Reference

The Cortland Street Drawbridge (originally known as the Clybourn Place drawbridge)[4] over the Chicago River is the original Chicago-style fixed-trunnion bascule bridge, designed by John Ericson and Edward Wilmann.[3] When it opened in 1902, on Chicago's north side, it was the first such bridge built in the United States. The bridge was a major advance in American movable bridge engineering, and was the prototype for over 50 additional bridges in Chicago alone.[5] The bridge was designated as an ASCE Civil Engineering Landmark in 1981, and a Chicago Landmark in 1991. | Design | Chicago trunnion bascule bridge[1] | Historic American Engineering Record (HAER) No. IL-138, "Chicago River Bascule Bridge, West Cortland Street, Spanning North Branch of Chicago River at West Cortland Street, Chicago, Cook County, IL", 9 photos, 2 data pages, 2 photo caption pages

Cortland Street Drawbridge | Invention & Technology Magazine Cortland Street Drawbridge Main Category Location Country The Cortland Street Drawbridge was the first trunnion bascule bridge constructed in the United States. In operation longer than any bascule bridge of its kind, it was a model for 53 of Chicago's 54 moveable bridges. The bridge leaves are supported at the shore end on a trunnion, or shaft. When the bridge is open or opening, the trunnion supports the entire dead weight of the leaf. The Cortland Street Drawbridge, a trunnion-bascule highway bridge, was the first of its kind and became the model for this type of urban transportation structure Cortland Street Drawbridge

| Design | Chicago trunnion bascule bridge[1] | The Cortland Street Drawbridge (originally known as the Clybourn Place drawbridge)[4] over the Chicago River is the original Chicago-style fixed-trunnion bascule bridge, designed by John Ericson and Edward Wilmann.[3] When it opened in 1902, on Chicago's north side, it was the first such bridge built in the United States. ^ Cortland Street Bridge, 1953. Historic American Engineering Record (HAER) No. IL-138, "Chicago River Bascule Bridge, West Cortland Street, Spanning North Branch of Chicago River at West Cortland Street, Chicago, Cook County, IL", 9 photos, 2 data pages, 2 photo caption pages Bridges in Chicago