Year constructed: 1910
Bridge type: Concrete Luten Arch
National Register of Historic Places status:
Listed
Length: 68 feet
Width: 15.5 feet
Spans: 1
FHWA: 244550
Jurisdiction: Marshall County
Location: 140th Street over Minerva Creek, 1.7 miles north of Clemons, Section 27, T85N-R20W (Liberty Township)
Details
Before 1908 Marshall County had contracted with an array of bridge builders for an even wider array of bridge types, ranging from simple timber pile structures to long-span, iron or steel trusses. In 1908, however, the county began dealing exclusively with Des Moines contractor N.M. Stark for substantial concrete bridges. Stark built concrete girders and slabs for the county, and for longer-span crossings he build concrete arches. For the arches he used a patented design by Indianapolis engineer Daniel Luten. Luten's arch featured a filled spandrel configuration with a distinctive horseshoe-shaped profile. As a licensee for Luten, Stark built numerous Luten arches throughout the state, but Marshall County remained one of his better clients in the early 1910s. In April 1910, after soliciting competitive bids, the Marshall County Board of Supervisors awarded a construction contract to Stark for six concrete bridges. Designed from Luten's standards by county engineer W.W. Morehouse, these similarly detailed filled spandrel arches were distributed throughout the county. They ranged in span length from 30 feet to 60 feet and collectively cost $14,090 to build. Stark completed all six structures by the end of the year. This single-span bridge over Minerva Creek in Liberty Township, designated as Bridge Number 217, was the longest of the six and cost $2,660. It featured a cambered deck and solid concrete parapet walls with incised panels. Since its construction in 1910, the Minerva Creek Bridge has carried local traffic in essentially unaltered condition.
Marshall County's almost exclusive dealings with Stark were to end in 1913, however, when the state legislature passed the Brockway-Balkema Act that April. The new legislation codified bridge contracting procedures and standardized bridge design under the aegis of the reorganized Iowa State Highway Commission (ISHC). N.M. Stark built numerous Luten arches in Iowa between 1905 and 1913, but relatively few remain in place today. The Minerva Creek Bridge is distinguished among these survivors for its long span and well-preserved condition. It is today a noteworthy, transportation-related resource [adapted from Fraser 1989].