The High Street Bridge is a double-leaf bascule drawbridge spanning 296 feet of the Oakland Estuary in the

San Francisco Bay Area The San Francisco Bay Area, often referred to as simply the Bay Area, is a populous region surrounding the San Francisco, San Pablo, and Suisun Bay estuaries in Northern California. The Bay Area is defined by the Association of Bay Area Go ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. It links the cities of

Oakland Oakland is the largest city and the county seat of Alameda County, California, United States. A major West Coast port, Oakland is the largest city in the East Bay region of the San Francisco Bay Area, the third largest city overall in the Bay A ...

and

Alameda An alameda is a Avenue (landscape), street or path lined with trees () and may refer to: Places Canada *Alameda, Saskatchewan, town in Saskatchewan **Grant Devine Dam, formerly ''Alameda Dam'', a dam and reservoir in southern Saskatchewan Chile ...

. The bridge is opened approximately 1,400 times a year. The bridge carries an average of 26,000 vehicles per year. The bridge was built when the Oakland Estuary was trenched, converting Alameda from a

peninsula A peninsula (; ) is a landform that extends from a mainland and is surrounded by water on most, but not all of its borders. A peninsula is also sometimes defined as a piece of land bordered by water on three of its sides. Peninsulas exist on all ...

to an

island An island (or isle) is an isolated piece of habitat that is surrounded by a dramatically different habitat, such as water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island ...

. The High Street Bridge is one of the four bridges and two tunnels that allow access to Alameda.

History

The estuary was originally spanned by an iron swing bridge, completed in 1894 by the Harrison Bridge Company for $24,747. In May 1901, a fire destroyed the swing span and part of the approaches, which were rebuilt the following year. Three bridges were built by the federal government in 1901 at High Street (road), Park Street (road), and Fruitvale Avenue (combined road and rail) in exchange for permission and rights-of-way to dredge the channel between San Antonio Creek and San Leandro Bay. After the three bridges were completed, they were left closed to allow road and rail traffic to pass, but never opened for marine traffic. The northern approach to the High Street Bridge was destroyed by a fire in May 1909, which also damaged the bridge; repairs were performed late in 1909. After pressure was applied by Senator George Clement Perkins and Congressman Joseph R. Knowland, the federal government turned the bridges over to Alameda County in 1910, conditioned on the county assuming responsibility for maintenance, staffing, and operation. The present bridge was designed by the County of Alameda Surveyors Office and constructed under the Federal WPA Program in 1939 at a cost of $750,000. It opened in December 1939. The bascule bridge was modernized in 1981 and 1996. The 1981 project included upgrades to electrical systems and motors; the 1996 project completely repainted the bridge, removing over of lead-based paint.

Design

The bridge normally opens both leaves to 45°, which accommodates most marine traffic; the maximum opening for each leaf is 76°. It is designed to safely operate in wind speeds of up to . Each leaf may be operated independently, allowing marine traffic to pass in case one leaf is inoperable. Each leaf has a main motor using electricity from

Alameda Municipal Power Alameda Municipal Power (formerly Alameda Power & Telecom) is a municipal utility serving the City of Alameda, California. Founded in 1887, it provides electricity to c. 34,000 residential, commercial, and municipal customers at rates up to 20 ...

, and a emergency motor for each leaf is powered from

Pacific Gas and Electric The Pacific Gas and Electric Company (PG&E) is an American investor-owned utility (IOU). The company is headquartered in the Pacific Gas & Electric Building, in San Francisco, California. PG&E provides natural gas and electricity to 5.2 milli ...

; using counterweights, full operation is possible using emergency power.

References

External links

* {{San Francisco Bay watershed Bridges in Alameda County, California Bascule bridges in the United States Bridges completed in 1939 Road bridges in California Buildings and structures in Alameda, California Buildings and structures in Oakland, California Steel bridges in the United States 1939 establishments in California