, and it was used on most subsequent US diesel submarines through the 1960s. The only other navy to adopt the system before 1945 was the British Royal Navy in the U-class submarines, although some submarines of the Imperial Japanese Navy used separate diesel generators for low-speed running.
In a diesel–electric transmission arrangement, as used on 1930s and later US Navy, German, Russian and other nations' diesel submarines, the propellers are driven directly or through reduction gears by an electric motor, while two or more diesel generators provide electric energy for charging the batteries and driving the electric motors. This 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.
During World War I, there was 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 the conflict. Even before the war, the GE 57-ton gas-electric boxcab had been produced in the USA.
In the 1920s, diesel–electric technology first saw limited use in switchers (or shunters), 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 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, 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. Hydraulic transmissions are claimed to be somewhat more efficient than diesel–electric technology.
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 the Allison EP hybrid systems, while Orion Bus Industries is a major customer for the BAE HybriDrive system. Mercedes-Benz makes their own diesel–electric drive system, which is used in their Citaro.
In the automobile industry, diesel engines in combination with electric transmissions and battery power are being developed for future vehicle drive systems. Partnership for a New Generation of Vehicles was a cooperative research program between the U.S. government and "The Big Three" automobile manufacturers (DaimlerChrysler, Ford Motor Company, and General Motors Corporation) that developed diesel hybrid cars.
Diesel–electric propulsion has been tried on some military vehicles, such as tanks. The prototype TOG1 and TOG2 super heavy tanks of 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.
Sailing Yacht A is a sailing yacht launched in 2015. The vessel is a sail-assisted motor yacht designed by Philippe Starck (interiors, exteriors) and built by Nobiskrug in Kiel, Germany for the Russian billionaire industrialist and philanthropist Andrey Melnichenko.Its propulsion consists of a variable-speed hybrid powerplant with two lineshaft controllable-pitch propellers that is sail-assisted by a three-mast fore-and-aft sailing rig. The freestanding carbonfiber rotating masts were manufactured by Magma Structures at Trafalgar Wharf, Portsmouth. Doyle Sailmakers USA manufactured the three fully automated carbonfiber/taffeta full roach sails. The furling booms were built in Valencia by Future Fibres. The rigging of this yacht was developed partially to be implemented on cargo ships and to be used for commercial use. The vessel features an underwater observation pod in the keel with 30 cm (12 in)-thick glass. It is the largest private sail-assisted motor yacht in the world.Sailing Yacht A was delivered by Nobiskrug on February 3, 2017, and left Kiel on February, 5, 2017. It exited the Baltic Sea in light mode on near-empty fuel tanks in order to clear the Drogden Strait with minimum draught. It underwent final sea trials and the final fit-out at the Navantia shipyard in Cartagena, Spain. According to media reports, Sailing Yacht A was handed over to the owner on May 4, 2017 in Monaco by the project team led by Dirk Kloosterman having completed her final sea trials in the Navantia shipyard at Cartagena, and final tests and inspections at Gibraltar. Boat International called it "the boundary pushing superyacht".
Building site: Kiel
Naval architecture: Nobiskrug & Dykstra Naval Architects
Exterior design: Philippe Starck
Interior decoration: Philippe Starck
Diesel powerplant: two MTU 20V 4000 M73L 2,050 rpm 3,600 kW lineshaft engines
Electric powerplant: four 14,050–24,050rpm 2,800 kW hotel generators driving two Vacon 4,300 kW lineshaft motors
Transmission: superimposable/clutched diesel-electric transmission controlled by DEIF systems
Propulsion: Andritz Hydro / Escher Wyss & Cie. 5-bladed controllable-pitch lineshaft twin screw
Emission Treatment: Emigeen, 4x DPF (soot filtration) on DGs.BelAZ 75600
The BelAZ 75600 is a series of off-highway, ultra class haul trucks developed and manufactured in Belarus by OJSC "Belarusian Autoworks" specifically for transportation of loosened rocks on technological haul roads at open-pit mining sites worldwide under different climatic conditions.The trucks have a diesel-electric transmission. Engines are Cummins QSK78 (model 75600) or MTU 20V4000 (model 75601) generating 2610 or 2800 kW respectively.British Rail Class D3/7
The British Railways Class D3/7 were a class of 0-6-0 diesel electric shunting locomotives built as LMS Nos. 7080–7119. The class were built from May 1939 through to July 1942 by the London, Midland and Scottish Railway at their Derby Works using a diesel electric transmission supplied by English Electric.
They were a modified version of the 1934-vintage Class D3/6 (LMS 7069-7079) diesel shunters based on the English Electric 6K diesel engine of 350 horsepower (260 kW), but had jackshaft transmission necessitating a significant increase in body length. The D3/6 had two axle-hung traction motors instead, and this feature became commonplace in more modern designs built after World War II.British Railways D0226
D0226 and D0227 were two prototype diesel shunting locomotives built in 1956 by English Electric at its Vulcan Foundry in Newton-le-Willows to demonstrate its wares to British Railways. They originally carried numbers D226 and D227, their Vulcan Foundry works numbers, but these were amended in August 1959 to avoid clashing with the numbers of new Class 40 locomotives.
They were both of 0-6-0 wheel arrangement and were fitted with English Electric 6RKT engines of 500 hp. They were painted black with an orange stripe along the middle of the bodyside, which turned into a 'V' at the nose end. The major difference between the two locomotives was that D0226 had diesel-electric transmission and D0227 had diesel-hydraulic transmission.
BR tested both locomotives at its Stratford depot in East London. D0226 has been preserved at the Keighley and Worth Valley Railway, but D0227 was scrapped.CGR class S1
Ceylon Government Railway Class S1 is a class of diesel multiple unit train-set built by English Electric for Ceylon Government Railway.CIE 301 Class
The Córas Iompair Éireann 301 Class locomotives were the first diesel locomotives used on the CIÉ network, this class of 5 being built between 1947 and 1948 by the company for shunting use, particularly in the railway yards on Dublin's North Wall. They were a six coupled (0-6-0 wheel arrangement) locomotive, fitted with a Mirrlees TLDT6 engine of 487 horsepower (363 kW) with diesel-electric transmission via two Brush traction motors. Unusually, they lacked train vacuum brakes, although air brakes were provided for the locomotive itself.They were initially numbered 1000-1004 in the steam locomotive number series, but were subsequently renumbered D301-D305 in order. The locomotives were used on yard pilot and transfer freight duties, although number 1000 hauled a freight train from Dublin to Cork during trials. Two locomotives were stored from 1960 and the rest had followed by 1972, though officially they remained in stock until 1976. All five were scrapped in 1977.Combined diesel-electric and gas
Combined diesel-electric and gas (CODLAG) is a modification of the combined diesel and gas propulsion system for ships. A variant, called the combined diesel-electric or gas (CODLOG) system, contains the same basic elements but will not allow simultaneous use of the alternative drive sources.A CODLAG system employs electric motors which are connected to the propeller shafts (usually 2). The motors are powered by diesel generators. For higher speeds, a gas turbine powers the shafts via a cross-connecting gearbox; for cruise speed, the drive train of the turbine is disengaged with clutches.
This arrangement combines the diesel engines used for propulsion and for electric power generation, greatly reducing service cost, since it reduces the number of different diesel engines and electric motors, requiring considerably less maintenance. Also, electric motors work efficiently over a wide range of revolutions and can be connected directly to the propeller shaft so that simpler gearboxes can be used to combine the mechanical output of turbine and diesel-electric systems.
Another advantage of the diesel-electric transmission is that without the need of a mechanical connection, the diesel generators can be decoupled acoustically from the hull of the ship, making it less noisy. This has been used extensively by military submarines but surface naval vessels like anti-submarine vessels will benefit as well.Diesel locomotive
A diesel locomotive is a type of railway locomotive in which the prime mover is a diesel engine. Several types of diesel locomotive have been developed, differing mainly in the means by which mechanical power is conveyed to the driving wheels.
Early internal combusition locomotives and railcars used kerosene and gasoline as their fuel. Dr. Rudolf Diesel patented his first compression ignition engine in 1898, and steady improvements in the design of diesel engines reduced their physical size and improved their power-to-weight ratio to a point where one could be mounted in a locomotive. Internal combustion engines only operate efficiently within a limited torque range, and while low power gasoline engines can be coupled to a mechanical transmission, 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 2.5 m (8 ft 2 in)-wide locomotive frame, or 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 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 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 USA, diesel-electric propulsion was brought to high-speed mainline passenger service in late 1934, largely through the research and development efforts of General Motors from 1930–34 and advances in lightweight carbody design by the Budd Company.
The economic recovery from the Second World War saw 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. Diesel–hydraulic transmissions were introduced in the 1950s, but from the 1970s onwards diesel–electric transmission has dominated.List of locomotives in China
A list of current and retired locomotives in the People's Republic of China.Mercedes-Benz Cito
The Mercedes-Benz Cito (coded as O520) was a low-floor midibus built by EvoBus for Continental Europe between 1999 and 2003. Unusual for buses at that time, it had a diesel-electric transmission and was planned to have a hybrid engine or a fuel cell at a later stage. The Diesel engine was positioned above the rear axle.
The bus was available in three lengths: 8.1 metre, 8.9 metre, and 9.6 metre long and it has a width of 2.35 m. It has a capacity ranged from 31 passengers, 34 passengers and 38 passengers.Motor ship
A motor ship or motor vessel is a ship propelled by an internal combustion engine, usually a diesel engine. The names of motor ships are often prefixed with MS, M/S, MV or M/V.Engines for motorships were developed during the 1890s, and by the early 20th century, motorships began to cross the waters.PKP class SM30
SM30 is a Polish series of diesel shunting locomotives used by PKP and industry, built by Fablok, Chrzanów (factory designation Ls300E). They were also used for a local traffic.Petrol–electric transmission
Petrol–electric transmission (UK English) or gasoline–electric or gas–electric transmission (US English) is a transmission system for road, rail and marine transport that avoids the need for a gearbox. The petrol engine drives a dynamo, which supplies electricity to traction motors, which propel the vehicle or boat. The traction motors may be driven directly or, in the case of a submarine, via a rechargeable battery.
Petrol–electric transmission was used in certain niche markets in the early 20th century. For example in the petrol–electric railway locomotives produced in Britain for use on the War Department Light Railways during World War I or for privately owned Arad & Csanad United Railways. In France, the Crochat petrol–electric transmission system was used for standard gauge locomotives (up to 240kW of electrical power).
After World War I, petrol–electric transmission was largely replaced by diesel–electric transmission but, in the 21st century, it is making a comeback in hybrid electric vehicles.Portuguese train type 9630
The Série 9630 are a class of diesel multiple unit trains built for the metre gauge lines of Portuguese Railways (CP) in the Porto area. The trains were built in Portugal by Sorefame and entered service in 1991.These trains were specifically built for and initially used on local train services from Trindade station in Porto. Built with diesel-electric transmission, they were designed for easy conversion to electric multiple units. Instead of electrifying the Porto-area metre gauge lines, it was decided to extensively modernise the system and rebuilt the network completely as part of the Porto Metro (which has been built to 1435mm standard gauge). The closure of these metre gauge lines in 2002 for modernisation left the Série 9630 (and the older Série 9600) units redundant.
Seven two-carriage units of Série 9630 were transferred to the Vouga line, where (as of March 2012) they remain in service. Since 2009 the Vouga line has been CP's only remaining metre gauge line. This line is, however, also threatened with closure; such a closure would render the Série 9630 units redundant for a second time.SNCF Class CC 65500
The SNCF Class CC 65500 diesel locomotives were built by CAFL and CEM between 1955 and 1959. They were used on heavy express freight in the Paris area, being commonly seen on the Grande Ceinture lines around Paris.SNCF Class C 61000
The SNCF Class C 61000 (+ TC 61100) diesel shunters were built by Compagnie Electro-Méchanique (CEM) between 1950-1953. 48 locomotives were built, numbered C 61001-61048. They were used for heavy shunting duties around Le Havre.Two traction motors were fitted to the two end axles, all the axles being coupled by coupling rods.Transmission (mechanics)
A transmission is a machine in a power transmission system, which provides controlled application of the power. Often the term transmission refers simply to the gearbox that uses gears and gear trains to provide speed and torque conversions from a rotating power source to another device.In British English, the term transmission refers to the whole drivetrain, including clutch, gearbox, prop shaft (for rear-wheel drive), differential, and final drive shafts. In American English, however, the term refers more specifically to the gearbox alone, and detailed usage differs.The most common use is in motor vehicles, where the transmission adapts the output of the internal combustion engine to the drive wheels. Such engines need to operate at a relatively high rotational speed, which is inappropriate for starting, stopping, and slower travel. The transmission reduces the higher engine speed to the slower wheel speed, increasing torque in the process. Transmissions are also used on pedal bicycles, fixed machines, and where different rotational speeds and torques are adapted.
Often, a transmission has multiple gear ratios (or simply "gears") with the ability to switch between them as speed varies. This switching may be done manually (by the operator) or automatically. Directional (forward and reverse) control may also be provided. Single-ratio transmissions also exist, which simply change the speed and torque (and sometimes direction) of motor output.
In motor vehicles, the transmission generally is connected to the engine crankshaft via a flywheel or clutch or fluid coupling, partly because internal combustion engines cannot run below a particular speed. The output of the transmission is transmitted via the driveshaft to one or more differentials, which drives the wheels. While a differential may also provide gear reduction, its primary purpose is to permit the wheels at either end of an axle to rotate at different speeds (essential to avoid wheel slippage on turns) as it changes the direction of rotation.
Conventional gear/belt transmissions are not the only mechanism for speed/torque adaptation. Alternative mechanisms include torque converters and power transformation (e.g. diesel-electric transmission and hydraulic drive system). Hybrid configurations also exist. Automatic transmissions use a valve body to shift gears using fluid pressures in response to speed and throttle input.Vandal (tanker)
Vandal was a river tanker designed by Karl Hagelin and Johny Johnson for Branobel. Russian Vandal and French Petite-Pierre, launched in 1903, were the world's first diesel-powered ships (sources disagree over which of the two, Vandal or Petite-Pierre, was the first). Vandal was the first equipped with fully functional diesel-electric transmission.
In the 1890s oil industry searched for an economical oil-burning engine, and the solution was found by German engineer Rudolph Diesel. Diesel marketed his technology to oil barons around the world; in February 1898 he granted exclusive licenses to build his engines in Sweden and Russia to Emanuel Nobel of the Nobel family. The Russian licence cost Nobel 800,000 marks in cash and stock of the newly founded Russian Diesel Company. The Saint Petersburg engine plant was a quick success; it started with diesel-powered industrial pumps for oil pipelines and soon grabbed the mass market for flour mill engines. It produced more diesel engines than any other concern in the world.In 1902 Karl Hagelin, "a veteran of the Volga and sometime visionary", suggesting mating diesel engines to river barges. He envisioned direct shipment of oil through a 1,800-mile route from the lower Volga to Saint Petersburg and Finland. The canals of the Volga–Baltic Waterway dictated use of relatively small barges, making use of steam engines uneconomical. Diesel engine seemed a natural choice. Hagelin believed that reversing the engine and regulating its speed could be done with an electrical transmission, and contracted Swedish ASEA to test the electrical drive system. Hagelin then recruited naval architect Johny Johnson of Gothenburg to design the ship. Johnson placed the diesel engine and electric generator in the middle, and the electric motors in the stern, driving the propellers directly. The holds were separated by longitudinal (rather than transverse) bulkheads running the length of the ship, a feature that became common on ocean-going tankers.
The ship's powerplant (3×120 horsepowers) was built by Sweden by Swedish Diesel (Aktiebolaget Diesels Motorer) and ASEA. Each engine had three cylinders with a bore of 290 mm and stroke of 430 mm. They ran at a constant 240 rpm, and the electrical transmission, controlled by a tram-like lever, varied propeller speed from 30 to 300 rpm. The hull was built at Sormovo shipyard in Nizhny Novgorod and towed to Saint Petersburg for the final assembly. Its size (244.5 × 31¾ × 8 feet) was taylored to the canals of the North rather than the Volga. Named Vandal, it commenced commercial operation in the spring of 1903. Vandal was accidentally damaged on its maiden voyage, repaired and served on the Volga route for ten years.
The larger Sarmat, with four 180 h.p. engines, was launched next summer. Unlike Vandal, Sarmat's engines could be coupled to the propellers directly, bypassing the electrical drive and saving up to 15% of engine power that would be otherwise lost in the electric transmission. Sarmat operated until 1923; the hulk was moored in Nizhny Novgorod until the 1970s.
The new ships attracted public and professional interest and brought in new orders. Plant payroll expanded to more than a thousand men, but growth brought in management problems. Rolf Nobel, Ludwig Nobel Jr. and Hagelin split with Emanuel over the future of diesel-powered shipping. Hagelin's proposal to convert existing steam-powered fleet to diesel engines was rejected by Emanuel. Hagelin quit, and accepted the post of Swedish consul general in Saint Petersburg. In 1907 Hagelin and Johnson designed a 4,500-ton tanker, and again Emanuel Nobel rejected the proposal. The inventors sold their blueprints to Merkulyev Brothers of Kolomna who built the world's first true seagoing diesel-powered tanker, Mysl, in 1908. This, at last, compelled Emanuel to grant Hagelin sweeping rights to modernize the company fleet that reached 315 vessels in 1915.