Frozen Train Tracks? Set 'Em on Fire

It might look dangerous, but flames have kept switches moving and rails intact for a century. From a report: As if the horrors of the polar vortex were not already enough -- temperatures that look like typos, Canada Goose robbers, and something called frost quakes -- the nation's railroad system took a turn for the apocalyptic this week, too. Rails broke in three different places between Baltimore and Washington on Thursday, causing severe delays. Amtrak canceled dozens of trains passing through Chicago, and viral videos appeared to show commuter tracks in the city on fire. Of course, the tracks themselves were not burning -- they are made out of steel, prized for its tendency to rarely go up in flames. But the sight is still dramatic. The videos of the fires in Chicago last week show flames smoldering in patches of melted snow around the tracks.

Fires have been employed on railroads -- and remained the preferred fix for many a winter hazard -- for most of their roughly two-century history. While railroads have developed impressive tools for dealing with snow on the tracks, extreme temperatures remain a challenge. Though steel is flame-resistant, it's subject to cold, which can jam up railroads' many moving parts. When cold weather does wreak havoc on railroads, lighting fires on train tracks can serve a couple of uses. One is to thaw the switches that determine which track a train goes down, which is what Metra, the Chicagoland commuter-rail authority, said was going on this week. Switches are moving parts, and if ice gets into them, they can freeze in place. There are various types of switch heaters, which might use electric current or gas to melt ice -- or even an open gas flame, which is what's appearing in the Metra videos. Where there aren't switch heaters, crews might use temporary torchlike devices with a flame, the railroad equivalent of the smudge pots farmers use to keep citrus groves and apple orchards from freezing on cold nights.

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