Junction Road Hopewell 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 setting of active agriculture. Fields and/or wooded lots are at the bridge's adjacent quadrants. The road necks down at the 16'-wide bridge, which is on an S-curve.

Physical Description

The 1-span, 62'-long, pin-connected Pratt pony truss bridge is conventionally composed with built-up compression members and eyebar tension members. The upper chords are toe-out channels with cover plate and battens. At least two panels of the upper chord on one truss have been irreversibly altered by strengthening with beams bolted to the inside of the channels and the battens replaced by welding. The verticals are angles with lacing bars. The end posts have section loss and at least one has an irreversible welded repair with the addition of material as a strengthening measure. Sign posts have been welded to the end post cover plates. U-shaped hangers at the lower panel points support rolled floorbeams, but although this is the original connection method, it appears that several of the hangers have been replaced and several of the remaining older hangers are bent. The flooring system has been rebuilt/strengthened with extra lines of transverse floorbeams added between the panel points by welding the beams to the lower flanges of the stringers. The lower lateral cross-bracing rods have either been lost, damaged, and/or broken. Some rods have been welded to the floorbeams. The bridge has riveted lattice railings and a timber deck. The builder's plaque at the end post has been broken and half of it lost with only the words "Bridge Company, Muncie, Ind." remaining. The bridge is supported on concrete abutments.

Integrity

The integrity of original design has been impacted by irreversible welded repairs and strengthening measures (upper chord, end posts, lower lateral bracing). The repairs are judged to date ca. 1970.

Summary of Significance

The ca. 1905 Pratt pony truss bridge is conventionally composed and a later example of its design by the Indiana Bridge Co. (IBCo), a prolific builder in Indiana and adjacent states. None of the truss details are technologically significant. As well, there are alterations that have had an impact on the integrity of design. There are more complete and distinguished examples of pin-connected trusses in the county, including some distinguished examples by this fabricator (6842364, 6833861, 6831826, 6838235). Although the date of construction of this bridge is not documented by available county engineering records, it is judged ca. 1905 based on the conventional design and comparison with other documented IBCo bridges in the county, which all date to the mid to late 1900s. The not eligible recommendation of the prior ODOT inventory remains appropriate.

IBCo of Muncie, Ind., was organized in 1886, acquiring the assets of the Indianapolis Bridge Co., which had failed, with plans to move the machinery to Muncie. By 1889, the company was producing more than 100 bridges annually. IBCo's primary market was Indiana counties, but it also sold to counties in adjacent states and made an effort during the late 1890s and early 1900s to expand its market to the south and west building as far south as Louisiana and as far west as Iowa. The company also had some success selling bridges in western Ohio counties, like Preble. The Indiana DOT bridge survey (1987) reported that IBCo truss bridges were among the most numerous built and surviving in the state, and generally were "simple" and "minimally decorated." After 1910, IBCo continued to build bridges, but finding that the truss bridge market was shrinking, it became better known for its steel-frame buildings. The company still is in operation under the name of Indiana Bridge Midvale Steel as a fabricator of structural-steel buildings and components.

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. Ohio has three covered bridges that use this combination configuration, but they are all modern reconstructions based on the Pratt patent. 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'. Significant surviving examples of all-metal Pratt trusses mostly date to the last quarter of the 19th century, and they are found with thru, pony, and the less common bedstead configuration. Prior to about 1890, a variety of panel point connections were in widespread use (including bolts, cast-iron pieces, and pins), but engineering opinion was coalescing around pins as the most efficient and constructible. Many of the connection details were proprietary and associated with individual builders or companies, and thus earlier examples are generally taken to be technologically significant in showing the evolution of the design. Later 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. This marked the end of the pin-connected Pratt's technological evolution and, in fact, it was soon waning and eclipsed in the highway bridge market by more rigid, rivet-connected truss designs, particularly the Warren but also riveted Pratts. The transition to riveted connections, which happened even earlier with railroads than highways, was in no small part due to concerns about stress reversals at the pins under heavier loads and improvements in pneumatic field riveting equipment in the early 1900s. In Ohio, Pratt truss highway bridges, whether pinned or riveted, were almost always built under the auspices of counties and local units of government; the Pratt was not a standard design of the state highway department.

In Ohio, there are 185 Pratt trusses dating from ca. 1874 to 1945 with at least 60 dating prior to 1900 (Phase 1A, 2008). The technologically significant unaltered examples of pin-connected Pratt trusses for the most part date prior to 1900 and have documented or attributed builders and dates of construction and/or significant connection or member details. Later post-1900 examples are less technologically significant. Significant unaltered examples of riveted-connected Pratt trusses date from ca. 1900 to 1915.

Bridge Considered Historic By Survey: No