On November 4th, 1901 the firm Noble and Modjeski was engaged by the Southern Illinois & Missouri Bridge Company to design a railroad crossing near the town of Thebes, Illinois. Alfred Noble was a mentor of Ralph Modjeski when both were employed under George Morrison for the design and construction of the Frisco Bridge in Memphis, Tennessee.
On February 4th, 1902 the Directors of the Southern Illinois & Missouri Bridge Company approved the final design of the new bridge. Preliminary construction would commence in April of the same year. Shown here is the approved bridge location relative to the town of Thebes, Illinois.
Construction begins with the grading of the Missouri approach in April of 1902. Shown here is construction progress in March 1903 of the concrete arch approach structure which are some of the earliest examples of large-scale concrete arch bridge technology.
Construction of the Thebes Bridge superstructure commenced in the Spring of 1904. The main river spans were erected from each side of the river without any falsework in the water which saved time and money, and simultaneously improved safety. The main spans were connected at the center of the structure in March of 1905 as shown in this image.
In May 1905, the construction of the Thebes Bridge was completed. The new structure was and still is one of the most unique railroad bridges in the world, featuring a five span cantilever truss system. Shown here is a view of the west end portal (top) and the testing/dedication ceremony (bottom) on May 25, 1905 to demonstrate the exceptional strength of the bridge.