Othmar Hermann Ammann (March 26, 1879 – September 22, 1965) was a Swiss-born American structural engineer whose designs include the George Washington Bridge, Verrazano-Narrows Bridge, and Bayonne Bridge. A residential building is named after him on the Stony Brook University campus.
Biography
Othmar Ammann was born in Schaffhausen, Switzerland in 1879. His father was a manufacturer and his mother was a hat maker. He received his engineering education at the Polytechnikum in Zürich, Switzerland. He studied with Swiss engineer Wilhelm Ritter. In 1904, he emigrated to the United States, spending his career working mostly in New York City. In 1905 he briefly returned to Switzerland to marry Lilly Selma Wehrli. Together they had 3 children- Werner, George, and Margaret- before she died in 1933. In 1924, he became a naturalized citizen of the United States. He then married Karly Vogt Noetzli in 1935 in California.
Ammann wrote two reports about bridge collapses, the collapse of the Quebec Bridge and the collapse of the original Tacoma Narrows Bridge (Galloping Gertie). It was the report that he wrote about the failure of the Quebec Bridge in 1907 that first earned him recognition in the field of bridge design engineering. Because of this report, he was able to obtain a position working for Gustav Lindenthal on the Hell Gate Bridge. By 1925, he had been appointed bridge engineer to the New York Port Authority. His design for a bridge over the Hudson River was accepted over one developed by his mentor, Lindenthal. (Lindenthal's "North River Bridge" designs show an enormous, 16+ lane bridge that would have accommodated pedestrians, freight trains, rapid transit, and automobile traffic. The bridge, which would have entered Manhattan at 57th Street, was rejected in favor of Ammann's designs primarily due to cost reasons.) Ultimately, this became the George Washington Bridge. Under Ammann's direction, it was completed six months ahead of schedule for less than the original $60 million budget. Ammann's designs for the George Washington Bridge, and, later, the Bayonne Bridge, caught the attention of master builder Robert Moses, who drafted Ammann into his service. The last four of Ammann's six New York City bridges — Triborough, Bronx-Whitestone, Throg's Neck, and Verrazano-Narrows — were all built for Moses' Triborough Bridge and Tunnel Authority. In 1946, Ammann and Charles Whitney founded the firm Ammann & Whitney. In 1964, Ammann opened the Verrazano Narrows Bridge in New York, that had the world's longest suspended span of 4,260 feet, and the world's heaviest suspension bridge of its time. The Verrazano Narrows Bridge is currently the eighth-longest span in the world and the longest span in the Western Hemisphere. Ammann also assisted in the building of the Golden Gate Bridge in San Francisco, which is currently the ninth-longest span.
Works
Othmar Ammann designed more than half of the eleven bridges that connect New York City to the rest of the United States. His talent and ingenuity helped him create the two longest suspension bridges of his time. Ammann was known for being able to create bridges that were light and inexpensive, yet they were still simple and beautiful. He was able to do this by using the deflection theory. He believed that the weight per foot of the span and the cables would provide enough stiffness so that the bridge would not need any stiffening trusses. This made him popular during the depression era when being able to reduce the cost was crucial. Famous bridges by Ammann include:
Bust in George Washington Bridge bus station
The George Washington Bridge was originally designed to have its steel structure riveted with stone. The stone was omitted from the final design because of the cost constraints. The cost constraints were due to the great depression. With Ammann's managerial skills he was able to complete the bridge ahead of schedule and under budget.
The Bayonne Bridge is the only bridge of Othmarr's design that is not a suspension bridge; rather it is an arch bridge.
The Bronx-Whitestone Bridge had to be reinforced after only one year of operation. The bridge was perceivably moving during high winds. Warren Trusses were initially implemented to stiffen the bridge spoiling its streamlined classic looks. The trusses have been removed and the wind problem has been solved using "lightweight fiberglass aerodynamic fairing, triangular in shape that was installed along both sides of the bridge that slices the wind as it passes over the bridge."[1]
In addition to his work on bridges Ammann also directed the planning and construction of the Lincoln Tunnel.
References
- Rastorfer, Darl (2000). Six Bridges. New Haven: Yale University Press. ISBN 0300080476.
- Billington, David (2003). The Art of Structural Design. Princeton: Princeton. ISBN 0300097867.
Kavanagh, Thomas C. (1979). “Othmar Hermann Ammann”. Memorial Tribute: National Academy of Engineeing. 1, 7-9.
Lienhard, John H. (1997). “No. 698 Othmar Ammann”. <http://www.uh.edu/engines/epi698.htm>. (October 25, 2007).
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