Red Cedar State Trail - Gilbert Creek Bridge

Located on the south side of Menomonie, this bridge carries the Red Cedar State Trail over Gilbert Creek. The previous bridges at this location consisted of timber pile trestle structures, which were periodically renewed. In 1944, the bridge would be rebuilt with the current structure, using a secondhand truss span. Currently, the bridge consists of a standard 98-foot, 6-panel, pin-connected Pratt pony truss span, set onto timber pile substructures. The main span is approached by three timber pile trestle spans on the south end, and four timber pile trestle spans on the north end. The truss span uses a standard design, with a traditionally composed floor, heavy members and large pin connections. Typical of spans of this design, the endposts and top chord consist of built-up members, which use a plate on one side and X-lacing on the back side. The vertical members of the truss are composed of solid beams, and the bottom chord is composed of built-up members, with heavy X-lacing. The floor is composed of two large girders for stringers, and large floorbeams. The diagonals of the truss consist of eyebars, and the counters are constructed of slender rods.

The truss span was originally fabricated in 1900 by the Lassig Bridge & Iron Works, which fabricated many spans using this design in the late 1890s. Originally, the bridge was located at Bridge #Z-708 across the Wapsipinicon River at Olin, Iowa. When that line was double tracked in 1913, the single track bridge was replaced by a larger double track truss bridge, and the three spans reused at various locations in Lincoln County, Wisconsin. One span was reused at Bridge #G-368 across the Pine River south of Merrill, Wisconsin, where it continues to serve railroad traffic today. Another span was reused at Bridge #G-1900; located across the Copper River on the New Wood line a few miles northwest of Merrill. The third span was reused at Bridge #G-1904; located across the New Wood River on the New Wood line in rural Lincoln County. After the New Wood line was abandoned in 1943, the steel spans were removed, and reused at other locations. The span from Bridge #G-1900 was reused at this location, and the span from Bridge #G-1904 was reused at an unknown location.

This style of span was used extensively by the Milwaukee Road. First developed in the mid-1890s, the design provided a strong and cost effective span for medium length spans. A number of different span lengths were developed using this design, although the spans largely used very similar design features. Typical of Milwaukee Road bridges, a number of different contractors built these spans, depending on which firm offered the best price. Dozens of examples of similar spans were constructed throughout the Midwest, and many continue to survive today. Railroads often reused steel and iron spans, as it was a cost effective way to rebuild bridges without requiring large amounts of new material. Often, when a span was no longer sufficient for mainline use, it could be reused on a branch line. As was the case with this bridge, occasionally the branch line would be abandoned, and the span would be moved a second time. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being moderately significant, due to the truss design.