Railway Box-Girder Bridge Erected by Launching

The first major steel-deck railway bridge in America, the 2110-ft single-track Kansas City Southern Railway bridge over the Arkansas River near Redland, Oklahoma, is a continuous box-girder structure having nine spans. Approximately 2400 tons of ASTM A588 (50-ksi yield) weathering steel, left unpainted, were used. The 24 individual box units, ranging in length from 42 ft to 117 ft and in weight from 44 tons, were shop-fabricated by welding. At the site, box units were bolted together in trains behind each abutment and rolled or launched across the spans, supported on sliding-type (skidway) units located at the abutments and piers. The two trains met and were spliced at the middle of the channel span. An extensive erection strength investigation was required because each girder panel had to pass across one or more skidway units and therefore had to be adequate to withstand the various combinations of moment, shear, and reaction that occurred. Web and flange erection strengthening and stiffening were found necessary. Pier and abutment stresses and stability were reviewed.