Plastic Explosive
rste...@fast.net
errors in films really bother some of you so I'm giving all of you a supreme
opportunity.
I'm a lowly film student, and I'm researching the operation of the
British SAS in conjunciton with the French Resistance(and any illumination
info there is also welcome). The SAS and the resistance use plastic
explosives in many ways. In one account I was reading they use some as a
'hand grenade' to stop/destroy the front truck in a convoy. One British chap
uses some to get the fire going. And of course they use it to take out
bridges, train tracks, trains, planes... generally making a nuisance of
themselves.
What I would like to find out more about the history of plastic explosive,
use of the stuff in WWII, particular hazards, how it was made, where it was
made, who made it(U.S./U.K.?), ways to get the stuff to go off.
A thousand thanks for any information you have on the plastic explosives and
any comments thoughts(hints and tips) about WWII filmmaking.
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Velovich
>errors in films really bother some of you so I'm giving all of you a supreme
>opportunity.
How abouty a modern (tens years out of service) Infantryman trained (a
little) in the use of this?
PE (we call it C-4, even when it isn't), is toxic.
You can burn it, it's great to heat water in a "tommy cooker".
It is shock resistant, that is, gunfire will NOT set it off.
It can be molded around corners to improve it's explosive power.
PE can be used as a grenade, but this requires a fuse mechanism of some
sort. PE requires a blast to set it off. A fuse in a blasting cap can be
done, very dangerous. Electrical ingition is MUCH preferred, much safer.
If you mold explosives (or pack rigid explosives) around the object being
attacked, it sends the force into it from several directions. This really
allows things like girders and rails to be cut with less explosive more
reliably.
Also, you might have seen things like sandbags being packed over the
explosives once they are placed. This is to contain part of the explosion,
also a matter of increasing overall power. You see, explosion are a globe of
expanding energy. They will follow the path of least resisance. If placed
against a railroad rail, and not "tamped", then most of the PE is exposed to
the air, which provides little resistance to the blast. Wasted energy. By
placing several loaded sandbags against the explosive, some of the otherwise
wasted energy is forced into the target of the demolition.
PE was used as a general explosive. Still is. It is stable, won't go bang
if dropped, yet has more power than TNT. It compares favorable to
Nitroglycerine. Nitro is VERY unstable.
<*> V-Man
A Knight is sworn to Valor
His Heart knows only Virtue
His Blade defends the Weak
His Word speaks only Truth
His Wrath undoes the Wicked
Delete the ".CanDo" from my addy to reply!
casita
>I'm researching the operation of the
>British SAS in conjunciton with the French Resistance(and any illumination
>info there is also welcome). The SAS and the resistance use plastic
>explosives in many ways.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
summer of 44.They were all trained in guerilla tactics and were experts in
demoltion. Their role was to co-ordinate the resistance in their area and to
arrange arms for Masquisards if thought appropriate."
for a vivid description of these activities in July 44 you should read
Massacre Over the Marne by Oliver Clutton-Brock or contact his publisher
for some contacts.
BTW I think the young sailor named Homer in " Best years of our Lives" lost
his hands in a training accident with the stuff as an instructor in the US
Army. I think he wrote a book about it and his rehabilitation.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
CRH III
rste...@fast.net wrote in article <74jo2a$flg$1...@nntp6.u.washington.edu>...
> Ok all you nitpickers and grognards
>
> I'm a lowly film student,
Without going into too much detail, most explosives are made of TNT, which
melts before it explodes, so it can be poured into bombs and shells. Too
sensitve to use alone it was cut with all kinds of stuff and broken down
for different uses. The base explosive goo was called, cyclonite by the
Americans, RDX by the British and Hexogen by the Germans. The Brits cut
their stuff with beeswax for shells (composition A), more TNT and a little
beeswax for bombs (composition B) , and with plasticizing oil for
demolition work(composition C). C became known as plastic explosives so it
would be a British invention.
Hillbrath
A very good message about plastic explosive, but I can't help make a few
comments.
>
> PE (we call it C-4, even when it isn't),
Both C-3 and C-4 were in use in about 1960. I am sure that they were only up to
"C" or "C-2" in the WW II.
All "Comp Cs" are based on the explosive called RDX, among other things. RDX
has a really amazing chemical structure, which I won't try to draw here. It is
something like TNT on steroids. (Nitrogen-carbon bonds and Nitro groups are
where the energy is stored in most explosives. TNT has a six carbon ring with
three nitro groups tacked on. In RDX, three of the carbons are replaced by
three nitrogens.)
RDX was developed sometime after WW I, in great secrecy on both sides. Much
time has been spent on figuring out what the letters "R-D-X". Letters which
were apparently selected at random as a way of concealing the nature of what
was being discussed. But there are a lot of ingenious proposed phrases anyway.
Unlike TNT, which can be melted and poured into shells or whatever in the pure
form and is adaquately insensitive in the pure form, RDX cannot be melted, and
is too sensitive in the neat form to be used as a military explosive.
The first explosive containing RDX was "Comp A" and consists of RDX and a bit
of bees wax, (and some eye of newt, wing of bat, etc.) and is produced in
pellet form which is poured into the shell and pressed (very carefully, do not
try this at home) to increase the density. Comp A is mainly used in stuff like
20mm projectiles.
Then, oddly enough, came "Comp B" which was much more satisfactory than Comp A.
It is a blend of RDX and TNT (and other stuff, probably). It is roughly as good
as Comp A, and is meltable and almost as insensitive as TNT. It was a general
purpose, but "up scale" filler for all sorts of stuff. It was especially
valuable for shaped charges, where its higher detonation velocity vastly
improved performace.
Comp C came next, and was only used in the form of "Engineer Blocks" as a
demolition explosive. Not in any prefilled shells, bombs, charges, etc.
> is toxic.
Yes, but, then everything, including TNT, gasoline, etc. etc. is.
> You can burn it, it's great to heat water in a "tommy cooker".
Yes, it is amazingly stable in small quantites, "safe as houses." But, don't
try burning big piles of it.
When I was at the Ordnance School, the local EOD team liked to hang around at
the school when they were not doing their disposal thing. They always seemed to
have lump of Comp C in their pocket, sort of their "Badge of Office." And, they
would tear off a piece and set it on fire for the green lieutenants at the
slightest provocation.
> It is shock resistant, that is, gunfire will NOT set it off.
Yes, that is what they tell the guys that have to use it. It is not as safe as
TNT, which is not totally safe, itself. Don't try this at home, either.
[snip a bunch of stuff that is "good enough"]
>
> PE was used as a general explosive. Still is. It is stable, won't go bang
>if dropped, yet has more power than TNT. It compares favorable to
>Nitroglycerine. Nitro is VERY unstable.
>
True, it has more power, and higher "brisance" than TNT, but is more sensitive.
But, not nearly so sensitive as Nitroglycerine.
Henry Hillbrath
rste...@fast.net
the deal is.
And while we're on the topic of explosives I wonder if I might test your
acumen again and find out...
What is and how much is the explosive in a Satchel Charge?
I know it's terribly wrong of me to base my historical military
knowledge on movies, but if I recall a Sachel Charge is about 12" by 12" by
4" and weighed a couple pounds. A soldier would get close to some bunker
pull a cord on the charge and dump the charge through the observation slit on
the bunker. Give it about five or six seconds(probably wrong) and boom!
Let me know what you think. And thanks for the info on plastic again...
Jim Garner
>
> Without going into too much detail, most explosives are made of TNT, which
(snip snip)
Are or were? Way I hear it, explosives nowadays are vastly more powerful
than in WW2 days. Is this correct? What was the ratio of power/mass in
WW2 compared to today? anybody know?
--
Jim Garner, sage and dogsbody.
an...@freenet.carleton.ca http://www.ncf.carleton.ca/~an410
(613) 526-4786; 759B Springland, Ottawa, ON K1V 6L9 Canada
"The best-laid femmes go oft astray"
Velovich
>pure
>form and is adaquately insensitive in the pure form, RDX cannot be melted,
>and
>is too sensitive in the neat form to be used as a military explosive.
RDX can be extracted from the plastic compound it's suspended in, VERY
dangerous, but it can, and you get a shock sensitive explosive. For OSS work,
this might be useful to the original poster. RDX Pancakes, RDX-coated
Newspaper, that stuff. This puts the explosive power in a more concentrated
form, if more dangerous.
Like I said, I was a grunt. I also read a lot.
Velovich
TNT, usually about 3-10 lbs, but the US Army's current issue Satchel Charge
is 16 blocks of C-4 at 1 KG each.
>I know it's terribly wrong of me to base my historical military
>knowledge on movies,
A satchel charge exists primarily as to give the field soldier a handy-sized
bundle of HE (High Explosive) that has a handle. This is so he can throw it
once the fuse train is going. In a given unit or on a given operation in WW
II, all satchel charges would be the same weight of HE. VERY important. This
allows all the guys to carry one, and when the charge needed was larger than
one satchel charge, you had uniform wieghts to use for calculating the number
of Satchel Charges needed for the job.
Demo calculatons are important for destroying large target.
That help?
Tim Marshall
posts...but...but...
I am disappointed that with the "Hillbraith Bait" 8) of "Tommy Cooker",
Henry did not rise to the occasion to espouse his theory on Sherman
superiority, etc, etc.
Tee hee, sorry 8)
On 9 Dec 1998, Hillbrath wrote:
Carey Sublette
rste...@fast.net wrote in message <74jo2a$flg$1...@nntp6.u.washington.edu>...
>Ok all you nitpickers and grognards... I have a feeling that all those
little
>errors in films really bother some of you so I'm giving all of you a
supreme
>opportunity.
>
>British SAS in conjunciton with the French Resistance(and any illumination
>info there is also welcome). The SAS and the resistance use plastic
>'hand grenade' to stop/destroy the front truck in a convoy. One British
chap
>uses some to get the fire going. And of course they use it to take out
>bridges, train tracks, trains, planes... generally making a nuisance of
>themselves.
>
> What I would like to find out more about the history of plastic explosive,
>use of the stuff in WWII, particular hazards, how it was made, where it was
>made, who made it(U.S./U.K.?), ways to get the stuff to go off.
The first "plastic explosive" was blasting gelatin, patented by Nobel in
1875. It is nitroglycerin thickened with dissolved nitrocellulose (about 7%)
to form a jelly-like mass. If more nitrocellulose is added the mass becomes
quite stiff and is no longer pliable, and in this form is used in smokeless
powder (double base propellant) such as cordite. Blasting gelatin was used
for specialized blasting tasks requiring molding, much like modern plastic
explosive, but was not really suitable for military use due to handling and
safety problems.
'Modern' plastic explosive compositions date back to 1932, when Stettbacher
patented the conversion of PETN into a dough-like mass using a 10-30%
admixture of nitroglycerin or nitroglycol.
Better compositions deleted the use of nitroglycerin and mixed the powdered
high explosive (usually RDX, sometimes PETN, or a mixture of either with
TNT) with non-explosive plasticizers which provide better texture and
storability, and also desensitize the explosive to impact shock.
RDX and PETN are both around 30% more powerful than TNT. RDX is less
senstive to shock than PETN and is preferred by the U.S. military.
Carey Sublette
RDX and PETN are
Hillbrath
>Are or were? Way I hear it, explosives nowadays are vastly more powerful
>than in WW2 days. Is this correct? What was the ratio of power/mass in
>WW2 compared to today? anybody know?
Well, let me say that I am not right up to date on this, I certainly do not
have any current "inside" data.
However, I can give you some relevant data.
First, I think that Comp B is still the most common military explosive. Comp B
was used in WW II, although it was not as dominant as it became later.
Second, you ask about power/mass comparisons.
Explosives are pretty complex, and the definition of the performance of
explosives, and the measurement of performace is also complex.
Power/mass (and I won't bother with power vs. energy, but for those that want
to bring this up, I do know the difference.) is closely related to specific
impulse in rocket propellants. In fact, in some cases, there is no difference
in explosives and rocket propellants, because they are the same thing.
I do know something about rocket propellants, and some of the highest
performance rocket propellants available are RDX (actually, HMX, the "eight
way" sister of RDX is usually used) and nitroglycerin. There are no really
magically better solids available.
More important for military applications than specific impulse is "brisance"
which is closely related to detonation velocity. Brisance and power are not
closely related.
AFAIK, RDX in some form is still the preferred explosive for shaped charges.
Some years ago, there were some guys near Seattle that were hyping new
"aerospace derived" explosive technology. They particularly claimed much higher
brisance. There was an accident, oddly enough involving ammonium nitrate, a
very "low tech" explosive used as a raw material, and an equally low tech
coffee pot, which destroyed the plant.
(OK, if I leave it at that, someone will want to know how a coffee pot blows up
an explosive plant. The story I heard was that therewas a truck of AN which was
being delivered. The driver stopped at the guard shack and went inside. While
he was there, the coffee pot in the guard shack set something on fire, which
eventually burned the guard shack, and then the truck, and eventaually the fire
found something more exciting, and the whole plant went up.)
As far as I know, the company went bust, and no one took up the technology,
indicating that there is not really seen to be that much payoff for a more
complex and expensive explosive.
Henry Hillbrath
Velovich
>I am disappointed that with the "Hillbraith Bait" 8) of "Tommy Cooker",
A tommy cooker is a small metal stand for hexamine tabs, which is used to
heat up water for a meal or to heat the meal itself.
rste...@fast.net
velo...@aol.com.CanDo (Velovich) wrote:
> > What is and how much is the explosive in a Satchel Charge?
>
> TNT, usually about 3-10 lbs, but the US Army's current issue Satchel Charge
> is 16 blocks of C-4 at 1 KG each.
So what kind of damage can one expect from one of these? Also what
kind of delay is on it... I mean if I were a grunt with one of these I'd like
to know I can get far enough away that it won't KIA me too.
Also my understanding is that things like C-4 and Composition B were
created so that they were safe on the battlefield. A bullet striking it
won't set them off, right? But I'm not so sure I'd want to be running about
or near someone with one of these if what's in it was TNT(like the sticks of
dynamite). One stray bullet or shell fragment and BOOM... no more squad.
So I'm going to make an assumption here... during WWII the sachel charge
used some form of plastic explosive, and I've simply misconstrued what you
wrote.
Thanks for your help.
Velovich
>Are or were? Way I hear it, explosives nowadays are vastly more powerful
>than in WW2 days. Is this correct? What was the ratio of power/mass in
>WW2 compared to today? anybody know?
There *are* more powerful conventional explosives, but they are FAR more
expensive to make. Octol is one - it's used as the implosive HE on Nukes.
VERY expensive. C-4 is cheap and reliable.
rmacd...@microd.com
<an...@FreeNet.Carleton.CA> wrote:
> "CRH III" (c.ha...@mindspring.com) writes:
>
> > Without going into too much detail, most explosives are made of TNT, which
> (snip snip)
> Are or were? Way I hear it, explosives nowadays are vastly more powerful
> than in WW2 days. Is this correct? What was the ratio of power/mass in
> WW2 compared to today? anybody know?
Composition B and Composition C-4 are still the two most used explosives
by the US Military and most of NATO. They are inexpensive to manufacture
and store, relatively stable and fairly safe to handle.
Most of the special use explosives that are more powerful cost a lot more
and are often even harder to set off since they are more powerful due to
being even more stable. Also for a lot of jobs less powerful explosives
such as Amatol or ammonium nitrate are better for jobs like cratering due
to their lower velocity.
Different jobs require different explosives. If you have to push a bunch
of dirt, use a low velocity explosive. If you want to cut metal, use a
high velocity explosive like C-4 (and shaping the charge helps).
Some of the real powerful stuff like Octol, which is sometimes used to
initiate Nukes, are real stable, hard to set off, usually needing a cap
and booster and are relatively expensive to manufacture.
Generally for your average HE/HEAT round, look for Composition B (TNT &
RDX mix) and for expensive weapons like SAM's look for something slightly
more exotic.
But there is still nothing to replace C-4 for general purpose mayhem.
I could probably get more detailed, but my manuals are in storage.
--
Richard A. Macdonald, E.A.
SSG (Ret), USA, ADA (16P34)
Dedicated follower of Fra. Luca Pacioli, Master Juggler
"Gib mir Schokolade und niemand wird verletzt!!!
Hillbrath
>>Unlike TNT, which can be melted and poured into shells or whatever in
>>the pure form and is adaquately insensitive in the pure form, RDX cannot
>>be melted, and is too sensitive in the neat form to be used as a
>>military explosive.
> RDX can be extracted from the plastic compound it's suspended in, VERY
>dangerous, but it can, and you get a shock sensitive explosive. For OSS
>work, this might be useful to the original poster. RDX Pancakes,
>RDX-coated Newspaper, that stuff. This puts the explosive power in a
>more concentrated form, if more dangerous.
I am not quite sure if there is a point here, but, when I wrote this it
occured to me that I was using "military explosive" in a somewhat
specialized sense, which is one that is used in the explosives field, and
which I was taught in the Ordnance School, but which is proably not clear
to the "American public."
A "military explosive" (and I don't know the exact limits) is an explosive
that is suitable and practical for use in military operations. That does
not mean that the military only uses military explosives, certainly not in
special situations, like last ditch defenses, if anything else is
available.
In the World War II era, military explosives were things like TNT, Comp A,
B, C, and some others like torpex, amatol, etc.
Nitroglycerine, dynomite, unblended RDX etc. were not considered military
explosives. I am not even sure what the correct name for the other major
class of explosives is. but just to have something to call it,
"commercial" explosives.
One of the differences in commercial and military explosives is
sensitivity. It isn't desirable for commercial explosives to be more
sensitive, but it is tolerated. As Velovich points out, it is possible to
extract a purer form of RDX from Comp C (or A and B, for that matter) it
is very easy to extract purer NG from dynomite, even if you don't intent
to, which is another reason dynomite isn't considered, or used as, a
military explosive.
But, the big difference in Military and Commercial explosives is
detonation velocity. High detonation velocity is important in military
explosives, expecially in the performace of shaped charges, but also in
fragmentation, etc.
Commercial explosives are mainly use in applications, like mining, in
which what you would like to have is a lot of big chunks of stuff, not a
smaller amount of fine dust. This is called "heaving"(which improves with
lower detonation velocites) and military explosives are not good at it,
so military explosives are just as undesirable in commercial applications
as the other way around.
There was not such a great difference in the WW II era, but since then,
military explosives have not changed a lot, and a lot of new commercial
explosives have been developed that are even less like military ones, in
that they have even lower detonation velocites and therefore better
"heaving."
Henry Hillbrath
Velovich
>kind of delay is on it...
OK - LOTS of agonizing detail here! You have been warned!
A satchel charge of 5 blocks of C-4 (5 kg tot.) one blasting cap
(non-electric) for each (makes sure evrything goes bang), and fuse cord
from each to a central fuse cord. It's recommended that there be TWO
firing trains, as this ensurse that if one fuse fails, the other will
still fire the charge.
A fuse igniter is a small cylinder that has a pull ring on one end, a
hole for the fuse in the other. Pull the ring, the fuse ignites. Think
Mission Impossible - a fuse cord is lit with a fuse igniter of a book of
matches, burns to the caps, they go bang, PE goes BANG!
Safe distance is 300 meters for up to 27 pounds of HE (any type). Yes
this is straight from a manual. This is straight line distance. If there
is a solid corner that the charge won't demolish, get around the corner
and you are quite safe. Think this way - you have a 5 block charge of C-4
against a steel fire door. Cinderblock building. Forty feet away is a
corner you could go around. Once you determine if the charge will
demolish the building itself (no), you can go around the corner. Blast
waves do not travel around corners unless deflected.
Fuse can be cut from a roll (that is how it comes, on a spool) to
desired lengths. There are always minor variances in manufacturing
standards, so test a length of fuse from each roll to be used. Usually,
they will be the same. I cannot find or recall burn rates of fuse, but it
is predictable based on how long the fuse is.
Take you satchel charge, get the sling off your body (usually carried
slung accross the body), pull out the fuse igniters, pull them in rapid
succession (remember! Dual priming for sure firing), grab sling, throw to
target!
To blow a 2 foot wide hole in 2 feet thick *good* masonry, you'll need
138.25 lbs of C-4, but if you put half a dozen filled sandbags over the
charge, you only need 76.8 lbs of C-4!
To blow a 4 foot wide hole in a brick/drywall/2x4 wall, you need:
Tamped with sandbags:
110 lbs C-4
Not tamped, just sitting there:
200 lbs C-4
To blow a door open, one satchel charge would do nicely. Throw one
against a pillbox door, get much the same.
Got an AT gun inside a sandbag emplacement? One thrown SC will do
great!
>A bullet striking it
>won't set them off, right?
Right. But a satchel charge is ready to go. Your blasting caps are
inserted, and they are shock sensitive, should only be handled with gloves
incase you squeeze too hard. A bullet *might* hit that, make it all go
off.
> But I'm not so sure I'd want to be running about
>or near someone with one of these if what's in it was TNT(like the sticks of
>dynamite).
TNT is like C-4 - VERY stable, won't go bang without a small explosion
against the HE itself. It's the caps that must be promed that are
dangerous. Dynamite is different. it is Nitroglycerine-impregnated
Sawdust (or some such) and is VERY shock sensitive. Not as sensitive as
Liquid Nitro, but still sensitive.
> So I'm going to make an assumption here... during WWII the sachel charge
>used some form of plastic explosive, and I've simply misconstrued what you
>wrote.
Or TNT blocks. Big difference is that C-4 is more potent for a given
amount. Also, C-4 can be molded around an I-Beam or pipe. As in Pipeline
for petroleum or I-beam for a bridge girder.
Little item for you. It is considered artistry to cut several I-Beams
(with C-4, by molding around the beam itself, don't need much HE at all)
on a bridge underside and not bring down the bridge. If you use grease
and dirt to camoflage the cuts, and wait till the enemy train comes along,
while the bridge had enough strength to hold itself together (if you did
it right), the weight of the train will bring down the bridge while the
train is on it.
Christopher Morton
> Demo calculatons are important for destroying large target.
And they issue a little data card to help you do it. It has formuli
for cutting various structural members, cratering roads, and denying
access to bridges, among other things.
A handy item to have.
--
"Give a man a fire and he's warm for a day, but set fire to him and
he's warm for the rest of his life."
Terry Pratchett
Christopher Morton
wrote:
>> So what kind of damage can one expect from one of these? Also what
>>kind of delay is on it...
>
> OK - LOTS of agonizing detail here! You have been warned!
<Excellent detail snipped>
US Army "FM 5-25, Explosives and Demolitions" and the Special Forces
programmed text on demolitions make a handy combination for looking up
such information.
They're also handy for keeping annoying conversation from your
neighbors on long bus trips to a minimum.... : )
Carey Sublette
Jim Garner wrote in message <74mtri$4...@dgs.dgsys.com>...
>"CRH III" (c.ha...@mindspring.com) writes:
>>
>> Without going into too much detail, most explosives are made of TNT,
which
>
>(snip snip)
>
>Are or were? Way I hear it, explosives nowadays are vastly more powerful
>than in WW2 days. Is this correct? What was the ratio of power/mass in
>WW2 compared to today? anybody know?
The current level of explosive performance is actually at the same level as
that reached in WWII - although explosives that were somewhat exotic and had
specialized uses then are now standard.
There are different ways of measuring explosive performance, but for general
purpose use the best measure for comparison is probably the heat of
explosion (measured in calories/gram). The classic standard military
explosive TNT has an HOE of 1080 c/g (according to the U.S. Army Engineering
Design Handbook AMCP 706-177), although it is usually assigned a nominal
value of 1000 c/g. The more powerful explosives adopted around WWII RDX,
PETN, and HMX, had HOEs of 1280, 1385, and 1356 respectively (according to
the above manual) making them roughly 30% more powerful. The most powerful
explosives in use though are not pure chemical compounds, but mixtures of
high explosives with powdered aluminum. Mixtures containing just the above
three explosives plus aluminum would be the most powerful, but due to
sensitivity problems (and to allow melt casting or easier hot pressing into
munitions) they are invariably mixed with a certain proportion of TNT. The
composition known as torpex (introduced during WWII) is a 42/40/18 mixture
of RDX/TNT/Al with an HOE of 1800 - almost twice as powerful as straight
TNT. Most munition fillings used today are similar to this (RDX is preferred
to PETN and HMX because it is the least sensitive of the three).
For comparison the HOE of nitroglycerin is 1600 c/g, and the most energetic
composition I can find in the manual is MOX-1 (a mixture of ammonium
perchlorate, aluminum, magnesium and tetryl) with 2087 c/g. I think the
rocket-fuel derived liquid astrolite compositions (containing ammonium
nitrate, hydrazine, nitromethane, etc.) may have even higher energies, but
their low density makes them less suitable for use in munitions.
For use in shaped charges the preferred explosive is HMX, which has the
highest detonation pressure (empirically described as "brisance") of any
standard explosive.
Exotic high energy compounds continue to be developed, but none have seen
extensive military use due to various shortcomings (like cost).
Returning to WWII plastic explosives, in addition to the C compositions
mentioned by others, the U.S. military developed and used an RDX and motor
oil composition (85/15) called RIPE during the war.
Carey Sublette
John D Salt
[Excellent and highly informative material snipped]
> To blow a 2 foot wide hole in 2 feet thick *good* masonry, you'll need
>138.25 lbs of C-4, but if you put half a dozen filled sandbags over the
>charge, you only need 76.8 lbs of C-4!
> To blow a 4 foot wide hole in a brick/drywall/2x4 wall, you need:
>Tamped with sandbags:
> 110 lbs C-4
>Not tamped, just sitting there:
> 200 lbs C-4
I'm surprised to learn it needs so much. If "mouseholing" -- that
is, assuming the intention of rushing through the hole as soon as
it's made -- would one have to use these sorts of weights, or would
cunning districbution of the explosive allow you to make do with less?
All the best,
John.
--
John D Salt Dept of IS & Computing,| Barr's Law of Recursive Futility
Brunel U, Uxbridge, Middx UB8 3PH | [BLORF]: If you are smart enough
Disclaimers: I speak only for me. | to use one of these... you can
Launcher may train without warning.| probably manage without one.
Velovich
>is, assuming the intention of rushing through the hole as soon as
>it's made -- would one have to use these sorts of weights, or would
>cunning districbution of the explosive allow you to make do with less?
It is possible to use lesser charges, but then you must tamp the first and
second charges. You could use one charge to weaken the wall, the next to
actually breech it.
Ofcourse, think of the results of putting a charge on a door. Sure, it's a
likely avenue of approach, the bad guys will expect you there, but the force of
the explosion will net you an advantage.
In war, the use of satchel charges isn't dont for breaching walls too much.
Too wasteful.
Rangers and Commandoes would use them to destory things in a raid, tho, and
that is where they come into their own.
Also, OSS/SOE troopers would make good use of them in this fashion, but in
more of a sabotage vien. Smaller charge, placed with greater precision on an
easier to kill target, like a switchboard or bridge girder.
Then we could go into what you can do with teh contents of a drug store in an
occupied country. Legally available materials could be used to extract the RDX
from C-4 and the RDX could be used to impregnate a newspaper (one sheet at a
time) for an innocuous charge a worker coudl carry right past the guard into
the (Vichy French) munitions plant. Another worker would have the priming
device, and great fun would be had by all, with wine and cheese to follow.
Another innocent-looking RDX ploy is explosive flour. You can bake it into
pancakes or bread (what ever you do, don't scorch it!) that when wetted down
can be molded into something like C-4 and primed. It fires wet. Both RDX
Floour and Newspapers still need a blasting cap or other explosive initiator.
Carl Alex Friis Nielsen
<750svn$6...@dgs.dgsys.com>...
> In article <74rg8o$k...@dgs.dgsys.com>, Velovich <velo...@aol.com.CanDo>
wrote:
> [Excellent and highly informative material snipped]
>
> > To blow a 2 foot wide hole in 2 feet thick *good* masonry, you'll need
> >138.25 lbs of C-4, but if you put half a dozen filled sandbags over the
> >charge, you only need 76.8 lbs of C-4!
>
> is, assuming the intention of rushing through the hole as soon as
> it's made -- would one have to use these sorts of weights, or would
> cunning districbution of the explosive allow you to make do with less?
>
According to my training a standard 5 kg satchel charge should blow a
hole large enough for entering a normal north European brick building
(throug the outer wall) without the sandbags.
If you have the time to prepare, 4 0.5 kg TNT charges put on some
wooden frame to give proper spacing should also do the job.
Ok I am talking modern plastick explosives, so it might be more effective
than WW2 plastic explosives, but the TNT should be the same.
--
Carl Alex Friis Nielsen
Love me - Take me as I think I am
Millsbomb
In article <74mtri$4...@dgs.dgsys.com>, an...@FreeNet.Carleton.CA (Jim Garner)
writes:
>Are or were? Way I hear it, explosives nowadays are vastly more powerful
>than in WW2 days. Is this correct? What was the ratio of power/mass in
>WW2 compared to today? anybody know?
Hello,
In WW2 we used one pound Gun Cotton slabs, it had a tapered round
hole in the middle, into which a G/C Primer fitted, we also used TNT blocks
for demolition as well.
The slabs were 'wet' GC and the primers were 'dry' with a detonater hole in the
middle and came in black metal tubes holding about 10. The 'wet' slabs were
not sensitive and could be broken by hand, the 'dry' primers were 'very'
sensitve and great care had to be taken.
Gun Cotton was made by soaking raw cotton in Nitric Acid and the bye product of
the explosion was Nitric Acid and water, so not suitable for guns, for which it
was intended, to replace gunpowder. Raw Cotton was a essential military
commodity during both World Wars.
I used to make home-made Claymore's on the Mozambique Border in Rhodiesa during
1977/80, using Plastic in old 'disk harrows' full of 'nuts,bolts and stones'
to hang in trees, everyone gets a bit <G>
Bob.
If your officer's dead and the sergeants look white,
Remember it's ruin to run from a fight:
So take open order, lie down, and sit tight,
And wait for supports like a soldier.