UP Forked Creek Bridge (Wilmington)

Located in Wilmington, this deck girder bridge once carried the former Chicago & Alton Railroad over Forked Creek near Kankakee Street. The first bridge at this location was likely a timber pile trestle, constructed when the line was first built. In 1884, the bridge was rebuilt with a four span deck plate girder bridge as part of a double tracking project. During the mid-1880s, the C&A invested significant capital into constructing new iron and stone bridges to replace timber bridges. By the 20th Century, the bridge had become too light for traffic, and would be rebuilt. In 1929, the southbound (west) track would be replaced with new deck plate girder spans. The following year, a spur track would be added to the west face of the bridge, giving the structure its final appearance.

At the time of replacement, the bridge consisted of four 41-foot deck plate girder spans, set onto stone and concrete substructures. During the 1929-1930 reconstruction, the original stonework was encased in concrete, and the substructures extended for the third track. The west and center track both used a standard design, consisting of heavy girders and heavy bracing. The east track used a typical design for the mid-1880s, with lightweight girders, separate stringers and a lower lateral bracing which used slender iron rods. The superstructure was fabricated by three different contractors, with Detroit Bridge & Iron Works fabricating the east track; American Bridge Company fabricating the center track and McClintic-Marshall Corporation fabricating the west track. The substructures were constructed by unknown contractors.

Deck plate girder spans were commonly used by railroads, as they were durable and easy to construct. These types of spans evolved significantly since originally being introduced in the late 1870s, as evidenced by the spans on this bridge. In 2017, the bridge would be replaced by a new single track girder span as part of a high-speed rail project, and a second track was added to the new bridge in 2023. The new bridge reuses portions of the original stone abutments, which were reconstructed to accommodate the modern superstructure. Overall, the bridge was in fair condition at the time of replacement, but did not meet the needs of the proposed high-speed rail coordinator. While a historic report of the corridor evaluated this bridge and determined it was "unremarkable", the author strongly disagrees with this assessment. Very few girder spans from before 1890 remain intact today, and this bridge was an excellent example of such a span with minimal alterations. The author has ranked the bridge as being locally significant, due to the common design and older age.