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Re:Rule Allows Natural Gas Transport by Rail in Dense Areas by jjk166 on Tuesday December 29, 2020 @10:16AM (#25570469)
It's not enough to just aerosolize the LNG, it needs to mix with air in a rather narrow fuel-air ratio of 5-15% to burn. Further the flame front speed of methane in open air is only 4 mph - it won't explode, though as the flame front spreads it might kind of look like an explosion (think about what it looks like when you light a gas stove or grill). Such a fireball can potentially ignite things in close proximity, but there won't be a pressure wave that damages structures, so you can't have a situation where one tank 'exploding' causes other tanks to explode, though in a crash it's easily possible multiple tanks are damaged.

Natural gas is an explosion hazard in enclosed spaces. If you walk into your house and smell gas, that's very dangerous. Note also that even if there is no explosion hazard, fire is still dangerous.

If you are uncomfortable with rail transport of crude, that's a perfectly legitimate stance to take. Honestly, transporting any flammable substance (and many non-flammable ones as well) does pose risks. If you know the risks and benefits and think the former outweigh the latter, let people and especially your representatives in government know. However, society generally seems to accept rail transport of oil and similar chemicals, so outrage over the transport of a less dangerous substance seems like it would be more likely to come from a place of ignorance than rational analysis.

Re:Rule Allows Natural Gas Transport by Rail in Dense Areas by uep on Tuesday December 29, 2020 @11:17AM (#25571260)
Your statements do not seem to be consistent with those in the article.

> Ray Mentzer, a chemical engineer at Purdue University, spent his career working on LNG projects for Exxon Mobil. He says the specially designed containers that transport hydrocarbons have a good safety record. But he says transporting the gas through densely populated areas increases the risk if there's a leak.

> "It's not flammable until it's vaporized, but it's going to be vaporized pretty darn quickly and then it's going to seek an ignition source," he says. "Believe me, it will find an ignition source pretty darn readily."

I will also note that those train tracks in the town in the photos had a derailment only a few years back. I am familiar with the area and know people who live there.

https://response.restoration.noaa.gov/about/media/train-dera...

Re:Rule Allows Natural Gas Transport by Rail in Dense Areas by jjk166 on Tuesday December 29, 2020 @11:57AM (#25571802)
There is no inconsistency. Natural gas is most certainly flammable once it's vaporized (it would be a very poor fuel if it wasn't), but there's a big difference between something being flammable and something being explosive. If you have a big leaking tank, it is very likely that it will catch fire, and no one really wants a big raging fire in a residential area, but that fire will only burn at the leak where fuel and air are mixing. It's very difficult out in the open to form cloud of natural gas and air with a uniform mixture such that it can all burn at the same time, and even then the flame front is too slow to cause a damaging explosion.

I would also note that the engineer's use of informal language here is clearly alarmist.