Cameron Railroad Crossing

Authors note: A schematic of this bridge has been provided above

Located in the small town of Cameron, this unusual girder bridge carries the former Atchison, Topeka & Santa Fe Railway over 180th Avenue, a BNSF Railway line (former Chicago Burlington & Quincy Railroad), and the abandoned Rock Island Southern Railway. It is believed that the first bridge at this location was a timber structure, constructed with the intent of being replaced by a steel bridge in the 1890s or early 1900s. In 1904, the bridge would be replaced by a through and deck plate girder bridge, crossing 180th Avenue and the CB&Q. The bridge would be heavily modified in 1907, when the Santa Fe double tracked this line. Additional spans were added to the east end of the bridge at this time, giving the bridge its current configuration.

The superstructure of the bridge consists of a combination of through and deck plate girder spans, set onto stone, concrete and steel bent substructures. The bridge runs at a heavy skew, utilizes a ballast deck, and has had several modifications. Spans #1 and #2 consist of heavily skewed through plate girder spans; with a 71-foot through plate girder, and a second shorter span which varies between 41 feet and 46 feet. These two spans were constructed during the 1907 reconstruction of the bridge. Span #1 initially crossed the Rock Island Southern Railway, which has since been abandoned. Span #3 crosses the BNSF Ottumwa Subdivision (former CB&Q), and consists of a large continuous through plate girder span. The outer girders, which were fabricated in 1903, consist of a 101-foot and an 18-foot girder. The inner girder consists of an 87-foot and a 32-foot girder, added to the bridge during the 1907 widening. Span #4E consists of a 36-foot deck plate girder span, fabricated in 1899 and 1900. It is unknown if this span was originally used at another location, or if it was installed on the original bridge. Span #4W consists of a 30-foot deck plate girder. The northern girder was fabricated in 1907, while the southern girder was fabricated in 1903. Span #5 consists of a 70-foot deck plate girder, constructed to cross 180th Avenue. The inner girders were fabricated in 1904, while the outer girders were fabricated in 1907.

The substructures of the bridge consist of stone constructed in 1904 and concrete, which was added in 1907. The east abutment is entirely constructed of concrete, and consists of a stepped design, on account of the skew of the structure. Pier #1 consists of a diagonally constructed steel bent, set onto concrete footings. Pier #2 consists of a stepped stone pier, which was modified in 1907 to carry the north side of the structure. Pier #3W consists of a concrete column, set east of the BNSF tracks, while pier #3E consists of a concrete capped stone column, set west of the BNSF tracks. Pier #4 consists of a short stone pier, originally constructed for the 1904 structure. Pier #5 consists of a stone pier, which was capped with concrete and extended to the west with concrete. Pier #6 consists of a steel bent on a concrete footing, carrying the north track. The west abutment consists of a stone and concrete structure, which utilizes a stepped design.

Because of the unusual nature of the structure, a number of different designs and modifications are present in the bridge. The through plate girder spans largely follow a standard Santa Fe design, with rounded ends and a floor constructed of numerous parallel floorbeams. The deck plate girder spans also use a typical Santa Fe design, with a traditionally composed bracing system. The use of girder spans was popular with railroads throughout the United States, as the simple design was both durable and easy to construct. Widening of the 1904 spans of the bridge was accomplished by two different methods. Span #3 was widened by separating the original single track bridge, shifting the structure, and installing a new girder line and floor for a second track. Span #5 was widened by reconstructing the interior bracing, using one new girder and one 1904 girder in each span. Railroads typically widened structures by constructing a new bridge, or extending the existing structure. It is unusual for a bridge to have been widened in the manners described above. 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 unusual variety of designs and alterations.