Tuesday, April 16, 2013

Amador County, California Bridges: Middle Bar Bridge across the Mokelumne River (2)

February 2013 (38.29778°, -120.75000°) Middle Bar Bridge
The Middle Bar Bridge has many nice features such as the stamped plates above the bridge portals, the concrete curbs to protect the truss members (and pedestrians) from vehicles, the laced handrails and truss members, the riveted top and bottom chords, etc. The deck is a corrugated steel plate covered in bitumen. I wonder if this bridge was considered innovative when it was built? My feeling is that even in 1912 this was considered an old fashioned bridge for a back country road.

Unfortunately, this historic bridge is beginning to show the effects of time. It currently has a sufficiency rating of only 35.7 out of 100, mainly due to the limited load-carrying capacity of the truss. However, the bridge looks in pretty good shape and it only carried 70 vehicles a day in 2011.
Creative Commons License
Amador County, California Bridges: Middle Bar Bridge across the Mokelumne River (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

No comments: