Explosion In Tianjin, China

JoeJester

Joined Apr 26, 2005
4,390
According to wiki, the suitcase nuke yield is about 0.19 kT. The physical damage might not be much, but the psychological damage to a city would be much greater. Irradiation fear would be rampant.

5 kT is the smallest nuclear weapon in the U.S. by law in 1994, but that was repealed in 2004.
 

strantor

Joined Oct 3, 2010
6,782

I don't know what the official death toll is, someone mentioned 50 in this thread. I read 17 somewhere. Watch the video I linked and you tell me. Maybe 17 bodies were found, but my WAG is that for every body found, there's at least 100 bodies that were Instantaneously erased from existence.

Chinese media; honest, impartial.
 

GopherT

Joined Nov 23, 2012
8,009
Couldn’t we cram 20 kiloton of TNT into a semi trailer?

That’s not that big. We now have transports that can drop semis, don’t we?.
Let's see, 20kilotons is 20,000 tons. Which is 40,000,000 lbs. So, no. We could not cram 40 million pounds into a semi-trailer.
 

nsaspook

Joined Aug 27, 2009
13,086
I am sorry to disappoint you but, those are imported along with just about everything else.
I must say that the Chinese are the world's experts in large industrial explosions. The Tianjin product line will be hard to beat even with advanced US technology, workers and materials.

RIP to those who died but I expect more demonstrations of this product in China that was tested in Texas in 1947.


http://www.bbc.com/news/world-asia-china-33945293
The evacuations came after an apparent change in wind direction, and as police confirmed the highly toxic chemical sodium cyanide was found near the site.
...
Meanwhile Chinese President Xi Jinping urged the authorities to learn the "extremely profound" lessons and keep "safe growth" and "people's interest first" in mind to avoid similar accidents.
 
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nsaspook

Joined Aug 27, 2009
13,086
It's fascinating to look at the relative motion of the ground wave making objects jump up vs the speed in the air wave pushing things over to the observer.

http://i.imgur.com/ruY55kK.gifv

What ever happened to 'Duck and Cover'. People seem to think that image on the phone protects them like a shield until it's too late to run or kiss the ground.
 
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GopherT

Joined Nov 23, 2012
8,009
It's fascinating to look at the relative motion of the ground wave making objects jump up vs the speed in the air wave pushing things over to the observer.

http://i.imgur.com/ruY55kK.gifv

What ever happened to 'Duck and Cover'. People seem to think that image on the phone protects them like a shield until it's too late to run or kiss the ground.
After seeing that video, it looks more like a vapor cloud explosion than "explosives". A vapor cloud explosion is simply a massive release of an organic solvent or gas that fills an area (usually because of a high pressure line break or vessel rupture). So much "fuel" fills an area that it cannot burn - then, it dissipates to an ideal level that can burn. Suddenly, an ignition source is contacted and... boom. Used by the militaries of the world since the late 1960s and known as thermobaric weapons - see wikipedia (unconfined vapor cloud explosion will re-direct there too).
https://en.wikipedia.org/w/index.php?title=Thermobaric_weapon&redirect=no

Interesting sections from Wikipedia article...


https://en.wikipedia.org/wiki/Flixborough_disaster
cyclohexane

https://en.wikipedia.org/wiki/Buncefield_fire
gasoline and various other refinery products.


The results of these explosions are very similar to those of grain dust fires (explosions).

Explosives, on the other hand, are molecules that contain both the oxidizer and fuel (nitrogen and/or oxygen oxidizer atoms with carbon and hydrogen fuel atoms all in one molecule) - heat, pressure or impact can detonate it but when it goes, it goes with so much force the shock wave it devastating. There would have been no time to watch the explosion. Few explosives can make an aerosol cloud or vapor cloud like the one shown. The boiling points are usually well above the detonation or, if boiling point is low, then the quantities processed at any given moment are much smaller than seen in the china or Texas City explosions. Texas City was a vapor cloud explosion
In Dangerous Goods Classification, the molecules that make vapor cloud explosions are generally categorized as flammables, not explosives.

Texas City explosion
Ammonium Nitrate (Unknown if additional fuel was mixed into the NH4NO3 but the Oklahoma City bomb was Ammonium Nitrate + Fuel Oil. Fuel oil could have dumped into the hull during the initial fire on the ship, then the big explosion.
 
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nsaspook

Joined Aug 27, 2009
13,086
After seeing that video, it looks more like a vapor cloud explosion than "explosives".
...
Ammonium Nitrate (Unknown if additional fuel was mixed into the NH4NO3 but the Oklahoma City bomb was Ammonium Nitrate + Fuel Oil. Fuel oil could have dumped into the hull during the initial fire on the ship, then the big explosion.
I agree, the major part of it wasn't a high explosive effect.
It moves from a intense fire to an initiation burst small shockwave to a massive shockwave then to an heaving explosion that lasts a long time.
 

JoeJester

Joined Apr 26, 2005
4,390
Any idea's of that video from the satellite's time scale? From the initial blast light, you can see something move southwest quickly. A quick estimate on Google Earth showed the distance to be about 20+ miles. It was a few seconds on the video ... and if that were realtime, that is one fast moving object.
 

nsaspook

Joined Aug 27, 2009
13,086
Any idea's of that video from the satellite's time scale? From the initial blast light, you can see something move southwest quickly. A quick estimate on Google Earth showed the distance to be about 20+ miles. It was a few seconds on the video ... and if that were realtime, that is one fast moving object.
If you mean the other white glob it looked liked a sensor overload defect or a reflection off a filter/lens because it was so bright.
 
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Lemme get this straight:

RE: The OK City blast: Credible sources and twenty years' scrutiny have established that ~ 1.25 Tons (2,500 lbs) of explosive killed ~170 in a city of ~600,000 (moderate population density)...

But RE: The Tianjin blast: We're told that a (conservatively) estimated 21 tons (42,000 lbs) of explosive killed Ca. 100 in a city of ~13,000,000 (high population density)...

Yeah, ok - Whatever!:rolleyes:
 
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GopherT

Joined Nov 23, 2012
8,009
Lemme get this straight:

RE: The OK City blast: Credible sources and twenty years' scrutiny have established that ~ 1.25 Tons (2,500 lbs) of explosive killed ~170 in as city of ~600,000 (moderate population density)...

But RE: The Tianjin blast: We're told that a (conservatively) estimated 21 tons (42,000 lbs) of explosive killed Ca. 100 in a city of ~13,000,000 (high population density)...

Yeah, ok - Whatever!:rolleyes:
There is a difference. The OK city event had all components (fuel and oxidizer) in the 1.5 tons. The oxidizer for the China event was closer to 45 tons of equivalent energy per 21 ton ISO Tank.

The 21 tons might have been the first fire of an ISO Tank and they assume that is what blew. More likely, the first fire caused the neighboring tanks to heat up, blow their pressure relief valves and make a cloud of vaporized solvent. I would not be surprised if 4 to 10 neighboring tanks blew their relief valves because of the first fire.

Now, assuming each tank that blew their relief valves contained 21 tons of fuel (solvent, hexane, what ever), then, 21 tons hexane get combined with 3.5 tons of atmospheric oxygen and all of that in about 14 tons of nitrogen that serves as a heat transfer/momentum transfer solvent that is evenly blended into the mess. In total, you get nearly 40 tons of blasting momentum. Much slower shock wave than OK city but roofs collapse much more easily than walls. Multiply that by 4, 8 or 10 tanks that actually vented, then you get what we saw.

Also, there was post event fire and coating of ash/soot that made the whole event worse.

As for number of people, the OK event was next to an office building - without notice. The Tianjin event was in the middle of a container farm at a port. There was also some advance notice that an issue was about to happen as the first fire broke out. Most people in my industry know to run because the neighboring tanks are the bigger issue. The first tank is just a fire - a tank that already ruptured. In other words, you are not wrong about the quantity of fuel but for the population density, I think you are comparing apples to oranges in the immediate area of the event.
 
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