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Julius Kahn (March 8, 1874 – November 4, 1942) was an American engineer, industrialist, and manufacturer. He was the inventor of the
Kahn system, a
reinforced concrete
Reinforced concrete (RC), also called reinforced cement concrete (RCC) and ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having hig ...
engineering technique for building construction.
The Kahn system, which he patented in 1903, was used worldwide for housing, factories, offices and industrial buildings. He formed his own company,
Trussed Concrete Steel Company
The Trussed Concrete Steel Company was founded in 1903 by Julius Kahn, an engineer and inventor. Its headquarters were in Detroit, Michigan, and its steel factory was in Youngstown, Ohio. The long company name changed to a shortened versi ...
, as a manufacturing source for his inventions. He also founded United Steel Company and was chairman of
Truscon Laboratories
Truscon Laboratories was a research and development chemical laboratory of the Trussed Concrete Steel Company ("Truscon") of Detroit, Michigan. It made waterproofing liquid chemical products that went into or on cement and plaster. The products ...
.
Early life and education
Kahn was born in
Münstereifel, Germany, March 8, 1874. He immigrated to the United States with his family in 1880, entering at the port of
Baltimore
Baltimore ( , locally: or ) is the List of municipalities in Maryland, most populous city in the U.S. state of Maryland, fourth most populous city in the Mid-Atlantic (United States), Mid-Atlantic, and List of United States cities by popula ...
, Maryland, where they briefly lived.
They continued to
Detroit
Detroit ( , ; , ) is the largest city in the U.S. state of Michigan. It is also the largest U.S. city on the United States–Canada border, and the seat of government of Wayne County. The City of Detroit had a population of 639,111 at th ...
, Michigan, where he was raised, along with five brothers and two sisters.
[
]
Their father Joseph (1860–1924) was a rabbi and ran a restaurant where Julius worked; he also sold newspapers.
[ Mother Rosalie was skilled in music and art. Kahn's elementary education was in ]Detroit Public Schools
Detroit Public Schools Community District (DPSCD) is a school district that covers all of the city of Detroit, Michigan, United States and high school students in the insular city of Highland Park. The district, which replaced the original Detr ...
. He completed the normal four-year high school curriculum in three years.
Kahn, assisted financially by his older brother, architect Albert
Albert may refer to:
Companies
* Albert (supermarket), a supermarket chain in the Czech Republic
* Albert Heijn, a supermarket chain in the Netherlands
* Albert Market, a street market in The Gambia
* Albert Productions, a record label
* Alber ...
, attended the University of Michigan
, mottoeng = "Arts, Knowledge, Truth"
, former_names = Catholepistemiad, or University of Michigania (1817–1821)
, budget = $10.3 billion (2021)
, endowment = $17 billion (2021)As o ...
.[ He received a ]Bachelor of Science
A Bachelor of Science (BS, BSc, SB, or ScB; from the Latin ') is a bachelor's degree awarded for programs that generally last three to five years.
The first university to admit a student to the degree of Bachelor of Science was the University of ...
and a degree in Civil Engineering in 1896.[
]
Career
Reinforced concrete and Truscon
After graduating from the University of Michigan, Kahn began his career as an engineering draftsman for the Union Bridge Company The Union Bridge Company was a bridge fabricator and contractor with works in Buffalo, New York, (believed closed in 1890 per HAER references) and Athens, Pennsylvania. The Union Bridge company was formed in 1884 as a merger of several other bridge ...
of New York. He worked as an engineer for both the United States Navy
The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage ...
and the U.S. Army Corps of Engineers
, colors =
, anniversaries = 16 June (Organization Day)
, battles =
, battles_label = Wars
, website =
, commander1 = ...
from 1896 to 1903. Kahn also was employed by C. W. Hunt Company of New York. In 1900, Kahn moved to Japan for two years, laboring in engineering, construction, and maintenance of iron and sulfur mines.[
Kahn returned to Detroit in 1903, joining ]Albert Kahn Associates
Albert Kahn Associates is an architectural design firm in Detroit, Michigan with a second office located in Miami, Florida. It was established in 1895 and is still active. Recent work includes being awarded third place in thVirtual Modeling Sta ...
, an architectural firm founded by his brother Albert in 1895.[ Kahn's first assignment was collaborating with key architect Ernest Wilby in ]Ann Arbor
Anne, alternatively spelled Ann, is a form of the Latin female given name Anna (name), Anna. This in turn is a representation of the Hebrew Hannah (given name), Hannah, which means 'favour' or 'grace'. Related names include Annie (given name), ...
on the University of Michigan's new College of Engineering
Engineering education is the activity of teaching knowledge and principles to the professional practice of engineering. It includes an initial education (bachelor's and/or master's degree), and any advanced education and specializations that ...
building. Kahn's focus was testing specific materials for sufficient strength in supporting the new building.
Kahn and Wilby wanted to use reinforced concrete
Reinforced concrete (RC), also called reinforced cement concrete (RCC) and ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having hig ...
for the building's floors, in place of traditional wood supports. Kahn had previous experience in reinforced concrete with the U.S. Army Corps of Engineers. During the construction of U.S. War College building in Washington, D.C., he initiated methods improving the then existing technology of reinforced concrete by beginning work developing the Kahn system of steel bars. This new concept for reinforced concrete steel bars was the basis of the steel production company he later founded.[
Kahn understood the structural challenges inherent in the existing method of concrete reinforcement used at the end of the nineteenth century. The main problem was slippage of the steel within the hardened concrete, which weakened the structure. He experimented in his brother's basement, where he developed an improved type of reinforced beam called "the Kahn Bar".][ Kahn patented his invention in 1903, the first of more than 75 patents awarded to him.]
The Jordahl (Jordahl GmbH) Company’s founders, Norwegian Anders Jordahl Anders Olsen Jordahl (April 4, 1878 – February 18, 1969) was a Norwegian-American engineer, inventor, entrepreneur and artist.
Anders Olsen Jordahl was born at Elverum in Hedmark, Norway. His parents were Ole Jordahl and Mary (Furer) Jordahl. ...
and his Swedish partner Ivar Kreuger
Ivar Kreuger (; 2 March 1880 – 12 March 1932) was a Swedish civil engineer, financier, entrepreneur and industrialist. In 1908, he co-founded the construction company Kreuger & Toll Byggnads AB, which specialized in new building techniques. B ...
, acquired the marketing rights to the Kahn system in Europe in 1907. Today, the company attributes the “… seeds of its founding …” to Albert and Julius Kahn’s passion for concrete. Kahn formed Trussed Concrete Steel Company
The Trussed Concrete Steel Company was founded in 1903 by Julius Kahn, an engineer and inventor. Its headquarters were in Detroit, Michigan, and its steel factory was in Youngstown, Ohio. The long company name changed to a shortened versi ...
(Truscon) to manufacture his beams. He was the president, but spent much of his time in the design room.[ The company was headquartered in Detroit, with manufacturing in ]Youngstown, Ohio
Youngstown is a city in the U.S. state of Ohio, and the largest city and county seat of Mahoning County, Ohio, Mahoning County. At the 2020 United States census, 2020 census, Youngstown had a city population of 60,068. It is a principal city of ...
. Kahn chose Youngstown in 1907 as the ideal location because the city's proximity to steel production in Mahoning County
Mahoning County is a county in the U.S. state of Ohio. As of the 2020 census, the population was 228,614. Its county seat and largest city is Youngstown. The county is named for a Lenape word meaning "at the licks" or "there is a lick", refer ...
and reduced shipping costs.[
]
Management
Kahn served as a director of the Mahoning Bank, the First National Bank, and Dollar Bank. In 1927, he was elected chairman of the Youngstown Chamber of Commerce
A chamber of commerce, or board of trade, is a form of business network. For example, a local organization of businesses whose goal is to further the interests of businesses. Business owners in towns and cities form these local societies to ad ...
grade elimination committee, and a director of the street car committee in 1928. He was the president of an eponymous realty firm in Detroit.[ In 1930, Kahn was honorary chairman of the Allied Jewish financial campaign. He was also a member of several committees in metal-related industries as well as a member of the proxy committee that opposed the merger of Youngstown Sheet & Tube Company with Bethlehem Steel.][
Kahn was the founder of United Steel Company in ]Wooster, Ohio
Wooster ( ) is a city in the U.S. state of Ohio and the county seat of Wayne County. Located in northeastern Ohio, the city lies approximately south-southwest of Cleveland, southwest of Akron and west of Canton. The population was 27,232 at t ...
and chairman of Truscon Laboratories
Truscon Laboratories was a research and development chemical laboratory of the Trussed Concrete Steel Company ("Truscon") of Detroit, Michigan. It made waterproofing liquid chemical products that went into or on cement and plaster. The products ...
in Detroit. He was president of Truscon Steel Company from its inception in 1905 until 1935, when it was taken over by Republic Steel Corporation
Republic Steel is an American steel manufacturer that was once the country's third largest steel producer. It was founded as the Republic Iron and Steel Company in Youngstown, Ohio in 1899. After rising to prominence during the early 20th Centu ...
.[ He then became a vice president for Republic, serving until 1939.]
Writing and publishing
Kahn wrote several published articles on engineering and on the steel business. One article titled "Confidence and cooperation", discussed the ills of industry.[ Kahn was also a member of the ]American Society of Civil Engineers
American(s) may refer to:
* American, something of, from, or related to the United States of America, commonly known as the "United States" or "America"
** Americans, citizens and nationals of the United States of America
** American ancestry, pe ...
, which awarded him The Collingwood Prize for his paper "The Coal Hoists of the Calumet and Hecla Mining Company" in 1889.[
]
Inventions and impact
Kahn experimented and developed reinforced concrete construction materials, with at least 75 patented inventions in the field by 1934. His first patent was "Kahn Trussed Bar", also called "the Kahn Bar" or "Kahn Bar System", patented in 1903. The Kahn bar was a straight steel beam whose edges were slightly bent, resulting in improved stress distribution "wings" that increased tension strength. It was the principal product of the Trussed Concrete Steel Company, although the company manufactured many prefabricated steel products, as well as complete buildings — all used in construction around the world. Kahn's co-workers noted that he would stop whatever he was doing to write down an idea immediately, no matter what else was engaging him.[ Additionally he encouraged Truscon employees with financial incentives to develop new and improved ideas to benefit the company.][ For example, employee David H. Morgan was financially rewarded for inventing a new type of airplane hangar door, subsequently manufactured by Truscon.][
The Kahn system of reinforced concrete was adapted by his brother Albert Kahn, an architect, for design and construction of industrial buildings. By 1939, Kahn's system was used in 134 U.S. cities and was adopted by builders in Africa, Europe, Canada, China, Brazil, and Mexico. The system was used in the first two automobile factories in the U.S., ]Packard
Packard or Packard Motor Car Company was an American luxury automobile company located in Detroit, Michigan. The first Packard automobiles were produced in 1899, and the last Packards were built in South Bend, Indiana in 1958.
One of the "Thr ...
and Cadillac
The Cadillac Motor Car Division () is a division of the American automobile manufacturer General Motors (GM) that designs and builds luxury vehicles. Its major markets are the United States, Canada, and China. Cadillac models are distributed i ...
, progenitors of the most prodigious industry of the 20th century. His unique engineering and construction method was also found in airplane plants, warehouses, docks, foundries, creameries, filtration plants, rubber factories, steel plants, silos, distilleries, smelters, and textile mills.
The steel-reinforced concrete automobile factory has been heralded as one of the architectural breakthroughs of the 20th century. Many named the 1905 Packard Motor Car Company’s building No. 10 in Detroit as the first edifice built for the largest and most swiftly growing industry in the early 1900s. Albert Kahn was the designer and architect for this use of the Kahn system in construction devoted entirely to the car. However, the first was actually the Cadillac Motor Car plant in Detroit. Ironically, Julius Kahn supervised the engineering and construction of both buildings, using his patented system to make essential contributions to the construction and automotive industries in the US.
There were two significant construction accidents in buildings using the Kahn system in the early 20th century. The first, in November 1906, occurred in Long Beach, California
Long Beach is a city in Los Angeles County, California. It is the 42nd-most populous city in the United States, with a population of 466,742 as of 2020. A charter city, Long Beach is the seventh-most populous city in California.
Incorporate ...
, when parts of the Bixby Hotel collapsed during construction. Also, that November, the Eastman Kodak Building in Rochester, New York
Rochester () is a City (New York), city in the U.S. state of New York (state), New York, the county seat, seat of Monroe County, New York, Monroe County, and the fourth-most populous in the state after New York City, Buffalo, New York, Buffalo, ...
, gave way. Investigations of both accidents found the quality of workmanship seriously at fault. Both queries came to the conclusion that the Kahn system was not to blame for either faulty design or errors; rather, poor construction techniques were responsible.
Trussed Concrete Steel Company manufactured a product with a brand name of Hy-Rib
Hy-Rib was a brand name for a product manufactured by the Trussed Concrete Steel Company. It is an engineering reinforcement system for floors, walls, and ceilings of buildings and houses. This product is a derivative of the Kahn Trussed Bar f ...
starting in 1909. It was a steel meshed sheathing with deep stiffening ribs. It was filled with cement or plaster and used for floors, walls, and ceilings of houses, factories, and commercial buildings. It was a product derived from the Kahn Trussed Bar for beams and columns of reinforced concrete. Hy-Rib products were also used in the construction of tunnels
A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube constr ...
, conduits, flume
A flume is a human-made channel for water, in the form of an open declined gravity chute whose walls are raised above the surrounding terrain, in contrast to a trench or ditch. Flumes are not to be confused with aqueducts, which are built to tr ...
s, culvert
A culvert is a structure that channels water past an obstacle or to a subterranean waterway. Typically embedded so as to be surrounded by soil, a culvert may be made from a pipe, reinforced concrete or other material. In the United Kingdom ...
s, silo
A silo (from the Greek σιρός – ''siros'', "pit for holding grain") is a structure for storing bulk materials. Silos are used in agriculture to store fermented feed known as silage, not to be confused with a grain bin, which is used t ...
s, cistern
A cistern (Middle English ', from Latin ', from ', "box", from Greek ', "basket") is a waterproof receptacle for holding liquids, usually water. Cisterns are often built to catch and store rainwater. Cisterns are distinguished from wells by t ...
s, chimney
A chimney is an architectural ventilation structure made of masonry, clay or metal that isolates hot toxic exhaust gases or smoke produced by a boiler, stove, furnace, incinerator, or fireplace from human living areas. Chimneys are typic ...
s, and water tank
A water tank is a container for storing water.
Water tanks are used to provide storage of water for use in many applications, drinking water, irrigation agriculture, fire suppression, agricultural farming, both for plants and livestock, chemi ...
s. Its technology cut down on labor time in construction.
Personal life and death
Kahn married Margaret K. Kohut, daughter of rabbi Alexander Kohut
Alexander (Chanoch Yehuda) Kohut (April 22, 1842 – May 25, 1894) was a rabbi and orientalist. He belonged to a family of rabbis, the most noted among them being Rabbi Israel Palota, his great-grandfather, Rabbi Amram (called "The Gaon," who die ...
, on December 23, 1903. Margaret was born in Hungary in 1876; later, her family immigrated to the US. The Kahns had three children: Gisela (1906–2000), Katherine Kay (1909–1954), and Julius Kahn Jr. (1912–2009), all born in Detroit. Kahn enjoyed a one-year retirement "to private life" in 1939. In 1940, he exited retirement and became an executive of another steel fabricating company.[ Kahn died at the age of 68 of ]pneumonia
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...
on November 4, 1942 in Cleveland
Cleveland ( ), officially the City of Cleveland, is a city in the U.S. state of Ohio and the county seat of Cuyahoga County. Located in the northeastern part of the state, it is situated along the southern shore of Lake Erie, across the U.S. ...
, Ohio.[
]
References
Bibliography
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External links
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"
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{{DEFAULTSORT:Kahn, Julius
1874 births
1942 deaths
People from Birkenfeld (district)
19th-century German Jews
American people of German-Jewish descent
Concrete pioneers
Culture of Detroit
20th-century American inventors
20th-century American architects
19th-century German architects
Jewish architects
Art Deco architects
Artists from Detroit
German emigrants to the United States
People from the Rhine Province
University of Michigan College of Engineering alumni
Architects from Detroit