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This investigation ignores a key question: How many kg of ammonium nitrate was actually in the warehouse. Surely that's extremely important to the models. They

by yyyk 6y ago

This investigation ignores a key question: How many kg of ammonium nitrate was actually in the warehouse. Surely that's extremely important to the models. They only mention an mtv news report mentioning the stated figure of 2750t. That figure comes from the ship's documents. Yet there are estimates that suggest the actual explosion is only equivalent to 1000-1500t[0], or 700-1000t[1]. If the actual amount of nitrate was lower that the stated figure this strongly suggests some form of smuggling was involved, and someone was siphoning off the material. This would immediately explain the enormous 'negligence' that let this incident happen in the first place. [0] https://www.bbc.com/news/world-middle-east-53668493 https://www.bbc.com/news/world-middle-east-53668493 [1] https://www.occrp.org/en/investigations/a-hidden-tycoon-african-explosives-and-a-loan-from-a-notorious-bank-questionable-connections-surround-beirut-explosion-shipment https://www.occrp.org/en/investigations/a-hidden-tycoon-afri...

JoeAltmaier 6y ago
Or it degraded in the humidity? Not sure how that would play out.
- yyyk 6y ago
  I (not an expert) don't think trace materials or humidity can explain the size of the explosion being 1/2 to 1/4 of stated storage. That must require significant chemical changes. I suspect these changes would appear in the plume or type of explosion; Yet no investigation finds any evidence of any type of material not in the original documents. So we have 'raw' ammonium nitrate possibly contaminated with trace materials - which brings us back to the explosion weight being inconsistent with the documented weight.
eCa 6y ago
2750 tonnes, not kg.
- yyyk 6y ago
  Ouch. I wrote kg instinctively. Corrected.
aaronmdjones 6y ago
The first link suggests the blast was equivalent to 1000-1500 tonnes of TNT. Ammonium nitrate is not as powerful as TNT (Trinitrotoluene); therefore you require more of it for the same effect. Edit: The second link is probably misquoted and is also an estimation in terms of TNT. This is common; nuclear weapon yields are also stated in terms of TNT for example, despite not containing any.
- yyyk 6y ago
  Good point. Any idea what would be typical TNT value of 2750kg of Ammonium Nitrate?
  - aaronmdjones 6y ago
    According to [1]; 880kg (Edit: Though you meant to ask for 2750t, in which case, 880t). Not far off the estimated yield of the blast. Note that the effectiveness would be affected by contaminants and storage conditions. [1] https://en.wikipedia.org/wiki/TNT_equivalent#Relative_effectiveness_factor https://en.wikipedia.org/wiki/TNT_equivalent#Relative_effect...
mcdevilkiller 6y ago
Tonnes of TNT. In this case, a kiloton, or one and a half. That's the standard for measuring explosions.
dredmorbius 6y ago
Getting all of an explosive charge to detonate (rather than simply oxidize or be distributed by an existing blast) is already a challenge in designed explosives. This was a bomb, yes, but a happenstance one spread nonuniformly over a large region of warehouse. It's not unlikely that a considerable portion of the ammonium nitrate was blown away by the first-to-detonate material. Speculation, very much not my area. Informed by earlier reading however.
rtkwe 6y ago
In an unconfined fire when it's not intentionally detonated it's not surprising that not all of it would have detonated because the entire mass would not be under the right conditions to detonate at once even during the detonation of the rest of the pile.
gridspy 6y ago
Important source material to consider this question is [0] "Lebanon blast: Ammonium nitrate behind many industrial accidents" Basically the AN is an oxidizer and as such a chemical that "intensifies combustion" and so must not be combined with fuel or oil. Since it was contaminated, the contaminants are potentially combustable themselves. The warehouse was also likely filled with partially combusted gases from the tyres, fireworks or other burning material. So the explosion that did occur was not just the Ammonium Nitrate, but a mixture. As other writers have discussed, the blast would not have fully involved all the material either - some would be lost and some would remain unburnt. [0] https://www.aljazeera.com/news/2020/8/5/lebanon-blast-ammonium-nitrate-behind-many-industrial-accidents https://www.aljazeera.com/news/2020/8/5/lebanon-blast-ammoni...
- iSnow 6y ago
  Nah, you can detonate AN by itself, the oxygen from the nitrate part happily oxidizes the ammonium which will cause the nitrogen to depart the compound and release a lot of energy and gas. The contaminants just enable the reaction to switch from burning through deflagration to detonation.

by yyyk 6y ago

JoeAltmaier 6y ago

Or it degraded in the humidity? Not sure how that would play out.

yyyk 6y ago
I (not an expert) don't think trace materials or humidity can explain the size of the explosion being 1/2 to 1/4 of stated storage. That must require significant chemical changes. I suspect these changes would appear in the plume or type of explosion; Yet no investigation finds any evidence of any type of material not in the original documents. So we have 'raw' ammonium nitrate possibly contaminated with trace materials - which brings us back to the explosion weight being inconsistent with the documented weight.

eCa 6y ago

2750 tonnes, not kg.

yyyk 6y ago
Ouch. I wrote kg instinctively. Corrected.

aaronmdjones 6y ago

The first link suggests the blast was equivalent to 1000-1500 tonnes of TNT. Ammonium nitrate is not as powerful as TNT (Trinitrotoluene); therefore you require more of it for the same effect. Edit: The second link is probably misquoted and is also an estimation in terms of TNT. This is common; nuclear weapon yields are also stated in terms of TNT for example, despite not containing any.

yyyk 6y ago
Good point. Any idea what would be typical TNT value of 2750kg of Ammonium Nitrate?
- aaronmdjones 6y ago
  According to [1]; 880kg (Edit: Though you meant to ask for 2750t, in which case, 880t). Not far off the estimated yield of the blast. Note that the effectiveness would be affected by contaminants and storage conditions. [1] https://en.wikipedia.org/wiki/TNT_equivalent#Relative_effectiveness_factor https://en.wikipedia.org/wiki/TNT_equivalent#Relative_effect...

mcdevilkiller 6y ago

Tonnes of TNT. In this case, a kiloton, or one and a half. That's the standard for measuring explosions.

dredmorbius 6y ago

Getting all of an explosive charge to detonate (rather than simply oxidize or be distributed by an existing blast) is already a challenge in designed explosives. This was a bomb, yes, but a happenstance one spread nonuniformly over a large region of warehouse. It's not unlikely that a considerable portion of the ammonium nitrate was blown away by the first-to-detonate material. Speculation, very much not my area. Informed by earlier reading however.

rtkwe 6y ago

In an unconfined fire when it's not intentionally detonated it's not surprising that not all of it would have detonated because the entire mass would not be under the right conditions to detonate at once even during the detonation of the rest of the pile.

gridspy 6y ago

Important source material to consider this question is [0] "Lebanon blast: Ammonium nitrate behind many industrial accidents" Basically the AN is an oxidizer and as such a chemical that "intensifies combustion" and so must not be combined with fuel or oil. Since it was contaminated, the contaminants are potentially combustable themselves. The warehouse was also likely filled with partially combusted gases from the tyres, fireworks or other burning material. So the explosion that did occur was not just the Ammonium Nitrate, but a mixture. As other writers have discussed, the blast would not have fully involved all the material either - some would be lost and some would remain unburnt. [0] https://www.aljazeera.com/news/2020/8/5/lebanon-blast-ammonium-nitrate-behind-many-industrial-accidents https://www.aljazeera.com/news/2020/8/5/lebanon-blast-ammoni...

iSnow 6y ago
Nah, you can detonate AN by itself, the oxygen from the nitrate part happily oxidizes the ammonium which will cause the nitrogen to depart the compound and release a lot of energy and gas. The contaminants just enable the reaction to switch from burning through deflagration to detonation.