Wednesday, January 2, 2013

Nevada County, California Bridges: Donner Summit Bridge (2)

December 2012 (39.3196 Degrees, -120.3189 Degrees) Donner Summit Bridge
This is as close to the Donner Summit Bridge as I could get in a pair of running shoes.

Apparently, the 1996 rehabilitation (and seismic retrofit) of this bridge was quite extensive, as reported on Syblon Reid Contractor's Website. Very tall shoring was used while the spandrel columns were replaced. The abutments and arch bases were strengthened. The deck was widened and safer barrier rails were installed. The project was completed on time even though 20 feet of snow had to be removed in June to gain access to the bridge site.

The Donner Summit Historical Society Website discusses the activities of people at this site during the past thousands of years. The ancestors of the Washo People carved petroglyphs in rocks at this site more than 1500 years ago. The surviving members of the Donner Party were rescued here. The first transcontinental highway (the Lincoln Highway) and the first transcontinental railway were constructed here.

The history of Highway 40 and the Donner Summit Bridge is available on several websites. Before the bridge was constructed, Highway 40 had grades as high as 18%. When I-80 was completed in 1964 Highway 40 was given to Nevada County. The bridge was so deteriorated from the harsh weather that the county originally planned to remove it. However, the Donner Summit Community worked hard with fundraising campaigns, letter writing campaigns, etc and the bridge was preserved.

Several newspapers reported that in 2007 a bear became stuck on one of the arch ribs after being frightened by traffic. The bear was sedated and fell into a net placed under the rib. The net was lowered to the ground and the bear eventually wandered off.
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Nevada County, California Bridges: Donner Summit Bridge (2) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.

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