This bridge is a rare surviving example of a pre-1900 bridge built by the Mt. Vernon Bridge Company. This company became prolific in the 20th Century in fabricating parts for bridges, including large bridges. However, very few example survive from this company's early years as an 19th Century bridge builder. The bridge's most unusual detail is the complete lack of sway bracing or struts. Only lateral bracing is used. Rather than using tension rods for the lateral bracing, heavier angle is used and is bolted to the truss, likely a requirement of the extra work the lateral bracing must do without any struts. The bridge also has unusual hip verticals, which ends at the bottom chord with two loops, rather than one as found in typical eyebars. This design is commonly found on bridges built by the Wrought Iron Bridge Company, but is a detail that the Mt. Vernon Bridge Company used on more than one bridge as well.
Despite the significant number of historic truss bridges remaining in Morrow County (as of 2012), this bridge stands out as one of the most unusual, unique, and significant bridges in Morrow County.
HistoricBridges.org was absolutely aghast to find that this bridge was found Ineligible for the National Register of Historic Places in 2009 by the state's Historic Bridge Inventory. Firstly, HistoricBridges.org's position is that any pin-connected through truss that has fair or better historic integrity should be considered eligible, given their rarity, both in the state and nationwide. No state retains a population of pin-connected through trusses great enough to justify writing off such bridges as non-historic. However, most disturbing is the fact that the Historic Bridge Inventory does not consider the unusual prong-like detail for the hip verticals as noteworthy. Further, the bizarre fact that this bridge was built with absolutely no struts or sway bracing of any kind, and relies only on lateral bracing is completely ignored by the inventory! While the Morse Bridge Company built some bridges with this detail, the lack of struts or sway bracing on through trusses in the 19th Century is otherwise unheard of, and it is the only known example of the Mt. Vernon Bridge Company to display this detail. Furthermore, the inventory fails to acknowledge the rarity of pre-1900 Mt. Vernon Bridge Company bridges. These bridges are essential to document the history of a bridge company that seems to have been more prolific in the 20th Century.
Information and Findings From Ohio's Historic Bridge Inventory
The bridge carries a 1 lane rural road over a stream in a rural area of active farms. The bridge is on a vertical crest.
The 1 span, 85'-long, pin-connected Pratt thru truss bridge is supported on one ashlar abutment and one stone abutment. The trusses are traditionally composed with built-up compression members and eyebar tension members. The same prong-like connection used by the Wrought Iron Bridge Co. is used for the end panel floorbeam connections. Field splices were completed using bolts. The previously closed bridge was repaired by OBC in 2000.
Impact damage. Severe section loss.
Summary of Significance
The pin connected thru truss bridge is one of at least two fabricated by the Mount Vernon Bridge Co. and erected in the county in 1887. The company was established in 1880. Despite its age and the documented work of an in-state fabricator, the bridge has no innovative or distinctive details save for the floorbeam hangers, but that detail it not unique to the fabricator. The truss members are heavily rusted. This example, while pre-1890, is not historically or technologically significant. Pratt trusses were undoubtedly the most popular truss design of the last quarter of the 19th century and continued to be built into the 20th century, although eventually superseded in popularity by Warren trusses. The design, which initially was a combination of wood compression and iron tension members, was patented in 1844 by Thomas & Caleb Pratt. The great advantage of the Pratt over other designs was the relative ease of calculating the distribution of stresses. More significantly, it translated well into an all-metal design in lengths of less than 200'. Post-1890 Pratt trusses show a progression toward less variation in their details such that by 1900 the design was quite formulaic with few significant differences between the designs of various builders. In Ohio, there are 185 Pratt trusses dating from ca. 1874 to 1945 with at least 140 dating prior to 1900 (Phase 1A, 2008).
Bridge Considered Historic By Survey: No
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