The Final Leap Read Online Free PDF Page B

project of this magnitude was considered too daunting even though it would provide much-needed jobs. It didn’t help that the nearby Bay Bridge, connecting Oakland and Berkeley to the east with San Francisco, was already under construction, and all available government funding was allocated to it. The Golden Gate Bridge, as a result, had to be financed with bonds that would be paid back by revenues from future tolls.
    In 1923 the California State Legislature passed the Golden Gate Bridge and Highway District Act. The act gave San Francisco and five counties north of it the right to form a bridge district, borrow money, issue bonds, build a bridge, and collect tolls. In 1928, the Golden Gate Bridge and Highway District was established, consisting of San Francisco (which is both a city and a county), Marin County, Sonoma County, Del Norte County, and portions of Napa and Mendocino counties. (In 1969, the legislature approved a bill that expanded the district’s responsibilities to include bus and ferry service in the area. At that time the word “Transportation” was added to the district’s name.)
    After the district was formed, Strauss was named chief engineer of the bridge. His main task, early on, was to lobby for a ballot measure that approved construction. Multiple measures went down to defeat, and for awhile it looked like the bridge would never be built. At the same time, another problem emerged. Strauss’s original design was part suspension span and part cantilever structure. Its functionality was questionable, and its appearance was far from elegant. According to Golden Gate Bridge historian John van der Zee, it was “a ponderous, ugly structure of mixed parentage, based on erroneous survey information and precious little actual engineering.” Most local officials didn’t know enough to question the science behind the design. They were disappointed by the look of the bridge, though, and wanted something more inspiring, befitting the sweep of the bay and the international sophistication of San Francisco. Strauss brought in several consultants to help, among them Leon Mois-seiff and Charles Ellis.
    Moisseiff was born in Latvia and came to the United States in 1891 at age nineteen. When Strauss began working on designs for the Golden Gate Bridge, Moisseiff was considered one of the best bridge designers in the country, having designed the Manhattan Bridge, among others. It was Moisseiff who determined that it was possible to construct a single span suspension bridge across the Golden Gate Strait even though no bridge had ever been built at the mouth of a major harbor, and no suspension bridge that long had ever been erected.
    Unlike other spans, suspension bridges sway in the wind. They also expand in hot weather and contract in cold weather (the cables lengthening and constricting depending on the temperature). The longer the span, the more swaying and variation occurs, much like a clothesline. Given that the Golden Gate Bridge would be longer than any other suspension bridge in the world, it would sway more than any other. Based on the load it was supporting and the temperature, the bridge would deflect one to two feet both longitudinally and sideways, causing the floor of the bridge at mid-span to rise or fall ten feet from its normal elevation.
    Charles Ellis was a faculty member in the engineering department at the University of Illinois when Straus contacted him. It was Ellis, the author of
Essentials in the Theory of Framed Structures—
must reading for engineering students at the time—who crunched the numbers upon which calculations for the Golden Gate Bridge were based. The calculations were complex, done with a circular slide rule and an adding machine, and filled eleven volumes. Seven different rivers empty into the Golden Gate Strait, which at its deepest point is 335 feet. In addition, the area is marked by high winds, thick fog, and rough tidal action. Also, the