Chicago & North Western Railway Bridge #419

Located on the northeast of Benoit, this deck truss viaduct carries the former Chicago, St. Paul, Minneapolis & Omaha Railway over an unnamed tributary of North Fish Creek. The first bridge at this location was a tall timber pile trestle bridge, constructed when the line was first built. During the late 1880s and early 1890s, the Omaha Road made significant upgrades to this route, replacing timber bridges with steel and stone. This bridge was constructed in 1891 to replace the previous timber bridge. Currently, the bridge consists of a 80-foot, 7-panel riveted double intersection Warren deck truss span, approached by two 60-foot deck plate girder spans and two 20-foot deck plate girder tower spans. The bridge is set onto steel towers and stone substructures. The towers are composed of a combination of laced and slender solid members, which rest on stone piers. Lassig Bridge & Iron Works fabricated the truss span, while an unknown contractor completed the substructures. Typical of bridges in this area, the stonework was quarried at an unknown location, and consists of a reddish colored stone. The truss span consists of a combination of solid and laced members, typical of spans of this design. The viaduct is an impressive 60-plus feet above the surrounding valley.

While lattice truss spans were relatively uncommon through the United States, the Chicago & North Western Railway (C&NW) and Omaha Road used the design extensively. Other railroads in the Midwest also occasionally used the design, although not as frequently. Engineers for the C&NW and Omaha Road favored the design, due to its resilience and greater strength without sacrificing economy. Metal lattice truss designs were initially developed for railroad use in the 1870s, often using deep spans with numerous intersections. Through the mid-1880s, short to medium length spans were simplified into double intersection spans, as seen on this bridge. Most lattice spans through the 1880s and 1890s were constructed by the Lassig Bridge & Iron Works, which produced a vast majority of iron and steel bridges for the C&NW and Omaha Road during this era. While the Omaha Road stopped using lattice trusses in the early 20th Century, the C&NW continued to use lattice truss designs nearly exclusively into the 1920s. This shift represents one of the few known instances where C&NW and Omaha Road engineers had differing opinions on bridge design. Since abandonment, the deck of the bridge has been removed, and the bridge has become the property of Bayfield County. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The bridge retains a high level of historical and structural integrity. The author has ranked this bridge as being moderately significant, due to the truss design, age and imposing nature of this bridge.