Located west of Mt. Carroll, this unique pony truss bridge has been recycled for another use.
Originally built in 1872 as a 5-panel pin connected Pratt Pony Truss railroad bridge at an unknown location, the truss was disassembled and moved here in 1906. Upon reconstruction, it appears that new floor beams were added, likely of scrap components.
Upon relocation, the bridge was set onto timber substructures and approached by trestle. The bridge has served as a road bridge since then, allowing cars to safely cross above the busy mainline below.
Reusing railroad spans for overpasses is not a unique thing. However, over 95% of the original population of railroad bridges reused for road have been replaced.
The truss is extremely significant, due to the old age. It appears some modifications were made to the trusses themselves, but otherwise, they are largely unaltered. It is unknown where the truss came from, but it was likely a heavily constructed railroad span on a mainline.
Unfortunately, it looks like this one might meet the same fate as most others. The road has been closed since at least 2017, due to structural issues throughout the bridge. Unfortunately, the bridge is scheduled for demolition in the early 2020s.
Among the biggest issues is the south approach, which has begun to deteriorate significantly. Holes in the approach pavement indicate the abutment was compromised. The last time the timber components were replaced was in 1950, when both approaches were replaced.
Fortunately, the truss appears to remain in better condition than the rest of the bridge. However, the floorbeams are significantly deteriorated at the connections, although the truss members are not deteriorated. This furthers the evidence that the floorbeams were made of scrap material.
Overall, the bridge remains in a deteriorated and closed condition. While the approaches of the bridge are likely too far gone to be saved, the truss could feasibly be used elsewhere as a driveway or pedestrian bridge with some upgrades.
The author has ranked this bridge as being nationally significant, due to the unique example of a truss reused for road use.
The photo above is an overview.