Galena Railroad Bridge

Located in Galena, this through plate girder bridge carries the former Illinois Central Railroad over the Galena River. The first bridge at this location was a wooden swing bridge, constructed in the early 1850s when the line was constructed. In 1878, the bridge would be replaced by an iron swing bridge, fabricated by the Detroit Bridge & Iron Works. By the early 20th Century, the bridge had become too light for modern traffic. As the Galena River was still considered navigable as far north as Galena, a movable structure would be required. It is unknown how much traffic used the river, but the Illinois Central felt that constructing a bascule bridge would be the best solution. In 1913, Strauss Bascule Bridge Company would be retained to design a bascule span, and American Bridge Company was contracted to fabricate the steel at their Gary Plant. Gould Construction Company was reportedly retained to remove the old bridge and construct the substructures of the new bridge. However, railroad records indicate that this bridge was conducted by railroad forces. Newspaper articles indicate that workers of Gould Construction Company went on strike. The Illinois Central likely used company labor to finish the work. Work on the bridge began in 1913, and was completed by the end of 1914.

Originally, the bridge consisted of a 161-foot 3-inch Strauss trunnion bascule span, approached by two 70-foot through plate girders on the east side of the structure. The bridge would be set onto new concrete substructures, and was a point of pride for both the railroad and community. The bascule span consisted of a 62-foot anchor arm and concrete counterweight on the west end, and a 99-foot clear span. The clear span consisted of a 6 panel, riveted Warren through truss, and the anchor arm utilized an unusual design consisting of two triangular trusses, connected by a pin. Due to the short length, the span contained no portal bracing or sway bracing on the eastern portion. Several examples of this type of bascule bridge wee constructed throughout the United States, mainly concentrated around the Great Lakes. Relatively few of these types of spans were constructed in the Upper Midwest. This type of bridge functioned by rotating about a trunnion, a shaft running through the pivot point of the bridge. Nearly all bascule bridges designed by Strauss Bascule Bridge Company utilized a fixed trunnion, where the weight of the structure is always delivered to the foundations at the same point. This design is in contrast to rolling bascule bridges, which rolls to lift and transfers the load to different parts of the foundation.

In 1976, a train derailed on the bridge, destroying the bascule span. In response, a 62-foot and a 99-foot through plate girder span were installed onto the substructures remaining from the previous span. The replacement through girder spans appear to have been reused here from another location. A through girder span fabricated in 1976 would have likely used bolted or welded construction, while this bridge utilizes rivets. In addition, splice plates on the bridge appear to be constructed of bolts, possibly indicating that these spans were reassembled from another location. Missing plaques on the two spans could not be identified, and use a six bolt pattern. In addition, the spans use a traditionally composed floor, possibly indicating that they were constructed prior to 1950. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked the bridge as being locally significant, due to the common design.