hustler

iTrader: (6)

The man on the roof pic is great because he's on the wrong side of the building to see his work. It's time we banned stair cases that go to the roof.

Now, where is that celebrity that blamed the bombing on the 2nd Amendment again?

elesjuan

iTrader: (11)

Fireindc

iTrader: (13)

...these sketchy guys. They both have wires coming from their ears?

Braineack

iTrader: (62)

Let’s hope the Boston Marathon bomber is a white American - Salon.com

fooger03

iTrader: (2)

Ahh, crap - "arrest imminent in boston bombing"

This means there will soon be a face on this case.

I guess the flipside is that we can send a message to bad guys with pressure cookers everywhere: if you blow it, we will come. And get you. So don't do that.

Braineack

iTrader: (62)

he's already in custody.

Braineack

iTrader: (62)

chirpbirdchirp comments on Boston Marathon Explosion - Live Update Thread #8

Joe Perez

iTrader: (8)

Let me be very clear on this: I have absolutely no experience in handling explosive devices, nor will I be making a video in which I compare the relative performance of various device packages. I am an engineer, and I simply find it an interesting thought experiment to consider how various materials and structures perform under extreme conditions.


I'm struggling with that one a bit.

A conventional pipe bomb is of a relatively compact and efficient shape, and it could easily be concealed inside any number of plausible containers. You could hide a large one inside a thermos or a toy car, a number of small ones could be laid side-by-side inside the shell of a laptop computer, etc.

By comparison, a pressure cooker seems pretty damn conspicuous to me. Why on earth would anyone bring a pressure cooker with them to watch a marathon?


Yes, I can certainly see that. I've come across a fair bit of literature describing the use of pressure cookers in this context amongst individuals and groups affiliated with various middle-eastern revolutionary groups. The construction of these devices was specifically described in the "Open-Source Jihad" series of articles published by Inspire magazine (al-Qaeda's modern day version of the old Anarchist's Cookbook), etc.

What I cannot understand is why people started using this packaging in the first place. Is there a shortage of threaded iron pipe in the middle-east? Because it certainly seems to me, purely on the basis of speculative analysis, that the ole' tried-and-true pipe bomb would produce a more effective device in terms of yield for a given mass of material.



This is very interesting, as it de-bunks a line of thought I'd been heading down.

In trying to resolve the pressure-cooker conundrum, I'd been thinking a bit about propellants. Initially, I had simply assumed that the material used in the device was something like ordinary smokeless powder, which is cheaply and easily available all over the US. (It's used both by people who re-load their own cartridges, as well as by people who own and use muzzle-loading arms such as civil-war era Muskets and cannon.)

Then I got to thinking "Well, what if I'm wrong in that fundamental assumption? If a high-order explosive such as TNT or RDX or even something like ANFO were used, then the container of the device becomes less an active agent in determining its yield than simply a thing to put the explosive agent in and provide an affordance for packing shrapnel around."

But this notion kinds of ruins that, and puts me back at square 1. Cordite, for those who don't know, is simply a type of propellant which is used by numerous armies as an alternative to conventional gunpowder for both rifle cartridges and artillery shells. It is functionally similar to the powder which you'd find inside any civilian handgun or rifle cartridge.

Joe Perez

iTrader: (8)

Regardless of how paranoid one is about any given government, I don't see a lot of similarity between these two scenarios:

A: Military aircraft, under the control of an organized military agency reporting to a civilian leadership, are used to strike specifically designated targets. These targets are selected based upon their perceived strategic and tactical value to what is judged to be a belligerent entity. Collateral damage in the form of civilian casualties and damage to civilian property sometimes occurs as a result.

-vs-

B: An explosive device is detonated by an individual in the middle of a crowd gathered to witness an athletic event. This individual is acting outside of any recognizable military chain of command. The target of the attack is of no military value, and 100% of the individuals present at the target location are non-combatants.

rleete

iTrader: (21)

Re: pipe bombs. I remember an exercise with pressure vessels back in college. The premise was, you have a pressurized container, and it is well past it's working limit. Based on various configurations, which blows first, the sides or the ends? In almost all cases, the ends blow off first.

So, for maximum damage, you want more of a spherical container to give maximum dispersion.

Braineack

iTrader: (62)

so you hsouldnt place it next to a mailbox that will block a good portion of the blast?

rleete

iTrader: (21)

Unless you want the blast directed in that direction. It's all about the setup.

Ryan_G

iTrader: (8)

I thoroughly enjoyed this article.

Joe Perez

iTrader: (8)

Oh, absolutely.

I'm just thinking of materials which fit the definition of "improvised" in that they can be procured from common civilian suppliers (eg: Wal-Mart, ACE Hardware, Tractor Supply Co., Bass Pro Shops, etc.) Off the top of my head, I can't think of any spherical containers of this nature.

Perhaps something like a paintball-style CO2 tank?

I can't quite rationalize how one would analyze such a structure in this context. I do know that they are designed to routinely hold 800+ PSI while simultaneously being dropped on rocks, sat on, etc.

mgeoffriau

iTrader: (7)

Closest I can think of off the top of my head is a propane tank for a grill, but it's still mostly cylindrical.

Scrappy Jack

iTrader: (2)

There quite possibly IS a lot more ready access to pressure cookers among Middle East-based Islamic terrorist groups. I could see them being in every house and every corner market. I do not imagine a lot of Home Depots or Ace Hardwares in Pakistan and Yemen.


Furthermore, what if the lid of the pressure cooker allows for some degree of directional control of the blast and shrapnel?

The same witness who described smelling cordite also said he saw the window of one of the storefronts blown out in a distinct fan-shaped pattern. I have no idea what that means as I have literally zero experience with explosives of any kind beside almost blowing my fingers off with an M80 as a pre-teen.

EO2K

iTrader: (37)

WASHINGTON — On May 17, 2013, Senator Dianne Feinstein (D - CA) introduced the Assault Crock Pot Ban of 2013, a bill to stop the sale, transfer, importation and manufacturing of consumer grade slow cookers and high-capacity obese people feeding devices.

When asked to comment Rep. Diana DeGette (D - CO) provided the following:
When asked about the difference between a slow cooker and a crock-pot, Rep. Carolyn McCarthy (D - NY) had this to say:
During an interview with Good Housekeeping Vice President Joe Biden (D) advised crock-pot owners seeking delicious slow cooked meats to "Just visit their local neighborhood Arby's, home of the '5 for $6.95' combo".

Credit: Reddit

JasonC SBB

Pressure cookers will hold more active material than the average pipe.

I reckon their safety vents aren't an issue for bomb making purposes because they won't flow fast enough to reduce the explosiveness. They work well for venting steam.

Godless Commie

iTrader: (2)

I must add that a pressure cooker took out half of our kitchen on new year's eve back in 1980.

Turns out some food particle had blocked the safety vent.

JasonC SBB

What happened to the main vent?