The Kinzie Street Bridge was built in 1909. Its a single leaf bascule Pratt truss bridge and provides 105 ft of channel clearance when its open. We are looking at the trunnion side with racks along its rounded end. The operating machinery has pinion gears inserted into the racks that rotate the bascule span up and down (with the help of the counterweight). We'll take another look at this interesting bridge tomorrow.
Movable Bridges - Kinzie Street Bridge (1) by Mark Yashinsky is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.