improvised Linear Shaped Charge

[Vegeta]

Hi guys, nice to be back.....Uhm, I mean nice to be here. But it feels like I've been here before.....must have been in my previous life ;). But it's very nice anyway that the forum is back on, I need it somehow.
Now seriously: I want to share my experiences with you: I succeeded in improvising a linear shaped charge which is easily and quickly constructed from commonly available materials (that are cheap also).
I used plastic, glue and epoxystick to make a lightweight plastic container precisely the shape as those professional LSC's. The length was 60 cm and all kinds of metal profiles (with a 90 degree angle) can be taped to it. It takes just an hour or two to construct 4-6 of these.
At the site they can be filled with a liquid NM based explosive (which can be made on site too, that is, you have to mix two components to get an actual explosive). The LSC's I made contained about 160 g NM based explosive per meter (density of the explosive is about 1 g/m).
The effect observed when I used an aluminium liner (90 degree angle, 1.2mm thick and 10mm wide) and put the LSC on a mild steel object of about 3-4mm thick, and iniated it with about 3 gram AP and 20 gram booster (of the same explosive), was a very nice cutting effect.
And by cutting effect I mean that you really can see that the metal jet melted and pushed the steel aside and the edges of the steel are smooth and stretched out.
But when I used a brass liner with the same dimensions the cuts were really rough indicating that no jet was formed and the steel was merely punctured by fragments and the shockwave.
The same kind of rough edges (and not a real cutting effect) you get when you use no liner at all. The mild steel is spliced by the reenforced shockwave alone. And strangely enough the effect of this shockwave is stronger than with a LSC with brass liner.
Another strange effect was seen when I put a LSC with 3 different kinds of aluminium profiles on a railway track, which is (apparently) much harder. This time the liner which cuts smoothly through the mild steel didn't have any effect beside "painting" the track with an aluminium layer. An aluminium liner of 1.2mm thick but 15mm wide did have an effect but very dissappointing anyway. And a liner 2mm thick and 15mm wide had also no effect
(And a LSC with no liner produced the greatest effect!).
Now, I wondered why this happened and maybe here you guys can be of any help. That the effect on more toughened steel would be less, I expected. And the fact that the steel is massive also plays a part.
Maybe someone has some figures about strenghts of different kind of steel? (or figures of cutting/penetration action of LSC's on toughened steel and not mild steel like most of the time is given).
The only explanation for the results I could come up with was, that to produce a metal jet out of the solid metal liner takes a lot of energy. And sometimes it needs too much energy (in regard to the amount of explosive used), so no jet is formed. As occured with the brass liner, which is much heavier/denser and needs more energy to "evaporate". It also explains that the effect with no liner is sometimes bigger.
And when a (too) small liner is used no good jet is formed (which would explain the difference between the first two aluminium liners on the railway track).

Now, your ideas on this subject and LSC's in general is welcome.
And I wonder, could I patent this invention of mine? And how would I go about? I have never heard of plastic containers used for LSC's that can be filled on site with an explosive also made on site. But probably someone else has already patented it some how.

Any how, it's a lot of text, I know, but hopefully that's not too much a problem (although I'm new here ;) ).
And sorry about the other two posts, but that's not my fault; something went wrong with the computer. I tried to delete it but that didn't work.

[ 24 February 2002: Message edited by: Ray Quick ]

[Energy84]

Well, railway tracks are quite thick and would require alot more power to penetrate than a 3-4mm thick piece of mild steel. However, rail tracks are most likely made of hardened steel. When steel is hardened, it is becomes more britle (sp?). I'm not sure how to explain it exactly, but an example I've seen personally is a camshaft from a car engine that was dropped on the floor in a garage. Camshafts are hardened steel, and broke in half when it hit the floor.
So in my opinion, I don't even think you could penetrate a railroad track. You'd break it first. The only way to split it or make a hole in it is by welding or using thermit. Thermit is actually used to weld the tracks together. A charge of thermit is placed between the rails then a pressure is applied to both ends to push them together while the thermit burns and melts them together. Wow, a legit use for thermit... :D

[xoo1246]

Try using a wine-bottle with hollow bottom.
Those are rumored to cut through a couple of inches of steel. Well I havent tried it myself, and think about the standoff distance. Maybe one could manufacture liners from clay. My mother ha an owen to burn clay-pots.

[NoltaiR]

Not necessarily 'rumored'.. just download the video on the FTP called 'improvised C-4'.. part of the video deals with using wineglass bottoms to make shaped charges. And in the test done on the video, he blows a clean cut right through a inch and a half of steel.

[xoo1246]

Ok, I haden't made one myself. Therefore I couldn't say I knew how they would perform.

[ 05 March 2002: Message edited by: xoo1246 ]

[Yi]

Martini glasses also work, just break off the stem.

[Vegeta]

Do you really know what you're talking about and what a linear shaped charge actually is? Don't think so, so what the fuck are you babbling about a wine bottle charge?
And has it anything to do with my question? Don't think so.
If you don't know the answers to my questions, don't start talking bullshit or I'll will shove a hollow cone wine bottle up your tiny ass (or a stemless martini glass for that matter).

The Forum is not a fuckin' chatbox! I'm not here to make friends or for stupid small talk. I want answers to serious and specific questions. So if you don't know the answer to my question don't bother me with stupid remarks (or things I already know) but shut the fuck up! And go find some site for lonely 14 year old gay teens.

Why keeps the Forum attracting these idiots?
Isn't there a way to get (and keep) them out?
Maybe some test before you can register? Because this way it's no fun at all (and of no use at all) for people who are seriously interested in explosives. I thought that was what the Forum is about. Or am I mistaken?

[ 06 March 2002: Message edited by: Ray Quick ]

[Yi]

Xoo's comment about the improvised shaped charge was a response to a possible way of breaching through a railway track. Fair enough this is not exactly on topic, but it was a response to Energy's comment about the difficulty of cutting through railway track.
My comment was merely to offer an alternative liner to his. Again not strictly on topic, but still referring to the railway track you brought up.

None of the people (except you) in this thread claimed to know anything about Linear shaped charges. Neither were we chatting. Don't expect answers to everything, people may take a while to respond (if at all). Also not everyone will know and the Forum is not here as your personal info service. Improvised shaped charge methods may not be known to some.

I have a serious interested in the use of explosives and have been looking into an relatively simple LSC or a (FLSC if I think of a way) to experiment with.

Btw what was the NM based explosive you used? also How far did the cutting charges penetrate through the plate (in to the ground if they were against it).

I'm not going to keep anti-flaming/flaming so I'll stop now....

[Energy84]

First off, I don't like flame wars. And second, it's even worse when it's because of a silly misunderstanding.
The "wine bottle" charge that xoo was referring too was demonstrated in Ragnar Benson's Homemade C-4 movie. It should be on the FTP. Although it's not real C4 (it's really just ANNM), Benson uses the bottom half of a wine bottle as a liner for his shaped charge that he puts his "C4" into.
A wine bottle works because the bottom of it has a convexed (sp?) shape to it, making it ideal as a liner.
The idea of using a martini glass is basically the same thing. Just flip the glass upside down and use it's "cup" as a liner.

While we're on the subject of shaped charges, has anybody ever tried using an upsidedown champagne glass as a liner? I'm not sure it would work as well, but the colliding shockwaves could mabye increase the force of the jet? Or not, I don't know. I'm talking gibberish tonite. :(

[a_bab]

You wrote that your NM based explosive density is around 1 gram/cmc. This is a very low density, closer to AN. Even if NM looks to be powerful (and of course it is), I don't think that is suited for linear shaped charges. And linear shaped charges are used as far as I know for cutting thin steel plates, not railways. And are made with PETN or RDX based explosives. For cutting such a road you will need lots of explosive with a high density (you know, 1 pound of TNT for every inch of steel...)

[Mr Cool]

Ray Quick:
"I'm not here to make friends"
Don't worry, you won't if you carry on like that. And if you flame people, no-one will want to answer your questions.
OTT, pointless flames are not tolerated. If you want to flame people go to Queerpier.
If you want a source of information that won't talk back, go to your local library.
Just because you started this thread doesn't mean you own it. Threads get side-tracked, and as long as it doesn't go totally OT then that's OK.
"don't bother me with stupid remarks (or things I already know)"
It wasn't really a stupid remark. And like I said, you don't own this thread, therefore its contents are not solely for your benefit. OK, so you knew about wine bottle SC's - other's might not have done.


Admittedly the post about wine bottle shaped charges wasn't totally relevant to LSC's, but it didn't justify that little outburst of yours. I suggest you chill out.

[PYRO500]

Calm Down, before I take further action.
I believe that to attack hardend steel you are going to need something more brissant like Energy84 said, I don't think you will have much luck penetrating railroad rails with improvised linear shaped charges, but I recall something a while back describing how to destroy railroad racks, and it was simply C-4 pressed against the inside of the rails and tied on. Have you tried copper as a liner? and is there any backing to your charges?

[nbk2000]

Go to the FTP, download the '99 forum archives, and in it is a 100+ page document by (either Lawrence Livermore or Sandia)laboratories on the design criteria of LSCs. Can't get any more detailed or authoritative than that.

And you sure are copping an arrogant attitude for someone who's just shown up here. Rather reminiscent of "Stanfield" from the Forum. Same type of question, same snide attitude, same geophysical location.

[A-BOMB]

Forget shaped charges they give me a headache even though I got pretty good at them, just add 5 more pounds than you need works for me and the best cone I found was one of those kiddie road cone thing that they use to like run figure 8's through and that like. Then just pore in my MG,AL,AN,smokeless,potassium chlorate explosive pore in some acetone let dry and you got a hard block of explosive that detonats like craxy when you can get it to detonate at all 20 g of AP should do.

[CyclonitePyro]

Hey Ray, were you registered as Neil McCartey/McCartney something like that, at the old forum?

[Chris Shiherlis]

Ray is a good friend of mine. He get's irritated quite easily (and you don't want that:)).
He's on this project designing some LSC's. Not to cut railroad tracks of course. He just did that to test the effect of the LSC on hard steel. And since the effect was very dissappointing and different from the effect on mild steel he is looking for an explanation.
It surely has to do with the strenght of the steel and the fact that it's massive.
So all he asked for was some information about the strenght/kind of steel of railroad tracks. Or in what way it differs from structural steel. Because in the demolition industry they cut steal beams maybe just as thick as those tracks with LSC's and they are cut just like butter (would the same LSC cut as deep in that railroad steel? that's the question).
So if anyone knows this or where to find it please tell us (we're sort of into this together). Thanks.

[Mr Cool]

Well I don't know much about steel, but I thought of a way to improvise a LSC which you might be interested in.

Get a strip of Cu/brass/Al sheet a few mm thick, and bend it in half along it's length to whatever angle you want (bending will be easy with a few clamps and some steel bars, or even strong wood...). This will be the liner that forms the jet. For the explosive, use whatever crystaline HE you can get - not AN (etc.) though! - and make a paste out of it and NC/acetone. Mould this onto the outside of the liner, and let it dry. It may help to use a few layers, otherwise the centre will take a long time to dry and it's more likely to crack. Then get some fibreglass cloth and polyester resin, and coat the outside of the HE with it, and let the resin cure. This will make the LSC's HE immune to knocks and scrapes, otherwise the HE could flake off. Leave an inch of HE at the end without fibreglass/resin on, and tape your det to this area.

Might work.

[Ctrl_C]

if you are trying to destroy railroad tracks to derail a train...heres a solution. get a 2 ton bottle jack and a 3ft section of 4x4 lumber. place the jack against one rail and the 4x4 between the jack and the other rail. jack apart. easy.

[Chris Shiherlis]

What did I just say? I said: OF COURSE it is not used to blow up railway tracks! Don't you think Ray or I know how to blow up a railway track?! And wouldn't it be stupid to use a LSC for it?!
Ray developed a easy and cheap to improvise, lightweight, filled on site, effective LSC and you start talking about winebottles, blowing up tracks and gods knows what.
Don't you think he knows all that? Let me tell you it takes some knowledge to construct such a LSC.
And of course it is piss easy to construct a LSC with plastic explosives like Semtex (or crystaline HE made plastic e.g. with the Mr Cool paste metod (nice one)). Just put it on top of some metal angled profile.
But try that with a NM based (liquid) explosive (which is by the way very suited for the job because of the constant density and high VoD (not to mention the availability). The only disadvantage is that the density is (relatively) low as compaired to the RDX that is normally used and subsequently the power is somewhat less. So you use just a little bit more).

So please all I have to know is the difference between the steel of railway tracks and normal structural steel used in buildings. Or the difference in effect of a LSC on those kinds of steel.
Give me an answer to that and I'll be very pleased. That's the ONLY thing I need to know. You can consider other information as known.
Thank you.

<small>[ March 16, 2002, 06:29 AM: Message edited by: Chris Shiherlis ]</small>

[nbk2000]

I believe that RR track is annealed, making it very tough and ductile. Thus it resists crack formation that propagates the cut from an LSC.

[ENGINEERKILLER]

I don't have any experience with railroad track but I have cut forged tank barrels, homogenous(sp)tank skin and a couple of other materials.
If your using steel and steel alloys for your cone ,it's not gonna be very effective because the air is gonna be doing most of the work.Copper and glass are the ideal materials used for shape charges standoff in my experience seems to be the best at between 1/3,3/4, the the the opening of the cone .
The best improvised LSC that I have made was from 1 1/2" diameter copper pipe split in half inside of a 3"diameter piece of pvc split in half,packed with c-4 and primed with detcord.I just used cardboard running along the side to generate my standoff.
I have been able to find the slugs formed by copper and and glass and there almost perfect teardrops in shape .With steel I have never been able to find the slugs so I am not certain what happens to them during the jet formation.

Hopefully I said something worth while .I gotta go to ST Louis(SP) to do something nobody would beleive I will be back tuesday night

[Chris Shiherlis]

OK, thanks. So the difference in effect I observed can be explained by the fact those RR tracks are much harder. So I will just have to test it again on thicker mild steel and with different liners to see what the maximum penetration depth of my improvised LSC actually is (because 3-4 mm in mild steel is not the maximum penetration depth. And considering the low density/power of the NM explosive the results will probably be better if I use some more. And I'll have to find out which liner gives the best result. Probably that one that cut just a little bit into the RR track will cut even deeper the original one used on mild steel). But for starters a 3-4 mm cut with just 160 g/m of this explosive, is nice I think.
But it will improve.

[Mr Cool]

Can you make TNP? A 50% solution of it in NM would probably give better results, if you think it's worth the cost and time to make the TNP.

[nbk2000]

There's a US patent (don't know the #) for a NM/TNP liquid explosive. It had some good performance numbers too. Try using "nitromethane" and "picric" in a search at <a href="http://164.195.100.11/netahtml/search-bool.html" target="_blank">http://164.195.100.11/netahtml/search-bool.html</a>

[Chris Shiherlis]

I could make it if I could find all the chemicals, glassware and time. But the thing about NM is the availability. I don't want it to be too much of a hassle, just buy the race fuel and use it as explosive. No chemistry, no hassle.
And if I decided to synthesise some explosive I would go for RDX of course. But thanks for the information anyway.