A Horseshoe for the River

A Horseshoe for the River. . , In this 1928 photograph, men work on the horseshoe dam that extends from the trash sluice on which you stand. Hennepin History Museum, The first major attempt to tame the river was a rare collaboration between two competing businesses, the Saint Anthony Falls Water Power Company on the east bank and the Minneapolis Mill Company on the west bank., Each company built half of a dam that stretched across the entire river by 1858. Both sides began with a section perpendicular to the shoreline, then turned upstream to meet in the middle of the river. Water could pass over the "V"-shaped middle section, popularly known as the horseshoe dam. The other sections were taller and held mills driven by waterpower., The east side of the horseshoe, after being moved several times, landed in its current location in 1887. The trash sluice beneath you, which allows debris to go around rather than over the dam, was part of this reconstruction. The timber cribs that originally formed the horseshoe were reinforced with limestone in the 1880s and 1890s, and later capped with concrete., "'Sage of the River' Says Bridge Is Safe" , Engineers were concerned that the piers for the proposed Third Avenue Bridge would damage the delicate structure of the riverbed. William de la Barre, an expert on local river conditions, had opposed a 1912 proposal for a concrete-arch bridge just upstream from the falls. "The day is either at hand or not far distant when the city must construct a bridge at Third Avenue South," he concluded; "it is inevitable." Yet he was "suspicious" of the stability of the location proposed for one of the piers. He also feared that the piers might alter the river's flow and affect power generation for the waterpower companies he represented., Concrete piers were built first. Then arches were erected on timber "falsework," which was removed when the arches were finished. Minnesota Historical Society, City engineer Frederick Cappelen, who had directed the construction of six bridges over the Mississippi, also worried about the pier placement and rejected the design. A steel-truss alternative that he proposed was considered too ugly. He came back with a curved alignment for an arched design that avoided the unstable area and met with De la Barre's approval. Although the bridge before you appears to have a concrete-arch structure, it is largely steel, featuring a reinforcing system patented by Austrian engineer Joseph Melan in 1898. The 2,223'-foot long bridge was completed in 1918 at a cost of $860,000., Two plans were rejected before one was approved for the bridge between Third Avenue South on the west bank and First (now Central) Avenue Southeast on the east bank. Cableways hung from towers on the riverbanks to transport construction materials. A.M. Richter, "A 2,223-Ft. Concrete-Arch Bridge Built on Reverse Curve," Engineering News, December 30, 1915, courtesy of James J. Hill Reference Library, Saint Paul