BNSF US-75 Bridge (Hull, North)

Located northwest of Hull, this steel stringer bridge is the northern crossing of a former Great Northern Railway mainline over US Highway 75. In the 1930s, the Iowa Highway Commission began improving state-maintained highways throughout Iowa. One of the projects selected was to relocate US Highway 75 to a straighter alignment between Perkins, Iowa and Rock Rapids, Iowa. Contracts for the project were awarded in 1930, and construction began that summer. As part of the project, two similar underpasses would be constructed under the GN tracks northwest of Hull, which were completed in 1931. Currently, the bridge consists of a 30-foot and two 26-foot steel stringer spans, set onto concrete substructures. The superstructure follows a standard design, with six shallow beams arranged into two sets of three and an open deck. The substructures also follow a standard design, with rectangular piers and square abutments with short parallel wing walls. An unknown contractor fabricated the superstructure, and an additional unknown contractor constructed the substructures. Steel stringer spans were commonly used by railroads, as they were durable and easy to construct. The only significant alterations to the bridge came in the 1990s or early 2000s, when the outer beams of the main span were replaced, likely due to repeated truck strikes. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being locally significant, due to the common design.