This bridge crosses Old Bean Creek which is so-named because
the current Bean Creek is a manmade drain just north of this creek, where the
CR-22 Bridge, a through truss, crosses.
This bridge has a different rusting paint scheme than the through truss. This
bridge has unusual v-laced railings present on it. The overwhelming majority of
truss bridge railings are latticed, not v-laced. The bridge is seated on
concrete abutments. A wood deck is barely remaining on the bridge. Vertical
members are v-laced. Battens are present under the top chord and end post. The
bridge is composed of four panels.
Information and Findings From Ohio's Historic Bridge
The bridge carries an abandoned road over a stream in a sparsely developed, rural setting.
The 1 span, pin-connected Pratt pony truss bridge is traditionally composed with built-up compression members and eyebar or rod tension members. The deck is gone.
Summary of Significance
According to ODOT's environmental review files, this abandoned bridge is former SFN 2634716, which was a surveyed non-select bridge in 1981. The 1919 pin-connected Pratt thru truss bridge is a very late example
of a common type/design and has no distinctive details or features. The builder is not documented by available county records. The not eligible recommendation of the prior inventory remains appropriate.
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design of the last quarter of the 19th century and continued to be built into the 20th century, although eventually superseded in popularity by Warren trusses.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
Photo Galleries and Videos: CR-22 Old Bean Creek Bridge