Rocky Fork Road Bridge

Information and Findings From Ohio's Historic Bridge Inventory

Setting/Context

The bridge carries a 2 lane road over a stream in a sparsely developed, rural setting.

Physical Description

The 1 span, 108'-long rivet-connected Warren pony truss has polygonal upper chord and verticals. The members are rolled sections.

Summary of Significance

"The 1928 Warren pony truss is a representative example of its type/design. It has riveted connections, typical of Warren trusses from about 1910 into the 1950s. It has no innovative or distinctive details, and it is not an early example of its type, design, or construction. It was advanced from reserve pool to select in 1994, presumably due to its documented builder and length, which is at the upper range of pony trusses. In comparison with the statewide population and the context of riveted truss bridge, it is not historically or technologically significant. It is recommended as not eligible. Warren trusses are the most common 20th century truss design found in Ohio and the nation. The Ohio Phase 1A survey (2008) has identified more than 500 examples dating from 1897 to 1961, accounting for well over half of the approximately 800 pre-1961 metal trusses. The Warren design was particularly well suited to rigid (riveted, and later welded connections), but not as well suited to pin connections; this helps to explain its popularity in the 20th century rather than the 19th century, although it is based on a British patent issued to engineers James Warren and Willoughby Monzani in 1848. In the U.S., the popularity of the Warren truss coincided with improvements in pneumatic field riveting equipment starting about 1900. The Warren, which is based on a series of equilateral triangles, is identified by its simplicity of design, ease of construction with equal-sized members, and ability of some diagonals to act in both tensions and compression. Warren trusses are often stiffened by the addition of verticals; they can also have polygonal (sloped) upper chords to achieve greatest depth at midspan. Warren trusses were a standard design of the Ohio State Highway Department in the 1910s and 1920s, but they achieved their greatest popularity with county engineers, who purchased the bridges from Ohio fabricators such as the Champion Bridge Co. and the Mt. Vernon Bridge Co."

Bridge Considered Historic By Survey: No