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Historic structures significant structures of the past th Golden Gate Bridge – 75 Anniversary. Courtesy of Reinhard Ludke. ® ith many great achievements, most modest amount of formal engineering train- the end result is the sum of the ing…”, says John Van Der Zee. “Strauss was a contributions made by all that strange, at times almost a self cancelling mixture participate. Neil Armstrong of conflicting traits: promoter, mystic, tinkerer, W Copyrightand Edwin “Buzz” dreamer, tenacious hustler, publicity seeker, and Aldrin, the Apollo 11 recluse. He was not a member of the American astronauts that stepped Society of Civil Engineers nor was he a graduate The Real Story – Structural on the moon on July of a college of engineering.” Engineers and Architects of 20, 1969, got there through the efforts of Strauss Hybrid Bridge Concept the Golden Gate Bridge 1000s of engineers and scientists. Engineers His answer to spanning the gate, Joseph Strauss worked behind the imagined a hybrid concept for the span that Part 1 scenes for years developing and supporting the included a steel truss bridge from the shore with moon landing program, but only Armstrong cantilevered steel truss from the main towers. By Reinhard Ludke, S.E. and Aldrinmagazine receive the tribute and went down Two suspension cables would be attached at S Tin history R for thisU accomplishment. C JosephT B. Uthe ends R of the topE chord of the cantilever, Strauss, visionary and promoter to span the with a stiff steel truss road deck suspended Golden Gate, receives the credit as the Engineer from the cables. Strauss submitted a design of the Golden Gate Bridge. Mr. Strauss, owner proposal for bridging the Golden Gate Strait of his own engineering firm, Strauss Engineering to O’Shaughnessy in June 1921, with a cost Reinhard Ludke, S. E. is a Bridge Corporation, in Chicago, Illinois, was appointed estimate of $17 million. Strauss called his solu- Engineer, Principal Structural the Chief Engineer by the Golden Gate Bridge tion a symmetrical cantilever-suspension hybrid Engineer, for Creegan + D’Angelo and Highway District Board of Directors on bridge. Once his design was made public by Engineers, San Francisco, CA. August 15, 1929. Joseph Strauss is the “statue” O’Shaughnessy in December 1922, the public He was the Past President of the near the bridge toll plaza, and he receives the voiced little opposition, even though the local Structural Engineers Association credit for spanning the gate. press described it as ugly. of Northern California, served In 1916, more than four decades after railroad In 1921, Strauss hired Charles A. Ellis, as the Director and Secretary entrepreneur Charles Crocker proposed a bridge Professor of structure and bridge engineering of the Structural Engineers across the Golden Gate Strait, James H. Wilkins, at the University of Illinois, to head up his engi- Association of California, and a structural engineer and newspaper editor for the neering staff in Chicago. Ellis joined Strauss was elected FELLOW of the San Francisco Call Bulletin, suggested spanning Structural Engineers Association the Gate. San Francisco City Engineer, Michael of California in 2010. 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, 1921 Strauss Symmetrical Cantilever-Suspension yearning for a career in the arts, with only the Hybrid Bridge Concept. 14 July 2012 STRUCTURE magazine Joseph B. Strauss Bridge Engineer Charles A. Ellis 1931 Suspension Bridge Elevation by Irving F. Morrow. Collection of the Golden Gate Bridge, Highway and Transportation District. Photo by Robert David. Engineering Corporation after a 14 year Dear Sir: Bridge Consultant Bridge Architect Leon S. Moisseiff® Irving F. Morrow teaching career in Civil Engineering at the In accordance with your letter of acceptance Universities of Michigan (1908 to 1912) and of June 8, 1925, I present herewith to you Illinois (1914 to 1921). The University of a report on a comparative design for a sus- City, and he was in close contact with O. H. Illinois had the preeminent civil engineer- pension bridge with a single span stiffening Ammann, Chief Engineer, Port of New York ing faculty in the United States in first half truss based on identical specifications and Authority. Moisseiff’s design incorporates sev- th prices as the cantilever-suspension type pro- of the 20 century. He had studied math- Copyright eral key features of the George Washington ematics and structural engineering theory posed by you for the Golden Gate Bridge Bridge design, including traffic live loads for and authored a textbook, Essentials in the at San Francisco and on which I made a long span suspension bridges, the allowable Theory of Framed Structures, which was a report to you on July 27, 1925. stresses, and anchorage of the cables in rock popular university textbook of that time. tunnels. The 1925 report suggests a bridge Respectfully submitted, Ellis quickly advanced to Vice President at that is very similar to the one that was built. /s/ Leon Moisseiff the Strauss company where he was in charge A continuous steel stiffening truss bridge deck of all bridge engineering, design and con- This letter included theReport on Comparative is suspended from the main cables. The towers struction supervision. Design of a Stiffened Suspension Bridge over rise from piers constructed in the water. Each The original September 1937 Report of the Golden Gate at San Francisco, California. tower is constructed of multiple riveted steel the Chief Engineer did not include detailed The seven-page report describes an all wire plate cells that form two large columns. The information about the roles played by Ellis cablemagazine bridge of the stiffened suspension type, two columns are braced together at multiple and by Leon S. Moisseiff,S a NewT York Rconsisting U of two parallel C wire cablesT spanned U levels, R into a transverseE frame. Architectural bridge engineer, who was developing new over two towers and anchored on each side features were added during the design to create mathematical methods for the analysis of into bedrock. The bridge had a span of 4,000 the Art Deco style that was popular at the time. suspension bridges. In Ellis, Joseph Strauss feet between towers and provided a clearance The 435-foot tall towers have a trapezoidal plan found the structural engineer he needed for of 200 feet above the high tide water. Two shape that tapers from 40 feet at the base to his dream of a bridge across the Golden 36-inch diameter main cables were described 20 feet top. Moisseiff estimated the suspen- Gate. Unlike Strauss, Ellis had no incli- as 91 strands, made with 25,700 high strength sion bridge construction cost as $19,400,000. nation to seek fame. The pair was quite wires, spaced 90 feet apart supporting the Eventually Strauss would speak of these con- odd – the sly businessman and a academic suspended steel roadway. ceptual ideas, who’s technical engineering was and professor, who found satisfaction in Together, Moisseiff and Ellis explored a practi- beyond his capabilities, as if they were his own. completing complex mathematical analysis cal application of Moisseiff’s deflection theory of continued on next page and engineering. suspension bridges. They made their bridge Ellis and Moisseiff had a profound influence design flexible enough to withstand the ADVERTISEMENT - For Advertiser ADVERTISEMENT Information, visit in the evolution of the final design for the gales that often blew through the Golden Golden Gate Bridge. In 1925, Strauss had Gate. The bridge would be lighter, longer, Ellis arrange for Leon S. Moisseiff, designer and narrower than any of its predecessors. of New York’s Manhattan Bridge, to serve Moisseiff believed that up to half the stress The easiest to use software for calculating on a “Board of Consultants” for the bridge caused by winds could be absorbed in a wind, seismic, snow and other loadings for district. He reviewed Strauss’s plans for a suspension bridge by the bridge cables and IBC, ASCE7, and all state codes based on cantilever-suspension hybrid bridge, and suspender ropes, and transmitted to the these codes ($195.00). found them to be practical from an engi- bridge towers and abutments. If a bridge neering standpoint and capable of being were designed to bend and sway with the Tilt-up Concrete Wall Panels ($95.00). www.STRUCTUREmag.org built within the estimated budget of $21 winds, the suspended structure – the road- Floor Vibration for Steel Beams and Joists million. Moisseiff had some concern about bed – would act as a counterweight and ($100.00). the hybrid bridge design and asked Strauss restore the bridge to equilibrium. Concrete beams with torsion ($45.00). to consider an alternate “all cable” design. At the time of his report, Moisseiff was Moisseiff noted this in his letter to Strauss working as a consultant on the design of Demos at: www.struware.com dated November 15, 1925: the George Washington Bridge, New York STRUCTURE magazine15 July 2012 The suspension span concept did not imme- This document details the bridge engineering diately become the leading design for the staff organization as follows: bridge. As late as 1929, Strauss continued to Computation of Stresses and the prepa- campaign for a bridge using his original sym- ration of stress sheets is assigned to the metrical cantilever-suspension hybrid design. Computation Division under the direction On August 15, 1929, the Board appointed of M.