By Craig Rawlings, FBN Editor
What should we do with all the small-diameter beetle-kill wood in the West? Some sharp minds and innovative products just might bring us one step closer to solving that dilemma.
One of those products was born in my own backyard. A few years ago, a very large partnership of local residents, recreationists, organizations and agencies worked together to build an innovative, 90-foot-long cable suspension bridge in the Rattlesnake National Recreation Area near Missoula, Montana. I was working at the Montana Community Development Corporation at the time and played a role in this effort myself by helping secure the U.S. Forest Service funding for it.
The final product is no ordinary bridge though. Designed by Brad Miller of HDR Inc., this crossing showcases the first ever use of lodgepole pine and small-diameter waste wood for a bridge. The pine is from beetle-killed trees in the Nez Perce National Forest. The decking is made from recycled plastic and sawdust and is the first demonstrated use of this product under a grant from the U.S. Navy. And the design allows individual wood members to be replaced as needed. Pretty cool stuff indeed, for what serves as a strong model for the use of under-utilized timber.
This summer, Brad, and co-author Tom Gorman, P.E. Ph.D. University of Idaho, wrote a whitepaper that takes the use of low-value, beetle-kill wood a step further. Essentially, they’ve designed and researched new techniques that use roundwood for wood i-beams and zig-zag decking. Extensive testing by the University of Idaho has shown high strength and favorable results using this ordinarily low-value wood. Their paper gives a good case for the suitability of these applications for pedestrian and short-span road bridges and other building construction beam applications. Click here to read their report (PDF).
Innovative and sustainably designed, locally manufactured new products that improve forest health and get people back to work sounds like a win-win to me. Please let Brad know your thoughts or suggestions on his designs in the comment section below. And if you know of other small diameter timber designs, we’d value your input!