CR-557 Bridge

Information and Findings From Michigan Historic Sites Online

Narrative Description

This single-span concrete steel bridge carries County Road 557 across the West Branch of the Escanaba River. The structure is configured as a 75-foot, steel stringer bridge, with rolled I-beams supported simply by massive concrete abutments with straight wingwalls. The outside webs of the spandrel stringers have been encased in concrete with a coved profile, giving the bridge an all-concrete appearence. The stringers carry a concrete deck, which has been surfaced with asphalt. This deck is bounded on both sides by MSHD standard concrete guardrails with classical fluted balusters and paneled bulkheads. Although unaltered, the West Branch Bridge has experienced serious concrete spalling on its guardrails.

Statement of Significance

Early in 1928 engineers for the Michigan State Highway Department delineated this concrete/steel bridge in Marquette County. The department designated the structure as Bridge B1 of 52-17-21 and in March awarded a contract for its construction to the P.J. Nickel Company of Ironwood. Nickel used a steel superstructure fabrication by the Massillon Bridge and Structural Company of Massillon, Ohio, to complete the West Branch Bridge later that year. Total contract cost: $20,016.19. Since its completion, the bridge has functioned in place, in essentially unaltered condition. The bridge's steel stringer configuration is one that MSHD used extensively for bridges in the 1930s and 1940s. Although the highway department had delineated a standard steel stringer design as early as the 1905-1906 biennium, the relatively shallow I-beams that were being fabricated by the steel mills limited their span - first to 30 feet, later 45 feet. When the mills began producing deeper beams in the late 1920s, MSHD could extend the spans of its steel stringer bridges. "When this type of structure was first put to use, "MSHD stated in 1930", rolled sections of sufficient strength were not available for spans greater than forty-five feet. It was necessary, therefore, to use relatively shallow fabricated deck girders for spans greater than forty-five feet. Rather recently, however, steel mills have improved their methods and are able to furnish rolled sections which, on proper spacing, are suitable for spans up to sixty feet." Built in 1928 with a span length of 75 feet, the West Branch Bridge is technologically significant as one of the first truly long-span stringer bridges undertaken by the highway department.