American system of watch manufacturing
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In the mid-19th century Aaron Lufkin Dennison became inspired by the manufacturing techniques of the United States Armory at Springfield, Mass. The "armory practice" was mainly based on a strict system of organization, the extensive use of the machine shop and a control system based on gauges. Aaron Dennison proposed to produce watches via these techniques and, along with a few others, founded the Waltham Watch Company.
The American system of manufacturing by interchangeable parts meant the establishment of working facilities for the entire manufacture. It meant that everything was made on the premises, not according to the plans or ideas or methods of work of individual workmen, but under the direct supervision of a company's foreman, according to gauges the company furnished, under conditions of time, cleanliness and care which the company prescribed.
Waltham soon found that it was necessary to invent, develop and build its own production machinery, special gauges systems adjusted to the smallest watch parts dimensions, new alloys & materials.
The chronology of production lessons at the Waltham Watch Company can be divided into three phases:
- 1849-1857 learning and experimenting
- 1858-1870 refining and gauging
- 1871-1910 automating and factory organization
The manufacturing of watches differed from other products that had earlier used the armory practices in two significant ways.
First, the high price of watches allowed for a large investment in research and development. The vast majority of the price of a watch was due to labor rather than materials and any system that could significantly reduce labor costs could significantly increase profits. Even after 40 years of manufacturing improvements, in 1910, labor accounted for 80% of the cost of watches made by the Elgin National Watch Company.
Secondly, watches require very strict tolerances and very few manufacturing defects. Previous products made via armory practices, such as fire arms, sewing machines, etc. had tolerances 10 to 100 times as loose. A watch gear that is offset by a few thousands of an inch from where it should be will cause increased friction, losing critical power that needed to be sent to the balance wheel and greatly accelerating the wear of the watch. Previous watch manufacturing techniques required expert watchmakers to recognize slight variations in part sizes in order to place each gear in the correct location or to make other adjustments during the manufacturing of each watch.
The Beginning of Standardized Production
Henry and James F. Pitkin were employed in the manufacture of jewelry in Hartford, Connecticut in the mid-1830s. Their business failed as a result of the panic of 1837, and the Pitkin brothers then turned their attention to the manufacture of watches. The brothers were able to construct rather crude machinery for the production of watches, in particular for the production of pallets. The first movement was completed in 1838, and Crossman reports that between 800 and 900 watches were completed in total up through 1845. Surviving examples of Pitkin watches show that the parts are in fact interchangeable, contrary to what is reported by Crossman.
A few years later, a reputable clockmaker by the name of Edward Howard and the watch repairman Aaron L. Dennison formed plans to construct a watch with interchangeable parts based on Dennison's visit to the Springfield armory. The pair constructed a factory in Roxbury, with financial backing provided by Samuel Curtis and D.P. Davis (a partner of Howard in his clock business). This company initially operated under the name of the American Horologe Company, but was quickly changed to the Warren Manufacturing Company to hide the purpose from foreign suppliers. The initial focus was on the production of an 8 day watch, however this proved to be too expensive and not very accurate. Instead, the attention was turned to a 30 hour watch, of a design very similar to what ultimately became the standard for an American 18 size watch. The first of these carried the serial number of 18, and was marked "Warren." This was completed in 1852. Approximately 80 "Warren" watches were produced, followed by about 900 marked "Samuel Curtis" and a further 4000 marked "Dennison, Howard, and Davis." The factory was moved to Waltham in about 1857. The basic design of this watch was carried on for several years as the 1857 model Waltham.
In order to reach these strict tolerances, watch manufactures largely manufactured their own machine tools and machine parts. Elgin manufactured almost two drill bits for each watch it manufactured. The knowledge of how to manufacture machines that could manufacture watches spread from Waltham to Elgin to dozens of other American watch companies and manufacturers of other products. Techniques such as jigs, stops and measuring devices on machines were not just refined, but other techniques were developed also. For example, statistical methods were used to reduce wastage. If a gear staff (axle) and a jewel bearing hole were designed to be a given size, then the parts that most closely met those design goals were used in the highest grade watches, while staffs that were too large would be matched to watch jewels with holes that were too large and together they could be used on lower grade watches.
- Hoke, Donald Robert; The Time Museum Historical Catalogue of American Pocket Watches; Time Museum Rockford, Illinois, U.S.A.
- Crossman, Charles S; A Complete History of Watch and Clockmaking in America; Compiled by Donald Dawes, from The Jewelers Circular and Horological Review
- Boston The Cradle of American Watchmaking
- The Boston Watch Co
- Origins of Waltham Model 57
- Time Museum Rockford, Illinois, U.S.A.
- Philadelphia Exhibition 1876 Report to the Federal High Council by Ed. Favre-Perret (1877)
- American and Swiss Watchmaking in 1876 by Jacques David
- The Watch Factories of America Past and Present by Henry G. Abbott (1888)
- Watchmaking and the American System of Manufacturing (2009)