2 ms·

There are plenty of petroleum distillates in a dockyard. Diesel, bunker fuel, kerosene, gasoline....not to mention other flammable hydrocarbons and powders. You

There are plenty of petroleum distillates in a dockyard. Diesel, bunker fuel, kerosene, gasoline....not to mention other flammable hydrocarbons and powders. You're assuming an 80% ratio ANFO/TNT but you're neglecting the mass of the FO, as well as the possibility of other oxidizers being stored near the blast site. I guess you could make some assumptions about the fuel based on detonation velocity as observed on video.

ashtonkem 6y ago
Properly mixed ANFO doesn't contain a huge amount of FO; ideally it's supposed to be 6% by mass. Good enough for a quick HN estimate, although I'd hope an actual after action report does better. A better calculation is that 2750 tonnes of AN would yield 2864 tonnes of ANFO, which is 2,291 tonnes of TNT equivalent. However, we know that the explosion wasn't stoichiometrically perfect, because of the brown NO2 clouds that were hanging over Beirut. Properly mixed ANFO should release only H2O, CO2, and N2. So we know that there was some level of explosive power that wasn't fully consumed. This is why I put the ANFO yield as the absolute theoretical max, I think in reality the actual yield was much much lower. Some other people have speculated that the fireworks like mini explosions between the first and second big explosions was actually ammonium nitrate decomposing, which would imply that this was a pure ammonium nitrate explosion and not one accelerated by some sort of oil or other fuel. If that's true, various manufacturers give the AN to TNT equivalent of poorly handled AN at 15-40% of TNT, giving a yield somewhere in the 412-1,100 tonne range.
- totalZero 6y ago
  > ideally it's supposed to be 6% by mass. Correct, but when you're talking about a difference of 1kt on a 3kt estimate, 6% is non-negligible IMO. > we know that there was some level of explosive power that wasn't fully consumed. Agreed, if there were no other oxidizers nearby then it's clear based on the reddish brown color of the smoke cloud that the AN was not consumed.

ashtonkem 6y ago

Properly mixed ANFO doesn't contain a huge amount of FO; ideally it's supposed to be 6% by mass. Good enough for a quick HN estimate, although I'd hope an actual after action report does better. A better calculation is that 2750 tonnes of AN would yield 2864 tonnes of ANFO, which is 2,291 tonnes of TNT equivalent. However, we know that the explosion wasn't stoichiometrically perfect, because of the brown NO2 clouds that were hanging over Beirut. Properly mixed ANFO should release only H2O, CO2, and N2. So we know that there was some level of explosive power that wasn't fully consumed. This is why I put the ANFO yield as the absolute theoretical max, I think in reality the actual yield was much much lower. Some other people have speculated that the fireworks like mini explosions between the first and second big explosions was actually ammonium nitrate decomposing, which would imply that this was a pure ammonium nitrate explosion and not one accelerated by some sort of oil or other fuel. If that's true, various manufacturers give the AN to TNT equivalent of poorly handled AN at 15-40% of TNT, giving a yield somewhere in the 412-1,100 tonne range.

totalZero 6y ago
> ideally it's supposed to be 6% by mass. Correct, but when you're talking about a difference of 1kt on a 3kt estimate, 6% is non-negligible IMO. > we know that there was some level of explosive power that wasn't fully consumed. Agreed, if there were no other oxidizers nearby then it's clear based on the reddish brown color of the smoke cloud that the AN was not consumed.