RCP&E Whitewood Creek Bridge

Located in Whitewood, this large through truss bridge carries a former Chicago & North Western Railway secondary line across Whitewood. The first bridge at this location was likely a timber pile trestle or timber through truss bridge. After a devastating flood damaged the original bridge in 1909, it was decided to build a larger permanent structure. Work on the present bridge began in October 1909, and was completed in April 1910. Currently, the bridge consists of a 175-foot, 8-panel, pin-connected Pratt through truss span, set onto concrete substructures founded on timber piles. The truss span was originally fabricated in 1897-1898 for use at the main channel bridge across the Mississippi River at Clinton, Iowa. When that bridge was replaced by a double track structure, several truss spans were released for reuse at various branch line locations along the C&NW. One span was installed at this location; two spans were installed at Oral, South Dakota; and another was installed at Niagara, Wisconsin. All four spans continue to exist in 2026.

The truss span is tall and heavily constructed, with massive members and large pinned connections. Both the top chords and endposts are composed of built-up beams, consisting of two channels connected by a solid plate on the top and X-lacing on the bottom. The bottom chords are unique, and are composed of a built-up beam with X-lacing on both sides at the outermost two panels of each span and eyebars at the center panels. Unique to this bridge, the bottom chord is set on top of the floorbeams, which gives this bridge an unusual appearance. The vertical members and crash bars of the span are composed of V-laced beams, while the diagonal members are composed of eyebars. The floor system uses a slightly modified version of a standard design, with four heavy plate girder stringers and heavy plate girder floorbeams. The bottom chord and truss members are connected to the floorbeams by use of a hanger system, consisting of two U-shaped brackets. Due to the depth of the truss floor, no lower lateral bracing is used in the span. The upper lateral bracing is composed of square steel bars, which are connected to the top chord and sway bracing by use of a U-shaped clamp, which is pinned through a plate in the top chord. Unique to this bridge, the portal bracing uses a solid pedimented design, with a deep lattice beam underneath. Rounded heel bracing is present underneath the lattice beam, which has decorative holes cut through it. A date cutout is present on the top beam of the portal bracing, but has been covered up by a steel plate. The sway bracing is composed of a V-laced strut on top and a solid strut below, which are connected by a similar lattice beam to the portal bracing. The abutments follow a standard design, with stepped wing walls extending perpendicular to the structure.

Detroit Bridge & Iron Works fabricated the truss spans, while the Cleary-White Construction Company constructed the abutments. Railroads often reused steel and iron spans, as it was a cost effective way to replace aging bridges on branch lines without requiring large amounts of new material. In particular, heavy truss spans used at major river crossings were popular candidates for reuse. The C&NW was unique for its choice of truss design, as this railroad preferred to use lattice spans wherever possible. Between the late 1870s and late 1920s, the C&NW nearly exclusively used various types of lattice trusses. This design was preferred by C&NW bridge engineers, as it provided greater strength and resiliency. The use of more traditional truss designs on the C&NW was uncommon during the late 19th and early 20th Century. Only a handful of non-lattice style trusses were known to have been constructed. In particular, the C&NW ordered several heavy Pratt truss spans in 1897-1898 for use at the Clinton bridge and another mainline bridge across the Cedar River. The use of this design likely was due to the Detroit Bridge & Iron Works designing the spans to meet the requirements of the crossing instead of the C&NW advocating for a lattice design. Pratt truss designs were arguably the most popular railroad truss design in the second half of the 19th Century, due to their strength, economy and simple design. By the turn of the 20th Century, this design had largely been superseded by heavier riveted Warren trusses, which provided greater strength and rigidity. Currently, this bridge remains in regular use, and the structure has seen no significant alterations. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being regionally significant, due to the truss design and history of the spans.