Liquid explosives

I’ve decided to split the speculation concerning the science that may have been involved in the plot into a separate post since it is getting long.

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p>Some experts think that the bomb might have involved TATP, the same compound used by the 7/7 bombers.

While there are several liquid explosives that could be used to bring down an aircraft, chemists believe it is more likely that terrorists planned to mix liquid materials that are not themselves explosive but can be combined into a bomb. The liquid explosives that are sufficiently destructive in their own right to blow up a plane are generally too unstable or too easily detected to be readily smuggled aboard.

A more subtle approach would be to combine two or more liquids that are stable by themselves, but which form a powerful explosive when mixed together. A prime candidate for this would be triacetone triperoxide (TATP), the explosive used by the July 7 bombers. Its two raw ingredients are both liquids, which could potentially be carried on board in sufficient quantities in containers such as bottles of shampoo or contact lens solution.

These could then be mixed in a toilet to make TATP, which is a crystalline white powder. The problem here is that the solid has to be dried before it becomes a reliable explosive. It can also be difficult to detonate, as attested by the failure of the attempted suicide attacks on London on July 21 last year.

The problems of assembling and then detonating an improvised bomb of this sort in an airline toilet could explain why the terrorists targeted so many aircraft. It is likely that many of the devices would have failed, so attacking 10 flights would have greatly increased the chances of blowing up one or two. [Link]

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p>There have also been at least two prior terrorist attacks planes using liquid explosives, KAL 858 and PAL 434. [Details follow after the fold]

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p>In 1987, KAL Flight 858 was destroyed using the explosives C-4 and PLX, the latter of which is a liquid:

PLX, or Picatinny Liquid Explosive, is a liquid binary explosive, a mixture of 95% nitromethane and 5% ethylene diamine. It is a slightly yellowish liquid. It was developed at Picatinny Arsenal during World War II for cleaning of minefields. It was to be mixed just before use. PLX was one of the explosives used to down Korean Air Flight 858. [Link]

More recent was the bomb that killed one passenger on board PAL Flight 434 in 1994 [Thanks Sage]:

On December 11, 1994, Flight 434 was on its second leg from Cebu to Tokyo when a bomb exploded, killing one passenger. Authorities later discovered that a passenger on the aircraft’s preceding leg was Ramzi Yousef, who United States authorities have branded a master Al-Qaida bomber and terrorist. He was later convicted of the first World Trade Center bombing, for which he was sentanced to death by lethal injection. Yousef boarded the flight under an assumed name…

US prosecutors said the device was a “Mark II” “microbomb” constructed using Casio digital watches as described in Phase I of Operation Bojinka of which this was a test. On Flight 434, Yousef used one tenth of the explosive power he planned to use on eleven U.S. airliners in January of 1995. The bomb was designed to slip through airport security checks undetected. The explosive used was liquid nitroglycerin, which was disguised as a bottle of contact lens fluid. The wires he used were hidden in the heel of his shoe. At that time, metal detectors used in airports did not go down far enough to detect anything there. [Link]

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p>Operation Bojinka was very similar to the plot that the British claim to have uncovered:

Starting on January 21, 1995 and ending on January 22, 1995, they would set the bombs on 11 United States-bound airliners that had stopovers all around East Asia and Southeast Asia… The bombs would have been timed before the operatives stepped off the planes. The aircraft would have blown up over the Pacific Ocean and the South China Sea almost simultaneously. If this plan worked, several thousand would have perished, and air travel would have been shut down worldwide for days, if not weeks. The U.S. government estimated the prospective death toll to be about 4,000 if the plot had been executed. [Link]

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p>Right now, the only method of detection of any potential explosive precursors seems to be the old fashioned taste test:

Liquids were banned, except for baby formula and prescription medicines, and travellers were being told to be prepared to show that these were harmless by tasting them at the security gate. [Link]

13 thoughts on “Liquid explosives

  1. Andrew Sullivan has a piece on a device called mubtakkar and wonders if this was the one that the terrorists wanted to use.

  2. Interesting post, Nara. In this case, what little the authorities have said indicates that the thread came from an explosive device not a chemical weapon.

  3. vicious cycle continues…each side points to another to justify one’s stand…whoever thought globalization, where every country would have economic stake, would bring lasting peace couldn’t have been more wrong…again,human nature plays its whimsical trick…too much peace is boring at times too!!……anyways, I was getting bored of predictable and expected developments from Lebanon…this is a nice new development…gives a lot to while away your time….

  4. After 9/11 for about a year, I was always searched twice, once also at the gate, and always had to take a swig from all my bottles of water. I can see why toilettries would be harder to test that way. I’m also not so sure that’s a good test—if you’re ready to committ suicide ina few hours, what’s the problem with swigging a shot of nasty chemical?

  5. Any Wu fans out there? Somehow, I’ve been listening to GZA’s Liquid Swords all day. Masterful.

    I’m overwhelmed, as my mind roams the realm My eye’s the vision, memory is the film Others act subtle, but they fragile above clouds They act wild and couldn’t budge a crowd

    Hmm. Inscrutable. But the RZA-produced beats are ill, and every song is as tight as a metaphor I can’t use in polite company. Just don’t sing this stuff out loud as you make your way through the airport. “I drop megaton bombs more faster than you blink/ Cause rhyme thoughts travel at a tremendous speed.” Nice sentiment, but the poetry might be lost on Homeland Security.

    Of course, the Brits have this problem solved: no iPods on flights. An entire generation is about to be bored out of their everloving minds.

  6. I work for UK Police. Even metioning the names of liquids here, let alone describing them is surely letting potentials murderers know how to make them?

  7. Rupinder – I understand your concern but in the states the New York Times has an explanation of how TATP is made, using nail polish and commercial hydrogen peroxide. This information is all over the American media right now. I included it as a service to our readers who wondered how real the threat of a liquid explosive was and what form it might take. All of this information is widely available in far more detailed forms.

  8. The whole idea is asinine…it would have been so much easier to put plastic explosives in their baggage, check it…(baggage and cargo that is “checked” at the ticket counter, go in the “cargo hold” and is not run through security..they say maybe about 5% is actually physically checked and they do not x-ray or swab (for explosives) in cargo..takes to long..you could put it in a laptop..for instance) get on the plane with a cell phone and detonate it with your cell phone….just like they did in Spain….why even try to smuggle “liquid explosives” on board…?

  9. 1) Triacetone triperoxide (TATP) is not a particularily easy explosive to make safely, however, it is extremely unstable if manufactured at elevated temperatures–normal manufacture would entail several hours. Quickly mixing ingredients might well produce an explosion, but the size and force would be unpredictable.

    2) Fingernail polish, as sold retail, has enough impurities in it to make it a poor choice for acetone source for the manufacture of TATP–but it would be easy enough to refill a bottle with pure acetone.

    3) These are technically HE (high explosives) and a very small amount, properly placed could bring down an aircraft. There are an infinite number of ways to get small amounts of anything on board an airplane (witness the notable ability of the Homeland Security airport security ‘testers’ to get onboard with guns despite searches and metal detectors.

    4) Mind you, the 9/11 skyjackers took over aircraft with what were essentially razor_blades a sharpened piece of plastic or a stick pen would have been as effective.

    5) The only “taste test” which will work for detecting such things is if the GUARD does the tasting, a little training and a person can control their reaction to most of these liquids–even strong acids.

    6) These guys were hiding the stuff in a false bottom anyway, they could have poured and drunk half the bottle without any effects–there would have been nothing in the poured liquid but what was marked on the bottle.

    7) Smugglers are still bringing stuff across boarders even with tight security, the same methods can work for explosives that work for cocaine, diamonds etc..

    8) The next step for terrorists is to determine how to create a weapon out of materials already on board the plane….

    You want to stop terrorists, then stop the social causes of terrorism. This is not a technical problem, it is a social problem, and technology can only provide stop-gap measures. To stop terrorism, you must stop the underlying social causes.

    Strip ’em down, knock ’em out, ship them as freight–a determined person can get nearly anything on board any transport–especially if they are willing to die.