Marcin Wichary documents a 2011 weekend chase of Chicago’s 27 bascule bridges during their spring sequential lift, with access inside a control tower.
Key Takeaways
Chicago opens 27 movable bridges in sequence each spring and fall to let boats reach Lake Michigan; four operator teams leapfrog in vans for efficiency.
Most are bascule bridges (French for “balance scale”) counterweighted so precisely that motors only tip the deck, not lift thousands of tons from rest.
The Cermak Road Bridge (1906) uses a rocking-chair pivot; the Amtrak Canal Street bridge is a traditional vertical-lift design, built at a visible slant.
In 1992, the Michigan Avenue Bridge under repair launched a 40-ton crane into lower Wacker Drive; a 285-pound wrecking ball landed in a parked Ford Escort.
The Kinzie Street railroad bridge has been permanently open since 2000 after the Chicago Sun-Times moved its printing facility to the suburbs.
Hacker News Comment Review
No substantive HN discussion yet; single commenter praised the photo angles and added a personal anecdote about watching the Congress expressway bridge open from a nearby office.
