Friday, October 10, 2014

Sonoma County, California Bridges: Old Basso Bridge across the Tuolumne River

September 2014 (37.64553, -120.49589 Degrees) Old Basso Bridge
There are many older bridges across the Tuolumne River in Stanislaus County but most of them are now closed to traffic. The Old Basso Bridge is a 373 ft bridge with a 286 ft long Pennsylvania through truss main span. These are a type of Pratt truss that includes a polygonal top chord, pins and cross-braces at different heights, and diagonal members that continue across several panels (see generic example below).
This type of design allowed lightweight structures and very long spans. It was named after the Pennsylvania Railroad that favored this design. We previously encountered this truss at the Healdsburg Bridge in Sonoma County.
E. H. Annear was the county engineer and Pacific Construction was the builder for this bridge in 1911. The bridge was retired from service when the new State Route 132 was built a little to the north in 1987. The Bridge was named after Angelo Basso (1846 to 1933) who operated a ferry across the Tuolumne River until the bridge was built at this site. Many bridges in the area were named after the previous ferry operator.
Creative Commons License
Sonoma County, California Bridges: Old Basso Bridge across the Tuolumne River by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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