This interesting bridge crosses the East Boyer River in Denison.
Built in 1902, the bridge features a standardized design. The main span of the bridge is a large Quadrangular Through Truss, while the approach is a simple through girder span. The entire bridge is set onto concrete substructures.
What is uncommon is the layout of the three tracks. The bridge appears to have been built by simply combining a single and double track structure. According to railroad sources, the single track span was added in 1910.
This creates a unique look, where the double track span uses M Frame portal bracing, and the single track uses an A Frame. The third track once carried a C&NW branch heading north to Wall Lake, which was abandoned 1942.
Overall, the bridge appears to be in fair condition. Years of flooding have resulted in the pier being reinforced with sheet metal on the bottom.
Historic photo of the bridge
The author has ranked this bridge as being regionally significant, due to the exceptionally unique triple tracked truss. This may be the only triple track truss ever built for the C&NW.
Unfortunately, the bridge will be replaced in late 2021. Union Pacific had offered the single track span for free, assuming one can move it. As of November 7th, 2020; replacement work had begun by building a new track to use the single track span while the double track portion is replaced.
The photo above is an overview. The bridge can be accessed from 8th Avenue.