This week San Francisco International Airport turns over its new control tower to the Federal Aviation Administration. The FAA will spend a year outfitting the 221-foot, torch-like, flared cylinder with its systems, testing them and training controllers. The concrete spine of the tower is tied, with steel cables, to a 7-foot thick mat foundation, which is supported by 140-foot deep piers that reach the bedrock below. The tower contains two dampers, each 37,400 pounds, which help the shaft to remain still in high winds and to withstand a magnitude 8 earthquake. The FAA provided the majority of the $120 million dollars needed for project.
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