Personal Reflections and Perspectives on Trail Bridge Building

Since 2009, Dennis Rawe has made a significant contribution to the design and construction of stiles and bridges for the Avon Trail. He has spent many hours sharing his expertise and over-seeing these projects.  In this article, he shares his thoughts and experiences.

I have a reputation for walking around the job site with my hands behind my back, and it is a fact — I do. There is a good reason for this.  I take some pride in providing work for as many members as I can. As they work I direct them and answer questions – and they love it. For many years I worked as a design engineer in the electronics industry and had to solve problems constantly – with some success. Having retired,  I missed the joy of design and innovation, until, that is, the Avon Trail needed stiles and bridges, challenges which I seized with fervour. I downloaded the Bruce Trail construction manual and learned the preferred style of building ‘trail hardware’. Costing materials and cost reduction exercises came easily as did adapting preferred methods to our needs.

The difficulty in the early days (2009) was in finding a construction crew.  Volunteers love to be useful so the trick is to provide enough to do simultaneously with enough equipment – this makes a successful crew. So the design of stiles, boardwalk sections and bridges needed to be within our capabilities with the efficient use of standard sized materials.

The specifications for each project were deduced rather than requested, the materials were selected so that a piece of trail hardware might last at least five years, hence pressure treated lumber and coated deck screws were used. The width of the stile treads and the bridge deck was set (for uniformity) at 30 inches meaning that four treads or slats could be efficiently cut from a standard dimension piece of lumber, namely 2x6x120” . Similarly the turns on the boardwalk were ‘standardized’ so that any angle in change of direction could be calculated easily.

Standard dimension lumber comes from the base dimension of a ‘board foot’ so the time the board is cut to a smaller size, due to the width of the saw blade, a 2×6 measures 1.5” x 5.5”. One Avon Trail standard that was set was a 0.5” gap between each deck slat so that there were two per foot, making calculations easy.

Weight was another consideration since the material had to be ‘carried in’, and sometimes a long way. Luckily the landowners have been very accommodating and allowed either driving across country or they have tractored it in. Several members of the Avon Trail have been farmers and have proven very capable when it comes to practical solutions. For example, the trundling of heavy eight foot sections of boardwalk is difficult over rough ground between trees. Rick Horst quickly came up with a single wheel as an under carriage – screwed midway to the BW section on its side. It took the weight allowing two stalwarts the freedom to maneuver.

Having the right equipment and plenty of room to work makes a big difference. One 24’ foot bridge was installed by just two members (one a farmer with a tractor) – this time the farmer had a ‘come along‘, a long strong wire with a ratchet, fixed to a tree stump at one end and the bridge at the other. Just enough to pull the bridge onto its other base.

Things do go wrong occasionally. One 24’ bridge loaded onto a hay wagon was backed up to a very deep ditch and slid off slowly onto the base already in position. Unfortunately a slight misjudgment caused the bridge to tilt into the water just after the cameraman had stepped off. Again farmer skill to the rescue – a rope, skids and hiker-power pulled it up into position.

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