CN Soldier Creek Bridge (Fort Dodge)

Located in Fort Dodge, this deck plate girder bridge carries a former Illinois Central Railroad mainline over Soldier Creek. The first bridges here consisted of a wooden Howe deck truss span, set onto stone piers and approached by timber pile trestle spans. The stone piers were most likely constructed in approximately 1870, as the railroad extended west. It is believed that the bridge was renewed at various times between the 1870s and 1890s. Between 1898 and 1901, the IC made significant improvements to this line, replacing many of the remaining timber bridges with concrete and steel structures. Between 1898 and 1899, this bridge was entirely rebuilt. A 77-foot deck plate girder span was installed, and the bridge rebuilt with concrete T-shaped abutments abutting the original stone piers. Frank Egan, an IC employee, oversaw the work of constructing the abutments, and John Matthews, a contractor from Galena, Illinois erected the new girder span. It is likely that the girder was fabricated by the American Bridge Works of Chicago, Illinois, which was fabricating steel bridges for the IC at the time. In 1936, the abutments were altered by constructing concrete encasements around the 1898-era work. The present structure was installed in 1946 as part of a larger improvement program along the IC. As part of the work, the original girder was replaced and the original stone piers were encased with concrete. It is possible that the original span was reused elsewhere after replacement.

Currently, the bridge consists of a 77-foot deck plate girder span, set onto stone and concrete abutments. The superstructure follows a standard design, with two heavy plate girders and an open deck. The substructures use a variety of designs, including concrete encased stonework and rebuilt abutments. T-shaped abutments were popular with the IC, as they allowed for a natural grade to be carried to the base of the bridge. American Bridge Company fabricated the superstructure, while an unknown contractor constructed the original stone piers; IC employee Frank Egan constructed the original abutments and unknown contractors encased and rebuilt the abutments and piers in 1936 and 1946. Deck plate girder spans were popular for railroad use, as they were durable and easy to construct. Encasing structures in concrete was a popular method with the IC, as it was a proven method to rehabilitate existing structures at a low cost. Since the 1946 reconstruction, the bridge has seen no significant alterations, and remains in regular use. Overall, the bridge appears to be in fair to good condition, with minor spalling noted on the abutments. The authr has ranked this bridge as being locally significant, due to the common design.