Big Slough Creek Bridge

Bancroft Ave. over Big Slough Cr., Nichols, Iowa

Photos 

Overview Looking Southwest

Photo taken by J.R. Manning in August 2013

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Description 

Located west of Nichols, this small-scale concrete bridge carries a gravel-surfaced county road over Hockeys Slough. The bridge consists of a single-span concrete rigid-frame structure, supported by concrete abutments. Although its dimensions are modest--spanning only 45 feet--the structural configuration of the bridge is noteworthy. The slightly arched, continuous reinforced concrete slab is tied rigidly into the abutments, forming a rigid-frame structure. The Iowa State Highway Commission designed the structure in the spring of 1937. Using the ISHC design, Muscatine County solicited competitive proposals and in June awarded a contract for this bridge and two others to Otto Wendling of Muscatine. Presumably completed later that year, this structure has functioned in place since, in unaltered condition. With notable engineers such as Thomas McDonald and Conde McCullough on its staff, the Iowa State Highway Commission was from the beginning a leader among state highway agencies in the standardization of bridge design. Immediately after its re-organization in 1913, ISHC began developing design standards for several short-span structural types. But within this framework of standardization, ISHC was continuously experimenting with innovative applications of existing and new technologies. This diminutive bridge in Muscatine County is evidently the result of ISHC experimentation. It and the other bridges let in the June 1937 contract employed rigid-frame configurations; this one uses a reinforced concrete slab. Further research is needed to determine the purpose and circumstances of this exercise, but it appears that the bridge is a formative application by ISHC in concrete rigid-frame. The Hockeys Slough Bridge was not the first concrete rigid frame bridge designed by ISHC. It is today distinguished as one of few such rigid-frame bridges (and the only rigid-frame slab) in Iowa-- an important transportation-related resource [adapted from Fraser 1991].

National Register information 

Status
Posted to the National Register of Historic Places on May 15, 1998
Reference number
98000492
Architectural style
Other architectural type; concrete rigid frame
Area of significance
Engineering
Level of significance
State
Evaluation criteria
C - Design/Construction
Property type
Structure
Historic function
Road-related
Current function
Road-related
Period of significance
1925-1949
Significant year
1937

Update Log 

  • September 15, 2013: Updated by J.R. Manning: Updated Status, Added Description and Added Photos

Sources