Motor car
By Rochelle Forrester
Ó All Rights Reserved
Publication Date 2006
Motor driven carriages had been experimented with ever since the invention of the steam engine. The steam engine however was to heavy for the amount of power it produced to allow it to drive any sort of road vehicle. It was not until the invention of the petrol fuelled internal combustion engine that there was an engine light enough and powerful enough to drive a vehicle on the roads.
The four stroke internal combustion engine was invented by Nikolas Otto, but his engine ran on gas. An internal combustion engine using petrol had been built by Jean Lenoir, in 1862, but it was to heavy and lacking in power for it to drive a road vehicle. The creation of a more powerful internal combustion engine fuelled by petrol was achieved by Gottlieb Daimler and Wilhelm Maybach, in 1883, which, because it turned faster than the gas engine, was more powerful for its weight. The first road vehicle powered by a petrol fuelled internal combustion engine was built by Karl Benz in 1885. The car could reach a speed of 8 mph with its engine which provided less than one horsepower. The car had a very unreliable electric ignition with a battery coil and spark plugs. The car also had a gearing system involving belts between pulleys of varying size so as to provide for different forward speeds. Belts were also used to transmit power from the engine to the wheels. The vehicle only had three wheels, two at the back and one at the front. The use of a single front wheel was designed to avoid problems with normal horse carriage steering, where turning was easy enough for horses but was very difficult for people.
The steering problem was solved in 1888 when Britain’s first petrol fuelled car was built by Edward Butler. Butler used the Ackermann system which involved the front wheels being connected by a rod so that they turned about a common center. This avoided skidding when the vehicle turned, making turning safer and easier. After the introduction of the Ackermann system nearly all cars had four wheels and nearly all of them used the Ackermann system.
Daimler did not produce a car for sale until 1895 as he concentrated on the production of petrol fuelled internal combustion engines. A two cylinder engine built in 1889 providing three and a half horsepower and which ran at 800 rpm became the standard engine for early cars. Daimler did produce experimental cars that introduced the modern transmission system using a friction clutch and sliding pinion gears so as to allow a range of forward speeds. This system could transmit more power than the belts used in Benz’s 1885 car. In the 1890’s Benz began to produce improved four wheel cars using the Ackermann system.
The standard design for motor vehicles became gradually established in the last decade of the 19th century. The engine began to be placed in the front of the vehicle as it was found this provided greater stability than placing the engine in the center or rear of the car. Four wheels on cars with the Ackermann steering system became standard. The transmission system became standardized with the introduction of the propeller shaft which ran under the car and drove the rear axle. The most common gearing system used the manually operated sliding pinion gearbox, although some cars used an epicyclic which was the predecessor of automatic transmission. The suspension consisted of four leaf springs that connected the axles to the body of the car. Pneumatic tyres were first introduced in 1895, although solid rubber tyres remained in use for commercial vehicles until around 1930. The breaking system used was improved when band brakes which applied pressure to the wheel hub were replaced by drum brakes which applied pressure to the inside of a drum revolving with the wheels.
The worlds first mass produced car, the Model T Ford, was introduced in 1908. Between 1908 and 1927 when production ended, 15 million Model T’s were built. When a conveyor belt was introduced into the manufacturing process, in 1913, the assembly time for the chassis fell from 12 hours to one and a half hours per car. The price of the Model T fell from $850 when manufacturing began to $260 per car.
Improvements to motor cars after World War I were limited and related mainly to improved engines and to better comfort and safety. Hand cranking was replaced with an electric starting system and the enclosed sedan began to replace open top cars. All steel bodies became common after the 1920’s. Hydraulic brakes on all four wheels became common and safety tyres with no inner tubes and instant self sealing became common in the 1970’s. Seat belts and air bags were also introduced to improve safety.
The effect of the motor car on society was immense. It gave the general public the freedom to travel when and where they liked unrestricted by time tables and with a privacy not available on public transport. It involved the creation of a major new industry with millions of jobs. Motor cars also became a leading cause of death by accident in wealthy countries and a major cause of pollution contributing to the green house effect.
The motor car could not be introduced without the prior invention of the internal combustion engine. Only that engine could provide enough power and was light enough to drive a road vehicle. Without the internal combustion engine there would have been no widespread motor car use in the 20th century. Once a reasonably efficient internal combustion engine had been invented the rest of what was required to produce a workable motor car was quickly put together. Transmission, gearing, braking, steering and suspension systems were already well understood and all that was required was to adapt them to the motor car. This is why the standard design for the motor car became established quite quickly, within about 20 years, after Benz’s first car was built in 1885.
The motor car could not be invented without the internal combustion engine, which was only possible due to the properties of gases and vacuums and the existence of suitable fuels such as petrol and oil. This shows how the properties of matter and materials in nature have had a major effect on human social and cultural history. If the properties of matter were different, for example gases did not expand when heated or it was not possible to create a vacuum, then there would have been no internal combustion engine and no motor vehicles.