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I am left speechless by the devastating explosion in Tianjin, China.

I've never been there, but have handled countless shipments through this port, which is one of China's main ones.

The footage of explosion and the aftermath is devastating.





Reuters video report on the aftermath: http://www.reuters.com/article/2015/08/ ... B220150813

Drone video of the aftermath: https://www.youtube.com/watch?v=qTRqVtXFuqQ

So far, 50 victims have been confirmed, with several hundred people being injured. But seeing the amount of destruction, I guess the final figures - if reliable figures will ever be released - will be much higher.

That moment in the drone video when I realised those were shipping containers

That moment in the blast videos, when you think, "damn, that's a huge explosion". And then comes the real one...

Holy shit.

I was horrified last night when the explosion was located on Google maps and there were apartment towers right across the road. Thankfully, with this mornings pictures, there were construction cranes on them, showing them to still be under construction and not occupied. A miracle in this disaster.

For sake of watching the video, I'm glad the person in the 2nd video didn't pull back more quickly. Seeing the effect of the 2nd explosion (in 2nd vid) might've made me want to floor it in reverse.

Click Click D'oh wrote:I was horrified last night when the explosion was located on Google maps and there were apartment towers right across the road. Thankfully, with this mornings pictures, there were construction cranes on them, showing them to still be under construction and not occupied. A miracle in this disaster.

I am honestly surprised that they are still standing. Chinese construction may be better than its reputation.

Check this video out, it's a compilation of several cell phone videos. The one starting at 2:36 gives a good idea of the size of the explosion. Those tiny silhuoettes in front of it are the apartment towers.



The explosion was visible from space, the shock wave has been picked up by seismic stations in the US.

How horrific. I wonder what the yields of those explosions were?

This incident brings to mind the PEPCON plant disaster in Henderson, NV from 1988 where improper storage procedures for excess stocks of ammonium perchlorate, a major ingredient for solid rocket fuel, cooked off when a fire at the plant broke out.

This report from Lawrence Livermore National Lab claims that two of the resulting explosions exceeded the equivalent of two kilotons of TNT. If that's accurate it's astounding that only two people died.

You can see them here (skip to 2:50 and 6:45):

JeffSFO wrote:This report from Lawrence Livermore National Lab claims that two of the resulting explosions exceeded the equivalent of two kilotons of TNT. If that's accurate it's astounding that only two people died.

The Tianjin explosion is estimated at the equivalent of something between 30 and 50 kilotons of TNT. But these look to be mere guesses. This explosion is beyond imagination.

Here is another horrifying video, filmed from far too close for comfort. It starts with a pretty bad-looking fire. Then comes a mindblowing explosion. Then comes the big one.



A photo of the crater gives an idea of the amount of destruction:



And the issue is far from over. The stuff that blew up there was sodium cyanide, and that stuff is pretty poisonous.

It has meanwhile rained in Tianjin, and the stuff that the rain left does not look healthy at all: http://shanghaiist.com/2015/08/18/first ... explos.php

The cause of the explosion looks to be confirmed as well, and it matches the rumours I heard from Chinese business partners on the day of the explosion. A medium-sized fire had broken out at a storage site for dangerous goods. And the first-responding firemen fought it with water, which was a disastrously bad decision.

I'm surprised you didn't hear glass shattering but maybe I missed that.

I wonder if the health affects of all of this won't be known or seen for some time...or if China may find a way to attempt to cover it up. In any case...wow...

This can't end well for that city.

GQfluffy wrote:I'm surprised you didn't hear glass shattering but maybe I missed that.

He was standing on the rooftop of his apartment building, watching for Perseids, when the explosion happened.

GQfluffy wrote:I wonder if the health affects of all of this won't be known or seen for some time...or if China may find a way to attempt to cover it up. In any case...wow...

So far, Chinese authorities have been suprisingly open in their communications, even in regards of the secondary threat by poisoned air and rain.

I guess they know that this is too big to cover up, even for them. But I also think that this disaster is very difficult to deal with, even for them.

GQfluffy wrote:This can't end well for that city.

True.

A business contact of mine who works for a major Chinese shipping line is on his way to Tianjin, to assess the aftermath and the impact it will have on shipping. Will be interesting to hear his report, will see to meet him for lunch once he's back.

Zak wrote:

JeffSFO wrote:This report from Lawrence Livermore National Lab claims that two of the resulting explosions exceeded the equivalent of two kilotons of TNT. If that's accurate it's astounding that only two people died.

The Tianjin explosion is estimated at the equivalent of something between 30 and 50 kilotons of TNT. But these look to be mere guesses. This explosion is beyond imagination.

Here is another horrifying video, filmed from far too close for comfort. It starts with a pretty bad-looking fire. Then comes a mindblowing explosion. Then comes the big one.



A photo of the crater gives an idea of the amount of destruction:



And the issue is far from over. The stuff that blew up there was sodium cyanide, and that stuff is pretty poisonous.

It has meanwhile rained in Tianjin, and the stuff that the rain left does not look healthy at all: http://shanghaiist.com/2015/08/18/first ... explos.php

The cause of the explosion looks to be confirmed as well, and it matches the rumours I heard from Chinese business partners on the day of the explosion. A medium-sized fire had broken out at a storage site for dangerous goods. And the first-responding firemen fought it with water, which was a disastrously bad decision.

Hiroshima and Nagasaki were ~ 15 and 25 kilotons each so that kind of puts things in perspective. This was huge.

The tragic irony here:



The 2 destroyed buildings on the left that were nearest to the explosion - that was the Tianjin Port Fire Department. The fire and the explosions took place literally right across the street from their main base.

More info on the exact location: http://www.gis.harvard.edu/services/blo ... nline-maps

Almost a mini nuke, save the initial pulse and the radioactive fallout. The secondary flash is what burned the paint off of the cars.

Wonder if there's a "before" type pic from anywhere around the area shown from Zak's pic (just to put in perspective how it looked beforehand).

Zak wrote:The Tianjin explosion is estimated at the equivalent of something between 30 and 50 kilotons of TNT. But these look to be mere guesses. This explosion is beyond imagination.

bhmbaglock wrote:Hiroshima and Nagasaki were ~ 15 and 25 kilotons each so that kind of puts things in perspective. This was huge.

Wow, those estimates are wildly high IMO. Thermally, the Tianjin explosion was nowhere near what either Little Boy or Fat Man produced (temps of the isothermal spheres of their fireballs are estimated to have been 300K C):

http://www.atomicbombmuseum.org/3_radioactivity.shtml
http://www.atomicbombmuseum.org/1_devastation.shtml

The temperature at ground zero in Hiroshima is estimated to have been 5.4K F and surface temperatures within a mile of the hypocenter were raised to well over 1K F. People not protected from the blast had their internal organs boiled away in an instant. Additionally, the overpressure of 9 PSI destroyed all buildings that weren't reinforced.

In other words, thousands of people in Tianjin would be dead if those explosions reached 30-50 KTs TNT equivalent. I've read that a firefighter was rescued at the site of the blast although I don't have any details, but I'd imagine he'd have been incinerated and obliterated by such a big explosion.

For what it's worth, some guy on YouTube has made an interesting back-of-the-envelope estimate of 3 kilotons for the potential yield by using the criteria listed below. He might be a complete crackpot but at least the estimate is consistent with similar incidents like the Halifax Explosion (2.9 kilotons), Texas City disaster (2.3 tons of ammonium nitrate exploded), and the previously mentioned PEPCON blast. In any case, we'll find out the truth eventually.

Ball park numbers:
1 mole of TNT ~ 250g
1mole of TNT exploding gives ~ 7 moles of gas.
1 mole of gas ~ 22.4 liters

so 250 g of TNT detonating gives ~ 150 liters of gas.
However the gas is not at room temperature (~300 k) but 2000K.
Gas expands ~ 7x when heated from 300 K to 2000 K.

So when 250g (1/4kg) of TNT is detonated, it creates a fireball ~ 1000 liters in size, or 1 cubic meter.

The fireball in the video is ~300m in diameter, or 150m radius.
This means the volume of the fireball is ~14 million cubic meters.

This means ~3000 tons of TNT would be required to make this fireball.

If the estimated diamter of the fireball is reduced to 150m, the volume of course goes down by a factor of 8.
This would still mean an estimated 300 tons would be required.

It certainly seems the chinese estimate of 20 tons of TNT seems on the light side!

JeffSFO wrote:Wow, those estimates are wildly high IMO.

Sorry, I misread / misquoted the source I read. The total amount of all explosions that took place (there were around 50) is supposed to add up to 30-50 kilotons of TNT.

The first of the 2 big explosions is estimated at the equivalent of 3 kilotons TNT, the second one (the really big one) is estimated by official sources at 21 tons of TNT.

Still one helluva bang.

JeffSFO wrote:Thermally, the Tianjin explosion was nowhere near what either Little Boy or Fat Man produced

That is true, but no one said it was. While explosive power is often measured in equivalents to the Hiroshima bomb, it is indeed a bit misleading, as the devastating effect of a nuclear bomb is not just caused by its explosive power, but also by the thermal reaction it creates.

So in terms of just explosive power, the Tianjin blast was about as powerful as the Hiroshima bomb, but without the thermal reaction, the effect was not quite as devastating, but certainly still bad enough.

JeffSFO wrote:Wow, those estimates are wildly high IMO. Thermally, the Tianjin explosion was nowhere near what either Little Boy or Fat Man produced

Spot on.

All you have to do is take a look at the aftermath to see the difference. The Tianjin explosion covered no where near one mile in diameter in it's direct effect. The Hiroshima explosion... Well, judge for yourself. And it was relatively small, in nuclear terms.



There simply is, IMHO, little comparison between the smallest nukes and the biggest conventional explosions. Even the "tiniest" battlefield tactical nukes take it to the next level, at around 1-10KT.

Zak wrote:Sorry, I misread / misquoted the source I read. The total amount of all explosions that took place (there were around 50) is supposed to add up to 30-50 kilotons of TNT.

No problem. The cumulative total certainly makes much more sense.

Zak wrote:So in terms of just explosive power, the Tianjin blast was about as powerful as the Hiroshima bomb

I've got to disagree on that because the supersonic shockwave created by the Little Boy bomb was still far more powerful than anything produced at Tianjin. It accounted for approximately 50-60% of the explosive yield of the bomb (percentages vary depending on the source) and was strong enough to pop out people's eyeballs and dislodge internal organs from their bodies. Structures that may have survived the initial overpressure from the blast were then hit with the high winds created by air rushing to fill the vacuum created by the blast.

http://www.pcf.city.hiroshima.jp/kids/KPSH_E/hiroshima_e/sadako_e/subcontents_e/08higai_3_e.html

What also complicates the comparison of yields are the differences in velocity of any given explosive detonation. For instance, nuclear weapons are "high energy" weapons in every respect: They're very hot, very explosive, very fast, and very radioactive (Gamma Rays!) so they're the ultimate high explosive. Conversely, the Tianjin explosions are examples of a "low explosive" because, from what I've read, their shockwaves were subsonic. Although they were demonstrably powerful, comparing them to a nuke can be misleading because they "burn" at different energy rates which limits the kind of damage they can do, comparatively.

Regardless, I agree it was a helluva bang.