OH-56 Salt Creek Bridge

Information and Findings From Ohio's Historic Bridge Inventory

Setting/Context

The bridge carries a 2 lane road over a stream in a rural area of active farms.

Physical Description

The skewed, 1 span, 146'-long, riveted Parker pony truss bridge has built-up chords and rolled I section web members. The end posts are vertical, not sloped, as is characteristic of most Parker trusses of this period. The gusset plates have been shaped to have curvilinear edges, rather than straight edges, giving them a "webbed" appearance. The bridge has rolled floorbeams, stringer, and a concrete deck. The deck was replaced in 1985 and safety shape barriers placed to the roadway faces of the trusses. The bridge is supported on concrete abutments with U-shaped wingwalls finished with balustrades.

Integrity

The bridge was rehabilitated in 1985.

Summary of Significance

The Parker pony truss was fabricated by the Mt. Vernon Bridge Co. for the state highway department in 1935. It is a well-proportioned, although technologically late, example of the bridge type/design. It has nice aesthetic detailing, including the gusset plates and wingwalls. It speaks well of the bridge bureau's attention to design under the leadership of D. H. Overman. There is a similar thru truss in Richland County on SR 13 (7000243). The bridge was rehabilitated in 1985, which included replacing the deck. The project does not appear to have diminished the integrity or the ability of the bridge to convey its significance, and it was approved with no adverse effect by the SHPO. The prior inventory included the bridge in the reserve pool. It is recommended eligible.Camelback and Parker trusses are members of the Pratt-family of trusses with sloped top chords Technologically, Camelback and Parker trusses differ only in the number of top chord slopes (Camelbacks have exactly five slopes, and Parkers have more than five slopes.) The sloped-chord trusses provide the greatest depth at midspan where it is needed to accommodate the stresses, meaning that less material is needed in their construction as compared to a parallel chord truss of similar span, but fabrication is made more difficult due to the varying lengths of the members. The sloped-chord trusses are often associated with longer spans where the savings in material is great enough to be worth the additional fabrication costs. The practice of sloping the top chords dates to at least the 1840s and appeared early in the development of metal trusses. As with other truss designs, pin connections were used from the 1870s to 1900s, and mostly phased out during the 1910s. Rivet connections were being used by the early 1900s and were prevalent from the 1910s to 1940s. Standardized rivet-connected Camelback and Parker designs were used by many state highway departments, including the Ohio State Highway Department. There are 23 trusses (8 Camelback, 15 Parker) in the Ohio inventory (Phase 1A, 2008).

Justification

The bridge as a later example of a common type/design has a moderate level of significance. Of the over 140 examples built between 1897 and 1960, only 13 predate 1910.

Bridge Considered Historic By Survey: Yes