The San Francisco-Oakland Bay Bridge Opens

Crossing the Bay

Before the bridge, people crossed San Francisco Bay between the two cities by ferry. Proposals for a bridge had been made since the 1870s, and in the early 1930s the state of California, with a loan from the federal Reconstruction Finance Corporation, took up the project. Construction began on July 9, 1933. Charles H. Purcell was the chief engineer, and the state's Division of Highways, now Caltrans, directed the work.

The Structure

The bridge, with its approaches, is a little over eight miles long. The western half, from San Francisco to Yerba Buena Island, consisted of two suspension bridges joined at a central anchorage. The eastern half crossed to Oakland on a cantilever span and a long viaduct. Between them is a tunnel through Yerba Buena Island, which was reported at the time to be the largest-diameter bored tunnel in the world. The roadway had two decks, with automobiles on the upper deck and trucks on the lower deck, which also carried interurban trains from 1939.

The Opening

The bridge opened on November 12, 1936, six months before the Golden Gate Bridge, which opened in May 1937. California's governor, Frank Merriam, cut a chain across the roadway in a ceremony on the Oakland side, and traffic began that day. Construction had taken about three and a half years, and the opening was part of several days of celebration. The total cost reported at the time was about 77 million dollars, including the terminal in San Francisco.

Later History

Interurban trains used the lower deck from 1939 until 1958, when the deck was converted for road traffic. The trains were operated by the Key System, the Sacramento Northern Railway and the Interurban Electric Railway, and they ran to the Transbay Terminal in San Francisco, which opened in January 1939. The October 17, 1989, Loma Prieta earthquake caused a section of the upper deck of the eastern span to fall onto the lower deck, and the bridge was closed for about a month. A new eastern span, built beside the old one as a self-anchored suspension bridge, opened on September 2, 2013, and the old span was dismantled.

Tolls and Treasure Island

The toll for a car at the opening was 65 cents. Treasure Island, an artificial island built from dredged fill beside Yerba Buena Island, was constructed in 1936 and 1937 as the site of the 1939 Golden Gate International Exposition. Since 1963 the bridge's upper deck has carried westbound traffic toward San Francisco and the lower deck has carried eastbound traffic.