Chicago & Alton Railway Bridge

Address: East of Ashland Ave., North of Archer Ave. (South Fork of the South Branch of the Chicago River) Year Built: 1906 Architect: Page & Shnable Date Designated a Chicago Landmark: December 12, 2007

The Chicago & Alton Railway Bridge was constructed for the joint use of three railroads: the Chicago & Alton, the Illinois Central, and the Atchison, Topeka & Santa Fe railways. Engineer, John W. Page of the firm, Page & Shnable, developed and patented the design of the bridge, which is known as a Page trunnion bascule. The Chicago & Alton Railway Bridge is significant for being the first of its kind erected for railroad use and it may be the only one left in existence. The superstructure is made from steel and operated by using two 124-horsepower motors mounted on a frame between two counterweights. These counterweights pivot and roll downward, tilting the bridge and giving it the appearance of the span rising effortlessly. The bridge's counterweights are contained within steel plates that visually blend with the structure giving it a graceful appearance. The bridge is visible from the Stevenson Expressway and Metra and Orange Line trains. Today, it is still in use, but its mechanism has been disabled, since it no longer is raised for navigational purposes.