The present bridge was preceded
by an earlier structure, which in turn replaced a ferry. The ferry service
was started in 1917 by two businessmen, Aven Hanford from Vallejo and Oscar
Klatt from San Francisco. Demand grew so fast (in 1922 the ferry carried
400,000 automobiles) that in 1925 Hanford and Klatt commenced the building
of a bridge, employing U.C. Berkeley engineering professor Charles Derleth, Jr. as Chief Engineer. Bridging the strong tidal current took 25 months and on May
21, 1927 the Carquinez Bridge opened for traffic (just hours after Charles
Lindbergh spanned the Atlantic by solo flight). The bridge was funded
In 1940 the state of California
took over and gradually reduced the tolls until crossing was free. With
traffic greatly increasing, it was decided in 1955 to build a twin parallel
bridge, 200 feet east of the existing structure.
The new bridge was designed
to match the original Carquinez Bridge and opened on November 25, 1958
incorporating many new features made possible by engineering advances since
the 1920s. These included the use of welded steel fabrication for the cantilever
spans, and T-1 steel, three times stronger than the usual steel used in
bridge construction. Nevertheless, it is currently under a major retrofit.
The bridge is 0.8 miles long with a tower height of 314 feet and a vertical
clearance of 148 feet.
Many of the components of
the 1927 bridge, now more than 70 years old, are deteriorating and difficult
to maintain. Because a major retrofit would be virtually impossible without
closing the bridge to traffic, it will be replaced by a two-pier suspension
bridge due for completion by 2003.