
It’s so cold in Chicago, crews had to set fire to commuter rail tracks - gscott
https://jalopnik.com/chicago-is-so-ridiculously-cold-that-the-railroad-track-1832177510/
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teilo
>When it gets to be several degrees below freezing, the metal of the train
tracks can contract to the point that it will pull up the bolts holding it in
place, or even stress fracture.

This is bad reporting. This is nothing new, and happens every winter. It is
only necessary to manually light them up with a kerosene soaked rope when
repairing a piece of track.

As should be obvious, below-freezing temperatures happen every year in
Chicago, and train tracks need to be repaired even in the winter.

~~~
cwyers
That doesn't say it's new, or that it doesn't happen every winter.

~~~
bunderbunder
The way the headline is worded, along with the fact that it's a headline in
the first place, implies that it's an unprecedented thing, even if the article
doesn't go out and state it.

Had they wanted to, they could have come up with a much less linkbait-y way to
talk about how track maintenance works in the winter.

~~~
gscott
Everyone outside of the areas where it gets cold enough for this to happen...
I found it fascinating. Hacker news is partly about hacking a problem to find
a solution and it seems this is a good hack. It's click-baity but you can
imagine yourself in the shoes of the original person looking at the problem
and going through the steps until they figure out that it can be solved by
burning a rope... it is interesting.

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dangus
Just a note, there is a difference between setting fires manually to tracks
and permanently installed switch heaters:

[https://metrarail.com/about-metra/newsroom/the-
signal/fighti...](https://metrarail.com/about-metra/newsroom/the-
signal/fighting-fire-switch-heaters-2)

~~~
toomuchtodo
But that isn't nearly as exciting of a clickbait headline as "setting fire to
railroad tracks on purpose".

I would be interested if any Metra folks could chime in as to why induction
heat isn't used instead of open gas flames.

[https://patents.google.com/patent/US5389766A/en](https://patents.google.com/patent/US5389766A/en)
(rail snow-melting by electromagnetic induction heating)

[http://indheater.com/](http://indheater.com/)

[https://www.youtube.com/watch?v=wpQi0DEcGWs](https://www.youtube.com/watch?v=wpQi0DEcGWs)

~~~
bunderbunder
The induction heaters you're linking are designed to be permanently installed.
They're perfect for switch heating, but probably not a cost-effective option
for maintenance work. You'd need to have the heaters installed very close
together over the entire length of the track, and the likelihood that any one
of them actually needs to be used to heat the track for repairs would be very
small.

A portable option might be possible, but then you'd have to mess with
batteries or generators or something to provide the power. Ropes soaked in
kerosene sounds to me like the "the cosmonauts used a pencil"† option.

† (Yes, I know that this is an urban legend.)

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ericd
Are there alloys that don’t have this level of thermal expansion/contraction
that could be used instead?

~~~
joezydeco
There are, but the cost of building thousands of miles of rails out of it
would be incredibly prohibitive.

~~~
ericd
Ah yep, I meant alloys that are reasonable to use for rail, including cost
restrictions.

I had heard that the TGV has welded rails rather than expansion gaps, which
necessitated a low-thermal-expansion alloy. But I don't anything about it
beyond that.

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bobm_kite9
This is good though, right?

In the UK the points regularly freeze at even just a couple of degrees below
zero, and the trains are just cancelled.

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forgottenpass
>as a smart race of human beings, still have to resort to medieval methods of
re-warming metal train tracks

Drinking water and eating food to stay alive is so outdated you guys.
Groceries don't even have touchscreens.

