C&NW Red Cedar River Bridge

Located in Menomonie, this lattice through truss bridge carries the former Chicago, St. Paul, Minneapolis & Omaha Railway Menomonie branch over the Red Cedar River and Stokke Trail (former Chicago, Milwaukee, St. Paul & Pacific Railroad). The first bridge at this location consisted of two 150-foot timber Howe through truss spans, approached by timber pile trestle spans. This bridge was last upgraded in 1893 with new trusses. As railroad traffic became heavier, wooden trusses were no longer suitable, and a permanent structure was desired. In 1921, the two truss spans would be replaced by a pair of secondhand steel through truss spans. The piers and timber approaches were renewed in 1941, and a steel stringer span was installed over the Milwaukee Road line in 1951, giving the bridge its present configuration. Currently, the bridge consists of two 150-foot, riveted quadrangular lattice through truss span, approached by four timber pile trestle spans on the south end. The north approach is comprised of seven timber pile trestle spans, a 35-foot steel stringer, and seven more timber pile trestle spans. The main piers of the bridge are set onto concrete pedestans, while the remaining substructures are composed of timber piles. The north end of the bridge is set onto a sweeping curve, and the steel stringer span is set at a heavy skew. An unknown contractor constructed the concrete bases for the piers.

The south truss span was reportedly fabricated in 1892, and the north truss span was fabricated in approximately 1890. Both truss spans were fabricated by the Lassig Bridge & Iron Works. This firm fabricated dozens of these lattice trusses for the Omaha Road and the Chicago & North Western during the late 19th Century. The truss spans were reused from unknown locations. It is possible that the two trusses were reused from spans across the Red Cedar River at Rice Lake, Wisconsin and across the St. Croix River at Gordon, Wisconsin. These two bridges were constructed in 1892 and 1891, respectively; and were both replaced in approximately 1920. Both spans use a standard design for the era, including a pedimented portal bracing with decorative heel bracing, a combination of built-up and solid members and a traditionally composed floor. Typical of this type of span, the bottom chord is constructed of two parallel beams, while the endposts and upper chord are composed of built-up beams with X-lacing on the back/bottom. Rolled members are used for the compression members near the ends of the truss, while inner compression members are constructed of V-laced members. The steel stringer span is traditionally composed for the era, using four shallow beams, arranged into two sets of two. Reportedly, this span was fabricated in 1951, but it is unknown if it could possibly be older.

This type of truss design is relatively uncommon throughout the United States. However, a few railroads preferred the design, such as the Chicago, Rock Island & Pacific Railway (Rock Island), the Chicago & North Western Railway (C&NW) and the Omaha Road. Spans constructed in the early 1880s for the Omaha Road featured an arched and pedimented lattice portal bracing, light sway bracing and laced members. The second generation was nearly exclusively constructed by Lassig Bridge & Iron Works between 1884 and 1900, and featured heavier members and a pedimented portal bracing. While the design fell out of favor for the Rock Island and Omaha Road around the turn of the 20th Century, the design remained popular with the C&NW into the 1920s. The discontinuance of the lattice design is one of the few examples of the Omaha Road and C&NW bridge engineers having differing thoughts on bridge designs. This particular span uses a design typical for the second generation of quadrangular lattice through trusses. Railroads often reused steel and iron spans, as it provided a cost effective way to rebuild bridges on branch lines without requiring large amounts of new material. Overall, the bridge appears to be in fair condition, with no significant deterioration noted. The bridge has been acquired by the City of Menomonie for potential future trail use. The author hopes that this bridge will be reused and preserved for generations to come. The author has ranked this bridge as being regionally significant, due to the truss design, age, size and unclear history.