Pigtail bridge
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A pigtail bridge is a type of road bridge, where the road curls and passes over itself. This allows the road to negotiate sharp changes in topography in limited space. Most pigtail bridges are found in the Black Hills of South Dakota, where they were first built.
The pigtail bridge design was invented in 1932 by Cecil Clyde Gideon, the self-taught superintendent of Custer State Park turned highway designer. He called them “spiral-jumpoffs”. During the planning for Iron Mountain Road, there was a need to negotiate sudden elevation drops while preserving natural features for this scenic highway; the corkscrew design allowed for a spectacular - although expensive - solution to this problem. In order to blend the bridges with their surroundings, natural materials such as local timber were used.
Most pigtail bridges were built by the Civilian Conservation Corps in the 1930's.
[edit] Notable Pigtail Bridges
- Three bridges on Iron Mountain Road
- One bridge on South Dakota state highway 87, in Wind Cave National Park
[edit] References
- Bernie Hunhoff, The Man Who Designed the Pigtails, South Dakota Magazine, 27 July 2006,
- Jim Pisarowicz, Pigtail Bridge, Wind Cave National Park, National Park Service
- Brochure, Welcome to the Peter Norbeck Scenic Byway, United States Forest Service
- Missouri River Bridges of South Dakota, 1920 to 1980, interview of Kenneth R. Scurr, Former South Dakota Bridge Engineer, by Emory Johnson, So. Dakota State University
