Historic structures significant structures of the past
Golden Gate Bridge – 75th Anniversary. Courtesy of Reinhard Ludke.
W
ith many great achievements, the end result is the sum of the contributions made by all that participate. Neil Armstrong and Edwin “Buzz” Aldrin, the Apollo 11 astronauts that stepped on the moon on July 20, 1969, got there through the efforts of 1000s of engineers and scientists. Engineers worked behind the scenes for years developing and supporting the moon landing program, but only Armstrong and Aldrin receive the tribute and went down in history for this accomplishment. Joseph B. Strauss, visionary and promoter to span the Golden Gate, receives the credit as the Engineer of the Golden Gate Bridge. Mr. Strauss, owner of his own engineering firm, Strauss Engineering Corporation, in Chicago, Illinois, was appointed the Chief Engineer by the Golden Gate Bridge and Highway District Board of Directors on August 15, 1929. Joseph Strauss is the “statue” near the bridge toll plaza, and he receives the credit for spanning the gate. In 1916, more than four decades after railroad entrepreneur Charles Crocker proposed a bridge across the Golden Gate Strait, James H. Wilkins, a structural engineer and newspaper editor for the San Francisco Call Bulletin, suggested spanning the Gate. San Francisco City Engineer, Michael M. O’Shaughnessy, the lead engineer of the San Francisco Hetch Hetchy water system, contacted bridge engineers to consult with them about the feasibility and cost of bridging the Golden Gate. Most speculated that a bridge would cost over $100 million. Joseph Strauss, who had designed nearly 400 bridges, claimed it could be built for $25 to $30 million. This man, “Joseph Baermann Strauss was an undersized man with a Napoleonic ego, yearning for a career in the arts, with only the
The Real Story – Structural Engineers and Architects of the Golden Gate Bridge Part 1 By Reinhard Ludke, S.E.
Reinhard Ludke, S. E. is a Bridge Engineer, Principal Structural Engineer, for Creegan + D’Angelo Engineers, San Francisco, CA. He was the Past President of the Structural Engineers Association of Northern California, served as the Director and Secretary of the Structural Engineers Association of California, and was elected FELLOW of the Structural Engineers Association of California in 2010.
The online version of this article contains detailed references. Please visit www.STRUCTUREmag.org.
14 July 2012
most modest amount of formal engineering training…”, says John Van Der Zee. “Strauss was a strange, at times almost a self cancelling mixture of conflicting traits: promoter, mystic, tinkerer, dreamer, tenacious hustler, publicity seeker, and recluse. He was not a member of the American Society of Civil Engineers nor was he a graduate of a college of engineering.”
Strauss Hybrid Bridge Concept His answer to spanning the gate, Joseph Strauss imagined a hybrid concept for the span that included a steel truss bridge from the shore with cantilevered steel truss from the main towers. Two suspension cables would be attached at the ends of the top chord of the cantilever, with a stiff steel truss road deck suspended from the cables. Strauss submitted a design proposal for bridging the Golden Gate Strait to O’Shaughnessy in June 1921, with a cost estimate of $17 million. Strauss called his solution a symmetrical cantilever-suspension hybrid bridge. Once his design was made public by O’Shaughnessy in December 1922, the public voiced little opposition, even though the local press described it as ugly. In 1921, Strauss hired Charles A. Ellis, Professor of structure and bridge engineering at the University of Illinois, to head up his engineering staff in Chicago. Ellis joined Strauss
1921 Strauss Symmetrical Cantilever-Suspension Hybrid Bridge Concept.
