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zaibatsu
March 6th, 2003, 03:54 PM
shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted December 17, 2000 07:09 PM
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I want to make shaped charges for punching holes threw thick steel and concrete.I only have access to annm.Has anyone made shaped charges with annm?Im looking for a homemade meathods coz I have very few tools and fewer skills.So in short I want all ideas on cheap and dirty shaped charges that have been tested and work.Thank you.

PYRO500
Moderator
Posts: 1466
From: somewhere in florida
Registered: SEP 2000
posted December 17, 2000 09:59 PM
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you dont have what's nessisary to make shaped cherges

SATANIC
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Posts: 232
From: australia
Registered: SEP 2000
posted December 17, 2000 10:08 PM
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uh huh. annm is not strong enough, nor has a fast enough det. velocity. and as you say yourself, you don't have the necessary tools.

sealsix6
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Posts: 154
From: NYC,NYC,USA
Registered: NOV 2000
posted December 17, 2000 10:09 PM
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What exactly is a shaped charge and how can one be made?

MacCleod
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Posts: 215
From:
Registered: DEC 2000
posted December 17, 2000 10:39 PM
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Am I the only one here who's seen Ragnar Bensen's "homemade C-4" video?.Dam'n,I must be getting old.He builds a shaped charge from the bottom half of a wine bottle,fills it with AN/NM,and detonates it,cutting a hole through a girder over an inch thick!.He also shows in detail how to clean/dry the AN,and the ratio of NM to AN that he uses.Used to be able to order it from Delta until they pussied out and quit selling things of that nature.If you can find a copy,it's worth picking up.Anyway,to answer sealsix6's question,a shaped charge is an explosive mass which is so shaped that when detonation occurs the explosive energy is concentrated in one direction,giving the charge greater penetrating effect than ordinary charges of the same volume.The bottom of the charge is cone-shaped(can use steel or aluminum funnels and a tin can for imp. container).When the charge is shot,the pressure developed collapses the cone from top to bottom,creating an extremely powerful jet of gasses(10,000 to 30,000 feet per second,depending on explosive used)to exit the bottom of the charge."Improvised Shaped Charges"(Gov.manual)lists exp.velocities from 20 to 28,000 f.p.s. as effective for these charges;AN/NM falls within this range at roughly 20,100 f.p.s.

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[This message has been edited by MacCleod (edited December 17, 2000).]

CragHack
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Posts: 606
From:
Registered: DEC 2000
posted December 17, 2000 11:16 PM
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a shape charge is actually a fairly simple device, and if made corectly has TONS of power. the purpose of one, is to create a molten jet of a dense substance to cut through hard metals and shit. an explosive is molded around a material in such a way that, that material is compressed into a jet and "shot" into the thing needed to be cut. they are really cool. i have seen shaped charges (on tv) that generate 1 million psi on a specific point, they cut through hardened steel like a hot knife through butter.

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Cricket
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Posts: 160
From: USA
Registered: OCT 2000
posted December 17, 2000 11:36 PM
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A shaped charge is an explosive charge that is shaped to be the most effective (generaly most damage or penetration). Think of a car roof. You could blow a hole in it by puting a big ball of C4 on it and detonating it. Or you could get a bag of quick mix (fast drying) concrete and puting it in a 5 gallon bucket. Then add water and put a cup in it. After its dry, cut off the unused bucket and fill the cup with C4 (or what you can get). Put it on the top of the car and detonate. In the first example the gas from the C4 would much rather hit the car and move away into the air. In the second, with all the concrete on top of it, it dont have much of a choice of where it can go so it pushes out the metal. It will always have some effect on the shit used to shape the charge, but alot more energy goes to the metal than without the concrete. Shaped charges are used to use a minimal ammount of explosive to do the maximum annount of damage. These are usefull if you dont have much explosive, but must do some damage. The reason the army uses these is because in the long run, it can save alot of money. Also if you have an anti-tank missile, if you dont use a shaped charge, you will have to have much explosive to do not so much damage and also a bigger missile to hold all the explosive(less room and more weight).

MacCleod
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Posts: 215
From:
Registered: DEC 2000
posted December 17, 2000 11:53 PM
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Here's a basic design for an improv. shaped charge:find 3 steel or aluminum funnels of the same size and a tin can or pipe that these just fit into the open end of.Cut the narrower part of the funnels off,stack them one on top of another.Tape them into the end of the can/pipe pointing upward (height of exp.should be twice the height of the cone;i.e.-4 in. cone=8 in.container).Next attach 3 dowel rods to the sides of the container to provide a standoff distance from the target surface of .75 to 1.5 times the base diameter of the charge;a container measuring 4 in. across the bottom would require a standoff of 3 to 6 inches.Fill the container with H.E.and prime in the top dead center.This should do the trick!.

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CragHack
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Posts: 606
From:
Registered: DEC 2000
posted December 18, 2000 03:53 PM
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a couple things here, cricket, your description of a shaped charge using the example you used is, well, sorta wrong. a shaped charge makes a molten jet of liqued that punches a hole (or cuts) something. it is not the directed blast of the explosive itself. also, when making a shaped charge you want to use a dense metal. copper is perfect for use in shaped charges. dense, yet soft. aluminum is to "un"dense, and steel is way to hard. i have actually watched a show on television where they used copper based shaped charges. they did tons of damage. the charge i talked about above, the 1 million psi one, i think was made with copper as the metal. if you want to make on at home to fart around with, copper is the choice to use.

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CragHack
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Posts: 606
From:
Registered: DEC 2000
posted December 18, 2000 05:27 PM
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here you go, here is a shaped charge using copper as the metal to be formed into a jet.

if the image does not work, here is a link to it:

<a href="http://www.geocities.com/assqwertyu/images/shapedcharge.jpg" target="_blank">http://www.geocities.com/assqwertyu/images/shapedcharge.jpg</a>

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[This message has been edited by CragHack (edited December 18, 2000).]

sealsix6
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Posts: 154
From: NYC,NYC,USA
Registered: NOV 2000
posted December 18, 2000 05:29 PM
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Thanks guys!!!

shady mutha
Frequent Poster
Posts: 149
From: australia
Registered: SEP 2000
posted December 18, 2000 05:40 PM
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Cheers..Is there anyway to direct the blast?

Anthony
Moderator
Posts: 2304
From: England
Registered: SEP 2000
posted December 18, 2000 06:28 PM
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This is the first link I could remember to some shaped charges, these ones are actually for sale!
<a href="http://www.ribbands.co.uk/prdpages/5-5inch.htm" target="_blank">http://www.ribbands.co.uk/prdpages/5-5inch.htm</a>

They're a tad expensive but do give some stats. Oddly enough, they have no standoff legs, I'm guessing that the cylinder shaped part of the charge acts as a stand off and you just fill the cone shapped bit.

For the record, you don't have to have a liner with shaped charges, the jet of hot super high pressure gas from the explsoive is plenty enought to cut things. I think the ones on this site don't havea liner.

CragHack
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Posts: 606
From:
Registered: DEC 2000
posted December 18, 2000 07:44 PM
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well all the shaped charges i have seen, on demolition shows on tv, have used a metal liner to form the jet.

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Ctrl_C
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Posts: 225
From:
Registered: NOV 2000
posted December 18, 2000 09:14 PM
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all the ones i have seen are more like long pieces of angled coppper (like a wedge) with explosive inside the angle

nbk2000
Moderator
Posts: 1091
From: Guess
Registered: SEP 2000
posted December 19, 2000 10:12 AM
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This photo illustrates what a military shaped charge design looks likes. As you can see it has a copper cone and not much explosive to it, but it will penetrate about 4" of armor. And it's only an inch and a half wide.

This is a bomblet for cluster bombs.

The shaped charge that anthony linked to was designed for use in missiles (so it appears) so there's no need for standoff legs. That's provided by the missles body. And it does have a copper liner, look at the bronze coloration on the inside.

Copper is good, but depleted uranium, tantalum, and tungsten are better because they're harder and denser. But warhead design gets more complicated using these because they need preheating just before detonation to get above transition temperature so they have suitable properties to form the jet or fragment.

And don't forget to add lighter flints to your explosive just behind the liner so the flints can ignite any flammables the charge may release.

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Bubba
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Posts: 71
From:
Registered: DEC 2000
posted December 20, 2000 12:45 PM
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THe technical name is a "Monroe" shaped charge right? named after the scientist who first made it. Used in RPGs etc. Cool design, I imagine the guy (Monroe) was a genius.

MacCleod: I have that video also...I also have it in .AVI format on a cd. I collect vids, and .PDF books of te same kind. Cool stuff. I am never going to make anything that dangerous, I just like the "Hows" of it. Cool stuff!

ENGINEERKILLER
A new voice
Posts: 9
From: ft irwin c.a.
Registered: DEC 2000
posted December 21, 2000 12:03 AM
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the picture is of an m-42 submunition it will punch about 2 inches of steel it,s 2 inches long and about 1 1/4 inches in diameter i've taken the pepsi challenge with my improvised shape charges and i gotta say glass is the way to go the long shape charges are for cutting they are called linear shape charges most shape charges that you buy will have the approriate standoff built in

chokster
A new voice
Posts: 16
From: Australia
Registered: SEP 2000
posted January 04, 2001 10:01 PM
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Ok I have alot of ANNM and I want to make a shape charge, I also have some 3/4" tube to make the cone out of this when i shape it will make the cone 1" to 1 1/2" wide and i will fit this inside a steel pipe and the explosive will be ANNM with a AP detonator also the opposite side of the pipe from the cone would be sealed with a pipe cap. Now can someone tell me how long the pipe has to be how much ANNM i should use and the stand off disstance ( I was going to use an 1" )

MacCleod
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Posts: 215
From:
Registered: DEC 2000
posted January 05, 2001 12:51 AM
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All the info I've seen on imp. shaped charges suggests the explosive depth should be twice the height of the cone;I imagine more wouldn't hurt,though.The standoff should be .75 to 1.5 times the diameter of the base(If your pipe measured 2" across the open end,you could go with 1.5" up to 3" standoff legs).

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Mr Cool
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Posts: 991
From: None of your bloody business!
Registered: DEC 2000
posted January 05, 2001 07:35 AM
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If you want to make a really effective SC, then you'll need something with a higher det. vel., like around 8000 m/s. ANNM will work I expect, but I doubt it'll be as efficient.
I read that the physics involved in SC's are similar to that when you drop a drop of water into a pool (yes, that's right!). The drop lands and causes an indentation (the shape of the shaped charge). Gravity (or the force of the explosion) forces the sides of this indentation to come together. The result: that little drop of water that shoots up an inch or so after the drop has landed, or a column of dense gas at 10000 m/s!

blackadder
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Posts: 313
From: London
Registered: DEC 2000
posted January 05, 2001 12:21 PM
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I've read about terrorists who dig tunnels under buildings, and when under the building they put about 10 sacks of ANNM together, then surround the massive charge with sandbags, and soil after that. This compresses the expanding gases/shit and directs it towards the building, exerting the maximum force on the building and nothing else. I don't think you'll do this, but hey, you never know.