Petrol–electric transmission (UK English) or gasoline–electric transmission or gas–electric transmission (US English) is a

transmission system :''See Transmission (mechanics) for a car's transmission system'' In telecommunications, a transmission system is a system that transmits a signal from one place to another. The signal can be an electrical, optical or radio signal. Some transmissi ...

for

vehicles A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), wate ...

petrol engines A petrol engine (gasoline engine in American English) is an internal combustion engine designed to run on petrol (gasoline). Petrol engines can often be adapted to also run on fuels such as liquefied petroleum gas and ethanol blends (such as ...

. Petrol–electric transmission was used for a variety of applications in

road A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of ...

rail Rail or rails may refer to: Rail transport *Rail transport and related matters *Rail (rail transport) or railway lines, the running surface of a railway Arts and media Film * ''Rails'' (film), a 1929 Italian film by Mario Camerini * ''Rail'' ( ...

, and marine transport, in the early 20th century. After

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 ...

, it was largely superseded by diesel-electric transmission, a similar transmission system used for

diesel engines 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-calle ...

; but petrol-electric has become popular again in modern

hybrid electric vehicles 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 intended ...

. Petrol–electric transmission was used in certain niche markets in the early 20th century, such as in the petrol–electric railway locomotives produced in Britain for use on the

War Department Light Railways The War Department Light Railways were a system of narrow gauge trench railways run by the British War Department in World War I. Light railways made an important contribution to the Allied war effort in the First World War, and were used for the ...

during

or for privately owned Arad & Csanad United Railways. In France, the Crochat petrol–electric transmission system was used for standard gauge locomotives (up to 240 kW of electrical power).

Description

Petrol-electric vehicles follow a series hybrid architecture. A

spark ignition A spark-ignition engine (SI engine) is an internal combustion engine, generally a petrol engine, where the combustion process of the air-fuel mixture is ignited by a spark from a spark plug. This is in contrast to compression-ignition engines, ty ...

internal combustion (IC) engine acts as the prime mover, powering 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 ...

which converts the rotational energy into electrical energy. The generator charges a battery pack and drives a

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 ...

that provides

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 ...

for the vehicle to move. Hybridpeak

The engine is usually smaller that what would be required for powering a conventional petrol vehicle of the same size. The engine usually runs at its optimum high efficiency

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 ...

, powering the generator. When extra power is needed for acceleration or for climbing gradients, both the engine and the battery pack powers the motor. When the engine produces more power than is required at the road wheels, the surplus is used to charge the battery. Petrol-electric vehicles typically doesn't require any stepping up or transmission as electric traction motors can operate at a wide rpm range at peak efficiency. The Engine generator pair is a compact unit that isn't connected mechanically to the road wheels. The connection is purely electrical.

Advantages

* Electric traction motors are more efficient than IC engines in stop-and-go driving, typically the case in urban and suburban routes. * The IC engine can be made smaller than what is usually required to move a similar sized pure gas-powered vehicle. IC engines are their own

air pump An air pump is a pump for pushing air. Examples include a bicycle pump, pumps that are used to aerate an aquarium or a pond via an airstone; a gas compressor used to power a pneumatic tool, air horn or pipe organ; a bellows used to encourage ...

s and have poor efficiency at low speeds. So IC engines have to be made larger than what is required for conventional gas-powered vehicles. This is not the case for petrol-hybrid vehicles where an electric motor provides traction. Electric motors can deliver peak torque at a wide range of RPMs. Small engines result in a compact design and more space. * IC engines can operate at their peak RPM range throughout and improve mileage. IC engines operate at peak efficiency at higher RPMs, In petrol-electric vehicles, the engine can keep running at these speeds as the motor is the one delivering traction. This results in lesser fuel usage and harmful emissions. This isn't the case with conventional vehicles where the engine has to slow down when the vehicle brakes. * Petrol-electric vehicles have an idle-stop function where the engine can be shut off during idling or during long deceleration. *

Regenerative braking Regenerative braking is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In this mechanism, the electric traction mo ...

is possible with Petrol-electric vehicles. When the brakes are applied, the traction motor can be switched to act as a generator and charge the battery pack. A magnetic resistance force acts on the wheels to slow them, while the battery is charged. Conventional brakes use frictional braking force only, which dissipate and waste rotational energy as heat. Regenerative braking saves energy, they are used in combination with friction brakes for anti lock braking (ABS). * Petrol-electric vehicles can deliver additional power when it is demanded by the driver, like during hard acceleration or climbing a gradient. They also have

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 ...

and can deliver step-less power.

Disadvantages

* Electric motors are less efficient than conventional IC engines for long distance driving at consistent high speeds, as is seen in highways and expressways. * Petrol-electric vehicles have many energy-conversion steps, which can result in reduced efficiency due to energy loss at each stage of the transition. * Petrol-electric vehicles, and typically most series hybrid vehicles need two electric machines, a

coupled to the engine and a motor/generator coupled to the wheels. * They need larger electric traction motors.

Historical applications

Road

Examples of

using petrol–electric transmission include the

Tilling-Stevens Tilling-Stevens was a British manufacturer of buses and other commercial vehicles, based in Maidstone, Kent. Originally established in 1897, it became a specialist in petrol-electric vehicles. It continued as an independent manufacturer until ...

bus (UK) and the

Owen Magnetic 1920 Owen Magnetic Touring Car ad, from '' House Beautiful'' magazine The Owen Magnetic was a pioneering American brand of hybrid electric luxury automobile manufactured between 1915 and 1922. Car models of the brand were notable for their use of ...

touring car (USA). File:1914 Tilling-Stevens double-decker bus.jpg, Tilling-Stevens petrol–electric bus File:1920 Owen Magnetic Touring Car ad.jpg, Owen Magnetic touring car 1920 advertisement File:St. Chamond.jpg, St. Chamond tank

Rail

Examples of petrol–electric rail vehicles include the North Eastern Railway 1903 Petrol Electric Autocar,

Doodlebug (rail car) Doodlebug or hoodlebug is a nickname in the United States for a type of self-propelled railcar most commonly configured to carry both passengers and freight, often dedicated baggage, mail or express, as in a combine. The name is said to have ...

GE 57-ton gas-electric boxcab Before diesel engines had been developed for locomotive power in the 1920s and 1930s, many companies chose to use the gasoline engine for rail motive power. The first GE Locomotive was a series of four-axle ( B-B) boxcab gasoline-electric mach ...

Weitzer railmotor The railmotors of J. Weitzer ''Engine- & Waggon-Building & Iron Casting Joint-stock Company'' ( Hu.: ''Weitzer János Gép,- Waggongyár és Vasöntöde Részvénytársaság'') were Europe's first self-propelled railcars with internal combustion ...

and the petrol–electric locomotives built for the

by Dick, Kerr & Co. and

British Westinghouse British Westinghouse Electrical and Manufacturing Company was a subsidiary of the Pittsburgh, USA based Westinghouse Electric and Manufacturing Company. British Westinghouse would become a subsidiary of Metropolitan-Vickers in 1919; and after Metr ...

. In France, the ''

Crochat-Colardeau Crochat was a French railway equipment construction company founded in 1899 by Henry Crochat. It is best known for building locomotives and railcars with petrol-electric transmission. History Reference * 1899 - Company founded by Henry Crochat * ...

'' system of Henry Crochat and Emmanuel Colardeau was used in some petrol–electric railcars. File:Autocar at Filey Station.jpg, North Eastern Railway Autocar at Filey Station File:Doodlebug ebt m1.jpg, Gas–electric "Doodlebug" railcar File:Dick Kerr & Co Petrol Electric Locomotive.jpg, Dick, Kerr & Co. petrol electric locomotive under construction File:AMTP 020 Crochat.jpg, Crochat petrol electric railcar preserved at

Pithiviers Pithiviers () is a communes of France, commune in the Loiret Departments of France, department, north central France. It is one of the Subprefectures in France, subprefectures of Loiret. It is twinned with Ashby-de-la-Zouch in Leicestershire, Eng ...

File:Weitzer ACSEV hybrid railmotor.jpg, Weitzer railmotor produced for

ACsEV The ACsEV (Aradi és Csanádi Egyesült Vasutak, En.: Arad & Csanad United Railways) were a Hungarian joint-stock railway company. Till 1920, the network had a length of 391 km. Since 1903, the company bought more than forty petrol-electri ...

Marine

Most

submarines A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely o ...

that served in

were diesel–electric. However, some petrol–electric submarines had been built before the war. Examples include:

Plunger-class submarine The ''Plunger'' class was an early class of United States Navy submarines. In the first years of their service, they were used primarily as training and experimental vessels for the newly formed "silent service" to familiarize naval personnel w ...

(USA),

A-class submarine (1903) The A class was the Royal Navy's first class of British-designed submarines. Thirteen were built by Vickers at Barrow-in-Furness between 1902 and 1905 as an improvement on the US . Design and construction While there was considerable var ...

(UK),

SM U-1 (Austria-Hungary) SM ''U-1'' or ''U-I'' was the lead ship, lead boat of the U-1 class submarine (Austria-Hungary), ''U-1''-class of submarines or U-boats built for and operated by the Austro-Hungarian Navy (german: kaiserliche und königliche Kriegsmarine or ). ' ...

, Russian submarine Krab (1912). File:USS Plunger - NH 42620 - cropped.jpg, USS Plunger S2-1 File:Russian submarine Krab.jpg, Russian submarine Krab

Military vehicles

Petrol–electric systems were tested on the British Mark II tank, American Holt gas electric tank and French Saint Chamont in 1917. The latter used the

system of Henry Crochat and Emmanuel Colardeau. This allowed the left and right traction motors to run at different speeds for steering and is detailed in patent US1416611. The 1936 prototype

Char G1 The Char G1 was a French replacement project for the Char D2 medium tank. Several prototypes from different companies were developed from 1936 onwards, but not a single one had been fully completed at the time of the Fall of France in 1940. The ...

P was also designed with a petrol–electric drive.

Ferdinand Porsche Ferdinand Porsche (3 September 1875 – 30 January 1951) was an Austrian-German automotive engineer and founder of the Porsche AG. He is best known for creating the first gasoline–electric hybrid vehicle (Lohner–Porsche), the Volkswag ...

was the main developer of these drive trains for military vehicles in

Nazi Germany Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...

. He created the VK 3001 (P) prototype and VK 4501, of which 91 units were produced as the Porsche Tiger. They were later converted into Ferdinand, and subsequently

Elefant The ''Elefant'' (German for "elephant") was a heavy tank destroyer used by German Wehrmacht Panzerjäger during World War II. Ninety-one units were built in 1943 under the name Ferdinand, after its designer Ferdinand Porsche, using VK 45.01 ...

, tank destroyers. Another noteworthy design was the 188-tonne Porsche type 205 prototypes, commonly known as the

Maus ''Maus'' is a graphic novel by American cartoonist Art Spiegelman, serialized from 1980 to 1991. It depicts Spiegelman interviewing his father about his experiences as a Polish Jew and Holocaust survivor. The work employs postmodern technique ...

super-heavy tank.

Modern applications

In the 21st century, petrol–electric transmission has gained a new lease of life in

. Examples include:

Ford Fusion Hybrid The Ford Fusion Hybrid is a hybrid electric vehicle, gasoline-electric hybrid powered version of the mid-size car, mid-sized Ford Fusion (Americas), Ford Fusion sedan (automobile), sedan manufactured and marketed by Ford Motor Company, Ford, now i ...

;

Honda Civic Hybrid The is a series of automobiles manufactured by Honda since 1972. Since 2000, the Civic has been categorized as a compact car, while previously it occupied the subcompact class. , the Civic is positioned between the Honda Fit/City and Honda Acc ...

;

Toyota Prius The is a car built by Toyota which has a Hybrid vehicle drivetrain, hybrid drivetrain, combining an internal combustion engine with an electric motor. Initially offered as a four-door Sedan (automobile), sedan, it has been produced only as ...

References

{{DEFAULTSORT:Petrol-electric transmission Gasoline engines Automotive transmission technologies