This bridge is a traditionally composed example of a pony truss bridge with pinned connections. The bridge continues to carry light vehicular traffic. During the site visit, HistoricBridges.org found that the bearings and
lower portions of the end posts were buried in dirt and gravel. The simple task of taking a shovel, broom, hose, or combination of the three getting this dirt away from the metal of the bridge would be a simple task that could be carried
out by county forces for little cost and would go a long way to preventing further deterioration of the bridge. While surface transportation funding and money is often limited, there really is no reason to not carry out such simple
maintenance tasks that will nevertheless provide significant benefits for the bridge.
Information and Findings From Ohio's Historic Bridge
The bridge carries a 1 lane, unimproved road over a stream in a sparsely developed, rural setting.
The skewed, 1 span, 41'-long, pin-connected Pratt pony truss bridge is supported on ashlar abutments. The trusses are traditionally composed of built-up compression members and eyebar tension members. Some
floorbeams have been strengthened by welding plate to the web.
Deterioration and impacted rust.
Summary of Significance
The ca. 1890 pin-connected Pratt pony truss bridge, although complete, is a short-span example that has no distinctive details or features. The builder and year built are not documented by available county
records. The not eligible recommendation of the prior inventory remains appropriate. It appears to be the work of the Massillon Bridge Co.
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the 19th century and continued to be built into the 20th century, although eventually superseded in popularity by Warren trusses.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'. 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.
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
Photo Galleries and Videos: Center Corners Fredericktown Bridge
Original / Full Size Photos A collection of overview and detail photos. This gallery offers photos in the highest available resolution and file size in a touch-friendly popup viewer. Alternatively, Browse Without Using Viewer
Mobile Optimized Photos A collection of overview and detail photos. This gallery features data-friendly, fast-loading photos in a touch-friendly popup viewer. Alternatively, Browse Without Using Viewer
Maps and Links: Center Corners Fredericktown Bridge
This historic bridge has been demolished. This map is shown for reference purposes only.