Mount Orne Covered Bridge

Lancaster, New Hampshire

The Mount Orne Bridge is a 266-ft-long, two span structure constructed in 1911. The bridge spans the Connecticut River, connecting Lancaster, New Hampshire, with Lunenburg, Vermont. This span utilizes four Howe type trusses, spaced 16 ft apart for a one-lane bridge.

Following a truck accident at the bridge, DuBois & King was selected by the Town of Lancaster and the Town’s insurance carrier to evaluate damage to the bridge, design repairs, and administer implementation of repairs during construction.

The bridge was struck by an oversized tractor-trailer, which resulted in considerable damage to the bridge. The extent of damage included the total destruction of the east portal (NH side portal) and numerous upper lateral bracing members. Damage also occurred to top chord truss members on the upstream and downstream east spans and on the west portal siding.

Design of repairs included the replacement of several upper lateral bracing timbers, reconstruction of the top chords of the east truss spans, reconstruction of the east portal and siding, and repairs to the west portal siding. Repairs were also made to the damaged metal roof and roof rafters at the east end of the bridge. A construction estimate for needed repairs was provided to the Town and the Insurance Carrier. Construction of repairs and replacement members was completed in three months.