Bridge L4013 on Township Road 126 over dry stream bed
Bridge number: L4013
Year built: 1915
Engineer: Alfred J. Rasmussen
Overall length: 12 feet, 6 inches
Overall width: 18 feet, 2 inches
Adapted from the National Register of Historic Places nomination form prepared by Jeffery A. Hess. Bridge No. L-4013 was listed on the National Register of Historic Places in 1990.
Bridge No. L-4013 is a singe-span, stone-arch bridge that carries an unpaved east-west road over a branch of Riceford Creek. Located in a wooded rural area of Houston County about 8 miles west of the Caledonia, the bridge is built of coursed-ashlar, buff-colored limestone. The bridge displays a semicircular arch with a 12-foot, 6-inch span. The limestone matches farmstead foundations in the general vicinity, strongly suggesting a local origin for the stone. The quarry has not been identified. The voussoirs are well-blocked and uniform, measuring 8 inches in width and 12 inches in height. Joints are about 1-inch thick. Except for a few crude patches of repainting, the mortar has almost completely disintegrated from the intrados joints. The arch, however, retains its shape without any signs of settling. The arch springs about 4 feet above grade from sharply defined impost ledges that extend outward from the intrados about 6 inches. Constructed on a slight skew, the bridge has an overall width of approximately 18 feet. Spandrel walls are continuous with slightly flared wing walls. To protect the foundations from the scour, the stream bed under the bridge has been paved in concrete. Photographs from the 1950s and 1960s show stone parapet walls with pipe-metal railings on both sides of the roadway. These features have been removed, leaving a ragged masonry line flush with the roadway. None of the alterations affects the bridge's most significant elements, which are the design of the impost ledges and the configuration of the arch itself.
Bridge No. L-4013 is historically significant for the engineering embodied in the bridge design and construction. Constructed in 1915, the structure is important as the only surviving, authenticated example of an early 20th century, state-designed, stone-arch bridge. Since its design is replicated in other counties, the bridge provides strong evidence that the Minnesota State Highway Commission attempted to standardize stone-arch bridge construction in much the same way that it sought to create uniformity in the design of steel and concrete bridges.
The Minnesota State Highway Commission was officially organized in 1905 to improve the quality of roads and bridges in the state. To fulfill its responsibilities, the commission assigned field engineers to assist county governments with highway projects and prepared a series of standard bridge plans. Standardized bridge plans are known for beam spans, plat girders, low and high trusses, reinforced concrete slab and girder bridges. Although commission reports do not mention a stone-arch plan, the commission's field engineers apparently had at their disposal a standard short-span design appropriate for the limestone region of southeastern Minnesota. In January, 1915, for example, Houston County requested Alfred J. Rasmussen, the commission's engineer for that county to make a survey and draw plans for a bridge in Section 20 (southwest quarter of northwest quarter) of Black Hammer Township. The county approved the plans a month later. Although county records provide no further information on the project, the bridge presumably was built by the end of the summer.
Constructed in 1915, the structure is important as the only surviving, authenticated example of an early 20th century, state-designed, stone-arch bridge. Since its design is replicated in other counties, the bridge provides strong evidence that the Minnesota State Highway Commission attempted to standardize stone-arch bridge construction in much the same way that it sought to create uniformity in the design of steel and concrete bridges.