Orient Bridge

Information and Findings From Ohio's Historic Bridge Inventory

Setting/Context

The bridge has been closed to traffic and bypassed by a modern structure. It is open to pedestrians. The setting is rural with an abandoned grist mill located several hundred yards upstream. To the east are the grounds of the state correctional institution at Orient. A lengthy steel girder railroad viaduct crosses the valley to the south.

Physical Description

The 1 span, 225'-long, 15 panel, double-intersection Pratt (Whipple) truss is traditionally composed of built-up compression members and eyebar or rod tension members. It has built-up lattice portals with urn finials and decorative builders plaques. The upper lateral bracing has decorative quatrefoil cut outs. Due to the great depth and length of the truss, there is sublateral bracing composed of rods with turnbuckles. The floorbeams are supported from the lower-chord pins by U-shaped hangers. The floorbeams carry metal stringers and a plank deck. The bridge is supported on ashlar abutments.

Integrity

Welded repairs and strengthening measures noted at the end-panel floorbeam hangers and southeast end post and lower-chord section. Deck is in poor condition with many planks exhibiting rot and holes. Vegetation is entwining the ends of the bridge. Several trees are growing from the abutments or wingwalls causing damage. Some basic maintenance is required.

Summary of Significance

The 1885 double-intersection Pratt thru truss bridge is a complete and technologically significant example of an increasingly rare bridge type/design. There has been no significant changes in the bridge's integrity since the prior inventory, although it has been bypassed. The eligible recommendation remains appropriate. This is a rare extant example of the short-lived Ohio fabricator that Darnell curiously lists as being in business between 1884 and 1888. The 1880 (earlier than Darnell cites the company as being in operation) Stanton Station Road bridge in Hunterdon Co. NJ is another example of the company's work. Both bridges are thru trusses, but the details between the two bridges are very different. One similar to the New Jersey example was lost in Indiana (see bridgehunter.com for 1879 Iroquois River Bridge).

Double-intersection Pratt trusses, also known as Whipple or Murphy-Whipple trusses, were among the most successful of long-span thru truss designs (up to 300' long) of the 1860s to 1890s for both railroad and vehicular crossings. Surviving examples are uncommon nationally and considered technologically significant; Ohio with at least 14 identified examples dating from 1881 to 1898 (Phase 1A survey, 2008) has a very high number in comparison to most other states. The truss design is characterized by diagonals that extend over two panels. In 1847, Squire Whipple, one of America's foremost bridge engineers, developed the design figuring that the double-intersection configuration increased the depth of panel without altering the optimal angle of the diagonals, thus allowing for increased span length. His design was further refined in 1859 by John W. Murphy, the talented chief engineer of Pennsylvania's Lehigh Valley RR, who substituted wrought-iron pins for cast-iron connecting pieces, thus developing the connection detail that would prove to be advanced construction practice for this and other truss designs for the next several decades. Ohio's surviving examples, which mostly date to the 1880s, were not cutting edge for their time, but they show how the form had evolved into the preferred long-span thru truss design of the period. Most have documented associations with prominent Ohio-based fabricators.

Justification

The bridge is an example of bridge type/design important to the development and maturation of the pin-connected thru truss bridge. They date from 1881 and concentrated in the 1880s. Even though there are more than 12 extant examples in Ohio, each built in the 1880s has high significance based on overall scarcity (everywhere but in Ohio) of the design. This is a major and technologically significant bridge type. The bridge has high significance.

Notes

Bypassed. Field check 2/10/2000. Bridge in good condition over Big Darby Creek. No survey form/photos in the Pickaway County folder (June 2004). The old SFN 6503756 is now associated with the modern bridge that bypassed the truss. [New SFN is 6503764]

Bridge Considered Historic By Survey: Yes