Sarah Holder is a staff writer at CityLab covering local policy, housing, labor, and technology.
Actually, yes. Thanks to extreme cold hitting the Midwest, Chicago is lighting the Metra commuter train rails on fire to keep the steel from contracting.
Hey, have you heard? It’s cold out there.
“There” being the U.S. Midwest, and specifically Chicago, which has been gripped by historically frigid temperatures. As a polar vortex encases the city, wind chills are predicted to reach -44 on Wednesday. People are bundling; mail carriers are staying home; almost 1,500 flights are cancelled. Also the train tracks are on fire. Wait, what?
Relax. This is not the D.C. Metro. Things are going according to plan: Chicago’s Metra commuter rail agency is purposely setting the tracks ablaze. During extreme cold spells, train operators routinely do this to prevent or repair “pull aparts,” which is what happens when steel tracks are exposed to quick temperature drops and contract in response. Bolts fly, cracks form, and eventually, the rails can separate or break between joints. Some gaps are minor enough that trains can continue rolling over them at slower speeds, but they can create delays and derailment risks.
This week’s staggering weather has already taken its toll on Chicago rail commuters: On Wednesday morning, Metra reported delays of nearly an hour for Union Pacific Northwest trains, according to the Chicago Tribune. (Amtrak straight-up cancelled all its trains to and from Chicago on Wednesday and most of Thursday.)
Chicago is so ridiculously cold that they've set the railway tracks on fire pic.twitter.com/bXJ2SKcCQH— Newsweek (@Newsweek) January 30, 2019
So Chicago had to start some fires. The process itself is pretty simple: “Get some old rags and other combustibles, soak ’em in oil, lay ’em next to the rail, start ’em on fire,” explained a commenter on the train talk forum Trainorders.com. (Some rail companies use a product called the Fire Snake instead of a diesel-soaked rope.) The heat will cause the rail to expand again. Then the tracks can be bolted back together. As this video shot by Chicago’s ABC-7 in 2017 shows, during this repair process, locomotives can roll right over the flaming rails, because trains are METAL AF.
(Fun fact: During extreme summer heat, rail operators have the opposite problem—metal rails expand and warp, creating a phenomenon known as “sun kinks.”)
Warming up train switches, which Metra spokesman Michael Gillis told the Tribune were also acting up on Wednesday, isn’t as dramatic. “To keep switches operational, Metra uses hot air blowers (kind of like hair dryers), electrified metal (like a curling iron) and gas flames (which look like a gas stovetop),” DNA Info reported back in 2017.
Trains are famous for their ability to laugh at the elements, even when other modes are grounded. But even mighty locomotives—which are also capable of plowing through giant snowbanks with immensely satisfying swooshes—must take extra precautions in this kind of extreme cold. Temperatures are predicted to ease somewhat by the end of the week. Til then, stay warm, and watch out for Fire Snakes.