Chicago & Northwestern Railway Bridge

Address: South of Kinzie St., East of Canal St. (North Branch of the Chicago River) Year Built: 1907 - 1908 Architect: William H. Finley Date Designated a Chicago Landmark: December 12, 2007

Located just north of the Loop, the Chicago & Northwestern Railway Bridge is an early example of an overhead counterweight bascule bridge based on the patents of Joseph Baermann Strauss. Strauss was a prominent engineer who later achieved fame as the designer of San Francisco's Golden Gate Bridge. The Chicago & Northwestern Railway Bridge was reported to be the world's longest and heaviest bridge of its type at the time of its completion. The single-leaf bridge is made from heavily-bolted steel girders and plates whose superstructure consists of a fixed tower and an overhead counterweight comprised of concrete, reinforced with a steel skeleton. The leaf's axis of rotation, the main trunnion, is located about halfway up the tower and power is provided by a pinion which engages a rack on the operating strut to raise and lower the leaf. Today, the bridge is no longer in service, due to the rerouting of passenger traffic and dwindling freight traffic. It is locked in a raised position creating a massive steel silhouette familiar to residents of the Near North side and commuters on Brown Line and Metra trains.