Begun in 1933 during the depths of the Depression, the San Francisco-Oakland Bay Bridge employed hundreds of men working two six-hour shifts for three years and seven months and was completed two months ahead of schedule on November 12, 1936, at a cost of $78,000,000. Declared a masterpiece of functional engineering, the eight and one-half mile span became the longest bridge of its kind in the world. Yerba Buena Island linked the two bridge crossings, and engineers tunneled through solid rock to create the world's largest diameter bore tunnel, excavating it to a width of 65.5 feet and a height of 52.8 feet. The excavated rock helped form Treasure Island, site of the 1939 World's Fair and later a United States Navy base. The bridge was designed with two levels of traffic, automobiles on the top level and trucks and fast electric trains on the lower level. Those trains carried passengers to cities throughout the East Bay and as far north as Chico, 128 miles away, but they could not compete with the freeways and made their last run in 1958, after which the tracks were removed for more auto traffic. The anchorage between San Francisco and Yerba Buena Island, known as Moran's Island after deep-water footing expert Daniel Moran, was built not on solid ground but from steel cylinders encased in concrete. At the center of the west crossing, the world's largest pneumatic timber caisson, measuring 97 by 192 feet, was towed into place and sunk by releasing compressed air, and concrete was poured between the cylinders. The resulting pier was the equivalent of a 40-story building covering half a city block. The massive anchorage for the twin suspension bridges was built on a rocky ridge 220 feet below, and this ancient underwater rock formation fixed the route of the bridge to its San Francisco origins at Rincon Hill. Wally Ortez, who at age 78 recalled getting work as a 19-year-old rigger in 1933, remembered feeling lucky to have a paycheck and proud to help build the bridge, and he ran along a catwalk 540 feet above the bay during lunch. When the bridge opened on November 12, 1936, searchlights celebrated the occasion, but on October 18, 1989, a 7.1 earthquake severed a span and closed the bridge. After repairs, workers riveted a traditional iron bridge troll to the mended joint as protection against future catastrophe and as a symbol of the bridge and the workers who built and repaired it. During construction, 23 men lost their lives: Louis R. Knight, William H. Morotzke, E.S. Hill, Lloyd H. Evans, Harold Schwates, George J. Weikert, Donald McEachern, Bernard Hauffman, R.L. Poole, Adolph Silversen, Christy Thompson, Henry Dennington, Arthur Lamoreaux, Michael Edward Markey, Walter Vanderburg, Marion Tavares, Ed Correll, Paul Shelton, Charles Bazzili, Roy C. Bishop, Paul Gurley, George Zink, and W. Aguado.
