Andover, NH is home to two covered bridges. The first bridge is the Keniston Bridge built over the Blackwater River in 1882 by Albert R. Hamilton at a cost of $745.57.
The lattice work on the side is not just ornamental but also provides support for the bridge. A lattice truss structure allows a substantial bridge to be made using planks and lower-skilled labor, rather than heavy timbers and more expensive carpenters. It’s also easier to handle and move planks rather than timbers.
The town rehabilitated the bridge in 1981. To do work on the foundation or abutments, the engineers lifted it from its foundation using two cranes and moved it to a temporary site. The problem was that the site was only a few feet above the water level. The engineers had to work quickly to finish fixing the abutments and return the bridge to its place before heavy rains and rising waters caused the river to rise and damage the bridge.