Year constructed: 1915
Alternate name: Pearl Street Bridge
Bridge type: Concrete Filled Spandrel Arch
National Register of Historic Places status: Listed
Length: 64 feet
Width: 23.7 feet
Spans: 1
FHWA: 010310
Jurisdiction: City of Shellsburg
Location: SW Sells Street (Pearl Street) over Bear Creek in Shellsburg, Section 14, T84N-R9W (Canton Township)
Details
Located in downtown Shellsburg, near the eastern edge of Benton County, this medium-span concrete bridge carries Pearl Street across Bear Creek. The Shellsburg Bridge dates to 1915. That March the Benton County Board of Supervisors passed a Resolution of Necessity for the Construction of a new 60-foot concrete arch bridge at this crossing. Using a special design by the Iowa State Highway Commission, the county solicited proposals from bridge companies to build the structure. On April 24th, the county received bids from Alfred Vinall, the Miller-Hey Construction Company, the Waterloo Construction Company, N.M. Stark, the Iowa Bridge Company and the Missouri Ballast and Construction Company. The board awarded the contract to Vinall. He apparently completed the Shellsburg Bridge later that year for a total cost of $6081.06. Since that time the structure has functioned in place, with no substantial alterations.
The state highway commission designed numerous concrete structures in the 1910s, both as standard plans and special designs. These consisted of concrete slabs and culverts for short-span crossings and girders and arches for medium spans; for long-span applications, ISHC typically delineated arches. The highway commission eschewed ornamentation on its rural bridges as an unnescessary expense. Located in an urban setting, on the other hand, the Shellsburg Bridge featured a more studied architectural expressionk with bichrome concrete detailing, molded concrete balustrades and incised spandrel panels. In this it differed from the majority of concrete structures built in Iowa in the mid-1910s. With its handsomely detailed and proportioned 60-foot span, it is a well preserved, relatively early example of urban bridge design by the state highway commission.