Power House Covered Bridge, Johnson Vermont
- Categories:
- Vermont
- Covered Bridges
- Queenpost Truss
The Power House Covered Bridge stands a short distance downstream from a former municipal hydroelectric generating station at cascades of the Gihon River. The bridge was built in 1870, twenty-five years before the generating station from which it derives its present name. The Power House bridge is one of three covered wood bridges remaining in the town of Johnson.
The covered bridges of Vermont are among its most cherished and symbolic historic resources. About one hundred of the bridges still stand in the state, the highest concentration by area of covered bridges in the United States.
Bridge Description
The Power House Covered Bridge consists of a single span supported by two flanking timber queenpost trusses. Each truss incorporates five iron suspension rods that extend from the upper apexes of the diagonal braces to the bottom chords. Triangular steel plates have been added to reinforce the joints between the lower ends of the principal diagonal members and the bottom chords at the ends of the trusses. The structure rests on abutments that have been either faced or rebuilt with concrete.
The Power House bridge is 63.5 feet long at floor level. The ends of the side walls flare outward to meet the gable ends, which overhang the floor 4.5 feet at each portal. The bridge is 19 feet wide and has a 16-foot roadway. The wood floor, which consists of planks laid flat and perpendicular to the trusses, is 57 feet long; it begins 2.5 feet inside the west portal and four feet inside the east portal. The approaches are paved.
On the exterior, the timbers pegged together to form the trusses (and side walls) of the bridge are sheathed with unpainted board and battens hung vertically. Unpainted flush boards hung vertically protect the lower ends of the trusses immediately inside the portals. The siding stops short of the eaves to leave strip openings along the tops of the walls. There are three large rectangular windows spaced regularly along each upper wall.
The gable ends are sheathed with unpainted flush boards hung vertically. The portal openings are rectangular. The medium-pitch gable roof, which does not overhang the gable ends, is covered with wood shingles.
South elevation and east portal (1974)
