page_title: Julius Kahn (inventor)
section_title: Mid life
hierarchical_section_title: Julius Kahn (inventor) / Mid life
caption_attribution_description: English: Albert Kahn Building 2009
context_page_description: Julius Kahn was an engineer, industrialist, and manufacturer. He was the inventor of the Kahn System, a reinforced concrete engineering technique for building construction. The Kahn System that he patented in 1903 was used worldwide for housing, factories, office and industrial buildings. His system was used in 134 US cities by 1939. His engineering system for building construction was also found then in Africa, Europe, Canada, China, Brazil, and Mexico. In Yokohama, Japan, his system was used in an automobile factory. His unique engineering system of construction was used also in airplane plants, warehouses, docks, foundries, creameries, filtration plants, rubber factories, steel plants, silos, distilleries, smelters, and textile mills.
context_section_description: Kahn received his higher education at the University of Michigan, which his older brother Albert helped finance. He received a Bachelor of Science and a degree of Civil Engineer in 1896. Upon graduating from U of M he did drafting work for the Union Bridge Company of New York. Another career position was with the United States Navy as an engineer. Another engineering position he had was with the United States Army Corps of Engineers. He also worked for C. W. Hunt Company of New York. In 1900 Kahn took a position in Japan in the engineering, construction and maintenance of iron and sulfur mines.
  Kahn moved back to Detroit in 1902 and joined Albert Kahn Associates, an architectural firm that his brother Albert had founded in 1895. Kahn's first assignment was in Ann Arbor. He worked on the new School of Engineering building at the University of Michigan in 1903 with key architect Ernest Wilby. He was to do tests and determine if certain materials were sufficiently strong to support the new building they were about to construct. In particular they wanted to use reinforced concrete for the building floor. Kahn had already worked with reinforced concrete with the U.S. Army Corps of Engineers. While he was working at the war college building in Washington, D.C., he thought of methods to improve the existing technology of old school reinforcement concrete. These new ideas were the basis of the steel company he founded later.
  Kahn saw the structural problems inherent in the experimental method of cement reinforcement used at the end of the nineteenth century. The main problem was slippage of the steel within the hardened concrete, which weakened the building. He experimented in his brother's house basement and developed a new type reinforced beam called "the Kahn Bar", where the straight steel beam was bent back some on the edges, making stress distribution "wings" to increase tension strength. He patented his invention in 1903. Kahn then formed his own company called Trussed Concrete Steel Company. He became its president, but spent much of his time in the designing room. The headquarters of the company was in Detroit, Michigan and the factory was in Youngstown, Ohio. Kahn decided on Youngstown as an ideal factory location because then they could use steel that was produced in the local area, cutting down on shipping costs.
caption: The Albert Kahn Building in Detroit, where Julius worked in fabrication designs
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