|This Week in American History
- January 9 15, 1914 -
Henry Ford Inaugurates the Automobile Assembly Line
On January 14, 1914, the Ford Model T automobile was produced on an assembly line for the first time. The designs and working models of shorter assembly lines for its component parts had been tested over the preceding year or so, and now each chassis of a future Model T travelled on a conveyor belt until it was completed and driven out of Ford's new Highland Park, Michigan factory. This method of mass production had its roots not only in the exhaustive tests conducted by Ford's engineers, but was also an extension of production processes that had begun right after the American Revolution.
Inventor Oliver Evans of Delaware, who served in the Pennsylvania Militia during the Revolution, built and patented a totally automated flour mill in 1785. George Washington, Thomas Jefferson, and other Founding Fathers paid Evans a fee for the plans, and built their own mills. Grain was delivered by wagons to the ground floor and was lifted to the top by waterpower. The grain then descended by gravity, meeting on its way a variety of rakes, bucket elevators, conveyors, and screw devices which dried, milled, spread, cooled, and sorted the grain until it exited as flour.
Whereas a regular flour mill, equipped with a miller and two assistants, generally produced 17 barrels of flour per 100 bushels of grain, Oliver Evans' mill, with one man to oversee its functioning, produced 21 barrels of superfine flour for every 100 bushels of wheat. This increase in productive capacity, and the concept of a smooth, automatic flow from raw material to finished product, was supplemented by the work of Eli Whitney, who spent most of his life trying to achieve the standardization and interchangeability of parts for firearms.
The work of Whitney and other inventors led to the spread of the "Armory System" of interchangeable parts from the Federal arsenals to private manufacturers. Many pre-Civil War firms, such as clock manufacturers, used the armory system, but the Singer Sewing Machine and the McCormick Reaper were not produced by that system until the 1880s. Mechanized conveyors were adopted for use in beer breweries in the late-18th Century, shortly after Oliver Evans demonstrated their usefulness in his flour mill.
The use of actual conveyor belts to move materials along from worker to worker was inaugurated by Edwin Norton, in 1885, in the manufacture of tin cans. The group of young mechanics whom Henry Ford had gathered together to help him manufacture the Model T studied all of these elements, plus the "disassembly" system of processing meat in the Cincinnati and Chicago stockyards.
Henry Ford did not invent the automobile or the assembly line, but he did determine to mass-produce the automobile in such a way that production per man-hour increased and the price decreased. When his early stockholders tried to dictate the car models he should make, he bought up all the stock in his company, for he was convinced that the only way to mass produce an automobile was to concentrate on materials, parts, and machine tools for only one model.
There were much more advanced car designs in Europe in the first decades of the 20 Century, but cars there were considered to be a luxury item for the titled and wealthy, so mass production was not considered. Ford, on the other hand, unleashed his mechanics to conduct production experiments with no preconceptions. Technological innovation by Ford, or in the firms that supplied its tools, was the order of the daywhen a new machine tool proved superior, all the old ones were replaced. And the profits from the sales were plowed back into the firm for further research and development. Beyond the initial $28,000 investment, the Model T financed itself for 18 years.
In 1908, before factory production had actually begun, Henry Ford set the goal of "a car a minute." By 1913, output was 1,000 cars a day, and in 1915, the one-millionth car came off the moving assembly line. This increase in production was accompanied by a continually declining price.
The assembly-line system, which began in a small way in 1913, and then was extended to different components of the car, was designed on the basis of bringing all work to the workers at waist level. The first assembly line was for the fly-wheel magneto, which had taken one man 20 minutes to assemble. The assembly line broke the work into 29 operations, with each worker adding something to it. This cut the time to 13 minutes, and then when the conveyor was raised to waist level, the time dropped to seven minutes. The next assembly line was developed for the motor itself, and then other processes were gradually added.
When it came time to design an assembly line for the car's chassis, to add all the other parts which had been completed on assembly lines, much of the resultant success was due to Clarence Avery, who had been young Edsel Ford's manual training teacher in high school. He took eight months to study every manufacturing operation at the Highland Park factory, and then he and other members of the team set up a windlass in a large open space and stretched out a rope 250 feet. The assembly line which they constructed had components placed at different intervals along the path, and the workers on the chassis were able to decrease the time from 12-and-a-half man-hours under the old system to five and five-sixths man-hours. The wheels, motors, and other components which the workers added to the chassis were brought to them on overhead trolleys which travelled from the sub-assembly lines.
In October, the line was shortened to 150 feet with more workers, and the man-hours dropped to slightly less than three hours per chassis. In December, continuing the experiment, the length of the assembly line was increased to 300 feet and the number of workers was again increased, leading to a time of two hours and 38 minutes. After Christmas, more men were added to the same line, but they pushed the assembly along by hand, which increased the time needed to finish. Then, on January 14, the chassis was carried by an endless chain, the beginning of the actual assembly line.
Over the next four months, more experiments were carried out on the line, and by the end of April 1914, the workmen had put together 1,212 chassis assemblies in eight hours. The Ford engineering staff, buoyed by these developments, began a search for other labor-saving opportunities in the various shops, regardless of former precedents and traditions that had grown up.
Henry Ford described how the operation worked: "In the chassis assembling are forty-five separate operations or stations. The first men fasten four mud-guard brackets to the chassis frame; the motor arrives on the tenth operation and so on in detail. Some men do only one or two small operations, others do more. The man who places a part does not fasten itthe part may not be fully in place until after several operations later. The man who puts in a bolt does not put on the nut; the man who puts on the nut does not tighten it. On operation number thirty-four the budding motor gets its gasoline; it has previously received lubrication; on operation number forty-four the radiator is filled with water, and on operation number forty-five the car drives out."
The turnover at Ford's factory during the time the assembly lines were being tested was very high, so he inaugurated the $5 a day wage level to keep his workers and also to enable them to buy the product they worked on. Many criticized the repetitiveness of work on the assembly line, but Ford replied: "I have heard it said that we have taken skill out of work. We have not. We have put in skill. We have put a higher skill into planning, management, and tool building, and the results of that skill are enjoyed by the man who is not skilled. Our skilled men are the tool-makers, the experimental workmen, the machinists and the pattern makers. They are as good as any men in the worldso good, indeed, that they should not be wasted in doing that which the machines they contrive can do better."
In May of 1927, the production of Ford's Model T was stopped. Other car manufacturers such as General Motors, Chrysler, and Packard were producing well-designed automobiles, and the public was buying them in large numbers. Ford's engineers took a year to retool the River Rouge plant for the new Model A, and from then on there were new models developed almost yearly. The change became known as "flexible mass production."
Henry Ford did not like the idea of new models every year, and some writers of the time asked the question: "How many automobiles can America buy?" The change from relying on highly specialized machine tools for just one model, to using at least some portion of machine tools that could be converted to other uses, had a positive result. It enabled Ford, at its famous Willow Run plant, and other manufacturers as well, to gear up production to provide war materiel under Lend Lease and to become the "Arsenal of Democracy" for the defense of the Americas against the Axis Powers.
After the end of the war, many industrial engineers and designers brought automation to a higher level, so that the 1990s John Deere tractor factory in Waterloo, Iowa was almost completely automated, watched over and repaired by a small and highly-skilled staff. Oliver Evans would not have been surprised.