Sibley Railroad Bridge

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Located on the southeast side of Sibley, this large through truss bridge carries the BNSF mainline across the Missouri River. The Kansas City, Topeka & Western Railroad obtained rights to construct a bridge across the Missouri River at Sibley in 1872. The Chicago, Santa Fe & California Railway acquired the rights to the bridge in 1884, and hired renowned engineer Octave Chanute to design a new high bridge. Chanute had previously worked on other significant railroad bridges, including the First Hannibal Bridge at Kansas City in 1869. It was determined that a location downstream of Sibley, known as Sibley Reef, would make the most suitable location to construct a bridge. Sooysmith & Company would be hired to construct the stonework for the bridge, while Edge Moor Bridge Works would construct the superstructure. Construction began on the single track bridge in March 1887, and the bridge opened to traffic in 1888. The 1888 bridge consisted of, from west (south) to east (north): one 80-foot deck plate girder, one 200-foot Pratt deck truss, three 396-foot Whipple through trusses, a 247-foot Pratt deck truss and two 173-foot Pratt deck trusses, approached by a 2000-foot long iron deck plate girder viaduct. All piers, except for the outermost piers, were constructed on steel caissons, and faced with sandstone from Strong City, Kansas. The approach viaduct was set at a heavy grade to meet a long fill on the north end of the bridge

During the late 19th Century, this line became heavily used and served as a critical route for the ATSF between Chicago and Kansas City. As trains became heavier, faster and more frequent, the ATSF sought solutions to replace the bridge. For two years prior to replacement, large engines were not allowed to work steam when crossing the main spans, and helper engines were used. It was initially proposed to construct a new bridge several hundred feet upstream, eliminating the large S-curve the bridge is on. This option would have required a lengthy extension of the approach fill on the east end. It was eventually decided to construct a new bridge to replace the old bridge at the same location. At the time of replacement, this bridge was the only portion of the Chicago to Kansas City line not double tracked. Although the possibility of constructing a double track bridge was considered, it was decided to rebuild the bridge as a single track gauntlet structure. It was believed that a single track bridge would be able to handle any capacity required in the future. The ATSF contracted American Bridge Company for the superstructure, and Missouri Valley Bridge & Iron Company for the new piers, alterations to the old piers, erection of the new spans and disassembly of the old spans.

Because of frost cracking, the upper rows of stone on each of the piers would be required to be reconstructed. The new bridge would be constructed of an 80-foot deck plate girder, two 100-foot deck plate girders to replace the southern deck truss, three 16-panel pin-connected Pennsylvania through truss spans to replace the Whipple trusses, a 247-foot, 10-panel pin-connected Pratt deck truss and two 173-foot 7-panel pin-connected Pratt deck truss spans. In addition, the north approach viaduct would be constructed with a 70-foot deck plate girder, followed by thirteen 90-foot deck plate girder spans, alternating with thirteen 45-foot deck plate girder spans set onto steel towers. The north end of the bridge would use two 60-foot spans, set onto a steel bent. The new piers, tower footings and repairs would be constructed of concrete. Due to War Department requirements, the new bridge could not be constructed on temporary wooden piers adjacent to the old bridge. Work on the new bridge was started in September of 1911. Ice jams took out falsework under the southern span in early 1912, and the three long spans were installed by January 1913. The deck truss spans would be completed by July 1913. Work on the new approach viaduct, as well as raising the approach fill 7 feet would be undertaken in tandem, and the crossing was completed in July 1915. The fate of the old spans is unknown, and there is no direct evidence to suggest any of them were reused elsewhere.

The total construction cost of the new bridge would exceed $1.3 Million, and represented a major undertaking for the Santa Fe. During the construction, traffic was rarely interrupted. While placing the floors and 90-foot spans, two trains daily would be detoured over the Wabash to allow for faster construction. The three large main spans were among the largest spans on the Santa Fe system. These spans were heavily constructed, with massive, built up members, large pinned connections and exceptionally heavy floor systems. The deck trusses follow a standard Santa Fe design, and use a lighter construction. The Santa Fe preferred pin connected trusses until the 1920s, as the railroad felt they were a tried and true design. The Santa Fe was among the last railroads to use exclusively pin connected truss bridges. The bridge was originally constructed with a ballast deck throughout, typical of Santa Fe bridges. Pennsylvania Trusses became popular in the late 19th Century, and eventually became the preferred design for long to extremely long truss spans. These spans were economical, durable and could handle heavy loads. The Pratt design was undoubtedly the most popular truss design in the 19th Century, but were replaced by heavier, riveted Warren spans during the early 20th Century. The entire bridge was constructed for Cooper E60 loading, which made it the heaviest constructed bridge between Chicago and Kansas City when it opened to traffic.

Since construction, a number of alterations have been made to the bridge. The original ballast deck floor was reconstructed in 1985, and the main trusses strengthened in 1992. Numerous other repairs can be found throughout the bridge, such as the replacement of plates on the approach viaduct tower. It is believed that the gauntlet track was removed at this time. Due to this bridge being the only single track segment between Chicago and Kansas City, BNSF has long desired to add a second track to this crossing. As of 2024, work has begun to construct a second parallel bridge immediately downstream. The construction of a parallel bridge signifies that this bridge is still in good condition, and should continue to carry traffic for the foreseeable future. The author has ranked this bridge as being highly significant, due to the large design and historic nature of the bridge.