s.e.m.t.e,x
No Fear
Don Thompson
properly.Wassamatter,you afraid the repressive regime in charge of the
British Isles might bust your chops???If you had a legitimate purpose you
wouldn't be afraid to spell the word semtex in your subject line or in the
text of your post.
--
Don Thompson
Another Thompson Scion
"No Fear" <lett...@homechoice.co.uk> wrote in message
news:3b0a...@news1.homechoice.co.uk...
Chris Murray
> is it true that (s,e.mte.x) smells like marzipan?
It's a mixture of RDX, PETN and various plasticisers (variable composition
essentially depending on how much of each HE was available).
The almond-like smell of some explosives is generally associated with
the presence of nitro aromatic compounds. It may be that some MNT or DNT
was used as a plasticiser but I doubt it. I've seen people quite happily
shaping Semtex with bare hands - the above compounds would give Semtex an
appreciable toxicity by skin contact.
Of course, they could also have made semtex with benzaldehyde or hydrogen
cyanide as components, both having an almond-like odour, but I doubt it...
IIRC, Semtex doesn't stand for anything (ie it's not s.e.m.t.e.x.), and
it was made in Czechoslovakia. The most well known variety was
Semtex-H, which is the one that the IRA are reputed to have about 2 tons
of. I don't think that it is made anymore.
There is an archive of Gerald Hurst's posts out there. There was
some detailed analytical information on a couple of the Semtex
compositions, and some other stuff also. (the archive is worth getting
anyway - there is some excellent info in there).
A word of warning - it's not indexed (unless it's been updated since I
last checked)!
http://www.geocities.com/CollegePark/Library/4196/
__________________________________________________________________________
Chris Murray #
#
PhD student #
Organofluorine research group # The views expressed in this message
Department of Chemistry # are my own, and do not necessarily
University of Durham # reflect the views of the University.
South Road #
Durham DH1 3LE #
U.K. #
__________________________________________________________________________
ni...@g8nyz.freeserve.co.uk
mean post Lockerbie manufactured product or pre? I only have experiance of
the latter ex terrorist product and that certainly does not smell of
Almonds, just a faint oily smell in bulk. It was made from variable
quantities of PETN & RDX in a styro-butadine rubber binder with a (Cairo?)
orange colour,... which happens to be carcinogenic...poetic justice?
The latter product may well smell of almonds, as Synthesia were one of the
first manufactures to include a tracer in plastic explosives & I believe
they used a small ammount of EGDN. This enables simpler vapour detectors to
be used by "the good guys" rather than the more complex/expensive
particulate instruments, in order to detect terrorist devices.
Nigel Cooper
"No Fear" <lett...@homechoice.co.uk> wrote in message
news:3b0a...@news1.homechoice.co.uk...
Boomer
Well, not really Chris, it stands for Semt-explosive, where Semt is part of
the word Semtin, as in Pardubice-Semtin, a town in Czechoslovakia, where the
firm Synthesia is located, the original manufacturing firm. The original was
PETN w/styrene-butadiene copolymer.
Some Semtex's, such as H, were 11 % Veg.Oil plasticizer, 44.5 % RDX & 44.5
% PETN. Vegy oil Semtex has one great thing, it lowers the vapor pressure
and makes it hard for NVA's and EDD's but at the same time has a
disadvantage, the oil likes to leak out and makes it easy for us to spot.
--
Boomer
WCW...@Bresnanlink.net
If You See Me Running You Better Catch-Up
"Chris Murray" <C.B.M...@durham.ac.uk> wrote in message
news:Pine.GSO.3.95-960729.101...@altair.dur.ac.uk...
:
:
Chris Murray
> "Semtex doesn't stand for anything "
>
> Well, not really Chris, it stands for Semt-explosive, where Semt is part of
> the word Semtin, as in Pardubice-Semtin, a town in Czechoslovakia, where the
> firm Synthesia is located, the original manufacturing firm. The original was
> PETN w/styrene-butadiene copolymer.
>
> Some Semtex's, such as H, were 11 % Veg.Oil plasticizer, 44.5 % RDX & 44.5
> % PETN. Vegy oil Semtex has one great thing, it lowers the vapor pressure
> and makes it hard for NVA's and EDD's but at the same time has a
> disadvantage, the oil likes to leak out and makes it easy for us to spot.
> --
> Boomer
>
> WCW...@Bresnanlink.net
Thanks, Boomer. I didn't check the Jerry archive prior to posting - I
should have done (oops). When you mention vapour pressure, are you talking
about the volatile components (other plasticisers) or NOx decomposition
products from the RDX? I don't know that much about explosives detection,
but I vaguely remember someone saying that PETN had very low emissions in
this respect, whereas RDX was easier to spot. Could be wrong though...
Cheers,
ni...@g8nyz.freeserve.co.uk
<ni...@g8nyz.freeserve.co.uk> wrote in message
news:9eg97u$50p$1...@newsg4.svr.pol.co.uk...
> Which Semtex? I will assume you mean Semtex H rather than 1A or 10. Do you
> mean post Lockerbie manufactured product or pre? I only have experiance of
> the latter ex terrorist product and that certainly does not smell of
> Almonds, just a faint oily smell in bulk. It was made from variable
> quantities of PETN & RDX in a styro-butadine rubber binder with a (Cairo?)
> orange colour,... which happens to be carcinogenic...poetic justice?
>
Boomer
(Nitrogen Vapor Analyzer), EVD (Explosives Vapor Detector) and EDD
(Explosives Dog Detector). The Vegetable oil lowers the vapor pressure, so
in lay terms it smells less.
Here some shit for you........
RDX=. .006 ppb (Particulate )
PETN= .018 ppb (Particulate)
Deta Sheet = < .0001 ppb (Particulate)
Det Cord = <.0001 (Particulate).......You must be seeing this one
Semtex = .002 ppb
C-4 = .00006 ppb.......Clean stuff. ah !
NG = 409 ppb
EGDN = 60,000 ppb
EGMN = >60,000 ppb
DNT = 145 ppb
AN = 12 ppb ( Particulate)
TNT = 9 ppb
The equilibrium vapor pressure is expressed in parts / billion explosives to
air. Most are measured with a GC-TEA ( for organics)
Vapor Pressure at different temps can be calculated Chris where;
log P = 14.14 - 6785 (1/T)
P= Vapor Pressure in Torr
T = Absolute Temp
For actual Torr VP's
EGDN = 4.8 x 10 exp-2
NG = 2.3 x 10 -4
TNT = 4.5 x 10-6
PETN = 1.1 x 10-9
RDX = 3.8 10-10
Found some typo errors in Yinon & Zitrin, so I adjusted some of the values,
e.g PETN was 18 ppt & RDX 6 ppt and the Torr values were also switched for
the two (had other refs.). How could RDX have a less ambient air value in
ppb and a higher Torr than PETN ?
--
Boomer
WCW...@Bresnanlink.net
Former US Army Bomb Technician (EOD)
Member; IABTI, NEODA,WEODF, ISEE & IPS
Casady
<C.B.M...@durham.ac.uk> wrote:
>On Tue, 22 May 2001, No Fear wrote:
>
>> is it true that (s,e.mte.x) smells like marzipan?
>
>It's a mixture of RDX, PETN and various plasticisers (variable composition
>essentially depending on how much of each HE was available).
>The almond-like smell of some explosives is generally associated with
>the presence of nitro aromatic compounds. It may be that some MNT or DNT
>was used as a plasticiser but I doubt it. I've seen people quite happily
>shaping Semtex with bare hands - the above compounds would give Semtex an
>appreciable toxicity by skin contact.
>
>Of course, they could also have made semtex with benzaldehyde or hydrogen
>cyanide as components, both having an almond-like odour, but I doubt it...
>
>IIRC, Semtex doesn't stand for anything (ie it's not s.e.m.t.e.x.), and
>it was made in Czechoslovakia. The most well known variety was
>Semtex-H, which is the one that the IRA are reputed to have about 2 tons
>of. I don't think that it is made anymore.
>
>There is an archive of Gerald Hurst's posts out there. There was
>some detailed analytical information on a couple of the Semtex
>compositions, and some other stuff also. (the archive is worth getting
>anyway - there is some excellent info in there).
>
>A word of warning - it's not indexed (unless it's been updated since I
>last checked)!
>
>http://www.geocities.com/CollegePark/Library/4196/
There is stuff by Hurst at this archive, and a lot more besides, on
both explosives and pyrotechnics, and a whole bunch more,
metal working, refrigeration, aviation, military, lots of stuff, and
I have read it all. It is pretty good, and well organized, and easy
to use, and I recommend it highly, although I can't and don't
guarantee that everthing there is absolutely the gospel. It
is stuff from USENet, after all.
And just for fun, off topic, but not much extra space here, and I am
watching it right now, a link to a webcam at the Miraflores Locks,
Panama Canal. The tropical sunset, it is something like 8 N latitude
is very fast, no twilight to speak of.
http://www.pancanal.com/eng/photo/camera-java.html
Casady
No Fear
and many thanks to the experts who answered my question."Don Thompson"
<flas...@ix.netcom.comghost> wrote in message
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