Julius Kahn (inventor)

Kahn was born in Münstereifel, Germany, March 8, 1874. He immigrated as a child with his family to the United States in 1880, entering at the port of Baltimore, Maryland, where they briefly lived.[3] They continued to Detroit, Michigan, where he was raised.[4] Kahn was six when he reached to Detroit. He had five brothers and two sisters.

Their father Joseph (1860–1924) was a rabbi and ran a restaurant.[5] Kahn helped in his father's restaurant business and sold newspapers.[3] Their mother Rosalie was skilled in music and art.[6] Kahn went to the Detroit Public Schools, where he received his elementary schooling. He completed the normal four-year high school curriculum in three years.[7]

Kahn received his higher education at the University of Michigan, which his older brother Albert, an architect, helped finance.[7][8] He received a Bachelor of Science and a degree of Civil Engineer in 1896.[3]

Upon graduating from U of M, Kahn worked as an engineering draftsman for the Union Bridge Company of New York.[3][9] He worked as an engineer for both the United States Navy and then for the United States Army Corps of Engineers.

Kahn 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. He worked there for two years.[3][7][10]

The Albert Kahn Building in Detroit, where Julius worked in fabrication designs

Kahn returned to Detroit in 1902, joining Albert Kahn Associates, an architectural firm that his brother Albert had founded in 1895.[3][7][11][12] Kahn's first assignment was in Ann Arbor for the University of Michigan.[12] He worked on the new School of Engineering building in 1903 with key architect Ernest Wilby.[13][14] He had to conduct tests to determine if certain materials were sufficiently strong to support the new building they were about to construct.[12]

In particular they wanted to use reinforced concrete for the building floor, to replace the traditional wood supports. Kahn had already worked with reinforced concrete with the U.S. Army Corps of Engineers.[15] 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.[7] These new ideas were the basis of the steel production company which he later founded.[3]

Kahn understood 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 the basement of his brother's house, where he developed a new type of reinforced beam called "the Kahn Bar". The straight steel beam was bent back some on the edges, making stress distribution "wings" that increased its tension strength.[7] Kahn patented his invention in 1903, the first of more than 75 patents he gained.[16]

Kahn formed his own company to manufacture such beams, called Trussed Concrete Steel Company (Truscon). He was its president, but spent much of his time in the designing room.[3][17] The headquarters of the company was in Detroit, Michigan and the factory was in Youngstown, Ohio.[15] Kahn decided on Youngstown as an ideal factory location because his company could use steel that was produced in the local area, cutting down on shipping costs.[3][7]

Kahn continued to experiment and develop reinforced concrete construction, having at least 75 patented inventions related to this topic by 1934.[18] Kahn's first patented invention was the "Kahn Trussed Bar", also called "The Kahn Bar" or "Kahn Bar System",[19] patented in 1903.[20] This was the main product of the Trussed Concrete Steel Company, although the company produced many prefabricated steel products, as well as complete buildings.[21]

Kahn's co-workers noted that he would stop what he was doing in order to write down an idea immediately, no matter what else he was engaged in.[18] Truscon employees were encouraged to come up with improvement ideas to benefit the company and would be rewarded financially if their ideas were used.[18] For example, David H. Morgan, a company employee, invented a new type of airplane hangar door. It was subsequently manufactured by Truscon and he was financially rewarded for his idea.[18]

Kahn belonged to the American Society of Civil Engineers. The society awarded him The Collingwood Prize for a paper he wrote in 1899 entitled "The Coal Hoists of the Calumet and Hecla Mining Company."[22] He was the founder of United Steel Company in Wooster, Ohio, and chairman of Truscon Laboratories in Detroit.[23]

Kahn later also served as a director for Mahoning Bank and the First National and Dollar Bank. In 1927 he was elected a chairman of the Youngstown Chamber of Commerce grade elimination committee, and a director of the street car committee in 1928. He was the president of a realty firm in Detroit that was named after him.

Kahn was an honorary chairman of the Allied Jewish financial campaign in 1930. He was also a member of several committees in metal-related industries. Kahn was a member of the proxy committee that opposed the deal of the merger of Youngstown Sheet & Tube Company with Bethlehem Steel.[3]

The Kahn family, 1921

Kahn married Margaret K. Kohut, daughter of rabbi Alexander Kohut, on December 23, 1903. Margaret Kohut was born in Hungary in 1876, and her family immigrated to the US. The Kahns had three children: Gisela (1906–2000), Katherine Kay (1909–1954), and Julius Kahn Jr. (1912–2009). The children were all born in Detroit, Michigan. Julius Jr. studied medicine at Ohio State University.[7]

Kahn was president of Truscon from its inception in 1905 until 1935, when it was taken over by Republic Steel Corporation.[9] He became a vice president for Republic, serving until 1939.[3]

Kahn retired "to private life" in 1939, which lasted one year. In 1940 he came out of retirement and became an executive of another steel fabricating company.[3] Kahn died 4 November 1942 in Cleveland, Ohio, of pneumonia.[9][3]

Kahn wrote several engineering articles and some articles on the steel business. One article titled "Confidence and cooperation", discussed the ills of industry.[3]

• Hy-Rib

• Michigan Historical Collections, Bentley Historical Library, University of Michigan, Albert Kahn Papers, 1896–2011
• Video on "Engineering Industrial Architecture: Albert Kahn and the Trussed Concrete Steel Company"
• Media related to Julius Kahn (inventor) at Wikimedia Commons