Othmar Hermann Ammann (1879–1965)

Bridge builder

Othmar H. Amman was born in Feuerthalen, near Schaffhausen in Switzerland, on 26 March 1879. After graduating from Zurich's industrial school, he studied structural engineering at ETH Zurich from 1898 to 1902, most notably under Wilhelm Ritter and Ludwig Tetmajer. Following his initial activities in Switzerland and Germany, he moved to the United States in 1904, eventually becoming an American citizen in 1924. Othmar H. Ammann died in Rye, New York, on 22 September 1965.

Revolutionizing bridge construction

Ammann already began examining the issue of bridging the one-kilometre-wide Hudson River between Manhattan and the residential areas of New Jersey at an early stage – initially as an employee of Gustav Lindenthal, the most prominent engineer in America at the time. When Ammann fell out with Lindenthal, he was eventually able to realise his steel suspension bridge project as chief engineer on behalf of the Port of New York Authority. He implemented the insight that as the dead load increases and therefore also the span, the importance of the roadway as a stiffening girder for the deformation of the load-bearing support structure recedes. With sufficiently heavy cable, the cumbersome-looking stiffening girders can be dispensed with altogether and the bridge seems more elegant. With the completion of the George Washington Bridge in 1931, Ammann had succeeded in spanning a distance of over 1,000 metres for the first time.The same year, the Bayonne Bay Bridge over the Kill van Kull, the largest steel arched bridge in the world at the time, was inaugurated. The impact of the construction of these two bridges is also evident in Europe.

Buildings and honours

From 1934 Ammann realised the 2.5-kilometre Lincoln Tunnel under the Hudson and the elegant Bronx Whitestone Bridge over the East River for the Triborough Bridge Authority. In 1949, he teamed up the American engineer Charles S. Whitney to found the firm Ammann & Whitney, which is still in business to this day. His final masterpiece opened a year before his death in 1964: the Verrazano Narrows Bridge over New York's Upper Bay estuary. The same year, President Lyndon B. Johnson awarded him the National Medal of Science, the first structural engineer to be presented with this accolade. Ammann received numerous honours throughout his life, including honorary doctorates from ETH Zurich (1930), New York University (1932) and Columbia University (1941).