Tish Creek Trail in Cascade Locks, Oregon, is located in a narrow gorge within a larger gorge along the Columbia River. Many hikers enjoy the trail for its beautiful scenery in all four seasons, and more come hoping to see the endangered northern spotted owls that nest in the area.
The trail included a pedestrian bridge made of steel and wood, but the bridge was no match for a devastating storm and collapsed. As the Columbia forest service considered all the requirements for a replacement, their search led them to a Bedford pedestrian bridge.
Meeting All The Challenges
The forest service’s list of requirements was long. As the failed steel-and-wood bridge proved, a bridge on the Tish Creek Trail would need to stand up to high winds and not buckle under the weight of heavy snow. It would need to be made of material that would remain stable and safe for decades. It would ideally have a look that helped it blend in with the scenery rather than be an eyesore. And — kind of a big deal — it needed to be installed in one day.
Only a Bedford ReadySpan pedestrian bridge checked every box:
- ReadySpan bridges are made with fiberglass-reinforced plastic (FRP), which won’t corrode, rot or warp and is also resistant to insects.
- Pound for pound, FRP provides the strength of steel at significantly less weight, and the Bedford engineering team ensures each design will meet the structural specifications. For the Tish Creek Trail, the 3-foot-wide by 40-foot-long bridge was designed and built to meet 90 psf for pedestrian traffic, 50 psf for snow and 20 psf for wind.
- The Tish Creek Trail pedestrian bridge from Bedford is brown with a cedar deck, so it meshes well with the landscape.
As for the quick installation: Because ReadySpan bridges are lightweight for easy transport to the installation site and assemble quickly with ordinary tools, most assemblies are handled onsite. In this case, the forest service had one day to install the bridge before the northern spotted owl nesting season began, which would require a delay of months. The Bedford team preassembled the bridge offsite, then it was helicoptered into position and secured to meet the deadline. Check out the Cascade Locks case study for news footage of the installation.
Q&A With ReadySpan Account Manager, Ted Harris
Q: How did the Columbia forest service know that a Bedford FRP bridge would meet their needs and handle the weather?
HARRIS: ReadySpan pedestrian, equestrian or light vehicle bridges are custom designed to meet our clients' load conditions to handle the various types of traffic. Our engineering team analyzes pedestrian, vehicle, snow, wind and seismic loads for each and every ReadySpan bridge. Bedford also includes a structural analysis at no cost to ensure that your bridge is just right for its intended use.
Q: The Tish Creek Trail required a 40-foot bridge. How long can a ReadySpan bridge be?
HARRIS: ReadySpan bridges provide our clients with clear span structures that can span up to 100 linear feet without any intermediary supports.
Q: What are other typical applications for ReadySpan bridges?
HARRIS: ReadySpan bridges can be used for state and county park trails, national park service trails, US forest service trails, greenways and other underdeveloped areas that have trail networks, municipalities and inner city parks, homeowners associations, golf courses, industrial applications within tank farms, water and sewage treatment facilities, and dam water control access. These industrial applications can require all types of bridges or crossing structures needed for maintenance and operations.
Whatever your bridge need, the ReadySpan team is here to help. Reach out with questions, request a quote or call 814-623-8125 to discuss your project.