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Black Canyon Road Bridge

Photos 

Photo taken by Historic American Engineering Record

View photos at Library of Congress

BH Photo #159211

Map 

Description 

The Black Canyon Road Bridge is a concrete arch bridge that exemplifies the technological innovation known as the Thomas Three-Hinge System. The bridge is one of only three existing examples designed by William Thomas in California. It is remarkably unaltered and its original setting is still intact. The bridge was determined eligible for the National Register of Historic Places during a 1987 California Historic Bridges Survey by the California Department of Transportation.

-- Historic American Engineering Record

Facts 

Overview
Open spandrel Concrete arch bridge over Santa Ysabel Creek on Black Canyon Road
Location
San Diego County, California
Status
Open to traffic
History
Built 1913
Builders
- Thomas & Post (Design Firm)
- William M. Thomas (Design Engineer)
Design
Open spandrel concrete deck arch
Dimensions
Length of largest span: 80.1 ft.
Total length: 125.0 ft.
Deck width: 20.0 ft.
Recognition
Eligible for the National Register of Historic Places
Approximate latitude, longitude
+33.12389, -116.80000   (decimal degrees)
33°07'26" N, 116°47'60" W   (degrees°minutes'seconds")
Approximate UTM coordinates
11/518657/3665039 (zone/easting/northing)
Quadrangle map:
Ramona
Inventory numbers
CA 57C-361 (California bridge number)
BH 11406 (Bridgehunter.com ID)
Inspection (as of 07/2009)
Deck condition rating: Serious (3 out of 9)
Superstructure condition rating: Poor (4 out of 9)
Substructure condition rating: Poor (4 out of 9)
Appraisal: Structurally deficient
Sufficiency rating: 16.5 (out of 100)
Average daily traffic (as of 1991)
150

Update Log 

  • April 30, 2011: Updated by Craig Philpott: corrected spelling
  • June 3, 2010: Updated by Craig Philpott: refined design
  • March 27, 2010: New photos from Jason Smith

Sources 

  • Jason Smith - flensburg [dot] bridgehunter [dot] av [at] googlemail [dot] com
  • Craig Philpott - craigphilpott63 [at] gmail [dot] com
  • HAER CA-264 - Black Canyon Road Bridge, Spanning Santa Ysabel Creek at intersection of Black Canyon & Sutherland Dam Roads, Ramona, San Diego County, CA