Harpersfield Covered Bridge, Harpersfield Ohio
At one time, covered wooden bridges of over 500' in length were not uncommon in Ohio, but today, the Harpersfield Covered Bridge is of special significance because at 243' it is the longest such bridge remaining in the state. It is said that this bridge was built in 1873 by a carpenter by the name of Potter. The bridge takes its name from the village of Harpersfield. This area was the site of a grist and saw mill and the mill stream enters the Grand River at the dam which is just to the east of the bridge. A waterworks that generated electricity was built here in 1901. The road became part of the state highway system in the early 1930s and was known as SR 534. The state relocated the highway to the east and the bridge reverted to the county highway system in 1962.
The structure is a 2-span wooden truss covered bridge spanning the Grand River in Harpersfield Township, county road 154 at Harpersfield in Ashtabula County, Ohio. This old bridge has the typical high-boarded, vertical siding, a shingle roof and straight portals with overhang. The south abutment is the original cut-stone, while the center pier and northern piers are concrete.
The Harpersfield Bridge was built in 1873 on the Howe truss plan which was patented in 1840 by William Howe of Spencer, Mass. The Howe truss was a great advance in bridge engineering because it introduced the use of iron rods for the first time in a bridge truss. These iron rods could be tightened up by means of turnbuckles if necessary to straighten a sagging bridge and this made the Howe truss extremely popular with both the railroads and highway bridge builders. The Howe truss has wooden braces and counterbraces in the shape of X's with iron rods as the verticals. The Harpersfield Bridge is a 2-span Howe truss with a truss length of 236' and a clear span length of 230'. The total length of the bridge is 243', making it the longest covered bridge in the state. These measurements do not include the 142' steel truss span at the north end of the covered spans. The overall width of the bridge is 20'8" and the roadway width is 13'10". The overhead clearance is 11'10". The floor is laid lengthwise and is 2" x 6" pine. The top chords are 2-4" x 8" and 1-12" x 8* and the bottom chords are 4-5" x 5½" timbers. The chords and truss members are all of untreated pine. The siding is 1" pine boards. The roof is 2" x 6" rafters sheeted with ½" x 4' x 8' sheets of plywood and covered with spruce green heavy asphalt shingles.
The Harpersfield Bridge is and always has been unpainted. It was originally a 2-span covered bridge, but the great flood of 1913 cut a new channel around the north end of the bridge, necessitating the addition of the steel truss. It is believed that at that time, the original north abutment and center pier were either washed out completely or so badly damaged, that when the steel span was built, entirely new concrete piers and abutment were built. The south abutment is still the original cut-stone. Heavy snows of 1962-63 collapsed the roof and the bridge was closed while a new roof was put on. The original roof had been put on with square-cut nails. In November 1963, all the siding was replaced with the 1" pine boards mentioned above. According to the county engineer's office, the steel piers under the covered spans have been added in the past years as needed.
North portal and east side looking southwest (1975)
South portal and east side looking northwest (1975)
