The Bay’s New Landmark: The SAS tower is 525-feet-tall and echos the height of the four, 1930s suspension towers of the West Span (unseen to the right). By design, the SAS tower’s single, mile-long main cable presents a longer slope towards the Oakland side (left) and sharper drop on the San Francisco side (right). The new tower legs were assembled vertically on the steel mill’s dock in China before it was raised a final time in the Bay. One lift weighed nearly 2,500 tons. Lift One of the tower was comprised of four individual pieces each weighing over 1,100 tons. Photo credit: Caltrans
Rebuilding the Bay’s Famed Crossing
by Dan McNichol
T
he San Francisco-Oakland Bay Bridge is one of the busiest bridges on earth. Today, it’s being re-built. Replacing the famed crossing’s 75-year-old, earthquake damaged eastern span is one of the most sophisticated steel structures in the world. Soaring to 525-feet, the tower of the world’s longest SelfAnchored Suspension Span (SAS) is inspiring a nation to rebuild its infrastructure—its image. A minor portion of this newest American bridge was produced by one of the nation’s latest challengers—its biggest rival—China. The news that ZPMC, a Chinese steel company, won the $400 million contract to produce the SAS tower and deck segments sparked a media controversy. Why the strong opinion towards China? That’s another discussion for another day. Why was China able to produce vast quantities of steel in short time? That’s obvious. The Middle Kingdom is in the midst of a building boom that makes the construction of the Great Wall and the Grand Canal appear trite. Fifty percent of the world’s steel production happens in China. Japan produces just seven percent, which is sadly more steel than the United States produces. China is capable of fulfilling the largest orders of steel to be delivered anywhere around the globe. ZPMC delivered the SAS segments to San Francisco in the hulls of their own ships.
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TransportationBuilder
Nov.-Dec. 2011