So... Nitram. Ammonium nitrate. Nasty stuff when it goes bang. And 2,750 tonnes just went bang. It's a big number. It's hard to take in. Some context... (1)
If it's a solid lump, with a density of 1.72, I make it that it would be near as dammit a cube 11.7m on each side. If it was solid. It wouldn't have been solid, but that's how much mass you need to visualise... (2)
You'd normally see it in 500kg massive pallet sized sacks. So, about 5,500 of those. A sense of scale is starting to emerge, yes? (3)
There are really two things that are so horrible about this explosion. The heat and direct damage that caused people close by, and the shockwave. (4)
In that explosion, where you see a huge browny cloud, there's also the visible shockwave you can see in most of the footage. Want to know what the speed of sound looks like? That. It's as fast as that vibration can move through air (5)
The orange cloud would have had some NO in it, but of course when you've got that much of an explosive going off at once it's likely that it would be more or less hot enough for the reaction to go as far as it can. So not a lot of NO... (6)
So correct me if I'm wrong, but most of the reaction would be 2NH4NO3 → 2N2 + O2 + 4H2O. And yes, this is why bomb makers add other things to it, if you don't know why from looking I shan't explain what or why (7)
So what does that mean? It means that for every 2 moles (don't worry about it if you don't know, here it just means 80g) you get 7 moles of gas produced. Hot gas, expanding unbelievably fast. An explosion. (8)
I don't know what temperature the explosion would have reached. If anyone has that factoid, let me know. Shall we say 1000 C?(9)
At 1000 C 1 mole of gas takes up a tenth of a cubic meter. Give or take. Each mole of ammonium nitrate makes 3.5 moles of gas. Each mole of ammonium nitrate is 80g... (10)
...so within a few moments, at 1000C, over 12 million cubic meters of gas were produced. Give or take. It went from about 1,350 cubic meters of solid to, well, that. The shockwave you saw in the videos? That's what made it. (11)
Or if you compare the explosive power of TNT with nitram, it works out as the equivalent of over 1,100 tonnes. Yes, over a kiloton (12)
That's, what, a twelfth to a fifteenth the size of the bomb dropped on Hiroshima. It's comparable to a small nuclear warhead, a tactical rather than strategic weapon (13)
This is colossally beyond the scope of most accidents. It's beyond what is done in war with a single bomb, shy of nuclear weapons. This will prove to be one of the biggest accidental explosions in human history. This, bluntly, is terrifying. (Fin)
