There’s certainly a danger, but comparing the energy of these two things is misleading. A 110 hopper cars filled with coal would contain a similar energy. How the energy is released is critical. Otherwise we’d be apocalypse level fucked on a regular basis:
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'kin 'uge Bangalore torpedos! Nobody light a match…
Yes, these are the Architectural Digest construction kit stories kids can empathise with. It has a wonderful finish -because- it’s fireproof for 6 hours and someone’s gonna roll a dumpster right up in there for four plus.
Environmentalists: Trying so hard to be tongue-tied about population control because of Incel Modern divisions, yet ken to a way to hang onto environment not made of naptha-breathing novel organisms. [Turns and runs into the Miskatonic U. Safety Manual story.]
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Murica is more and more like Beirut every day.
I’d rather make stupid decisions to send poorly secured bombs through cities. You may be just asking questions, but your questions indicate that you either don’t understand the problem, or you are playing dumb. Neither is helpful. Explosive trains in populated areas don’t just kill the person who behaves recklessly, they take out huge areas. So, let’s use my neighborhood as an example, because I live about 1/3 of a mile from the tracks. We can use the blast radius of either the Cleveland natural gas explosion or the Lac Megantic as obvious choices. If we only blow up an area the size of the Cleveland blast it is about 1 square mile, Lac Megantic would give us roughly three. The population density of my city is about 9,000 per square mile. If it killed half the people in that blast radius it would be more than my state’s total Covid death toll for the smaller blast.
The single omnibus bill won’t be possible, but putting a team to work going through the register should be possible.
In the case of a fuel air explosion the manner of energy release is a lot more comparable than hurricanes or coal.
Normally they live far enough for derailment not to be a concern, but a lot of cities have major rail lines heading to their ports, airports or a central industrial area, which means nice waterfront buildings and downtown lofts are both likely to be in the blast area. Once your blast radius is measured in miles it starts blurring those class lines.
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Por que no los dos?
Refrigerator-sized meteorite nails the center car in a 35-car bomb train as it’s passing through Saint Louis …
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Fortunately, US railroads are famed for their impressively engineered tracks which give the sort of impossibly smooth ride which can only be compared to being trapped in a washing machine tumbling down a flight of stone steps.
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Nuclear physicists might disagree. But I understand the point you are trying to make. However, it wouldn’t be an efficient fuel air explosion from compressed gas. Getting the stoichiometric ratio is not easy. Plus you would get a deflagration, not a detonation. Whump vs wham. This leads to a difference brisance. Like being hit by a car at 30 vs 90 (maybe dead, vs definitely and in many pieces).
In other words, you’ll get a horrific mess. But direct measurements in ‘Hiroshimas’ are still hyperbole. Comparison in explosive force to Beirut is also off. There is ample evidence for the difference. Several high pressure gas pipelines that are 30-48 inches in diameter with pressure up to 1500 psi have exploded. Gas volumes would be comparable to a wreck of one of these trains. They made horrific messes and not insignificant loss of life, but did not have nuclear bomb or Beirut fertilizer explosion level devastation or death.
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Ammonium Nitrate is an explosive by itself. NH3NO3 gives Nitrogen N2, 1.5 H20 water molecules, and some leftover oxygen. If you were to mix it with a bit of fuel oil or sugar you would have a slightly better explosive, but it is quite good by itself. This is why the whole lot could go up Beirut as the shockwave passed through it, giving that spectacular white Wilson cloud ball. I saw some of the early Beirut footage, and it looked like a small nuke. At the time they were saying it was fireworks, but I was pretty sure it wasn’t. The overpressure in that shock wave would push over buildings, and black powder fireworks don’t do that. But you needed the fireworks to start the shockwave; ammonium nitrate is not that easy to detonate.
Now your liquid gas train may have the same energy but it is all as the reducing agent. To get the energy out, you would have to mix your liquid gas with air, and as you do that you will mix it with 80% Nitrogen. If you dispersed the gas, waited for it to mix with air, and then ignited it, this will give you a bang with the same energy, but it is more spread out, and probably subsonic. There would be fire and flames but most of that would probably go up in the air like the Hindenberg.
This is not to say it is safe. I am sure the people who legalised this have no more understanding than the folks in Lebanon who thought you could store fireworks with 3000 tons of ammonium nitrate because ‘why not have all the bangy stuff in one place, because that’s tidy’. They would sign it off because Money, and even if this train is not as deadly as it first seems, they will probably top it off with nerve gas and nuclear waste because More Money.
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My first thought was that we were bringing back the Peacekeeper nuclear garrison train, but that would more properly be a missle train.
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So they need to alternate and have every second train car carry the oxidizing agent?
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Ammonium nitrate is NH4NO3 (trivial quibble). Velocity of sound in methane at equal temperatures is sqrt (14/9), call it 30% faster than in air. Yes, it has to mix first but some of that is bound to happen before ignition. After ignition the temperature behind the shock wave is several times that in front, which propagates several times the speed of sound in cold air, igniting by compression as it advances.
Hot methane expands along with the front, which cools with expansion.
A train is the worst case since the initial blast shock will propagate through the steel cars and couplings faster than the gas shock, opening cars and releasing methane ahead of the front.
The leading edge of the blast won’t be as sharp, but since the hot core is much hotter the pressure behind the front advances faster than the front can. A kilometer away it’s all one big fireball almost totally combusted and the shock wave is still advancing faster than sound.
Thanks, working this out was fun.
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I think you mean “Democrat cities”
But seriously…one of the highlights of the chemistry sophomore seminar I ran was to have one of the national emergency response coodrinators come in and talk about various disasters, explosions, chemical spills, etc. A LOT of them involved trains. This move is NOT helping.
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We all know what the real bomb was:
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One thing I haven’t heard much about is whether there will be, like, a Truth and Reconciliation commission or something like that. Just for the purpose you mentioned above. Yeah, people should be charged with crimes, but figuring out the extent of the damage that was done, where all the money came from and went… that’s one of the few things I’d consider more important. Not that they’re entirely mutually exclusive, but I don’t think it’s exactly the same thing.
Nope. Not trivial: a sure sign that I finished a bottle of wine with supper because what was left wouldn’t keep. Falsus in unum, flasks in omnibus, I guess.
Yes. And I ought to know, as the side door of my house was knocked in by the Buncefield explosion shockwave in 2005 despite being 2 miles away, and the other side of the raised M1 motorway. That was just petrol and vapour that managed to be mixed in stoichiometric proportions.
The engineer in me has to wonder whether it would be safer to vent and ignite the methane deliberately in an accident. This would give a tall flame with convection, rather than a fog of vapour and air. But the right solution if you have methane might be to use it to generate electricity, and not do this at all.
Thanks.
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We really are an odd breed, aren’t we? We do problems like this for fun.
The local university operates a research unit (http://emrtc.nmt.edu) that does a lot with ANFO and more exotic stuff (like adding powdered aluminium to the mix to increase yield). We’ve gotten so that we hardly notice having the windows rattle and the ground shake, but every so often they do a big one (they have a mountain for a test range). We were at a wildlife preserve about 30 km away one day when we felt the ground jump. Looked back towards town as I started counting and then we heard the boom, about the time we saw the mushroom cloud rising over the mountain. That was a BIG one. (They do those in valleys that keep the force directed away from town or much of anything. The cattle who graze in the area see the preparations for a shot and go somewhere peaceful.)
On retirement I came here to do some more learning and picked up some of the kaboom physics. Fun stuff. I do believe that I should suggest the “bomb train” subject to Dr. Romero for a Masters project of some social benefit.
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Now look here, if we don’t let corporations blow up our cities the terrorists win.
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A Truth Commission is a good idea but whilst reconciliation after decades of political oppression was necessary to stave off potentially massive bloodletting in South Africa, you cannot have reconciliation with a short-lived criminal conspiracy.
Lock them up!
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It ain’t over till it’s over:
In the weeks since Beirut’s deadly chemical blast, residents have been sweeping up the broken glass and wiping down surfaces caked in dust. And it’s this dust that some say poses a major threat to the city.
“The most dangerous thing” right now, according to Greenpeace’sMiddle East and North Africa program manager in Beirut, Julien Jreissati, is that no one knows “what actually exploded besides ammonium nitrate” and, therefore, how toxic the dust is.
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