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Large explosion in Beirut... 23

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That video reminded me, to some extent, of videos taken on the streets of NY after the 9/11 attacks.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
This finds a bunch of videos.
Death toll now reported to exceed 135.

Known amounts of Hydrocarbons + Ammonium Nitrate is how "well behaved" fast unpacking of the nitrogen is encouraged.
Some of the large explosions cited in the AN disaster list below occurred without obvious presence of hydrocarbons which indicate that making a large pile of AN is an unpredictable risk. A risk I want to stay far away from.

Fred
 
Here's some before and after photos of the Beirut part area. The first was taken on May 31 of this year and the second was taken today:

Screen_Shot_2020-08-05_at_2.38.09_PM_ur1zy3.png


Screen_Shot_2020-08-05_at_2.38.33_PM_yenqoj.png




John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
This is devastating to more than just the local port area.
So many goods come in and out through the port that were lost in the destruction. New shipments cannot be handled here for a long time. The effects on the economy (already struggling) will be terrible.
Without knowing details about the port, questions immediately arise - will fuel and food be in short supply soon? How much capacity do the other port(s?) (Tripoli??) have?

More before & after shots

 
That large, tall white structure next to where the explosion took place, which amazingly was not completely destroyed, appears to be a grain elevator, and from the photos taken after the blast, appears to have been full of corn or perhaps soy beans (the material flowing out on the ground appears to be light yellow in color). Not sure about fuel supplies being lost as there didn't seem to be any large secondary fires. I suspect that the fuel docks were in another part of the port.

Also the container docks may have survived with little damage since, as can be seen in those pictures I posted earlier, to have been a good distance from the blast site. No, it appears that the blast took place where bulk material were off-loaded and stored, which makes sense that that's where the ammonium nitrate was stored in bulk containers stored in traditional warehouses.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
In fact, looking at those pictures it appears that the warehouse where that ammonium nitrate was probably stored was the one next to that grain elevator, since you can see a large crater where that warehouses had been located:

Screen_Shot_2020-08-05_at_10.09.24_PM_lhnhqr.png


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
Here's a shot showing the grain elevator after the blast:

Screen_Shot_2020-08-05_at_10.28.17_PM_njbr6u.png


John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
Any body explain the stages in the explosion, am I right in thinking the white ball is a supersonic shock wave when the majority of the Ammonium Nitrate detonated?
 
The energy released by the disassociation of all that Ammonium Nitrate creates a very high local pressure. The pressure is restrained only by the inertia of the surrounding air which moves outward at the speed of sound in air. The white ball is water condensing from the air in the very low pressure which immediately follows the shockwave over pressure.
Screenshot_from_2020-08-06_06-59-02_gblhln.png


There are papers like this one "Investigating Different Grounds Effects on Shock Wave Propagation Resulting from Near-Ground Explosion" that explain the physics.
Screenshot_from_2020-08-06_06-25-21_izwk3b.png


Screenshot_from_2020-08-06_06-37-49_u8ypwz.png


The energy in the shock close to the explosion is huge, as can be seen in what remains of the grain elevators. The rear is standing only because the crushing of the facing side concrete and the inertia and friction of the loosely packed grain absorbed the shock.

While somewhat fascinating, shock wave physics is a field I will stay far away from.
 
West, Texas, did not get blown off the map, and a year or so after the explosion, there was very little sign that anything had happened.
If I remember right, strong shock waves can travel faster than the speed of sound, which is basically the speed an infinitely weak wave travels.
 
Did y'all see the one video where you saw the blast and about 300ms later the house rattled seismically and then about 3s later the 3 times slower air wave showed up?


Thanks for pointing out that was a grain elevator AND why it survived! I was amazed it survived and thinking it was an apartment, that thousands would've died. Very glad it was otherwise. I'm also sure it saved hundreds of lives by producing a very large blast shadow behind it.

Keith Cress
kcress -
 
NH4NO3 Accident Comparisons:
2013 Waco, TX - 55 KKg
2015 Tianjin, China - 725 KKg
1947 Galveston, TX - 2,100 KKg
2020 Lebanon, Beirut - 2,700 KKg
 
A kkg is a tonne no?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Keith
If you look at the still image above from the cellphone, you can see the vapor cloud somewhat disrupted on one side. This could be the result of the pressure wave being disrupted by the grain elevator. - Other images seem to indicate the back side of the grain elevator was not "safe" the pressure wave would refract around the silo, and might still have created a significant over pressure.

human909 - we are splitting hairs - reasonable for engineers.
Near field - I agree that detonations do result in near field shocks that appear to travel faster than the speed of sound. The complete story is more complicated, as lots of physics, chemistry and thermodynamics is going on very quickly.
Far field - at some point the shock turns into a pressure wave which travels at the local speed of sound.

Fred

 
Yes, but the 'shock', or seismic, wave will travel through the ground even faster, so you may FEEL the shock before the 'sound' arrives.

John R. Baker, P.E. (ret)
EX-Product 'Evangelist'
Irvine, CA
Siemens PLM:
UG/NX Museum:

The secret of life is not finding someone to live with
It's finding someone you can't live without
 
Another historical ship/harbor explosion. Halifax, Nova Scotia explosion Dec 6, 1917.
2300 tons of picric acid, 200 tons of TNT, and 10 tons of guncotton.
 
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