WSOR Rock River Bridge (Janesville, South)

View an article discussing the construction of masonry substructures on the Janesville & Southeastern Railway (digitalized by Google)

Located in Janesville, this large deck plate girder bridge carries a former Chicago, Milwaukee, St. Paul & Pacific Railroad (Milwaukee Road) line over the Rock River. To facilitate the construction of this bridge and approach embankments, a long temporary trestle was initially constructed from the south side of the Rock River to a point near Racine Street. Throughout late 1900 and early 1901, work on filling the trestle and constructing permanent bridges was carried out. The present deck plate girder bridge was completed at this location in 1901. In approximately 1980, span #2 was replaced by a modern welded deck plate girder span, possibly because of deterioration or damage from a derailment. Currently, the bridge consists of a 60-foot, a 64-foot and four 85-foot deck plate girder spans, set onto concrete abutments and stone piers. In addition, the bridge is located on a heavy curve and is constructed at a heavy skew. The superstructure uses a heavy design, with two heavy girders and an open deck. The north abutment uses a unique design, with a large rectangular wall underneath the superstructure, and unusual sloped wing walls which extend at different angles to accommodate the unusual skew of the structure. The south abutment and south pier (pier #1) both use more traditional designs, and are in a rectangular shape. The stone piers use a round shape, which are founded on concrete pads supported by timber piles. Stone for the piers has a tan color, and was quarried at an unknown location. American Bridge Company fabricated the superstructure at their Lassig Plant in Chicago, Illinois; while employees of the Milwaukee Road Bridge & Building Department completed the substructures. Work on the bridge was carried out under the direction of Assistant Engineer Albert Reichman, while the bridge was designed by Onward Bates, Engineer and Superintendent of Bridges and Buildings. Deck plate girder spans were commonly used by railroads, as they were durable and easy to construct. Recent alterations to the bridge include the repair and encasement of the north abutment, which was completed in 2014. In addition, a concrete cap was added to pier #2 during this project. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being locally significant, due to the common design. Despite this, the heavy skew and curvature of the bridge make this structure unique in the area.