BNSF Marais Des Cygnes River Bridge (Boicourt)

Name	BNSF Marais Des Cygnes River Bridge (Boicourt) St. Louis-San Francisco Railway Bridge #C66.7
Built By	St. Louis-San Francisco Railway
Currently Owned By	BNSF Railway
Superstructure Contractor	Virginia Bridge & Iron Company of Roanoke, Virginia
Length	1067 Feet Total, 175 Foot Main Span
Width	1 Track
Height Above Ground	25 Feet (Estimated)
Superstructure Design	Warren Through Truss and Concrete Modular Girder
Substructure Design	Stone Masonry and Steel Pile
Date Built	1926, Approaches Reconstructed 1989
Traffic Count	20 Trains/Day (Estimated)
Current Status	In Use
St. Louisâ€“San Francisco Railway Bridge Number	C66.7
BNSF Railway Bridge Number	66.7
Significance	Moderate Significance

In 1868, the Kansas & Neosho Valley Railroad would construct a 21 mile railroad from Kansas City, Missouri to Olathe, Kansas. The same year, the name would be changed to the Missouri River, Fort Scott & Gulf Railroad (MRFS&G). In 1869, an additional 79 miles to Fort Scott, Kansas would be constructed, followed by 53 miles to Baxter Springs, Kansas in 1870. The route closely paralleled the Missouri/Kansas border. The MRFS&G would be sold to the Kansas City, Fort Scott & Gulf Railroad in 1869. The railroad would eventually be reorganized into the Kansas City, Fort Scott & Memphis Railroad (KCFS&M). The KCFS&M constructed a 13 mile extension to Miami, Oklahoma in 1896, followed by an additional 13 miles to Afton, Oklahoma in 1901. The KCFS&M would be leased by the St. Louis-San Francisco Railway (Frisco) and reorganized as the Kansas City, Fort Scott & Memphis Railway in 1901. This route served as one of two main connections between Kansas City and the Frisco mainline between St. Louis and Dallas, Texas. The Frisco absorbed the KCFS&M in 1928. The Frisco would build and acquire a respectable railroad network in the south central United States, with significant connections through Arkansas, Kansas, Missouri, Oklahoma and Texas. The Frisco was merged into the Burlington Northern Railroad (BN) in 1980. BN merged with the Atchison, Topeka & Santa Fe Railway in 1996 to form BNSF Railway. BNSF currently operates the Fort Scott Subdivision between Kansas City and Fort Scott, as well as the Afton Subdivision between Fort Scott and Afton. The route continues to serve as a critical mainline for BNSF.

Located near the ghost town of Boicourt, approximately halfway between Lacygne and Pleasanton, this large through truss bridge is the third crossing of the Marais Des Cygnes River along this route. The previous bridge at this location was likely an iron or light steel truss, constructed in the 19th Century. In 1926, a 175-foot, 7-panel pin-connected Warren through truss bridge would be constructed, reusing the stone piers from the previous bridge. The approaches originally were constructed of timber trestle, with a 60-foot deck plate girder span over Queens Road. The truss utilizes heavy members, riveted connections and an A-Frame portal, typical of spans from this era. In 1989, the approaches would be reconstructed with concrete modular girder spans, and new steel pile bents constructed. The Warren through truss was the preferred design for railroad trusses during the 20th Century, as it was strong and easy to design. Warren spans were typically used for medium to long length spans, generally ranging from 150 feet to 200 feet. The concrete modular girder spans appear to be a relatively early example of this design. The girders utilize precast T-beams, which also form a ballast deck. These types of spans have become increasingly common throughout the United States, as they allow for easy construction of replacement bridges. Overall, the bridge appears to be in fair to good condition, with no significant deterioration noted. The author has ranked this bridge as being moderately significant, due to the truss design.

Builder and build date	Virginia Bridge & Iron Company plaque
Railroad History Citation	ICC Valuation Information, Compiled by Richard S. Steele

BNSF Marais Des Cygnes River Bridge (Boicourt)

Boicourt, Linn County, Kansas