Cortland Street Drawbridge

Gazing upon the Cortland Street Drawbridge, it’s hard to believe it once revolutionized bridge design. This unassuming steel structure, spanning a mere 39 meters across the Chicago River’s north branch, holds a pivotal place in American engineering. The Cortland Street Drawbridge, originally the Clybourn Place drawbridge, opened in 1902. It marked a significant departure from the problematic swing bridges of the past. Those older bridges, with their mid-river piers, clogged the waterway and were prone to collisions. This innovative design, the brainchild of John Ericson and Edward Wilmann, eliminated the central pier. The Cortland Street Drawbridge was the nation’s first trunnion bascule bridge. Imagine two massive leaves, counterbalanced by enormous weights. These leaves could pivot upwards, like a giant seesaw, allowing tall ships to pass unimpeded. This “Chicago-style” bascule bridge was so successful that it became the prototype for over 50 more bridges in Chicago alone. Unlike its successors, the Cortland Street Drawbridge’s gears are visible, tracing elegant arcs above the roadway. It’s a testament to the ingenuity of its creators. Commissioned by Mayor Carter Harrison, Jr. and Public Works Commissioner Frederick W. Blocki, the bridge was a symbol of Chicago’s progress. It once carried not just cars and pedestrians, but also streetcars of the Armitage Avenue line, and later, electric trolley buses. Today, the machinery remains, a silent reminder of its active past. Though the bridge no longer lifts, its leaves clamped firmly together, its impact remains. The Cortland Street Drawbridge stands as a designated ASCE Civil Engineering Landmark and a Chicago Landmark. It’s a monument to the innovative spirit that shaped the city’s waterways.