Bridges Completed at Vaughn Hills and Moen

The final assembly of the remaining bridges at the Vaughn Hills and Moen Conservation Areas was completed in November and early December 2024. The activity is part of the project funded under a state grant obtained by Cindy Ayotte.

Bolton Trails get a State Grant.

The “core” Bridge team of Larry Kunz, Keith Silver, Chris DeMers, and Gordon Taylor assisted contractors Bob Hatch and Stephanie Frend in removing and reusing old bridges, assembling the new structures, building ramps and smoothing approaches. A diverse group of additional volunteers helped on several occasions including Drew Schaubhut, Abbie Maguire, Betsy Taylor-Kennedy, Nicholas Costanzo, Lisa Costanzo, John Mortimer.

The FRP bridges are at locations VH1, VH6, VH7 and VH8

The new bridges replaced old structures and were designed and engineered by Bob Hatch and Stephanie Frend. Unlike the first group of wooden bridges, these were built largely with FRP (Fiber Reinforced Polymer) supporting a decking of polymer grid.

They were set on abutments made from recycled HDPE which were held in place by 1/2′ rebars sunk into the ground. As was the experience on the wooden bridges, locating and leveling the abutments was one of the most time consuming parts of the work. Another task that required patience and time was ensuring that the frame was a true rectangle; components were loosely bolted together while measurements from corner to corner and along the center and small adjustments were made until the bolts could be fully tightened.

The final surface was pea stone on top of a thick composite material (GT117) identified by Bob. The ramps were built with rocks found mostly from nearby, filled with “graded base” and the final surface was strengthened with a proprietary polymer material called “Triax”.

Bob’s tractor and small tracked dump truck (the DT15) were used extensively to move material and old bridges.

Removing the old “High Bridge” at VH7. The old wooden bridge is in excellent condition and was moved to another location (VH4) by attaching wheels and towing using the DT15. It now crosses the tributary to this brook

An extensive part of the project was moving materials to the sites. Bob’s DT15 dump truck was loaded with as much as possible, but progress with it was slow sometimes because there uneven terrain often threatened to cause the vehicle to tip up.

Moving tools and material to VH1 bridge location

Fully loaded DT15 crossing VH7 on its way to VH6

Occasionally members of the team had to hang on to the side of the DT15 to act as counter weights. In this case materials were being moved to VH6

The bridges had several lengths:

VH1 10′
VH4 10′
VH6 10′
VH7 18′

Assembly of the bridges required bolting together, pre-cut sections of FRP. In general three types profiles of FRP were used: an i-beam for the “spine” of the structure with “c-channel” pieces around the edges. FRP angle brackets were used to hold the various parts together. This arrangement is very strong and was able to support the fully loaded DT15 when it weighed ~6500 lbs as it moved gravel, FRP, decking, rocks and pea stone up to VH6 and VH4.