Posted on 08/10/2006 9:49:54 AM PDT by Sax
Q&A: Liquid explosives
An alleged plot to blow up planes from the UK mid-flight and cause "mass murder on an unimaginable scale" has been disrupted, Scotland Yard has said. It is thought the plan was to detonate explosive devices smuggled in hand luggage on to as many as 10 aircraft.
BBC security correspondent Gordon Corera said the plan "revolved around liquids of some kind". One theory is that the attack may have involved liquid explosive being carried on to a plane in either drink bottles or cans. Dr Clifford Jones, an explosives expert from the University of Aberdeen, says even a small amount of liquid explosives carried on to an aircraft would result in a catastrophic explosion.
What are liquid explosives? The best place to start is with the term "high explosive"; these can be either solid or liquid. Of course, the most famous ones are solid, such as Dynamite and TNT.
One liquid explosive is a general use explosive that is used in quarries. However, I would not be surprised if it is possible to produce solid explosives in liquid form.
How do they work? Usually when something burns, it is subsonic and there is very little pressure effect. With high explosives, the rate of burning is extremely rapid and exceeds the speed of sound. As a result of that there is something called "overpressure" - pressure greater than the surrounding atmospheric pressure. Massive overpressure is not needed to cause damage. An excess of 1% can break windows, and an overpressure of 10% can harm or kill people and cause structural damage to buildings. An overpressure of just 2% could break the windows of the aeroplane, and 10% would wreck the aircraft and possibly kill the people in it before it reached the ground. By the time the damage is caused, the chemistry has finished and physics has taken over.
How are they made? There are such things as liquid explosives that are high explosives and they behave in exactly the same way as solid explosives, such as TNT. But there are also explosives that are made by mixing a solid and a liquid - one being the oxidant and the other being the fuel. Unlike most high explosives, they do not contain the fuel and oxidant in the same molecule but they do contain them in sufficiently close contact to cause a blast.
Are the components difficult to get hold of? No, it is very easy. Ordinary household substances could be used. Specialist knowledge or equipment needed to make? If someone wanted to obtain a solid high explosive in a liquid form, it would not be difficult for a trained chemical technologist. But if someone was using a backyard laboratory it is more likely they would go for the two component approach. Not a lot of experience is needed, the principles are quite simple but it would be a hazardous process of trial and error. I would not want to be messing about these things. It has been known for schoolboys to go home and attempt this and blow their house up.
Could an explosive device be carried on to an aeroplane? The size of a device necessary could be carried in hand baggage. Explosives in a toilet bag, certainly inside a shoulder bag would be enough to meet the terrorists' needs. They could be quite hard to detect because I do not think any of the things we have mentioned would respond to x-rays. For example, a liquid hydrocarbon fuel could pass as mineral water.
The question is how do you get something packed into a bag so it does not look suspicious?
Check out a French movie from the 1950s called "Wages of Fear"--a diverse group of men on the run for various reasons (seen in flashback) are in some godforsaken jungle town in South America (I think). A hundred miles away, there's an oil well explosion and they need nitro to blow it out. These guys are hired to drive a caravan of trucks containing nitro through jungles and over mountains. They only need one to get through...
It was also remade as "Sorcerer" in the late 1970s; Roy Scheider starring, William Friedkin directing, and a great soundtrack by Tangerine Dream. One of those rare remakes that might be better than the original, although it's debatable (by my friends, at least).
Interestingly, I think both have a Muslim terrorist among the "men on the run"--an Algerian in the first one and a Palestinian in the remake.
The chemical sniffers will find the paper explosive w/ no problem.
Regards,
GtG
Wasn't Astrolite sold as a commercial blasting agent? Seems like awfully problematic stuff for commercial use.
Not that I'm aware of.
Astrolites' only claim to fame is it has the highest detonation velocity. Commercial explosives really don't need to be all that fast, cheap yes if you are using them by the ton like ANFO. There are other factors that go into a choice of blasting agent like the flame temperature of the decomposition products. It may sound odd but "cooler" explosives find use in mining because they allow blasting in gassy or dusty conditions. The azide in your airbag generates a great volume of nitrogen and very little heat when it detonates to deploy the bag.
Regards,
GtG
Many moons ago, we did something similar using a fairly concentrated potassium chlorate solution. The best use we found for the impregnated paper was starting charcoal briquets. Put some sheets of the stuff underneath your charcoal and light, preferably from a distance. A blinding second later, all the coals would be nicely started and the paper gone.
Properly confined with a detonator and that paper could probably have done some damage. Chlorate was used as the oxidizer in some trench mortar detonables in WWI.
That sounds a bit like the engineering professor who stages a grill cook out every summer. He demonstrates the properties of liquid oxygen by pouring a pail full of LOX into a charcoal grill which has one burning coal atop a pile of cold charcoal. He really cooks the grill, in about ten seconds. The entire load of charcoal disappears in a flash along with most of the grill. Very impressive videos.
Regards,
GtG
Guess reporters for the Beeb don't watch many old westerns.
Check it out, this guy is really nuts, 3 gallons of LOX and 40 pounds of charcoal in three seconds.
Regards,
GtG
Hi RAC,
You're right. The stability of pure nitro is nebulous at best. Movement could cause it to go "high order", which would definitely spoil the entire day for whoever was carrying it !
EODGUY
I've carried a fountain pen for years (can't take good shorthand with a ballpoint) and I've never been stopped or even given a second glance. That's surprising, now that I think of it, because one of my favorite pens is an all-metal, hex-barrel Rotring Newton
http://www.rotring.de/www.rotring.com/products/writing/c_newton.html
Think I'll pack my favorite pens in my checked luggage from now on. Security checks have already cost my a pocket knife and a Zippo that I'd owned for more than 30 years.
By banning every single thing on a flight... doesn't that mean the Terrorists have won?
What next? Cutting open then human body and implanting explosives in the abdomen? Then detonating said explosives? We'll have to ban people next! Then no one will fly. This is ridiculous and totaly out of control. How many more freedoms must we give up because of a bunch of misguided rock worshipers?
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