Covered Bridges on Two Wheels

Dover Road, on which this bridge is located, is a popular short-cut road. The pounding of everyday traffic, including school buses and emergency equipment took its toll on the bridge. And of course, very few original covered bridges can handle the weight of today's extremely heavy fire equipment. In order to prolong its life, many attempts to strengthen the bridge were undertaken.

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My research thus far has led to conflicting stories as to timelines and repairs attempted. To the best of my knowledge, this is a brief summary. At some point (thought to be around 1950), steel I-beams were installed replacing the wooden floor beams under the deck. These were subsequently removed in 1979 and replaced with wood once again along with an ill-conceived modification to the lattice. The lattice work led to wracking, bowing and the introduction of a negative camber to the bridge... sure signs the bridge was failing.

In 1980 huge glue-laminated beams were installed to keep the bridge from collapsing. The Google Street View images captured in 2009, and currently the most recent images, show the beams as you "pass through" the bridge. At one point during this troubled existence, the east end of the bridge was apparently raised to keep water from running down the hill into it. Reportedly this was unpopular with the locals and the bridge was subsequently lowered back down on that end, once again letting water in. Of course, wood that gets a constant soaking is not ideal.

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Finally, in 2001, the Vermont Historic Covered Bridge Committee began discussion on how to best preserve the bridge. While various methods were discussed, it ultimately was decided that the bridge could not remain as-is with the demands of traffic in this area. A faithful replica of the original bridge was constructed with almost the exact same dimensions. In order to achieve the strength needed, the dimensions of the two top chords, and the upper bottom chord were increased slightly. The lower bottom chord (which is out of sight, below the floor) was constructed of glu-lam beams. The floor beams, which in the original bridge had gone from wood to steel and back to wood again, are now glu-lam beams as well. The lattice members are the same dimensions as the original.

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The net effect? The replica bridge, from all angles above the floor, looks like a covered bridge constructed with traditional materials. It's not until you peek underneath do you see the modern glue-laminated beams used. While glu-lam may be modern, the construction techniques remain authentic. A well-designed solution.