IAIS Des Moines River Bridge

Located at Vine Street in downtown Des Moines, this large through plate girder bridge carries a former Chicago, Rock Island & Pacific Railroad (Rock Island) mainline over the Des Moines River. The first bridge at this location was reportedly completed in 1868, and consisted of wooden truss spans, likely set onto wooden substructures. In 1880, the bridge was replaced by a double track iron bridge, set onto stone substructures. This bridge consisted of four 6-panel, pin-connected Pratt through truss spans, which used a decorative lattice portal bracing and light members. It is unclear what contractor fabricated the 1880-era bridge, although it is known that the Rock Island had a relationship with the Keystone Bridge Company during that year. By the turn of the 20th Century, the original bridge had become too light for traffic, and it was decided to replace it with a heavier girder structure. Work on a present bridge began in late 1903, and was completed in 1904. The new bridge would use through plate girder spans, and require four new piers. It is unclear if the previous bridge was scrapped, or if it was reused elsewhere on the Rock Island system. Currently, the bridge consists of eight 77-foot through plate girder spans, set onto stone abutments, stone piers and concrete piers.

The superstructure follows a standard design for the era, with three lines of heavy plate girders, a standard floor and rounded and tapered girder ends at the ends of the bridge. The inner girder ends use a standard square shape. The floor is constructed of two stringers, heavy floorbeams and lower lateral bracing formed from L-shaped bars. All seven of the piers use a standard diamond shape, and the stone piers were capped with concrete during the construction of the present bridge. The abutments are mostly buried, but appear to use a standard rectangular shape. Stone for the substructures consists of a tan limestone, possibly quarried near Earlham, Iowa. American Bridge Company fabricated the superstructure, while an unknown contractor constructed the stone substructures in 1880. Bates & Rogers Construction Company constructd the concrete piers and completed the alterations to the stone substructures, and the Kelly-Atkinson Construction Company erected the girders. Through plate girder spans were popular for railroad use, as they were durable and easy to construct. Since the initial construction, the bridge has seen a few alterations, including the replacement of the stringers under portions of the north track. Today, only the north track remains in use, while the south track is unused. Overall, the bridge appears to be in fair condition, with no significant deterioration noted. The author has ranked the bridge as being locally significant, due to the common design.

Four railroad bridges once crossed the Des Moines River between Court Avenue and Market Street. The Des Moines Union Railway operated a bridge immediately north of the Rock Island bridge at Vine Street. This bridge initially consisted of three through truss spans, but has been altered throughout the years. Today, it is a popular pedestrian bridge and a landmark in Des Moines. The Rock Island operated a bridge at Vine Street, which was the first railroad bridge across the Des Moines River in Des Moines. This bridge initially consisted of wooden truss spans, constructed in 1868, before being replaced by four double track through truss spans in 1880 and finally by eight 77-foot through plate girder spans in 1904. Today, the bridge remains in use as part of the Iowa Interstate Railroad. The Rock Island also operated a single track bridge at Market Street, which carried the former Des Moines Valley Railway across the river. This bridge initially consisted of a wooden truss bridge, constructed in 1868. The wooden truss spans were replaced with iron truss spans in 1879, and finally by five riveted quadrangular lattice through truss spans in 1901. This bridge was fabricated by the American Bridge Company, and remained in use until it was removed in approximately 1975. A fourth bridge carried the Chicago, Burlington & Quincy Railroad across the Des Moines River at Elm Street. This bridge consisted of four 154-foot Pratt through truss spans, constructed in 1879 by the Union Bridge Company. This bridge was also removed in the mid-1970s.