WSOR Janesville Millrace Bridge

View an article discussing the erection process of this bridge (digitalized by Google)

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 Ice Age National Scenic Trail, a former millrace. 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. Currently, the bridge consists of two 114-foot deck plate girder spans, set onto tall concrete abutments and a stone pier. In addition, the bridge is located on a heavy curve and is constructed at a heavy skew. The superstructure uses an exceptionally heavy design, with two heavy girders and an open deck. Each plate girder is 9 feet tall, and weighs approximately 40 tons. The abutments use a unique design, with large rectangular walls underneath the superstructure, and unusual sloped wing walls which extend at different angles to accommodate the unusual skew of the structure. The center pier is constructed of stone, which is founded on a concrete pad supported by timber piles. This pier uses a rounded shape, typical for stonework along this line. Stone for the pier 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. Until the 1910s, girder spans often did not exceed 100-foot lengths, due to the complexities of erecting such massive pieces of steel. At 114 feet long, the two spans on this bridge were among the longest and heaviest constructed in the United States at the time. Recent alterations to the bridge include the repair and encasement of the abutments, which was completed in 2014. In addition, a concrete cap was added to the pier 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 moderately significant, due to the technical significance of fabricating and erecting such large plate girders in the early 20th Century.