samedi 7 septembre 2013

San Francisco Bridges to Visit

By John Feyd


There is no question that San Francisco bridges are examples of the most impressive and elaborate bridges in the U. S.. Bridges in San Francisco are known for many various reasons, if it is for their size or the mark they have made in history. Here's a few of the most unusual and notable bridges that San Francisco has to show off.

Hayward Bridge

Originally known as the San Francisco Bay Toll Bridge, the Hayward Bridge connects the San Francisco Bay with the East Bay. At about seven miles long, it is currently the longest bridge in San Francisco and it ranks as amongst the top 25 longest bridges globally. When the Hayward Bridge was initially built in 1929, the Hayward was only 2 lanes with a vertical lift span over the shipping channel. In 1967, the Hayward Bridge was remodeled from multiple steel girders and concrete trestle spans.

Oakland Bay Bridge

The first of its kind, the Oakland Bay Bridge is actually a tunnel plus two bridges that connect the eastern side of San Francisco and Oakland. The bridge was designed by Charles Purcell with construction kicked off in 1933 and opening in 1936. The first is a two spanned double-decker suspension bridge running 10,304 feet long and connecting Yerba Buena to San Francisco. After leaving the Yerba Buena tunnel, a 10,176 foot cantilever bridge continues to the Oakland Bay.

Golden Gate Bridge

The Golden Gate bridge was designed by the famous architectural designer Joseph Strauss and was finished in 1937 setting the standard for future bridges. The weight of the bridge is supported by two main cables, with each having 27,572 wires, equaling 80,000 miles of cable. Most obvious though is the orange paint that was painted on the bridge so that the bridge would be observable to ships in the fog. The Golden Gate is the first Bridge that ever used a safety net for the safety of the bridge workers during construction.

Richmond San Rafael Bridge

This wonderful double-decker cantilever and truss bridge is 29,040 feet long and was opened for traffic in 1956. It is nick-named the "roller coaster" bridge and many consider it to be one of the sturdiest bridges ever built. Notwithstanding it having a clearance of 185 feet this bridge has been thought to be hit by ships but hasn't had to close for repairs due to it. In truth a navy radar vessel and a World War Two battleship collided with the bridge both on the self same day.

Antioch Bridge

The original Antioch Bridge was built in 1926 by Aven Hanford and Oscar Klatt, it was initially the first toll bridge over the San Francisco tributary. But from the the start it had problems, due to a design flaw many ships collide into its narrow opening and in 1970 the lift span stopped working. In 1978 a new steel plate girder bridge was made and is now referred to as the Senator John A. Nejedly Bridge.




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