Railroad tracks on fire.

March 18, 2007 12:03 AM

So, when traveling on PATH toward Newark tonight, I noticed that some of the tracks were on fire.

The flames were visible from the window of a Newark-bound PATH train, from just before Harrison about a quarter of a mile past the station toward Newark. These flames weren't on the PATH tracks, but on several different tracks that Amtrak and NJ Transit use. They were mostly blue, and when the doors opened at Harrison, I thought I smelled a natural-gas smell, but it could have been my imagination. This was less than four hours ago (about 11:25 pm).

How on earth would natural gas (or whatever it was) get onto such a long stretch of tracks and ignite?

posted by oaf to travel & transportation (8 comments total)

I've heard that these burns are controlled to assist in fixing a break in the rail. Looks like Yahoo has already answered this one.
posted by rhapsodie at 12:29 AM on March 18, 2007

Or switch heaters. I've seen 'em on tracks myself. They do look like early 1900's technology applied to modern times, but I guess they must work well and, hey, it's not like USA exactly embraces the most modern train technology.
posted by mdevore at 12:33 AM on March 18, 2007

Natural gas has no smell; the odorant (mercaptan) is added before delivered to homes through pipelines. Natural gas (methane) is gaseous at atmospheric pressure and temperature, not liquid.

Liquid natural gas requires refrigeration for transportation and stores enough energy that you would probably notice if a leaking LNG tanker caught fire that close to you. I don't believe mercaptan is added until after LNG is "repackaged" and delivered to consumers.
posted by Blazecock Pileon at 12:41 AM on March 18, 2007

It's almost certainly switch heaters. In the area around Newark and Harrison there are a lot of switches, and it's important that they not freeze so that they can be operated at any time. The ones you saw were probably of the "open flame" design, which is indeed old technology but it still works well. The Long Island Railroad uses the same thing on the switches near Jamaica station; more than a few times I heard someone ask one of the train crew about the blue flames on the tracks.
posted by Godbert at 7:15 AM on March 18, 2007

PATH has those little fires going in just that area from time to time during winter. If you're in the area of the Harrison PATH at night, a gassy smell is not at all unusual any time of year, so I wouldn't tie them together.
posted by nj_subgenius at 7:18 AM on March 18, 2007

AskMe at its best.
posted by caddis at 8:26 AM on March 18, 2007

Looks like Yahoo has already answered this one.

That's what I get for searching for "rail" instead of "train."
posted by oaf at 10:04 AM on March 18, 2007

I think they use thermite, which makes a bright blue-white light, to weld sections of tracks together.
posted by electroboy at 6:40 AM on March 19, 2007