June 20, 2013

The San Francisco-Oakland Bay Bridge

In 1928, a San Francisco delegation urged Congress to pass a bill authorizing a bridge to connect San Francisco with Oakland and Berkeley-with 5 miles of water between. The legislation was defeated, but in 1932 Congress approved a $73 million loan with the endorsement of President Herbert Hoover. The first shovel broke ground in 1933, and 3 years later the span was opened to vehicular traffic with excited celebration. After competing ferries cut their fares in half in 1927, the bridge traffic amounted to 23 thousand vehicles a day. With the opening of the Golden Gate Exposition in San Francisco in 1939, tolls were reduced from 50 to 40 cents, and when cut further to 25 cents, the ferries gave up.

The roadway was built on two suspension bridges, with a central pier or anchorage at mid-channel. There are two decks: the top one handles six lanes for cars and light truck traffic. The lower deck carries three lanes for heavy trucks and multi-wheelers. There are also two streetcar (trolley) tracks provided. The structure is a combination of suspension and cantilever spans connected with a tunneled island.

Stamp Issue: 1939

No comments: