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.

Fast track structural inspection, evaluation, and rehabilitative design for historic covered bridge damaged by debris during Tropical Storm Irene. The 293-ft, two-span covered bridge suffered significant, localized damage to truss, roof framing, and floor framing members. The bridge was immediately closed until repairs could be made.

The Town of Campton and their insurance carrier requested DuBois & King to evaluate the damage and to design rehabilitative measures to repair the bridge. 3G Construction, a specialized covered bridge contractor, teamed with DuBois & King to perform the repairs. Repairs included replacing several upper lateral bracing timbers, replacing truss diagonals and vertical tension rods, and repairs/splicing of truss verticals and floor beams. Repairs were also made to the damaged metal roof and roof rafters.

The Blair Covered Bridge is a vital link between residents and businesses in the east and west sections of the Town and is a destination for tourists. Closure of the bridge forced residents to use a 9 mile detour, thus making repairing the bridge a high priority for the Town. The Blair Covered Bridge is listed on the Historic National Register and New Hampshire State Register of Historic Places. 3G Construction and DuBois & King, as a design-build team, previously designed and repaired the Town’s Bump Covered Bridge.