How much Switzerland is there in San Francisco? – structural engineer O. H. Ammann and the Golden Gate Bridge

It is a well known story that Swiss-born Johann August Sutter founded a colony by the name of New Helvetia in California in the mid-19th century. It is less well known that another Swiss citizen was essential to the construction of the Golden Gate Bridge, San Francisco’s famous landmark that celebrated its 75th birthday in 2012.

The Golden Gate Bridge under construction (ETH Zurich University Archives, Hs 1410: 19.301/7)

During the First World War, San Francisco’s City Engineer invited a series of engineers to submit feasible and economically viable proposals for the construction of a new bridge across the Golden Gate, the strait between the Pacific Ocean and San Francisco Bay. Among the proposals was one from Swiss engineer Othmar Ammann, although ultimately, Joseph B. Strauss, a German-American engineer, won the competition. The Swiss engineer lost out a second time when he failed to get the job of the Golden Gate Bridge’s Chief Engineer. However, Strauss’s original design (a hybrid of a cantilever and suspension bridge) was met with so much criticism that the contractor assigned a team of expert engineers, including Ammann, to advise Strauss.

Othmar Hermann Ammann graduated from ETH Zurich in 1902 and received an honorary doctorate from his alma mater in 1930. By then, he had made a name for himself as a leading expert in bridge engineering in the US.


Ammann’s diploma. He studied at the Polytechnic School from 1897 to 1902 (ETH Zurich University Archives, Hs 1410: 4.108)

His projects included the George Washington Bridge in New York, which was inaugurated in 1931, and was the longest suspension bridge in the world at the time. Ammann returned regularly to the West Coast to participate in the meetings of the Golden Gate Bridge Board of Consultants. On one of these trips, he met his second wife, the Swiss-born Kläry Vogt.

Minutes, records, and correspondence from the Board of Consultants reflect Amman’s work as a consulting engineer. There is controversy over the significance of his contribution to the building of the Golden Gate Bridge. However, the fact that the bridge was ultimately built as a pure suspension bridge points to his influence – a design whose elegance persists to this day.

In his later life, shortly before his death in 1965, Ammann also worked on projects to reinforce the Golden Gate Bridge and incorporate high-speed train lines in its structure.



Ammann in front of the Golden Gate Bridge. Ammann (2nd from left) was a member of the Board of Review
to add a rapid transit deck to the Golden Gate Bridge
(12 January 1962, ETH Zurich University Archives, Hs 1410: 19.301/39)

The ETH Zurich University Archives hold Ammann’s personal papers. The majority of them are indexed in an inventory and can be consulted in the reading room. Documents which are not yet indexed (including the records of the Board of Consultants), may also be consulted in exceptional cases.


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