Shooting Star Trail - Little Cedar River Bridge

Located between Adams and Rose Creek, this unique concrete girder bridge crosses the Little Cedar River just south of Minnesota Highway 56. Built in 1910, this is one of a handful of concrete deck girders constructed on the Milwaukee Road system. While reinforced concrete trestles were becoming commonplace in the early 1910s, railroads were trying to figure out what design provided the most economical solution, while also being able to reliably carry traffic. One of the more unique designs seen throughout the Milwaukee Road system is this type of bridge, a concrete deck girder. Using the same design features as a traditional steel deck girder, these spans appear to have been fabricated offsite. The main spans of the bridge feature lateral bracing, similar to X-bracing seen in steel girders. The abutments and piers were all cast in place using deformed steel bar reinforcement (rebar), and a ballasted deck was added to the top.

Not many of these spans were ever built along the Milwaukee Road. The railroad appears to have settled on a more common precast concrete slab design by 1912. While very few of these types of bridges were built, not many remain. From an engineering standpoint, these are highly significant developments in railroad bridge engineering. It is likely that the girders are heavily reinforced, particularly near the bottom to account for tensile stresses seen throughout the bridge. The spans themselves form an upside down "U" shape, typical to a deck girder.

The bridge across the Little Cedar River between Adams and Rose Creek consists of two spans, set onto a typical concrete "U" abutment and a rectangular reinforced concrete pier. The girders are approximately 5 feet in depth, and show markings of being board formed. It appears that the deck is a typical channel style ballasted deck, likely grouted and dowled into the girder upon initial construction. The spans are each 30 feet in length, approximately twice as long as a standard slab. While many of the slab bridges that came in later years are in poor to severe condition now, several of the known concrete deck girder spans remain in good condition. Today, the bridge serves as part of the Shooting Star State Trail. Overall, the bridge appears to be in good condition, and is well maintained. No major defects were found on the superstructure or substructure. The author has ranked this bridge as being moderately significant, due to the unique design.