Cortland Street Drawbridge

The Cortland Street Drawbridge over the Chicago River looks like any of the dozens of bascule bridges in the city, but this one was first. When it opened in nineteen oh two, it was the original Chicago-style fixed-trunnion bascule bridge, designed by engineers John Ericson and Edward Wilmann. The design uses counterweights on each bank to offset the weight of the bridge leaves, so the whole deck can be raised with minimal engine power.

It worked so well that Chicago built more than fifty more bridges using the same principle, and the design spread to cities across the country. Chicago became, for a time, the bascule bridge capital of the world. The Cortland Street bridge was recognized as an American Society of Civil Engineers Historic Landmark in nineteen eighty-one and as a Chicago Landmark in nineteen ninety-one.

It still crosses the river and still draws today, the grandfather of a whole family of movable bridges.