Bridging the Great Divide: Construction at Horton Grove

September 25, 2014

triangle land conservancy bridge

by Kyle Obermilller

In trail planning, you tend chose the path that follows the topography, a path that takes the hiker along the most beautiful and diverse sections of the property. More often than not, the trail will meander down to a creek or drainage both because it is beautiful and also because there is no better way to ease your mind than to relax to soothing sounds of a stream. When this occurs, a bridge usually has to be built so the trail can continue on its merry way. Building a bridge in the middle of the woods is no easy task, but is quite possibly the most fun part of my job.

Bridges can be as complex or simple as you make them. Bridge design must factor in the length, height, trail use, slope, weather patterns, flooding potential, and so much more. Up at Horton Grove, we have spent the past few weeks working on bridges on new trail sections. These range from small boardwalks of 10 feet to larger spans up to 34 feet in length. Steps and/or ramps will lead the trail onto these spans, which are constructed out of pressure treated pine for the base and locally milled cedar for the decking and hand-rails.

Building these monsters can be so much fun. From start to finish, it is a battle to keep everything level and even. The base must be level and straight on both sides before the stringers go on across the span. Cedar decking then comes down and is laid out across the bridge. Spacer blocks keep the cedar from getting too close to one another in order to let the decking drain rainwater and to increase the bridge’s life. The most fun part to me is when the decking is tacked in (usually one or two screws) and the drill team comes in to set it in more permanently. There are six screws per board, and about two deck boards each foot. On the 34 foot span, we have roughly 70 deck boards held down by six screws each. That brings us to a total of about 420 deck screws. Two or three people armed with battery powered impact drivers race across the bridge. The high pitched scream of the drills as we race board-by-board down the bridge sounds like the pit lane of the Indy 500.

So, next time you’re out walking down our trails and come to one of the many bridges we have out there, you can appreciate the down and dirty work that goes into them, knowing it is by far one of the greatest tasks of the job. Thanks for reading “The Dirt” and tune in next week for a look into my new task of the week, mega-monitoring Mondays where I’ll take you to some of TLC’s owned properties not opened to the public. Although it usually this occurs on Friday so I’ll have to come up with a more clever name by next week.

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