[AR] Re: PEPCON AP explosion report

  • From: Bruce Beck <bbeck7@xxxxxxxxx>
  • To: arocket@xxxxxxxxxxxxx
  • Date: Mon, 20 Jul 2015 11:18:57 -0600

All explosives have a critical diameter which is defined as minimum
diameter below which detonation will not propagate.When you get to large
diameter charges like 55 gallon barrels(2.5 feet) it is conceivable that
200micron AP charges might be able to propagate a detonation.It would be
interesting to know weather research of this sort has been undertaken and
what the results are.

On Mon, Jul 20, 2015 at 11:04 AM, James Padfield <james.padfield@xxxxxxxxx>
wrote:

You mean, if the AP is preheated, then it is more likely to go bang?


On 20 July 2015 at 19:01, Monroe L. King Jr. <monroe@xxxxxxxxxxxxxxxxxx>
wrote:

Heat

-------- Original Message --------
Subject: [AR] Re: PEPCON AP explosion report
From: James Padfield <james.padfield@xxxxxxxxx>
Date: Mon, July 20, 2015 9:58 am
To: arocket@xxxxxxxxxxxxx


Thanks for the info folks. All interesting stuff.
ATF don't classify it as an explosive (pure AP that is) until it gets
down
to < 15 microns. List of explosive materials is right at the end:
https://www.atf.gov/file/58741/download
Ok, at the risk of starting an argument then, if the AP stored at PEPCON
was indeed 200 um, why did it go high order like it did?
Contamination? A
couple of the reports mention that the polythene drums it comes shipped
in
may act as the fuel for the explosion.



On 20 July 2015 at 18:39, Bruce Beck <bbeck7@xxxxxxxxx> wrote:

Also I believe that the report or an abstract of it was published in a
Tripoli Report from when Bruce Kelley was publishing it.I am sure
it's in
my house somewhere but can't remember where at the moment.

On Mon, Jul 20, 2015 at 10:32 AM, Bruce Beck <bbeck7@xxxxxxxxx>
wrote:

See p 365 of the chemistry of powder and explosives by Tenney L
Davis.Also see p91 of the 2007 ATF Federal Explosive Law and
Regulations,
Orange book,list of explosive materials.

On Mon, Jul 20, 2015 at 10:18 AM, James Padfield <
james.padfield@xxxxxxxxx> wrote:

Bruce, please don't take this the wrong way, and I certainly don't
mean
to be rude, but can you back that up with hard data? Test reports,
for
example? I think you are probably right, but I need some evidence
to
support that.
James.



On 20 July 2015 at 18:15, Bruce Beck <bbeck7@xxxxxxxxx> wrote:

Don't be concerned if more than 15 micron particle size or when
mixed
with fuels at a concentration of 85% or higher.

On Mon, Jul 20, 2015 at 10:08 AM, James Padfield <
james.padfield@xxxxxxxxx> wrote:

Thank you, that is indeed interesting.

I may as well tell you what I'm specifically interested in, as
some on
this list may know the information I am looking for, or know
where to find
it.

I have just discovered that there are 5 x 200kg drums of AP being
stored across from my office. I am aware that AP's propensity to
detonation is dependent on the particle size, but can find no
definitive
information on the interweb. For example, I was looking to buy a
sample of
AP from Sigma Aldrich as a standard for analysis, and noticed that
according to the MSDS it is listed as H201 Mass Explosion Hazard
(or R3
Extreme Risk of Explosion in the old R phrases) (see link below).
Sigma
Aldrich give their AP particle size as > 45 micron.



http://www.sigmaaldrich.com/catalog/product/fluka/09910?lang=it&region=IT

Other information I can find seems to say that different states
in the
US classify it differently, the US Army classifies it as 1.1 at <
15 um,
etc etc...

Wikipedia says that the AP involved in the PEPCON explosion was
nominally 200 micron, so fairly coarse, in fact comparable to the
drums in
the store opposite my office. I am trying to confirm that figure
for 200
um as I am wary of trusting Wikipedia, hence why I'm trying to
find the
official accident reports.

So, anything anyone knows about whether I should be concerned
about it
or not would be welcome...


On 20 July 2015 at 17:22, Derek Lyons <fairwater@xxxxxxxxx>
wrote:

Not the requested report, but interesting none the less;

http://www.triodyne.com/SAFETY~1/SB_V10N3.PDF










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