Stemen Road Covered Bridge, Pickerington Ohio
The Stemen Road Covered Bridge was a locally-produced example of the truss design by William Howe which had widespread impact upon timber bridge construction through the whole second half of the nineteenth century.
County records show that the Commissioners contracted on August 10, 1888 with the Columbus Bridge Company for the construction of the span. That company operated in Columbus, Ohio, between 1885 and 1895. Price for the Stemen Road bridge was $500.75. Records show that there was no road at this point before 1866. What kind of span, if any, crossed Sycamore Creek at this point between 1866 and 1888 is not known.
The Howe truss dates from 1838 and revolutionized wooden bridge construction by its use of vertical tension rods. These replaced wooden members which were unsuitable for resisting tensile forces. Howe's design was patented, and between 1838 and 1846 the design underwent various modifications and improvements. During the second half of the nineteenth century the Howe truss was widely used in road and railroad bridges. The Stemen Road Covered Bridge is important as a modest example of this important invention.
The Columbus Bridge Company built the Stemen Road span under Howe's patent. Though short-lived, this firm had substantial facilities at its Columbus plant and supplied a large variety of iron products, both decorative and structural. It was best known for its metal bridges of various designs, and the fact that it also built timber spans has only recently become known.
The following description is of the bridge prior to its destruction by arson on June 18, 1985.
The Stemen Road Covered Bridge is a single-lane six-panel wooden Howe truss covered bridge. It dates from 1888 and is named for adjacent landowners by the name of Steman. County records occasionally refer to the bridge as the Stemen House Bridge, the name apparently a corruption of "Howe" or "Howe's."
Truss length is 70'6" and height is 14'4". The end panels are 12'5" in length and the four middle panels are 11'5". Upper and lower chords are pairs of 8"X13-3/4" timbers bolted together and mortised to receive the diagonal compression members. Single diagonals are 4"X8" timbers and paired diagonals each are 6"X7-l/2". In typical Howe truss fashion, the single diagonals pass between the paired ones, and where they join at the upper and lower chords paired 1-1/8" diameter iron rods pass through the upper and lower chords and provide resistance to tensile forces. The Howe truss is known for its innovative use of wrought iron tension rods. End posts are made up of four 3-l/2"X6" timbers and are vertical.
The portals are inclined at about 60 degrees, making the span look longer than it really is by about five feet at each end. Siding is plain vertical boards nailed to stringers which are fastened directly to the trusses. There are no side windows, but ventilation space of about 18" has been left between the eaves of the roof and the top of the siding. The gables above the portals have board and batten siding. Except for the roof, all the material in the bridge appears to be original or at least of considerable age. In 1970 and again in 1977 the roof suffered wind damage, the 1970 damage resulting in a new roof on the entire structure. Present roof is corrugated sheet metal.
Abutments and wing walls are regular ashlar sandstone and are in excellent condition.
The floor beams are supported by the tension rods and carry stringers to which the plank flooring is attached. The floor, like the rest of the structure, is in good condition and is posted for a five-ton weight limit. However, in December of 1978 a truck driver ignored the weight limit and attempted to take a 30-ton truck across the bridge. The floor collapsed for about half the length of the span, but no other damage occurred and the damage to the floor could be easily repaired.