Sciencemadness Discussion Board

Trying to heavily confine high R.E. energetic

Ral123 - 4-7-2013 at 03:01

Here's something that I agree is very dangerous, even at that small scale. I was wondering about how could a thick chamber be shattered by ETN. Thinner walls, specially from brittle materials tend to be shrapnel free from maximum density energetics, but that one gave fragments. Almost no fragments were given by EGDN/ETN/Tetryl in glass/thin metal/plastic.
http://www.youtube.com/watch?v=azy6m2zrMVE

Fantasma4500 - 4-7-2013 at 11:21

well highly brisant mixes are known to give off no actual danger at +15 metres as the glass somehow loses its speed as its a superfine dust because of the brisance
metal wont shatter the same way (hardened stainless steel?) but rather bend
if a material will bend or shatter means more than just alot
obviously glass will shatter (of what ive heard PVC will do the same thing as glass, potential test?)
where most types of metals will be able to be bended and some will shatter
i would consider a metal that would shatter to be much more dangerous as it would potentially give off much stronger fragments with much sharper edges
but again i havent seen much of fragments others than a zinc battery casing made into katana-sharpness pieces

the setup you had for that video wasnt very dangerous, only way if youre not in direct sight would be that it would go straight up in air, and then hit you in the head
and as you put wood on top of this thing i dont see this happening, really.

was that only blank fire ammunition, tho? you wrote corrupted blank fire ammunition :s?

bfesser - 4-7-2013 at 11:30

I apologize for my ignorance, but what does <a href="search.php?token=&srchtxt=R.E.&srchfield=body&srchuname=&f%5B%5D=3&srchfrom=0&filter_distinct=yes&searchsubmit=Searc h">"R.E."</a> stand for in the context of energetic materials? Scanning through a few threads and a quick Google/Wikipedia search haven't proven helpful. Thanks.

[Edited on 7/4/13 by bfesser]

Ral123 - 4-7-2013 at 12:24

Oh just that wikipedia thing. High R.E. means RDX, ETN, PETN, EGDN, NG.
Here's a test that shows how hardened steel becomes harmless dust(Tetryl):
http://www.youtube.com/watch?v=6rRg7ksNaZs
Here's a test that shows how PVC becomes harmless mist(EGDN):
http://www.youtube.com/watch?v=ELXmCqirmQ0
Here's a test that shows how glass becomes harmless mist(EGDN/ETN):
http://www.youtube.com/watch?v=LDZS7i8-pxE

Here's a test that shows how the low brisanse of AP turns PVC into nasty shrapnel:
http://www.youtube.com/watch?v=f-HtfnjKKhE
Here's a test that shows how the low brisanse of NC turns aluminium into nasty shrapnel:
http://www.youtube.com/watch?v=emv-xM0G8kU

The shape of the charge and the case is the other part of the story, flat surfaces can give shrapnel, even with high R.E. material. The no shrapnel due to high brisanse is the ideal case, so don't rely on it.

bfesser - 4-7-2013 at 14:45

Quote: Originally posted by Ral123  
Oh just that wikipedia thing. High R.E. means RDX, ETN, PETN, EGDN, NG.
I'm not sure if you attempted to answer my question here or not, but you did not actually answer it. Regardless, I think I just found the meaning in the Wikipedia disambiguation page. I guess I simply missed it last time.
<a href="http://en.wikipedia.org/wiki/Relative_effectiveness_factor" target="_blank">
Quote:
<strong>Relative effectiveness factor</strong> or <strong>R.E. factor</strong> is a measurement of an explosive's power for military demolitions purposes. It is used to compare an explosive's effectiveness relative to TNT by weight only, TNT equivalent/kg (TNTe/kg). This enables engineers to substitute one explosive for another when they are calculating blasting equations that are designed for TNT. For example, if a timber cutting charge requires 1 kg of TNT to work, it would take 0.42 kg of ONC, 0.6 kg of PETN, 1.25 kg of ANFO, or 2.22 kg of AN to have the same effect.
&hellip;
The bigger the R.E. number, the more powerful the explosive.<img src="../scipics/_wiki.png" />
</a>

[Edited on 7/9/13 by bfesser]