Amtrak's vertical lift bridge over the Chicago River Credit: Danielle A. Scruggs

If downtown bascule bridges are show ponies—with curved, double-leaf spans painted a deep maroon—vertical lift bridges are Chicago’s underappreciated workhorses.

True to their name, their spans lift vertically but stay parallel to their decks—as opposed to bascule bridges, which flip open at an angle (“bascule” is French for “seesaw”). There are seven vertical lift bridges in the city: just one over the Chicago River, but another six across the Calumet River.

If you’ve noticed them, you’ve probably seen the one that runs not quite parallel to Canal Street just south of 18th Street, its towers looming above the dry dock next door, its rust-colored bridge house perched precariously in the middle of its span. Or perhaps you’ve spotted the strange trio of bridges visible from the Skyway, looking like relics, with two of their spans perpetually in the air.

These bridges always seemed to be lost in time: impractical remnants that hark back to Chicago’s days as an industrial powerhouse. They’re monuments whose real purpose had been lost or obscured—like neighborhood fire-alarm boxes or the water towers on the tops of downtown buildings. Of course, I loved them. They were visually striking, but unwieldy: Surely modern engineering had developed a more efficient solution to waterway traffic in the years since these bridges had first been built?

In time, I would learn the truth. Vertical lift bridges were favored in the 1910s—unlike bascule bridges, they required counterweights only as heavy as the bridge span itself. That meant that the spans could be heavier, and were thus well suited for freight-train traffic.

Today, although a few are abandoned—including three over the Calumet—many are still surprisingly active, and still fill their original purpose.

The bridge near Canal Street is properly called the Pennsylvania Railroad Bridge No. 458. Completed in 1914, it’s presently owned and maintained by Amtrak. According to the company, all of its eastbound trains cross this bridge after leaving Union Station—that’s ten trains a day to Michigan and another four to the east coast. Add to that a slew of Metra and freight trains that also use the tracks, as well as trains that use the bridge to turn around in a nearby rail yard, and you have an astonishing 110 or so trains using this vertical lift bridge every day. And because river-barge traffic has the right of way (literally because whatever was there first has the right of way and the river was there first), the bridge must also lift to let water vessels past. Amtrak estimates that the bridge is lifted, on average, once every 48 minutes.

When asked if the company had considered replacing the bridge with something more modern, a spokesman said that for the amount of space Amtrak had on-site, there didn’t seem to be a bridge solution more practical than the one it already had.

I’m still attached to my misunderstanding of vertical lift bridges as charming and outdated, but I’m happy to know they’re more than just symbols of the past. For all the changes to our economy and landscape, vertical lift bridges are evidence that Chicago is still a hub, still the city that works.  v