The first thing that stands out about this pin-connected 1898 through truss bridge is how wide it is, even for a bridge built on a major urban road during this time it is very wide. Its overhead bracing also includes a longitudinal bracing running down the middle. This design hints that this is a bridge originally designed to accomodate a roadway with a streetcar. Perhaps due to this design, offering not only a wider roadway but also a heavier design, likely helped make this bridge feasible to rehabilitate (albeit heavilly) and preserve in the 21st Century. This is in fact what happened and the bridge remains open to significant downtown traffic as a result.
The bridge is a rare surviving example of a 19th Century pin-connected truss bridge built to serve a major city road. Most bridges in this type of location (busy/important city street) were demolished and replaced long ago with wider, stronger bridges. This bridge therefore offers a rare glimpse into what city bridges in the 1800s looked like.
While overall the preservation of this bridge is a great outcome and the bridge is a positive asset for the community, the rehabilitation of this bridge has a number of shortcomings that could have been avoided and still met the needs of the crossing however.
First, modern A325 bolts were used instead of historically correct rivets. The number of rivets replaced on this bridge is huge. It barely looks like a riveted bridge anymore. Further, the supplemental plates added to this bridge are all bolted as well. When you look at this bridge you see bolts, it is unavoidable. Rivets are not only historically accurate, but they simply look nicer.
Second, if you are going to hot dip galvanize a pin-connected truss bridge, you might want to consider either galvanizing or using stainless steel for the pins. The new pins on this bridge are neither and they have completely rusted, and this rust has streaked down all over the trusses below. It looks horrible. This does not make sense, because many engineers specify stainless steel for replacement pins. Why was this not done here?
The sidewalk railings on the bridge are modern, but are clearly designed to hint at the design of a historical arched latticed railing design. These are galvanized. The original railings on this bridge had cast iron posts at the ends. These were salvaged and reused on the bridge. However, much like the pins on this bridge this effort appears to have been a poorly executed afterthought. They were not galvanized (which might not be possible with cast iron), but neither were they painted a color that resembles the greyish/silver of galvanizing. Instead they were painted black so they don't harmonize with the rest of the bridge. Also, holes (likely for the original railing attachments) were left open on these posts. It doesn't take a genius to predict what happened here: people have stuffed trash and other junk inside the holes.
Information and Findings From Ohio's Historic Bridge Inventory
The bridge carries a 2 lane street over a stream in downtown Newark.
The 1 span, 157'-long, pin-connected Pratt thru truss bridge is traditionally composed of built-up compression members and eyebar or rod tension members. It has lattice portal bracing and upper lateral bracing. There are cantilevered sidewalks with lattice railings. The bridge is very wide for an 1898 bridge.
Rehabilitated in 2002.
Summary of Significance
"The 1898 pin-connected Pratt thru truss was sensitively rehabilitated in 2002 with a finding of no adverse effect. The 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."
The bridge is one of over 150 extant pin-connected truss bridges dating from 1874 for pony trusses and 1876 for thru trusses. Twenty six predate 1888 and represent the era of experimentation that evolved into standardized designs by about 1888. This example has moderate significance because the genre and the fabricator are so well represented in Ohio.
Bridge Considered Historic By Survey: Yes
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