UP Sheboygan River Bridge (East)

Located in Sheboygan, this large deck truss bridge carries the former Chicago & North Western Railway mainline over the Sheboygan River, New Jersey Avenue and 17th Street. In the early 20th Century, the C&NW made a number of improvements to the system, constructing cutoffs, bypasses and new mainlines at strategic locations to improve freight operations. While the investments cost millions of Dollars in capital, the new lines would help streamline freight service, bypassing congested port cities and passenger depots. One of the early improvements consisted of constructing a cutoff around Sheboygan, leaving the existing mainline on the south side of the city and rejoining it on the north side of the city. The new cutoff featured a large bridge over the Sheboygan River, which eliminated the need for a swing bridge, which delayed existing operations. Contracts for the cutoff were awarded in late 1905, and the cutoff was constructed in 1906. The bridge across the Sheboygan River initially consisted of two deck truss spans, approached by a deck plate girder span across 17th Street on the north bank of the river and three deck plate girder spans over an existing C&NW branch line and New Jersey Avenue on the south bank of the river. Initially, the bridge was constructed with short timber pile trestle approaches at either end. These approaches would help the approach embankments settle without damaging the permanent bridge, with the intention of replacing the timber spans with steel spans once the settlement had concluded. In approximately 1930, the approach trestles were replaced with a single deck plate girder span on either end, giving the structure its present configuration.

Currently, the bridge consists of two 161-foot, 9-panel, riveted double intersection Warren deck truss spans across the Sheboygan River. The north approach is composed of a 70-foot deck plate girder span and a 40-foot deck plate girder span; while the south approach is composed of a 76-foot, a 65-foot, an 80-foot and a 40-foot deck plate girder span. The main piers are constructed of stone, while the abutments and north pier are constructed of concrete. While the bridge was never double tracked, the substructures were constructed wide enough that a second track could be added if traffic ever warranted. In addition, the truss spans are set at a considerable skew, while the approach spans are mainly square. The truss spans use a typical design for the era, with heavy members and a standard floor. The top and bottom chord are both composed of V-laced beams, while the endposts are composed of solid rolled beams. The diagonal members are composed of a combination of solid rolled beams, V-laced beams and built-up beams connected by thin plates. The upper lateral, lower lateral and interior bracing of the bridge is composed of solid steel bars, typical for bridges from this era. The floor is simply composed, consisting of plate girder floorbeams at the panel points and two stringers. Unlike many lattice deck truss spans from this era, the spans on this bridge do not use vertical members at the panel points. The deck plate girders are all of standard design, consisting of two plate girders of various heights with an open deck. The substructures are also of standard design, and feature a number of different designs. The river piers consist of rectangular limestone piers with a large angled fender on the upstream side. The south approach piers consist of rectangular limestone, while the concrete piers also use a rectangular shape. The abutments use a typical design for the 1930s, with no notable wing walls and a standard rectangular shape. Stone for the stone piers consists of a white limestone, which appears to have been quarried at Duck Creek, Wisconsin. Pennsylvania Steel Company fabricated the deck trusses and longer deck girder spans, while an unknown contractor constructed the 40-foot spans. Widell-Finley Company began work on the stone substructures before going bankrupt, and the Widell Company completed the construction. An unknown contractor constructed the concrete substructures.

While lattice truss spans were relatively uncommon through the United States, the C&NW used the design extensively. Other railroads in the Midwest also occasionally used the design, although not as frequently. Engineers for the C&NW 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. Later additions included vertical members at key points to increase loading capabilities and the improvement of the floor systems. 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 during this era. The C&NW continued to use lattice truss designs nearly exclusively into the 1920s, and was among the only railroads in the United States still using the design into the 20th Century. Since the last reconstruction, the bridge has seen few significant alterations. Overall, the bridge appears to be in fair condition, with no significant deterioration noted. The author has ranked this bridge as being regionally significant, due to the truss design.