Collison Trestle

Located between Collison and Jamesburg, this large deck truss bridge carries the former Chicago & Eastern Illinois Railroad across the Middle Fork Vermillion River. Constructed in 1893, this bridge was one of the original structures construed on the Rossville-Sidell line. The bridge consists of a 130-foot, 10-panel, pin-connected Warren deck truss span, approached by a 30-foot and a 60-foot deck plate girder span on either end. The bridge is set onto stone substructures and steel towers, and is set approximately 60 feet above the river. The stonework was constructed by the MacArthur Brothers Company, which had the contract for constructing the line. An unknown contractor fabricated the superstructure, although it is plausible that the Detroit Bridge & Iron Works fabricated the structure. Stone for the substructures was quarried at an unknown location, but appears to be a greyish limestone.

The deck truss span uses a unique design, which is balanced on towers supported by larger stone piers. While most deck truss spans used a vertical end frame at the ends of the spans, this bridge uses a diagonal endpost, which contains a middle connection. Members of the truss span consist of built-up compression members and solid tension members. The floor of the truss span uses an unusual design, where the ties are set directly onto the upper chord. In addition, while the 30-foot deck plate girder span appears to be a standard tower span, the 60-foot deck plate girder spans use a "fishbelly" design, which was required due to the dimensions of the towers. These towers use built-up members, and are anchored to stone piers and pedestals. Similar viaducts were constructed across the Okaw and Kaskaskia Rivers in 1892 and 1896, respectively. The Kaskaskia River viaduct was fabricated by the Detroit Bridge & Iron Works, which appears to have constructed numerous spans for the C&EI. Warren trusses became popular in the 20th Century, but were mainly constructed as riveted structures. This bridge uses a rare pin-connected version of the Warren truss design. Since the initial construction, the bridge has seen relatively few alterations. Connections of the truss span were reinforced in the 20th Century with high strength bolts, and some minor repairs were made to the stonework. Currently, the bridge is sitting abandoned, and its future is uncertain. Overall, the bridge appears to be in poor condition. While the superstructure is in good condition, a portion of the north river pier (pier #2) has begun to fail, and will eventually result in the collapse of the bridge if left untreated. The author has ranked this bridge as being highly significant, due to the truss design, age and size of the bridge.