Barker-Stewart Island Railroad Bridge (South)

Located near the center of Barker-Stewart Island in Wausau, this pony truss bridge carries a former Chicago & North Western Railway spur over a channel of the Wisconsin River. In the 19th Century, Barker-Stewart Island served as an important industrial hub for the City of Wausau, and was one of the main places where pulpwood floating down the Wisconsin River was intercepted and loaded onto railroad cars. A spur of the Milwaukee, Lake Shore & Western Railway was originally built between present-day Washington Street and the center of the island in 1881. The following year, the line was extended north and west, and the spur reached the west shore of the Wisconsin River. The first bridge at this location likely consisted of a wooden pony truss span, set onto timber substructures. A significant flood of July 1912 damaged the structure, and plans were made to replace the bridge. Instead of installing a new steel span, it was decided to reuse a secondhand iron span which had been strengthened. Work on the bridge was done throughout 1914, with the present bridge opening that year.

Currently, the bridge consists of a 72-foot, 6-panel riveted double intersection Warren pony truss span, set onto steel cylinder piers. The main truss span is approached by timber pile trestle spans on either end. The truss span was originally fabricated in approximately 1885 for Bridge #1213 near Spring Valley, Illinois. Based on the design, it is believed that the truss was initially fabricated by the Alden and Lassig Bridge & Iron Works. Local contractor Wausau Iron Works completed the new steel cylinder piers, while Illinois Steel Company strengthened the bridge by adding additional hangers to the bridge. While Bridge #1213 was replaced in 1908-1909, the span was stored at the Bridge Yard in Chicago until a feasible spot for reuse was found. Blueprints indicate that the bridge contains original trusses, floorbeams and stringers. The truss span uses a standard design for the era, with heavy compression members, riveted connections and modestly deep trusses. The top chord, bottom chord and endposts all use a channel, which is connected by a plate on the top. The compression members consist of solid rolled beams, while the tension members use L-shaped iron bars. The floor is comprised of two stringers and floorbeams set at the panel points, typical of spans from this era.

Railroads commonly reused steel and iron spans, as it was a cost effective way to replace bridges on branch lines and spurs without requiring large amounts of new material. Often, when a span was no longer adequate for mainline use, it could be reused on a branch line with minimal alterations. Pony truss spans such as this were used extensively by the C&NW throughout the 1880s, as they were durable, simple and cost effective. Dozens of similar spans were constructed for the C&NW, with most spans constructed by Leighton Bridge & Iron Works (1870s-1881); Alden and Lassig Bridge & Iron Works (1881-1885) and Lassig Bridge & Iron Works (1886-c. 1890). The design was ultimately superseded by heavier plate girder bridges, which were stronger and equally economical. Since the 1914 relocation, few alterations have been made to the truss span and bridge overall. Currently, the bridge is out of service, with no customers remaining on the spur. While its future is uncertain, it is hoped that the bridge can possibly be reused as a trail bridge in the future, preserving the history for generations to come. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being regionally significant, due to the design and age. In addition, the piers of this bridge appear to be one of the few locations that the Wausau Iron Works was contracted by a railroad company to construct bridge components.