Sunday, April 20, 2014

San Joaquin County, California Bridges: BNSF Bacon Island Bridge across the Middle River

April 2014 (37.93979 Degrees-121.53310 Degrees) Bacon Island Bridge
Three Hugo Abt designed bascule bridges carry the BNSF Railway across rivers in San Joaquin County. The Woodward Island Bridge across the Old River was studied in February and can be seen (in the distance) in the photo above. The Bacon Island Bridge across the Middle River will be studied today. We'll look at the 3rd Hugo Abt Bascule Bridge over the San Joaquin River next week.
The BNSF - Bacon Island Bridge is part of a long concrete trestle that carries the BNSF tracks over a cut made between Woodward and Bacon Islands. The BNSF - Woodward Island Bridge is at the western end of the trestle. All of the bascule bridges were built by the American Bridge Company between 1928 and 1930.
On an Abt bridge, a large weight is suspended from a tall steel truss. As the weight swings down, a shorter truss folds, which lifts up the adjacent steel girder span.  A photo of an Abt bridge in the open position is provided by the HistoricBridges Website

According to 'Movable Bridge Engineering,' the vertical clearance for the Bacon Island Bridge is 11 ft in the closed position. However, whether this bridge is still being opened is questionable. 
Railroad bridge engineers have little interest in bridge aesthetics, which results in their bridges having a very utilitarian appearance. Apparently, a lack of concern about aesthetics results in a strong aesthetic statement. 

These bridges carry freight and passenger trains across the California Delta.
Creative Commons License
San Joaquin County, California Bridges: BNSF Bacon Island Bridge across the Middle River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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