"Contents under pressure may explode" has never been more accurate. Pressure cookers heat food with steam, using increased internal atmospheric pressure to heat and trap steam beyond its normal limit of 212 degrees Fahrenheit. This same increase in temperature is exploited by a pressure cooker bomb to amplify the power of an explosion set off within.
A pressure cooker bomb, like the one used in Boston, takes the rapidly-expanding gasses in a typical gunpowder explosion and holds them under tighter atmospheric pressure. The resulting rupture is far more violent than if the gunpowder was placed in a non-pressurized container.
So where did the idea come from? It's hard to nail down. A report published by the Department of Homeland Security in 2004 describes pressure cooker bombs used by various rebels and militant groups in both India and Algeria; a later DHS report from 2010 mentions pressure cooker bombs used in Afghanistan, Nepal, and Pakistan, as well as an attempted use in Times Square.
Recent reporting on pressure cooker explosives tied to the Boston Marathon bombing note that al Qaeda's English-language magazine "Inspire" includes a pressure cooker bomb recipe, but the design predates the existence of al Qaeda by decades. The Anarchist Cookbook, an infamous manual known for its explosives instructions, discussed the explosive potential of pressure cooker bombs back in 1971.
Pressure cooker bombs have a long history and a diverse list of users. In India, they've been used by Maoists, as well as terror groups involved in Kashmir. In France back in 2000, an Algerian terror group attempted to use pressure cooker bombs. In Greece this past January, a pressure cooker explosion was attributed to anarchists. The materials used to make pressure cooker bombs are neither expensive nor unique, and the instructions are widely available. Claiming that "pressure cooker bombs are a signature attack" of any specific group is about as ridiculous as claiming "bullets are uniquely used by American soldiers."
In understanding and investigating the aftermath of the attacks, answers are going to be found everywhere but the nature of the bomb.
The above infographic, the first part of a four-parter over at USA Today, shows visually how these bombs work as well as possible prevention tactics. It's worth a look, for sure.
I was surprised when the FBI called them technically sophisticated devices. They aren't sophisticated or new, not even to local level ordnance disposal units.
I agree quasi. Ive no ordnance experience at all and this seems to me a survivalist like bomb. If they wanted to hurt people why would they use something that initially has a contained blast? Some of the energy had to be dissipated to actually blow the thing apart? Its odd for sure. If murder was motive, they did not seem very motivated, thank god. The loss of life is tragic.
What's next popsci, date rape recipes?
MrTrav,if you read the article,you would know why the explosive is confined-when the pressure cooker blows,it sprays shrapnel at much higher velocity than an unconfined detonation,especially if you are using a low explosive like black powder.Probably you could get a lethal blast using a few thousand match heads in a pressure cooker.Crude pipe bombs often are filled with match heads,and I wouldn't want to be near one when it blew.
for a explosion, You need heat and compression, without being contained most explosives would just burn and the gases would dissipate quickly, although some stand alone explosives exist, such as C4, the rule of thumb is they usually have to be in some type of container... as far as the stand alone explosives, including home made, a general rule for those is the more sensitive it is, the more powerful it is. Usually those tend to be the primary explosives to set off the lower volatile explosives, the primary would be things like TACC and Double Salts, where the lower velocity would be things like ANFO.
Not a good idea to post this information, and judging by the comments people are trying to refine their techniques.
dkella, this and more can be found in your local library - if you know where to look. If anything, articles like this inform people how suspicious items might appear. If you see a container that can hold pressure (propane tank, galvanized pipe, etc.) in a trash can at a large public gathering, CALL THE POLICE!!!!
I dont think this is wise popsci..
This may be common knowledge with terrorists in afganistan, but wait until some dumb kid blows up his whole house because he now knows: " The resulting rupture is far more violent than if the gunpowder was placed in a non-pressurized container."!
Its that part that I have a problem with you printing. Its nice to understand why a pressure cooker was used in Boston, but irresponsible to publish the details. Ya it might be in that book from the 70's, but so is a lot of misinformation that will get people hurt messing around.
6 new Popsci article suggestions for the kids:
1) How to skin cats correctly.
2) Cross burning safety tips.
3) Simple ways to remove the orange tips from squirt guns.
4) How to make a noose from your pillow case.
5) How to drug a prom date.
6) How to make a bomb just like on the news. (oops, check this one off our list)
Having information does not cause children to go wild destroying the place.
All of you nay-sayers on this article need to wake up. A problem child will cause problems, by any method they can. However, the average kid doesn't look at this and think, "well I know the science of how to build a bomb, I guess I have to now."
Seriously, does reading this make you want to commit acts of terrorism? Why do you think it would make a kid?
-Murf914- said it all in his contradictory statement, "Its that part that I have a problem with you printing. Its nice to understand why a pressure cooker was used in Boston, but irresponsible to publish the details. Ya it might be in that book from the 70's, but so is a lot of misinformation that will get people hurt messing around."
Re-read that last line.... so you want to keep information out of the hands of our youth, so that their MISINFORMATION causes problems, sometimes big ones.
"I sure wish someone had told me that if I don't treat a pressure cooker with respect, I might just blow up the house killing my whole family. Ge mister thanks for keeping me ignorant."
So if we completely ban information, or just more specifically, on explosives, combustion, and other exothermic chemical reactions. How are the youth of tomorrow supposed to discover new science and technology?
Humans were on track to go to mars, but then we decided to keep our children ignorant.