# How large was the explosion at Tianjin? **URL:** \ **Category:** Factual Questions\ **Created:** [August 13, 2015, 8:40pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772 "2015-08-13T20:40:18Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![yabob](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yabob/32/2821_2.png) [@yabob](https://boards.straightdope.com/u/yabob)\ **Post date:** [August 16, 2015, 6:47pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/21 "2015-08-16T18:47:48Z")
> [@Polar\_Iceman](#): > > Yes, but would the boom be triggered by flame?’ > > Again, my experience with nitrates is that they require a detonator to blast. Don’t know about calcium carbide, except if you mix it with water it makes a nice fizz. What causes the fizz is the acetylene that is produced, which is nice and flammable at any rate (this is how a carbide miner’s lamp works). ---
**Author:** ![Ruken](https://avatars.discourse-cdn.com/v4/letter/r/f475e1/32.png) [@Ruken](https://boards.straightdope.com/u/Ruken)\ **Post date:** [August 16, 2015, 6:51pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/22 "2015-08-16T18:51:16Z")
CaC2 releases acetylene, which is both inflammable and explosive. If any of it was contained in a way that could allow pressure buildup, that could cause enough of a shockwave. Or just burning organics in the presence of an oxidizer might do it. I am not a high energy chemist. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [August 16, 2015, 6:56pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/23 "2015-08-16T18:56:44Z")
> [@AK84](#): > > Considered suspect by whom? Stormfront users? I’d say that most people and governments consider any data coming out of China to be suspect, so it’s not just racists on a message board. If your default position isn’t to question what officially comes out of China then you either haven’t been paying attention or I have a bridge to sell you in Brooklyn…and you don’t need to do any checks on that, I totally have the authority to sell it. Just make out your check to XT and we are good to go… I don’t know about the seismic data specifically, but I know that a lot of people suspect the Chinese of fudging some of this kind of data wrt the Three Gorges Dam. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [August 16, 2015, 8:12pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/24 "2015-08-16T20:12:25Z")
> [@Polar\_Iceman](#): > > Has anyone yet identified the explosives involved? > I am curious because my personal experience with explosives is that they require a shock to detonate; ie: they require a detonator, and they do not explode when exposed to fire. > In fact in a previous career, we commonly burned C4 to heat our meals. > So what was the “explosive” in China that was detonated by flame? Composition C-4 (or just C-4, also known as “M112 Demo Block” or “Plastic Explosive No. 4’”) is deliberately designed as an insensitive munition requiring both high temperature and very high pyrotechnic shock to establish a detonation wave. Most other plastique and slurry explosives, as well as shaped charge energetics, used in demolition and excavation are similarly made safe for ordinary handling. Such materials can still detonate under certain conditions or if activated by a less-insensitive material, but they’re far from the only compounds energetic enough to create a very large and powerful detonation. There are many industrial compounds–including those used for pigmentation, fertilizers, industrial processing, and pharmaceutical manufacture–which have a high potential for detonability if not stored safely and with appropriate quantity-distance (QD) awareness. In addition to the PEPCON disaster (due to the stockpiling of amonium percholrate used as an oxidizer in the Shuttle solid rocket motors after the _Challenger_ failure), there are the 1947 Texas City amonium nitrate explosion, the Cleveland East Ohio Natural Gas explosion, the Ocean Liberty cargo ship off of Brest, France, et cetera. Even ordinary organic dust off of dry grain can be sufficient to create a very powerful thermobaric explosion capable to destroy a concrete grain silo and shatter windows up to a few miles away. It appears that a company which handles hazardous materials, Ruihai Logistics has a storage warehouse near the port. It would not be the first time that a company ignored safety regulations or standard practice by storing so much material in one area that it could create a chain reaction or large scale detonation (see PEPCON). In some cases, as with bulk processing of amonium nitrate, it is almost impossible to prevent a condition in which large amounts of material are in close proximity, and other preventative steps have to be taken. While any “news” coming out of China should be taken with a grain of salt, it is entirely likely that this was, in fact, an industrial accident and not some kind of subterfuge or concealing some other malicious activity. Stranger ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [August 16, 2015, 8:12pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/25 "2015-08-16T20:12:35Z")
> [@XT](#): > > I’d say that most people and governments consider any data coming out of China to be suspect, so it’s not just racists on a message board. If your default position isn’t to question what officially comes out of China then you either haven’t been paying attention or I have a bridge to sell you in Brooklyn…and you don’t need to do any checks on that, I totally have the authority to sell it. Just make out your check to XT and we are good to go… > > I don’t know about the seismic data specifically, but I know that a lot of people suspect the Chinese of fudging some of this kind of data wrt the Three Gorges Dam. No its not racists who believe that. Just parochial and provincial minded loons.:rolleyes: I don’t have a default position, but when official numbers are doubted, I want more than just “why believe these evil chicoms”. ---
**Author:** ![XT](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/xt/32/456_2.png) [@XT](https://boards.straightdope.com/u/XT)\ **Post date:** [August 16, 2015, 8:16pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/26 "2015-08-16T20:16:48Z")
[QUOTE=AK84] No its not racists who believe that. Just parochial and provincial minded loons. [/QUOTE] As well as everyone else, including the Chinese people themselves who have more than two working brain cells. But I can see you think it’s just racists and ‘parochial and provincial minded loons’ so no point in continuing with this I’d say. 😛 > [@](#): > > I don’t have a default position, but when official numbers are doubted, I want more than just “why believe these evil chicoms”. Then you haven’t been paying attention, basically, and are lashing out because you are profoundly ignorant on the topic. You should really rectify that before jerking your knee next time, but I’m fairly sure you won’t. C’est la vie. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [August 17, 2015, 3:50am UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/27 "2015-08-17T03:50:26Z")
Really? Show me some actual evidence that the numbers are cooked. Not bare assertions. Because if that is true, then such evidence will be easy to find. ---
**Author:** ![j\_sum1](https://avatars.discourse-cdn.com/v4/letter/j/8baadc/32.png) [@j\_sum1](https://boards.straightdope.com/u/j_sum1)\ **Post date:** [August 17, 2015, 5:26am UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/28 "2015-08-17T05:26:17Z")
There were two main blasts. The first was estimated at 3 tonnes TNT equivalent. The second larger one at 21. As for what caused the blasts, there are a number of possibilities. As is to be expected, exact details of the inventory of the site at the time are not particularly forthcoming. It seems that they were carrying multiple times the amount of sodium cyanide than they should have been. Who knows what else was there that people are keeping quiet about. Based on what I have been able to gather, it seems the larger blast was probably ammonium nitrate. There was also a significant amount of sodium metal that created the glowing cinder effect in some parts of the explosion. As for the initial fire and first explosion, well anything is a possibility. There is some speculation that firefighters may have made matters worse by pouring water on the fire – wet calcium carbide gives off acetylene gas. I have my doubts about this suggestion. Firstly, it is not that likely that firefighters would be using water at a dangerous chemicals store – not even in China and not even with a significant incompetence factor. The second thing is that acetylene is not really that explosive under most circumstances. The rate of combustion is limited by the extent to which the gas can mix with available oxygen. Incomplete combustion is common with acetylene. It is reported that there was a quantity of butanone (methyl-ethyl ketone) on the site. That might account for some of the first fire and also could potentially have caused an explosive mix with a nitrate salt (of which there was a lot.) Knowing how much work goes into grinding and mixing energetic materials to achieve a good detonation, I have some doubts about this scenario too. However, a fast deflagration can have a similar effect to a detonation in the kind of fire that was experienced. The main blast was extremely large and sudden according to video footage I have seem. That suggests a homogenous reactant and solid phase. Heterogenous reactants don’t achieve the same explosive potential. The only chemical I have heard that was present at the site that could possibly fit that description is ammonium nitrate. Truth is, we might never find out the exact cause. (My cites, various news items read over the past several days. But you can look these up yourself.) ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [August 17, 2015, 5:56am UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/29 "2015-08-17T05:56:02Z")
What interest does the Chinese government have in telling the truth? What interest does any authoritarian government have? How does it serve its purposes? ---
**Author:** ![j\_sum1](https://avatars.discourse-cdn.com/v4/letter/j/8baadc/32.png) [@j\_sum1](https://boards.straightdope.com/u/j_sum1)\ **Post date:** [August 17, 2015, 6:17am UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/30 "2015-08-17T06:17:24Z")
I think you are being a bit conspiratorial Alessan. On topic, [A possible list of the hazardous materials at the Tianjin warehouse | News24](http://www.news24.com/World/News/A-possible-list-of-the-hazardous-materials-at-the-Tianjin-warehouse-20150814) ---
**Author:** ![thirdname](https://avatars.discourse-cdn.com/v4/letter/t/d07c76/32.png) [@thirdname](https://boards.straightdope.com/u/thirdname)\ **Post date:** [August 17, 2015, 6:22am UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/31 "2015-08-17T06:22:36Z")
This a post of mine from another thread: > [@](#): > > I’m not buying the “21 tons of TNT” figure. A large aerial bomb (a large normal one, not a bunker buster) has half a ton of explosive and would typically destroy one decent-sized building. There’s no way this was only as powerful as 42 bombs, especially considering the blast radius will scale with the cube root of the yield, so a 21-ton explosion would only have 3.5 times the blast radius of a Mark 84 bomb. Also, the Oklahoma City bombing was around 3 tons of ANFO. Here’s a pic of the aftermath: [![](https://publicintelligence.net/wp-content/uploads/2015/04/oklahoma-city-bombing.jpg) ](https://publicintelligence.net/wp-content/uploads/2015/04/oklahoma-city-bombing.jpg) It didn’t even take out a whole block. I can’t believe that Tianjin is only 7 times as powerful as that. I’m gonna guess it’s in the hundreds of tons of TNT range, because it looks way too big to be in the tens, but too small to be in the kilotons. It doesn’t look like Hiroshima. Edited to add: I read somewhere, don’t have a source, that the 21-ton estimate came from seismological data. Perhaps it only represents the amount of energy transferred to the ground, not the whole explosion. ---
**Author:** ![Alessan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alessan/32/465_2.png) [@Alessan](https://boards.straightdope.com/u/Alessan)\ **Post date:** [August 17, 2015, 7:05am UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/32 "2015-08-17T07:05:47Z")
> [@j\_sum1](#): > > I think you are being a bit conspiratorial Alessan. No, I’m just old enough to remember Chernobyl. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [August 17, 2015, 1:45pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/33 "2015-08-17T13:45:21Z")
> [@Alessan](#): > > What interest does the Chinese government have in telling the truth? What interest does any authoritarian government have? How does it serve its purposes? Reassuring investors? Increasing confidence of business? Ensuring that your rather expensive factory complexes do not go kaboom. That people still continue to use their ports? ---
**Author:** ![Voyager](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/voyager/32/133_2.png) [@Voyager](https://boards.straightdope.com/u/Voyager)\ **Post date:** [August 17, 2015, 7:19pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/34 "2015-08-17T19:19:34Z")
> [@AK84](#): > > Reassuring investors? Increasing confidence of business? Ensuring that your rather expensive factory complexes do not go kaboom. That people still continue to use their ports? You listed some excellent reasons for them to lie. Governments interested in the truth don’t go running around deleting blog posts after all. And it is not just this. The government’s intervention in the stock market and their devaluation strategy has made a lot of people doubt the official growth figures. No smoking guns on this yet. Remember when the government got upset by the US embassy posting air quality figures based on their own measurements? The Soviets did the same thing. When a government’s reign depends on large part on their success, and when they control or try to control the media, are they more likely to admit failure or try to prevent news of the failure getting out? ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [August 17, 2015, 9:08pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/35 "2015-08-17T21:08:54Z")
> [@j\_sum1](#): > > There is some speculation that firefighters may have made matters worse by pouring water on the fire – wet calcium carbide gives off acetylene gas. I have my doubts about this suggestion. Firstly, it is not that likely that firefighters would be using water at a dangerous chemicals store – not even in China and not even with a significant incompetence factor. The second thing is that acetylene is not really that explosive under most circumstances. The rate of combustion is limited by the extent to which the gas can mix with available oxygen. Incomplete combustion is common with acetylene. It has been widely [reported](http://www.nytimes.com/2015/08/18/world/asia/tianjin-china-explosions-firefighters-chemicals.html) that the firefighters did attempt to use water to extinguish fires after the initial blast. > [@](#): > > In a phone interview on Monday, one contract firefighter defended the training he and his co-workers had received, but he acknowledged that they were not taught specific methods for fighting different kinds of chemical fires. > > The man, who declined to give his name and said that he was off duty the night of the explosions, said it was unfair to blame his co-workers for spraying water on the blaze. “No one told them the fire involved chemicals,” he said. This probably wasn’t the only cause, for other reasons you point out. But it certainly didn’t help. ---
**Author:** ![drachillix](https://avatars.discourse-cdn.com/v4/letter/d/48db29/32.png) [@drachillix](https://boards.straightdope.com/u/drachillix)\ **Post date:** [August 17, 2015, 9:46pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/36 "2015-08-17T21:46:58Z")
> [@j\_sum1](#): > > There is some speculation that firefighters may have made matters worse by pouring water on the fire – wet calcium carbide gives off acetylene gas. I have my doubts about this suggestion. Firstly, it is not that likely that firefighters would be using water at a dangerous chemicals store – not even in China and not even with a significant incompetence factor. It happens, even here. Not so many years ago Fresno fire cut the locks on a compound for a chemical distributor and not only were there water reactive materials on site, the toxic runoff forced the removal of something like 6 feet of topsoil from a huge area… ---
**Author:** ![msmith537](https://avatars.discourse-cdn.com/v4/letter/m/d9b06d/32.png) [@msmith537](https://boards.straightdope.com/u/msmith537)\ **Post date:** [August 17, 2015, 11:01pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/37 "2015-08-17T23:01:37Z")
[LIke…Michael Bay large.](https://www.youtube.com/watch?v=Q04fV4j7A1w) ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [August 18, 2015, 12:05pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/38 "2015-08-18T12:05:30Z")
> [@Voyager](#): > > You listed some excellent reasons for them to lie. Governments interested in the truth don’t go running around deleting blog posts after all. > And it is not just this. The government’s intervention in the stock market and their devaluation strategy has made a lot of people doubt the official growth figures. No smoking guns on this yet. > Remember when the government got upset by the US embassy posting air quality figures based on their own measurements? > > The Soviets did the same thing. When a government’s reign depends on large part on their success, and when they control or try to control the media, are they more likely to admit failure or try to prevent news of the failure getting out? The Chinese are 10,000 times more integrated and dependent on the global market then the Sovs ever were. Lyimg and obfuscation are counterproductive for them as it will only reduce confidence. ---
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [August 18, 2015, 12:56pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/39 "2015-08-18T12:56:38Z")
That may be so, but that does not mean China is open and transparent: [CNN, local Chinese media struggle to report on Tianjin explosion](https://www.hongkongfp.com/2015/08/13/cnn-local-chinese-media-struggle-to-report-on-tianjin-explosion/) > [@](#): > > A CNN reporter was blocked by unidentified men from reporting live on the Tianjin explosion outside a hospital on Thursday morning. > … > The CNN correspondent, Will Ripley, was speaking outside a hospital when he was confronted by several men, demanding him to end the live broadcast. Several men were heard shouting “stop recording” at the CNN crew. Ripley was seen saying “OK” multiple times before the live feed was interrupted. > The CNN anchor later commented from the studio that this is a usual case of reporting in the country, adding, “This is something that has happened many times over the years in any number of stories in China.” > > Local journalists in China also complained that they were blocked from reporting on the blast, Tencent news reported. A reporter who took photos inside a Tianjin hospital was threatened by security guards to delete the images. [CCTV Cuts Short Tianjin Press Conference After Uncomfortable Questions](https://thenanfang.com/press-conference-tianjin-explosion-cut-cctv-live-broadcast-questioning/) > [@](#): > > A government spokesperson told reporters the hazardous air was moving south-west and away from the city, hoping to dispel fears that the air is too toxic to breathe. In the video, reporters are asking him questions and he repeatedly tries to get up to leave. This continues until 1:27 of the video, when a reporter asks why so many residential homes were so close to a storage facility with toxic chemicals. > … > There is a moment of confusion as no one says anything, and the men giving the press conference look at each other. Then, the broadcast of the press conference is suddenly stopped short, and the viewer sees the CCTV anchor, who is also confused and not prepared. After mentioning that the viewer has been watching a press conference given by the Tianjin municipal authority, the broadcast goes to commercial. So far I’ve not seen any shift to openness and transparency in the Chinese government’s handling of this matter. I agree that in the long run, that is in their best interests, in my opinioin, bu t I don’t think that opinion is shared in China. ---
**Author:** ![AK84](https://avatars.discourse-cdn.com/v4/letter/a/85e7bf/32.png) [@AK84](https://boards.straightdope.com/u/AK84)\ **Post date:** [August 18, 2015, 1:50pm UTC](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772/40 "2015-08-18T13:50:13Z")
True, but stoping a recording outside a hospital filled to the brim with injured people and some poor functionary being underbriefed and out of his depth is hardly a coverup, especially in early days when they probably have little idea of what happened. [Previous page](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772.md?page=1) [Next page](https://boards.straightdope.com/t/how-large-was-the-explosion-at-tianjin/727772.md?page=3)