Sciencemadness Discussion Board

Explosions in NYC and Jersey Shore

camerican - 18-9-2016 at 09:27

Yesterday two bombs went off on the east coast and a third was found before it was set off. The device in NY probably used a high explosive-witnesses experienced a shockwave and saw a plume of white smoke.

The Jersey Shore bomb was apparently unconnected and probably used poorly mixed black powder. I say that because the bomb sent up a 25-foot plume of black smoke without totally destroying the plastic garbage can it was concealed in. So, I was thinking the "smoke" could just be powdered charcoal thrown up in the air. Or this was just a really small TNT charge, but you guys probably know better than me.

The third bomb is almost certainly a pressure cooker stuffed with black powder or smokeless powder, like the bombs used in Boston in 2012.

Anyways, that's about all I could figure out from the information in those articles. Hopefully we'll see more in the next week.

aga - 18-9-2016 at 11:04

Don't know anything much about the USA, but i thought that there were shops selling live ex-military hardware.

Is that actually true or just hollywood fiction ?

If true, making/deploying low quality bombs would be very odd.

Texium - 18-9-2016 at 11:22

That is false. There are military surplus stores but they don't sell live explosives, mostly just stuff like uniforms, combat boots, canteens, that kinda thing.

camerican - 18-9-2016 at 11:30

Quote:
Don't know anything much about the USA, but i thought that there were shops selling live ex-military hardware.


There are, you can see them in the classic documentary Commando :P

hissingnoise - 18-9-2016 at 11:51

One lead so far... might not be genuine?

http://www.independent.co.uk/news/world/americas/new-york-ex...

camerican - 18-9-2016 at 12:26

Thanks for the link, those close-ups of the dumpster are really good. Not sure about that Tumblr post referenced in the article-probably a joke in poor taste, but you can never tell.

aga - 18-9-2016 at 12:26

What i thought was that guns and ammo can be bought, of all kinds.

It would seem totally crazy to have shops selling ex-army atomic devices etc. so that probably does not happen, at least on the 'general public' level.

Basically, i do not know what can be bought in the US.

Home-made black powder based IEDs sound ridiculous *if* more powerful explosives are freely available.

My worry here is that it's another step in cracking down on the availability of chemicals by staging events like these as the pretext.

Do the gun shops sell grenades, mortar shells, rocket rounds etc as well as guns and ammo, legally or routinely illegally ?

camerican - 18-9-2016 at 12:55

Low explosives (usually propellants) are available in large quantities at most gun stores. High explosives are just as regulated as anywhere else, with the exception of primers for centerfire cartridges.

aga - 18-9-2016 at 12:59

Presumably 'low explosives' would perform better than home-made black powder ?

camerican - 18-9-2016 at 13:19

Sure. What's the deal with the quotes? I thought 'low explosive' was the only way to refer to stuff that can only deflagrate.

arkoma - 18-9-2016 at 16:44

smokeless powder and blackpowder are OTC here (Arkansas)

camerican - 18-9-2016 at 19:06

The bombs in NYC used a binary explosive mixture similar to Tannerite. I guess all that's left is to find out how they were detonated.

OneEyedPyro - 18-9-2016 at 19:45

Tannerite huh? Hopefully they don't start banning binaries and hopefully they catch him/them.

My guess is the detonator involved a mechanical timer rigged up to complete an electrical circuit between a battery and an E-match which in turn lit some type of cap. That seems to be a common setup in these types of attacks.

gdflp - 18-9-2016 at 20:00

Quote: Originally posted by camerican  
The bombs in NYC used a binary explosive mixture similar to Tannerite. I guess all that's left is to find out how they were detonated.

Read all of the NY Times articles, the bombs were triggered with cell phones. Not sure of the details of how that works, not really my forte.

camerican - 18-9-2016 at 20:17

Sorry, I should have made myself clear-I was referring to what kind of primary was used to initiate the detonation of the bomb.

Bert - 18-9-2016 at 21:08

Quote: Originally posted by camerican  
Low explosives (usually propellants) are available in large quantities at most gun stores. High explosives are just as regulated as anywhere else, with the exception of primers for centerfire cartridges.


Primers are classified as 1.4S for shipping- and are a class of explosives which may be bought and posessed by any adult in the USA with no license required, shipable (with an extra HazMat fee) anywhere in USA by ground. They are designed to produce hot gasses (flame) and hot particles to ignite propellants in response to a shock from a firing pin. They may contain some percentage of a primary explosive (Lead styphnate, DDNP or others) but primer pellet mixtures will not initiate common civil or military secondary explosives such as dynamites, PETN det cords, TNT & etc. I and numerous others have tried to do so- even after collecting the contents of numerous centerfire or rimfire primers, these formulations will not do the job.

Anyone with a moderate exposure to.the explosive arts and the desire could come up with higher performance and cheaper mixtures.

NedsHead - 18-9-2016 at 21:27

Peculiar that this event takes place right after America bombs dozens of Syrian troops helping ISIS recapture a city

Bert - 19-9-2016 at 03:56

Ned's head has been missing since the postmortem after he was hung, how would it have got internet access?

Bombs are unique weapons in that the attacker pretty much always leaves the whole weapon at or near the crime scene to be found and examined. If authorities care to do so, the origins will be known

hissingnoise - 19-9-2016 at 04:07

Quote:
Peculiar that this event takes place right after America bombs dozens of Syrian troops helping ISIS recapture a city.

If that's a joke, I don't quite get it?

NedsHead - 19-9-2016 at 04:11

You know your Aussie history Bert! I'm impressed, it's my iron helmet, it picks up and transmits wifi signals

hissingnoise - 19-9-2016 at 05:20

Quote:
You know your Aussie history Bert!

Yeah, it's all about Kelly?

NedsHead - 19-9-2016 at 06:36

My original comment was just a sceptical observation about the order of events, although it could just be the "signal amplifying" iron helmet talking, I'll switch back to tin foil shortly. yes, the follow up conversation with Bert was about Kelly

XeonTheMGPony - 19-9-2016 at 06:48

Quote: Originally posted by camerican  
The bombs in NYC used a binary explosive mixture similar to Tannerite. I guess all that's left is to find out how they were detonated.


Tannerite is NOT a Binary, it is a sensitized secondary explosive, all it is is Ammonium nitrate and aluminium, So what they really are saying it was a fertilizer bomb.

But given the general intelligence displayed by politicians I doubt the very big difference will matter.

As for initiation any half descent cap and a bit of booster will do, or with the aluminium sensitizer a half assed cap will do!

hissingnoise - 19-9-2016 at 07:37

Looks like they got him!

http://www.zerohedge.com/news/2016-09-19/two-police-officers...

camerican - 19-9-2016 at 07:46

Wow, that was fast! Good to see the guy in custody before he set anything else off.

arkoma - 19-9-2016 at 08:36

Quote: Originally posted by XeonTheMGPony  
As for initiation any half descent cap and a bit of booster will do, or with the aluminium sensitizer a half assed cap will do!


Yup, Tannerite will detonate from a bullet strike. I have a 5 gal bucket of nitrate I picked up from a fertilizer spill but its so damn humid here I'd have to invest in a vacuum desiccator to ever dry it.

hissingnoise - 19-9-2016 at 08:46

On arrest, his first words were; "Fuck, I suppose this means Trump's going to stiff me, too"?

zwt - 19-9-2016 at 08:59

Quote: Originally posted by arkoma  
Quote: Originally posted by XeonTheMGPony  
As for initiation any half descent cap and a bit of booster will do, or with the aluminium sensitizer a half assed cap will do!
Yup, Tannerite will detonate from a bullet strike.

Yeah, but not from a "Christmas light", or from being hit by a car, even one traveling over 300 mph.
I'm surprised to hear that "a half assed cap will do", but then I have next-to-no EM experience.

hissingnoise - 19-9-2016 at 09:09

Christmas lights make good, improvised ignitors!

zwt - 19-9-2016 at 09:13

So you're saying a glowing wire is all it takes to set off Tannerite? That contradicts most of what I've read.

Edit:
While researching this further, I discovered a New York Times correspondent claiming the bombs were in fact made with HMTD.

[Edited on 19-9-2016 by zwt]

hissingnoise - 19-9-2016 at 11:59

Quote:
So you're saying a glowing wire is all it takes to set off Tannerite?

Not nececcelery ─ and I didn't mention tannerite?

It will certainly, though, fire an improvised detonator!

zwt - 19-9-2016 at 14:08

Quote: Originally posted by hissingnoise  
I didn't mention tannerite?
My mistake. As your comment lacked any other context, I thought you were responding to my comment about the inability of such things as the filament of a Christmas light or a subsonic impact to reliably initiate Tannerite specifically. I agree that an incandescent light bulb filament could initiate a sensitive primary which could then set off a less-sensitive secondary, like Tannerite.

[Edited on 19-9-2016 by zwt]

camerican - 19-9-2016 at 14:35

Would the pressure cooker confine the AN/Al mixture effectively enough that it would transition to detonation after being ignited? Or would there have to be a primary involved?

Texium - 19-9-2016 at 15:51

Quote: Originally posted by NedsHead  
My original comment was just a sceptical observation about the order of events, although it could just be the "signal amplifying" iron helmet talking, I'll switch back to tin foil shortly. yes, the follow up conversation with Bert was about Kelly
Interesting, I had never heard of Ned Kelly. I always assumed that your username was a Game of Thrones reference.

OneEyedPyro - 19-9-2016 at 16:17

Quote: Originally posted by camerican  
Would the pressure cooker confine the AN/Al mixture effectively enough that it would transition to detonation after being ignited? Or would there have to be a primary involved?


AN/Al will not even sustain combustion let alone undergo DDT. It requires a detonator.

NedsHead - 19-9-2016 at 16:27

is that what people have been thinking about me? a grown man who has named his user profile after Game of Thrones? I wasn't even aware because I've never watched it, I don't even know if it's a television show or a movie

Texium - 19-9-2016 at 16:55

Quote: Originally posted by NedsHead  
is that what people have been thinking about me? a grown man who has named his user profile after Game of Thrones? I wasn't even aware because I've never watched it, I don't even know if it's a television show or a movie
Haha, it's a show on HBO, and a very good one. Personally I don't think it reflects badly on you at all, but I'm biased since I like the show.

[spoiler] There's a prominent character named Ned who gets beheaded at the end of season one and it was kind of a big deal.

NedsHead - 19-9-2016 at 18:43

Quote: Originally posted by zts16  
Haha, it's a show on HBO, and a very good one. Personally I don't think it reflects badly on you at all, but I'm biased since I like the show.


well that"s a relief,

even fictional Ned's have a hard time keeping their heads on their shoulders

Edit: it also explains why the user name "Ned'sHead" (with the apostrophe) was taken, I couldn't imagine why anyone else would want that user name

[Edited on 20-9-2016 by NedsHead]

Bert - 19-9-2016 at 20:10

Quote: Originally posted by NedsHead  
You know your Aussie history Bert! I'm impressed, it's my iron helmet, it picks up and transmits wifi signals


Read "The Fatal Shore" a while back. "I am a tedious sink of useless knowledge".

http://archive.org/stream/160103190gut/3190.txt

XeonTheMGPony - 14-10-2016 at 08:39

Quote: Originally posted by zwt  
So you're saying a glowing wire is all it takes to set off Tannerite? That contradicts most of what I've read.

Edit:
While researching this further, I discovered a New York Times correspondent claiming the bombs were in fact made with HMTD.

[Edited on 19-9-2016 by zwt]


All secondaries need a primary to set off, and higher powered primaries need a initiator such as heat spark of friction.

It is called an explosive train, so one can use a bit of wire and a match for the start of the train, then HMTD/TATP/lead azid, mercury fulimate and so on.

This then leads to the booster, this can be a mixture of a primary and secondary, or a fairly sensitive secondary.

Then your main bursting charge, but in the case of a sensitized explosive such as Am/Al One can use a simpler train with just two stages at the cost of slight higher chance of failure.

Thank fully the ones building these devices tend not to be the smartest to begin with! In the technical arts.

Metacelsus - 14-10-2016 at 11:18

Conversely, most people smart enough to build and deploy complex devices are also smart enough to know that doing so would be a horrible idea. However, one can cause plenty of terror with quite primitive methods (like a big truck moving very fast).