Backcountry Bridges
Gadbury bridge with one post
The project that helped lure me into leading a crew for the Inyo National Forest last month was to build a bridge. Unfortunately, bureaucracy happened. The wilderness supervisor had wanted and planned for a native bridge (built with trees and rocks gathered at the site, pretty much the coolest project you can do on a trail) but then the higher ups mandated a strength that could only be achieved with glued laminated lumber. By the time the engineers, hydrologists, trail managers, and everyone else got on the same page and agreed on a design, it was too late in the season to get the specified materials and build it. So, no bridge; my crew spent the month building rock steps and waterbars, instead.
Gadbury bridge at Barney Lake
A couple of members of my crew did help another crew built this Gadbury bridge at the outlet of Barney Lake on the Duck Pass Trail. The classic Gadbury is a log split in two and put side by side so the fat end of one half is fit against the skinny end of the other, equalizing the width, though this bridge here is a lodge pole pine cut in half, instead of split, with the tops chiseled to make a flat surface. A wrap of wire set in a groove at each end holds the logs together, and the ends of the bridge sit on rock sills so they won’t rot as quickly as they would on dirt. Quick and easy to build, and solid to walk on. The SCA blog has a 60 second slideshow/video of a crew building one, makes me jealous. The video goes pretty fast, but you can see the process of putting together the abutments, the stringers, and the railing’s joinery.
bridge at Garnet Lake
bridge at Garnet Lake
This is what I was expecting to build from the initial project description. It uses two big logs, canted on the sides to fit flush together.
bridge at Garnet Lake
Pretty good if the bridge has been there since 10/63. The posts are newer, set with bolts, and the rails fitted together with lap joints.
bridge at Thousand Island Lake
bridge at Thousand Island Lake
There’s something really pleasing about a rustic bridge. I’m still going through the photos of the rock structures that my crew built when the bridge got postponed. I’ll probably post some of them soon.
— Update — Through the magic of blogging, I now have a photo of the Barney Lake bridge under construction with the old bridge beside it. Thanks BruceinPA for sending the photo.
bridge at Barney Lake
This entry was posted on Tuesday, September 1st, 2009 at 8:19 am and is filed under trails. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
