Center Rd./ Tittabawassee RiverCounty: Saginaw
City/Township: St. James Twp.
Location: Center Rd./ Tittabawassee River
Year Built: 1927 About this Bridge: This multiple-span concrete/steel bridge carries Center Road across the Tittabawassee River in the southwestern quadrant of the city of Saginaw. The structure is configured as five 65-foot, steel stringer spans, with nine lines of rolled I-beams supported simply by massive concrete abutments and spill-through piers. The outside webs of the spandrel stringers have been encased in concrete with a coved profile, giving the bridge and all-concrete appearance. The stringers carry a concrete deck, which is bounded on both sides by MSHD standard concrete guardrails with classical fluted balusters and paneled bulkheads. Although unaltered, the Tittabawassee River Bridge has experienced some concrete spalling on its guardrails and spandrels. In the summer of 1926 engineers for the Michigan State Highway Department delineated this concrete/steel bridge over the Tittabasassee River. Located just south of Saginaw, the county seat, the bridge as proposed by the county road commission would carry Center Street. The department funded the structure as a State Reward bridge and in July awarded a contract for its construction to the Willits Brothers Construction Company of Bay City. Willits used a steel superstructure fabricated by the American Bridge Company to complete the bridge that following year. Total cost: almost $71,000. Since its completion, the Tittabawassee River 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 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 to 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 in use,” MSHD stated in 1930, “rolled sections of sufficient strength were not available for spans greater than about 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 1927 with a span length of 65 feet, the Tittabawassee River Bridge is representative of MSHD long-span beam bridge design of the 1920s.