BNSF Bridge #34.5

Located on the south side of Granite Falls, this large deck girder viaduct carries a former Great Northern Railway mainline over an overflow of the Minnesota River. The first bridge at this location likely consisted of a large timber pile trestle bridge, constructed when the line was first built. Around the turn of the 20th Century, the GN invested significant capital into this line, replacing timber bridges with steel, stone and concrete structures. In 1900, a new deck plate girder viaduct was constructed at this location. This bridge consisted of three 60-foot deck plate girder spans, set onto steel bents, stone footings and approached by timber pile trestle spans on either end. In 1929, the bridge underwent a major reconstruction, and the original girders were replaced and the stone pedestals encased in concrete. It is believed that the original bents were retained for the new bridge, and it is possible that the original girders were reused elsewhere after replacement. The most recent alteration to the bridge came in approximately 2000, when the timber spans at either end of the bridge were rebuilt with modular concrete girder spans, giving the bridge its present configuration.

Currently, the bridge consists of three 60-foot deck plate girder spans, set onto steel bents and concrete encased stone pedestals. Each end of the bridge is approached by a 35-foot precast concrete span, which is supported by steel pile substructures. The main spans follow a standard design, with two heavy plate girders per span and an open deck. The bents are formed by two posts, which form an "A" shape. These posts are constructed of two parallel channels, which are connected by a V-laced beam at the top, center and bottom; as well as lateral bracing at both levels. The pedestals consist of massive concrete blocks, which are square. Both approaches use a similar precast concrete "T" girder design, which was popular for railroad use in the late 1990s and early 2000s. An unknown contractor fabricated the superstructure, and an additional unknown contractor constructed the substructures. Deck plate girder spans were popular for railroad use, as they were durable and easy to construct. Several similar viaducts were constructed along this line, as deck girder viaducts provided the most economical design for long and tall bridges. Today, the bridge remains in regular use. 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.