Sciencemadness Discussion Board

Unconventional Shaped Charges

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enhzflep - 13-5-2007 at 23:08

Yes indeed Sir, I have used these very things in the past. US$50 is a VERY good price. We used to pay around Aus$80 for just a brass doming block - never mind the punches, or the fact this one is carbon steel. For the equivalent in Aus we're looking at 300 bucks...

As for AXTs idea, I don't see why it wouldn't work. Jewellers use a very similar arrangement for reducing the size of plain wedding bands. Obviously, rings are quite narrow or short compared to a piece of tube to be used for making cones, but the rings did indeed come out conical.

I'd be inclined to think you'd need a number of different dies, that changed angle. So you would have a slight reduction at the start of the series and a rather pointed mandrel (as the image above) at the end of the series. My guess is that you'd get away with perhaps 5 or six punch/die pairs.

Definitely worth investigating..

tito-o-mac - 16-7-2007 at 06:16

Hey check this out. It's rather similar to a shaped charge but it's an Explosively Formed Penetrator! An explosively formed penetrator (EFP), also known as an explosively formed projectile, a self-forging warhead, or a self-forging fragment, is a special type of shaped charge designed to penetrate armour effectively at stand-off distances.

Here's the description: A conventional shaped charge generally has a conical metal liner that projects a hypervelocity jet of metal able to penetrate to great depths into steel armour; however, in travel over some distance the jet breaks up along its length into particles that drift out of alignment, greatly diminishing its effectiveness at a distance.

Whereas for the EFP, on the other hand, has a liner in the shape of a shallow dish.The force of the blast molds the copper plate into any of a number of configurations, depending on how the plate is formed and how the explosive is detonated. Sophisticated EFP warheads have multiple detonators that can be fired in different arrangements causing different types of waveform in the explosive, resulting in either a long-rod penetrator, an aerodynamic slug projectile or multiple high-velocity fragments. A less sophisticated approach for changing the formation of an EFP is the use of wire-mesh in front of the liner: with the mesh in place the liner will fragment into multiple penetrators.

As a rule of thumb, an EFP will perforate a thickness of armour equal to only about the diameter of its charge, whereas a typical shaped charge will go through six or more diameters.

[Edited on 16-7-2007 by tito-o-mac]

Improvised_explosive_device_explosively_formed_penetrator_Iraq.jpg - 65kB

tito-o-mac - 16-7-2007 at 06:18

Formation of Explosively Formed Penetrator. here's a short clip: http://www.youtube.com/watch?v=JfCCXglrJuo


[Edited on 16-7-2007 by tito-o-mac]

Explosively_formed_penetrator.gif - 13kB

MRUD - 17-7-2007 at 11:44

Hi there.
I'm allways on this kind of penetrator, i have done also some tries with them.

The very first try wasn't a success, to thin not to blown apart




Target was a 5mm thick steel plate.

The second attempt wasn't a success too.




At this time, i think, the liner was to thick.

So my next project is with this liner.
2mm thick
50mm diameter
made from copper



hope getting better results with this one.

So long, hope you understand what i wanna tell you
Greetings from Germany.

MRUD

tito-o-mac - 19-7-2007 at 02:48

Can you explain more about picture 3 from top?

Do you have any measurment of the penetration? Anyway, just wanted to ask you something: when the explosives were detonated, did the container produce any shrapnel or stay intact? One more thing: the range from which you fire from will affect the shape of the charge, also the penetration. Too close and immature formation of the charge will reduce the penetration!

Here's a suggestion: A less sophisticated approach for changing the formation of an EFP is the use of wire-mesh in front of the liner: with the mesh in place the liner will fragment into multiple penetrators. Also use aluminium for greater penertration against concrete targets.

BTW remeber to show us your pics:D ( and if maybe a video)
Anyway all the best :)

tito-o-mac - 19-7-2007 at 02:50

The charges are generally cylindrical, fabricated from commonly available metal pipe, with the forward end closed by a concave copper or steel disk-shaped liner to create a shaped charge. Explosive is loaded behind the metal liner to fill the pipe. Upon detonation, the explosive projects the liner to form a projectile at a velocity well over 1 km/s, depending on the design and type of explosive used. This slug is projected towards the target at about two kilometres per second. The chief advantage of the EFP over a conventional (e.g., conical) shaped charge is its effectiveness at very great standoffs, equal to hundreds of times the charge's diameter (perhaps a hundred meters for a practical device).

It can travel up to perhaps 1000 charge diameters (CDs) before its velocity becomes ineffective at penetrating armour due to aerodynamic drag, or successfully hitting the target becomes a problem. The impact of a ball or slug EFP normally causes a large-diameter but relatively shallow hole, of, at most, a couple of CDs.

Try to beat the record of 100mm penetration MRUD!!:o

[Edited on 19-7-2007 by tito-o-mac]

[Edited on 19-7-2007 by tito-o-mac]

MRUD - 19-7-2007 at 08:54

Hi tito-o-mac.

At first, picture 3 schows the result of the first EFP i have build.
The liner in my first was made from zinc 0.8mm thick and i knew that this liner would never build any kind of projectile. Was only for testing, what would happen, with the liner. Means, is the impakt at the target far strewn or focused at the aimed point of impakt. So i can improve the following liners.
Charge was about 45g PETN.
Diameter of liner ~ 5cm
Distance around 10cm
As you can see, the liner wasn't intact at time of impact.

And second, i don't think i'm able to penetrate more than 2cm coused by the quantity of PETN i normaly use.
But 100mm is a fucking nice thick steel plate, who had done these? or is this a millitary build EFP?

Greetings

MRUD

tito-o-mac - 19-7-2007 at 21:56

Sorry, I was referring to a military build EFP. Remember the very first post the gut used ANNMSA ( I don't know whats that) but I think a Ammonium Nitrate NitroMethane Alumnium (ANNMAL) should also work, cos' its more readily available to obtain and if you do not want to use your PETN:)

Errr... I'm not too sure about the distance of 10cm. It seems a bit short to me though! One more thing: is the 2 cm liner thick enough to not disintegrate with the force of the explosion? Maybe a thicker liner would work.

Very good job anyway!:P;)
Greetings and all the best for the next project!

[Edited on 20-7-2007 by tito-o-mac]

weapon_graphicfull_4.jpg - 43kB

MRUD - 22-7-2007 at 12:48

All my charges based on try and error, the only reference i have are some patents and some suggestions from the internet.

So i hope the third liner will do a better job as the 2 before.
The first one disintegrated (he was to thin), the second one didn't, but he was to thick to form up an projectile (4mm of thickness, you can see, the hole in the plate is the same diameter as the liner had)
So i decided to try a copper liner between this thickness.
I give him a try. Also i can increase the distant couse this liner is formed more precisely as the 2 before, think, 20cm will worke to hit such a small target.
Hope to get the time to set up the charge of next weekend.
Then we can discuss the result.

Greetings

MRUD

[Bearbeitet am 22-7-2007 von MRUD]

tito-o-mac - 23-7-2007 at 02:58

Did you know there is a way to control the shape of the EFP? All u need to do is stick a tube with the desired shape you want at the centre of the copper plate, and it will mould in to the shape.

So far, got any more pics to show us on your progress?

[Edited on 23-7-2007 by tito-o-mac]

Attachment: Segmented kinetic energy explosively formed penetrator assembly - US Patent 6510797.mht (80kB)
This file has been downloaded 1533 times


MRUD - 28-7-2007 at 09:24

Here we go, EFP mark III.

I think, it's an nice result i got. Not the best, but better than expected

Target was a 5mm thick steel plate, distance to target around 40cm.
Got a nice hole in the plate, and the force was strong enougt to deform the 2cm plate behind.




At the target site


result





Greetings

MRUD

E-tech - 30-7-2007 at 09:58

Very well done, MRUD!
A few questions- how are you forming the copper? What is the final weight of the copper (before detonation, of course), and, what angle is the copper cone (again, before detonation)?

MRUD - 30-7-2007 at 12:53

The copper plate was formed with a "matritze" (don't know the english word) a picture will show you, what i mean. He was pressed between this to.


Liner weight was 37g, angle around 30°
And i (wasted) used 56g of PETN at this EFP.

UnintentionalChaos - 30-7-2007 at 13:10

The word you are looking for is a "die" Very nicely done.

Marsh - 8-8-2007 at 18:25

Have you thought about using a small shaped cavity between the copper plate and the energetic so that Monroe forces act on the plate, to somewhat shape it into a longer projectile? Then again, jet formation may penetrate the plate too easily.

Or, what about using a waveshaper in your energetic to form the plate to a more desireable shape?

Don't really know much about EFPs, just throwing some ideas out there.

kiknet - 31-8-2007 at 07:05

MRUD have you thought about in your next test ( if you do one ) attempting a long standoff for the EFP ( say a couple of meters? ).

Also I think it was here that someone asked why in rockets and certain military weapons that the shaped charge liner had a trumpet shape, I lost the reference but it was a military brochure for a rocket weapon system that said the trumpet shape creates a better BHE ( Behind Armour Effect ), basically I think that means it does more damage on the inside of the tank once it penetrates the amour.

franklyn - 18-11-2007 at 02:41

[Edited on 21-11-2007 by franklyn]

Optimimal Shaped Charge Characteristics.gif - 51kB

Bert - 19-11-2007 at 22:11

Downloaded ICEOWS, but I can't open the .ice file. Any suggestions?

HMTD - 21-11-2007 at 03:32

Franklyn, is it kind of joke? If so, it's not funny. I spent several hours to find a program to unpack your *.ice archive. Maybe you'll share the program you used to pack the files?

enhzflep - 21-11-2007 at 03:57

Ha, ha - nice one HMTD.
Spent several hours looking for an ACE unpacker??!

If you're serious, and you can't find an opener, try IZArc. Perhaps that will open these files - it definitely supports ACE files,
I'm just not sure if it will touch these files, in light of Bert's troubles.

Anyhoo, it's free and small.

HMTD - 21-11-2007 at 06:51

enhzflep , thanks but no thanks.

Do you see the difference between *.ACE and *.ICE files? Tell me - have you downloaded the file and unpacked it with IZArc(btw,good free program)? If so, then please tell me how,mine IZArc ignores the file even renamed to *.ACE. I'm just curious, where Franklyn got such unusual and rare(maybe very-very old) file format? There are so many free and good formats.

franklyn - 21-11-2007 at 12:51

Very Sorry about that , I assumed that most full feature
compression utilities such as Winrar and freeware
such as 7z are compatible , guess not.

Quote:
Originally posted by franklyn
Oops I had not noticed that these are available for download here
from the First CD of the Los Alamos Technical Reports Collection.

http://www.sciencemadness.org/lanl1_a/mainindex.html
Near the top of the list

LOS ALAMOS SERIES ON DYNAMIC MATERIAL PROPERTIES
PHERMEX Data Vols I , II , III
PHERMEX ( Pulsed High Energy Radiographic Machine Emitting X-rays )

LASL Phermex Data, Volume 1
http://www.sciencemadness.org/lanl1_a/lib-www/books/ph1.pdf
LASL Phermex Data, Volume 2
http://www.sciencemadness.org/lanl1_a/lib-www/books/ph2.pdf
LASL Phermex Data, Volume 3
http://www.sciencemadness.org/lanl1_a/lib-www/books/ph3.pdf

enhzflep - 21-11-2007 at 17:29

Well,

HMTD
(goes to get reading glasses and 1/2 eaten plate of humble pie)
Sorry about that HMTD. I'm _really_ having a dumb day today. Dunno how I misread that. sorry.

Frankyln,
Thanks for the extra info - curious bit of errata about the vunerabilities, Downloading the pdfs now. Thanks mate.

S.

HMTD - 22-11-2007 at 13:37

Enhzflep

It happens.

Frankyln, thanx for interesting pictures. Those people had so much fun 40 years ago. I can only imagine how much U238, Be, Hg,Pb were dispersed in these experiments.

[Edited on 11/23/2007 by HMTD]

zajcek01 - 13-12-2007 at 13:05

Here is my experience with a fully improvised shaped a charge.

A body was made from Actimel:
http://www.actimel.com/intl/img/actimel_varieties_visu4.jpg

It was cut right above and under that orange sticker, so I got a tube.

A 40W-E14 light bulb was cut in half and inserted in tube made from actimel. That was my liner.
A bulb looked like this :
http://www.bulbman.com/images/e14bccl101.jpg


A standoff was made from a toilet paper roll, and body was filled with ~80g cast PETN/RDX/Wax.

A detonator was made from 4g PETN/RDX and 0.5g AgN3

Here are the results:
http://shrani.si/f/1Y/jI/SW3cyoB/bw.jpg
http://shrani.si/f/1n/dL/2EXCr8ko/bw2.jpg
http://shrani.si/f/1h/9J/2Fxr6I1F/bw3.jpg
http://shrani.si/f/3A/z3/bI9kS5Y/bw4.jpg
http://shrani.si/f/o/sj/2dwSsoyy/c.jpg
http://shrani.si/f/3A/4q/42DZ790E/c2.jpg
http://shrani.si/f/3s/cP/1mtn0k7X/c3.jpg
http://shrani.si/f/2r/mi/1exyD26o/c4.jpg

PS. Sorry about the first B&W images.

StevenRS - 4-1-2008 at 15:04

If I were to hypothetically make my first shaped charge out of a .270 hunting brass, using the copper jacket of a .270 bullet as the liner, and use MEKP as a filler, would it work *at all*? I have a feeling MEKP is too slow, maybe adding it to AN in a 9(AN):1 ratio would work? I was also thinking methyl nitrate might be better, but sadly, I have no concentrated nitric acid, and no way of getting any. I also considered AP for about 1/4 of a second, but it scares me; I don't trust it, and I think it has a lower VoD than MEKP.

I am just looking for some penetration, something to tell me it worked, not anything amazing, that comes later, everyone has to start somewhere.
What kind of penetration should I be looking for for this setup, so I know what to expect?

Microtek - 5-1-2008 at 08:37

You can make charges that exhibit the Munroe effect using peroxides (I did it using AP a long time ago). You probably won't get an actual metal jet, but rather a focusing of shockwave and fragments, but if you choose a relatively soft target such as wood, then you'll be able to see the characteristic penetration.

Bert - 5-1-2008 at 20:33

Quote:
Originally posted by StevenRS
sadly, I have no concentrated nitric acid, and no way of getting any.


You are aware that many explosive compounds can be made with concentrated sulfuric acid and nitrate salts rather than sulfuric acid/prepared nitric acid?

[Edited on by Bert]

StevenRS - 5-1-2008 at 21:38

I was aware nitric acid could be made that way, but I thought it was not suitable for explosives production without distillation. I really hope I am wrong, can a mixture of nitrates and SA be used straight?

Bert - 5-1-2008 at 21:47

Yes. Search on roguesci.org forum.

Results of a 38mm SC

hinz - 31-1-2008 at 09:38

Here is the result of a 38mm shaped charge,it nearly penetrated 72 mm of mild steel(6x12mm mild steel plates welded together).
The HE in the main charge was about 95g 2:1 MHN/NM gel, density about 1,5 g/cm3. Primary was 0,5g Ag2C2*AgNO3/MHN mixture and 2g MHN.
On the bottom you can see the buckle made by the copper jet. On the first picture you can see the aluminium mandrel on which the copper liner was spun. The copper liner had an thickness of about 0,8-1mm(my copper spun liners don’t have an even thickness) and was parabolic formed. I think the copper colored dent was caused by irregularities in the thickness of the liner and thus irregularities in the copper jet.

[Edited on 31-1-2008 by hinz]

[Edited on 1-2-2008 by hinz]

upside wth mandrel.jpg - 34kB

hinz - 31-1-2008 at 09:47

Pic 2

Bottom.jpg - 32kB

nitro-genes - 1-2-2008 at 05:41

Nice one, 72 mm of steel is a long way! Could you please try to make a better picture of the formed jet channel? Just hold a strong light source next to the camera to make it better visible... :)

What was the appearance of the explosive btw? Did al of the MHN dissolve in the NM or was part of the MHN present as a suspension? From what I remember with PETN, only a small part actually dissolves in the NM, although MHN en PETN are not the same of course. But if so, you could improve the results by incorporating 4% of a binder like NC derived from ping pong balls to get a more homogenous explosive composition and achieve better jet formation...

Looks like your carrot was blown off-center resulting in the copper-coloured dent. This can be the result of many things and I noticed it on several occasions as well.

Were the variations in the liner thickness only present as a gradient going from 1 mm at the top of the cone to 0.8 at the base, or did you measure a difference in liner thickness along the base of the cone? The first doesn't harm jet formation and liners having a gradient in thickness from top to base are used in some SC designs. Don't forget to anneal your liner one final time when your finished spinning to remove stress in the metal that can also affect jet formation.

From what I calculated you used about 1 CD head height, (space between aphex of the cone and the detonator) but how long was the detonator and how was it placed? Sticking the detonator in the explosives composition and to make sure it is completely alligned with the longitudanal axis of the liner is nearly impossible. Therefore I normally only let the base of the detonator touch the explosive composition and don't stick it all the way in.

Nice work, keep it up! :)

[Edited on by nitro-genes]

hinz - 1-2-2008 at 16:49

Here are the close up pictures of the hole, quite difficult to get enough light in it. ;)

You're right, only a small amount of MHN dissolves in the NM actually. I kneaded a bit of the HMN/NM mixture to a piece of coffe filter, so the NM could soak into, and removed it afterwards. As the NM dried, there was only a little bit of MHN left o the paper, visible as a white spot.
I added the NM to the MHN to make it less sentitive, use some of the spare oxygen of MHN and to get the best density out of the HE without pressing it.

The liner thickness variated because the liner was sometimes stopped on the mandrel by the piece of brass and aluminium I uesd to push it onto, so some particles on the mandrel cut into the mandrel as well as into the fresh annealed and soft liner :( (difference in liner thickness along the base of the cone). This caused the round scratches on the mandrel as you can see in the first pictures. Needless to say that these were also cut into the liner, but fotunately not as deep as in the mandrel.

Yes i used about 1 CD head height, but I didn't measure exactly, I made it mostly "by eye" and after I soldered the liner onto the steel pipe, I poured water into the SC on a scale to get its volume and thus the amount of HE I had to prepare. Standoff was about 2,5 CD BTW.
Detonator was made from a 5ml syringe,plased inthe middle of the SC and sticked trough a plexi-glass plate, it had a diameter of about 13mm, it's too small on the picture, but the liner shape should fit quite well.

The carrot was oddly formed, first it made a big 18mm diameter hole, about 20mm deep in the steel and then continued further 40mm with a small diameter of about 8-4 mm from top to bottom, in the end, the copper colored dent was formed, as the dent lacks from impact craters from small particles.

[Edited on 2-2-2008 by hinz]

SC hole.jpg - 45kB

DNA - 6-3-2008 at 00:06

Hinz, how did you make your liner?

Bert - 6-3-2008 at 20:40

Quote:
Originally posted by DNA
Hinz, how did you make your liner?


He said spun Copper on an Aluminum mandrel...

Boomer - 10-3-2008 at 07:35

Looks we could all do better if we made better symmetry liners: Your 70mm and my 50mm for 38 and 25mm charges respectively equal only 2 CD, while 5-6 are 'normal' for military charges (which still have to be cost effective, i.e. no tantalum liners with HNIW charge). Special ones go even deeper, what's the record, 10 CD (Axt?)?

One of the reasons I moved on to LSCs. Plus, there's more possible targets for those.
I mean, who needs a 5mm hole in a safe, cash machine, or jeweler's window.... cool:

[Edited on by Boomer]

nitro-genes - 10-3-2008 at 08:47

Up to 9 CD is possible for a simple 60 deg copper cone, having a uniform thickness of 2% CD in combination with octol (350+kbar). Even with cyclotol (300+ kbar) 8 CD is possible, graph is listed in PATR under "Octol". Constraints are most definitely determined by the precision of charge and liner and the allignment for an amateur charge, and greatly determines the maximum streching ability of the jet. Military liner standards call for deviations no greater than serveral micrometers, which is out of reach for spun formed liners as well (without after-machining IMO). My last charge reached 4.2 CD penetration @ 3-4 CD standoff, but liner was spun from 1mm thick copper giving 0.8 mm wallthickness on average. (2.5 % of CD). I've made another liner with a wall thickness of ~0.6mm (1.9% CD) and could possible reach slightly deeper penetration, though 5 CD will be the absolute limit IMO...

Highest numbers I'm aware of were 10-11 CD for molybdenum trumpets and 12 CD using a hemisperical DU liner IIRC...

[Edited on by nitro-genes]

Penetration vs standoff for cyclotol and octol with copper liner.bmp - 40kB

KemiRockarFett - 28-3-2008 at 11:24

To increase the energy in the EFP it could be worth to put a mass around the explosive. WATER for instance. A couple of kg water around may be an easy way to increase the efficiency of the device.

LSD25 - 23-5-2008 at 11:42

Design, analyses & field testing information of a 0.7m shaped charge (apparently the worlds largest - some 440Kg), thought it might be of interest

Attachment: Design.analyses.fieldtestof.70cmshapedcharge.pdf (750kB)
This file has been downloaded 1559 times


NM/TNP- SCs

grndpndr - 24-5-2008 at 07:56

Becoming aware of the NM Picric acid patent almost makes me wish i hadnt dropped my scale model racing hobbys and disposed of 1/2 gall pure Nm few years back.

grndpndr - 29-5-2008 at 11:58

Not a unique SC the platter charge or miznay/chardin effect
has me omewhat confused s to the mechanism of te 2 materils commonly used in the platter charge.steel , quite possible a very hard yet ductile steel ad a copper alloy of some sort.The 2 charges utilize different materials in thier shaped concave platters the steel relyin exclusvely on kinetic energy as Ive personally witnessed which can be very effective given the size/wieght of the devices ad the effect of the sc charge inreduing d haping the steel platter to a similar shape/velocity as an armor piercing AT Gun round achievng some 6600 FPS from te shaped warhead.And why does the supposedly iranian designed /manufactured copper platter behave in an almost completely different manner stil relying on kinetic energy but in combination with what appears to be SC heat effect as well?In fcvI believe its the only weapon the Abrams tank crews are really concerned about capable f penetrting the near impenetrable front glacis plate and turett of the Newest Abrams w/the most modern cmpsite armor which easily shrugs off the newest gnerations of RPGs with the capabilitys of penetrating 12-18 in of homogenous steel armor! Not to mention the platter chargess far superior stndoff to normal SC heat weapons?We also began discussg i believe the propogation effect of to small det. tubing?Rather than the 5/16 OD f my presernt tubng or would a
slightly larger tube of say 3/8 od for a composite det of 2 gr.or more HE ?

LSD25 - 29-5-2008 at 17:20

The answer to why the 'supposed' Iranian designed ATGM's are so effective is spelled 'KORNET' (AT-14/9M133; http://en.wikipedia.org/wiki/AT-14). I strongly suspect that attempting to duplicate the amazing abilities of the 'new Iranian' weapons, will be frustrated by the fact that these weapons are not the ones that are defeating US/Israeli armour packages (you are dealing with the intersection of Iranian propaganda and science here). Unless you access the seriously highly classified Russian database entries for shaped charge weapons, you are unlikely to get useful information on this baby, you certainly won't get it from the Iranian websites.

grndpndr - 4-6-2008 at 11:13

Quote:
Originally posted by Axt
I can see where your incoherent jet theory is arising from, but most theorys seem to go to shit once you get the the extremes such as a cylinder, I wont speculate as to whats happening. Myuo posted some nice references regarding acceleration of jets through a cylinder, seemingly the effective VOD can be increased by using a hollow cylindrical cavity in its length since the accelerated jet initiates the explosive as it passes through it.

I will probably try greater standoff to define the jet effect. For all I know it may well be accelerated shock waves acting as a hole punch!, which should diminish quickly as standoff is increased.


[Edited on 28-6-2004 by Axt]


From what I understand of construction of a cylindrical shaped charge there should be 0 standoff so your shock wave/hole punch theory may be correct. My only real first hand knowledge is of military origin and the primary purpose of the imp. cylinder SC was to form a large hole of relatively short depth for use against pipelines, engine blocks,bulk petro. tanks etc

[Edited on 4-6-2008 by grndpndr]

grndpndr - 4-6-2008 at 11:21

I wasn talking about the Iranian ATGMs but the copper platters they are 'allegedly' supplying the insurgents that are then made into platter charges and your very correct any research of the matter of copper versus
steel yields very little info and NO dimensional info although I suppose Pics of the platters themselves an estimate could be made as to dimensions.No doubt the design parameters
of any warhead is a closely guarded secret likely the reason the chinese have a larger spying progrm underway than the russ at the height of the cold war.

I should have qualified the statement the only weapon Abrams tankers fear to the only IED Abrams tankers fear are the platter charges we've discussed and bulk explosive IEDs of several hundred Lbs.

[Edited on 4-6-2008 by grndpndr]

[Edited on 4-6-2008 by grndpndr]

LSD25 - 6-6-2008 at 22:21

aha, that does make it clearer - they are probably supplying the insurgents in Iraq something similar to that which they are supplying to Hiz'bollox in Lebanon, large EFP type projectiles based upon IED's.

http://www.defense-update.com/newscast/0207/news/010207_efp....

http://www.mnf-iraq.com/index.php?option=com_content&tas...

http://www.mnf-iraq.com/index.php?option=com_content&tas...

http://www.globalsecurity.org/military/systems/munitions/bul...

These aren't overly complex, simply a more advanced 'cheap trick', someone with some knowledge has contributed the original design, but after that even 'desert warriors:D' could acheive a high degree of manufacturing excellence (fucken hell, beat out a shallow copper bowl and mount it backwards).

This picture from Wiki should demonstrate why standoff is essential to the proper utilization of these:

http://en.wikipedia.org/wiki/Explosively_formed_penetrator

Shit happens quick, but it still ain't instantaneous, the penetrator/projectile still needs time and airspace to be explosively forged (the blast / air resistance caves the outer edges back onto the centre - where it forms a fairly well defined slug). Why they don't just setup a small machine shop (there are lathes & mills in Iraq, surely) and machine out or cast & then polish a copper cone and get the improved penetration is probably beyond argument, given the size of the charges they are using, they don't fucking need to.

grndpndr - 12-6-2008 at 11:34

I was priveledged to fire many LAWs at M113 APCs what suprised me the most now thinking back on it was how far a coherent jet stayed formed. The M113 as you may know is armored in relatively thin AL armor.Still the 66mm warhead of the LAW (advertised as capable of pen.12 in homogenous AP) penetrated both sides of the vehicle so It penetrated about an inch of hardened AL and then retained the coherehecy of the jet for another 4-5 ft penetrating the other side although with a diminished hole size.Yet we see these same vehicles with cage type predetonation protection from RPGs a much more powerful warhead near double the penetratin capability?My apologys if this has
become more of a military question in nature but perhaps
the fact of the coherency of the LAW s jet and I assume
other military heat warheads wll raise questions besides
simple penetration depth of a single target plate.Perhps space 2 test plates several ft apart?

PS;As far as size and improvised patter charges I would say
yes virtually any garage with few simple metalwrking tools
and access to a metals scrap heap has access to the makings of a crude but effective paltter charge,even a manhole cover backd with adequate explosive would cause catastrophic damage to a Light armored vehicle and possibly immobilize an abrams.Given the proper design parameters of an engineered device and slightly more sophisticated machine shop a clever machinist could likely urn out quite capable platters. i have a photograph of a captured imp device utilizing one of the copper platters supplied by iran
but w/o anything to compare its size to It simply appears to be a copper bowl inside perhaps 10+ in steel tubing.

[Edited on 12-6-2008 by grndpndr]

[Edited on 12-6-2008 by grndpndr]

LSD25 - 13-6-2008 at 07:47

Yeah, I know the terminology and I also know the equipment (in an almost biblical sense indeed). I used to drop 3 and a bit Kg bombs down tubes mounted in a turntable in the back of M113 variants. I have also utilized charlie guts-aches against immobilized cars which had been dumped on a range.

Yeah, by the look of the charges they could be beaten out by anyone with even rudimentary equipment (ball peen hammer and something to bash it out against). By the look of them the rest of the casing is only rudimentary, it doesn't have to be all that strong - the platter is only barely held in place so it would direct the force of the explosion extremely well away from the casing material. Even an steel pot should be sufficient, by the time it deforms the platter is well on its way.

As it is more a kinetic penetrator than a jet, the use of massive explosive charges would see the formation of fucking huge-mass, massive kinetic energy, penetrators which explains why they have succesfully been used against both Abrams & Merkavas (even the MkIV apparently, though the crew generally survive, not so with the MkII/III & the Mk.I chassis Namer APC).

BTW, see the Dove-ish contender who is touted to stand against Netanyahu saying that Iran will dissapear long before Israel? Wonder what is going to happen in Iraq & Afghanistan when both the yanks and Israel start on Iran? My tip is that we'll find out inside 12 months.

grndpndr - 13-6-2008 at 08:40

It would likely take a talented professonal copper smith and hardwood etc form to hammer a platter to relatively close tolerances but im sure it could be done with frequent reheating to resoften the copper alloy t prevent cracking .but with the vast investment in machinery and Im sure very costly manpower lol if even a small percentage f these were successfully detonated destroying/damaging $250,ooo humvees/damaging couple million dollar tanks/injuring-killing troopers a far more expensive bill, that would be cost effective.Or as i suggested earlier steel manhole covers and build 100lb platter charges also effective in a bind.



[Edited on 17-6-2008 by The_Davster]

LSD25 - 15-6-2008 at 04:26

As to the complexity of the weapons, look at this before you dismiss them out of hand as being beyond the capacity of this mob: http://www.armscollectors.com/darra/darra.htm The original article was written in the early '60's but I'd reckon this mob are fucking busy right now, wouldn't you?


The political shit left allover this thread has been removed.
-Davster


[Edited on 17-6-2008 by The_Davster]

[Edited on 17-6-2008 by The_Davster]

grndpndr - 25-6-2008 at 05:25

Iv searced this thread googled an perused a few books w/o luck finding any info on what the radius of a platter charge should be either steel or copper.As far as actually manufacturing one accurately even given the right dimension for a concave platter would be difficult a good mahinist MIGhT be ble to accurately turn a a concae lsteel/alumium plate be able to lathe turn an accurate plaltter.Better yet from standpoint of mass produtio the only practical relatively inexpensive method for mass produciondof after an expensve set up procedure manufacuring Dies etc would be a stamping mill.I did see an intersting example of the theory in practce was a quite small single handheld cevice that was dernate by sound of a passing vehicle and I believe a option for a pull type of fuse wth the capabiity of penetrting 40mm of armor palte at IIRC 25m ,.

[Edited on 25-6-2008 by grndpndr]

grndpndr - 27-6-2008 at 06:28

Im not sure if posting this crosses he line as "practical" Info
Im having a dfficult time wapping my tiny inellect around the subtle apparent differences? But is this is published by Uncle sugar the reprinting of which shouldnt ruffle any feathers as the " (whomever he may be) man" originally OKed the relaese of info.These are the basic dimensons; 2-2.5 in diam. steel pipe and 3-4 in long open at both ends naturally.And finally another pipe,a thin one of copper tubing 1/2-3/4 dia.x
1.5 in long open at both ends.

Expected penetrtion fron this device and a high VOD HE is 1.5
in. depth x 1.5in wide.An approximate 1/4n standoffcapparently produces the best results with this size device. (+1! for yesterdays SCOTUS Heller decision!!):D

grndpndr - 31-7-2008 at 01:36

Quote:
Originally posted by grndpndr
Iv searced this thread googled an perused a few books w/o luck finding any info on what the curvature of a platter charge should be.As far as actually manufacturing one accurately even given the right dimension for a concave platter would be a difficult project for a good machinist.

[Edited on 25-6-2008 by grndpndr]

My apologys I mispoke, I meant to say the dimensions of the the curvature of a concave platter SC.

tumadre - 6-10-2008 at 17:51

I thought this was worth digging up.
shows what a "good" shaped charge/EFP does.

Released on WikiLeaks 2 days ago.
LINK to pdf US_M1A1_tank_penetrated_in_Iraq_by_mystery_round

grndpndr - 12-10-2008 at 23:02

Obvoiusly the curvature of engineered platter may not be a easily found as I had hoped.Sucessful as far as improvised platters arent difficult to construct within obvious limtations of preformed scrap which can be impressive but enginered platters with opimum curvature for optimum effect seem far more diffcult to discover compared to basic dimensions for heat charges.Perhaps ive been remiss in my research?Or the info is somewhat a more closely quarded secreT?If anyone has advice as to patents/basic dimensons of platter charges
It would be very much appreciated.Thus far scrap steel platters made from high pressure gas cylinder protective valve caps and steel conainers to fit have ben quite effective with approx 1/4LB AN/NM and approximate 3inx
3/8 thick steel platter formed the approprate projectile shape with minimal standoff of 16-18in the projctile seemed fully formed w/o benefit of any scientifc proof however diameter of penertion of approx 1.5 in an complete penetration of a 7/8 mil steel witness plate of some 30 lb projected 30-40 ft into the air.Plus spallng and cracking around the penetration point
indicated HV and potential for greater results with purpose designed SC platter charges including possiblitys of off route
potential whch is already used by militarys round the world

Any leads to basic shaped charge platter design particularly thickness,diameter,curvature of platter.Though due to imp nature of the inquiry ive negleced copper as a possibility due to incresed difficulty but the use of copper as a platter materal would also be welcomed. Sincerely,grndpndr.

the request could be consired parctical in nature leading to a weapon but in fact is really a theoretical queston though admittedly with practial applictions though few threads ive seen have NO practical application.Failing any help i can always reusme patent seaches/basic demolition/imp techniques perfectly legal I would assume being publshed by The governmet?

Nerro - 28-11-2008 at 16:52

What would be the result of using a really light, really hard metal like Ti or a really heavy, really soft metal like Pb? Presumably The cone angle for Ti would be large and the cone angle for lead would be very sharp. How would these factors influence the formation of the jet? Would the lead form a stream of drops or would the sharp angle prevent that? Would the Ti form a bullet? I've been trying to come to a sensible conclusion but you guys seem to be so much better informed than I am...

grndpndr - 16-12-2008 at 03:50

"By you guys"I hope you dont include me as im a novice in any and all facets of theoretical work/chemistry.I simply look at whats used by those who have the letters in back of thier names and millions in research $$s to do the heavy lifting.
IIRC lead is a poor choice why i cant answer but artices Ive read , sources I cannot recall disount lead as a HEAT charge cone material.Titanium i havnt even heard mentioned though I would imagine it doesnt have the density required.The only materials ive heard of in the context of affordable/effective cone materials are steel,glass and copper the material used depending on the expected target.Glass and steel seem to be used in very large,up to 40lb SC used to make holes in gravel-concrete roads/runways to depths suitable for insertion of cratering charges.While copper seems the material of choice for AP cone charges.While steel and copper are both used
in platter charges to produce different effects.The steel forms
projectiles of various complexity depending on design while copper platters seem to perform similarly to HEAT charges but with perhaps greater standoff ranges than smilarly sized heat charges.FWIW

For myself im curious why depleted uranium isnt an excellent platter for use in platter charges?perhaps an abnormal amt. of HE would be required to cause the DU platter to take the desired shape but DU is obviosly not brittle so it should be able to be formed and near diamond hard making penetration uncommon and velocity retention (range) exceptional.Peraps it is used or stockpiled for use if needed
but due to public perception not acnowleded?

[Edited on 16-12-2008 by grndpndr]

DNA - 12-1-2009 at 07:23

Is there any more info available about the glass liners for conically shaped charges.
AXT I also sent you a U2U about this could you have a look please?

hissingnoise - 30-1-2009 at 07:43

It's been suggested that hemispherical, or broadly concave liners in shaped-charges are more effective for jet formation and penetration than conical liners.
Being lens-shaped, it would appear that this suggestion is correct, but that may not be the whole story.
Concave copper liners would certainly be easier to fabricate than the conical variety, but is the assertion true, does anyone know---axt perhaps?
Sidney Alford (and he *should* know) of "explosives.net", IIRC, still seems to be using conical liners.

grndpndr - 2-2-2009 at 14:16

Not to be snide but suggested by who?As as im aware the near max penetration is achieved by a 45-60degree cone shaped copper
liner most of the professionally engineered platters penetrating in excess of 6
cone diameters.Homemade copper cones usually penetrate on the order of 2 cone diameters as do imp glass platters such as martini glasses although in militry use glass is usually confined to the larger shaped charges intended to make larger holes to accomodate cratering charges of 40lbs plus.Steel is also known to be used in these large SCs.Perhaps cost has something to do with the material used.Concave copper liners are normally used in EFPs with gret penetrating and and standoff properties.Steel and other had dense naterials such as steel is also used in EFPs
basically forming a solid projectile at a minmum of 1-2 km/sec
producing a hole in my experience approx 11/4in the size of the concave platter(3in) from ahout 18 in completely penetrating 5/8 target plates of 30-40 lbs producing spalling very similar to HV cannon projectiles with a garage 3in high [pressure gas cap cut to fit 3in steel tube container with welded steel bottom concetrating all available power into the platter device the 1/4lb AN/NM 70/30 hE w/#6caps tossing the 30lb test plate 40-50 ft skyward.These are home or rather garage imrovisations !using technlogy a bwildering array of EFPs copper and steel with the copper taking in seemingly both aspects of the efp and a SC with great standoffs.The steel EFPs are capable of forming an astounding array of projectle to suit different purposes,multiple targets etc also with substantial standoff.They at least present a serious chllenge to the HEAT SC.

DNA - 10-2-2009 at 04:55

Isn't there any more information available about the glass liners?
I am about the have some conically shaped glass liners to be made for me.
But I'm not sure which angle to take, I'm thinking around 60* but isn't there like more of an optimum?

grndpndr - 10-2-2009 at 07:25

why not experiment with the glass liners at hand? Ive heard a glass funnel with the spout removed and the resulting small hollow plugged with epoxy etc.or a martini glass or other beverage container with the stem removed can make very good liners. I think only by experimentation will you discover which liner angle will work best with your device.
If Im not mistaken there is a drawing of what appears to be a well thought out device using a 50mm glass funnel as a cone and otc PVC plumbing components in this thread.Besides it wouldnt hurt to read the entire post and then some if your expecting a device that works at all.:D

DNA - 10-2-2009 at 08:56

I've read the entire thread, and also done quite some reading about glass liners.
I was just wondering if there is a ideal thickness. I can have some perfectly conically shaped liners made so there is no need for martini glasses with epoxy etc.

grndpndr - 11-2-2009 at 07:48

A 50 MM glass funnel/with the hole plugged w AL and glue worked well enough for AXT to penetrate 2 in steel witness plate with clean entrance and exit holes.Not bad for an improvised device made from OTC components.:P

Microtek - 11-2-2009 at 09:05

1.6 g PETN with a 10 mm cone made from rolled up copper foil penetrated 2 cm stacked steel for me. I believe that the good efficiency even at these small charge sizes are due to the fact that I used my lathe to make a charge with quite high axial symmetry.
So, I would suggest looking for a way to maximize charge accuracy before varying other parameters too much, as I think that it is a more critical design variable than most others.

gnitseretni - 11-2-2009 at 10:18

a cone from copper foil.. I like that! But how do you pack the PETN to a high density without the cone collapsing on ya? I mean how strong a cone can you make from foil?!

Microtek - 11-2-2009 at 14:33

The cone had practically no mechanical strength. I made the charges as follows:

The bodies were Al tubing, 12 mm OD, 10 mm ID. An end plug was made from epoxy (over a placeholder for the charge to ensure a square inside bottom). When cured this endplug was drilled in the lathe to produce a 4 mm axial hole for the cap. A 4 mm mandrel was machined and placed through the cap hole (so acting as placeholder for the cap). The body was then placed in a sleeve I had made for the pressing operation. The best way I can describe it is by saying that the charge body as described was held much like a cartridge casing in the chamber of a gun.
This allowed me to use a ram which was contured like the inside of the cone to press the charge. Then, with most of the pressing done, I placed the cone on the tip of the ram (a bit like a condom if you will), and finished the pressing operation. When the ram was withdrawn, the copper cone was left in the cavity.
I had calculated beforehand how much PETN was required to get to 1,7 g/cc, given the space in the body, so I just kept spooning it in and pressing until the required amount was in there.

In passing I might mention that this rather elaborate setup was made to experiment with pressed powder cones. I used copper powder made by reducing CuO with hydrogen, but the results were very dscouraging. That was why I did the foil based charge as a comparison.

grndpndr - 12-2-2009 at 07:06

I had read that one way to initiate large AT HEAT charges was to make a minature SC to detonate on impact in the nose firing a jet to the rear of the projectile initiating a detonator.Im afraid I cannot recall the source as I expect to catch flak but how many of you have photographic memories or record sources for items of interest.Im well aware it sounds counterintuitivebut more Ideas have been tried and ultimately abandoned than are in use.

Microtek,1.6g or 1.6 oz PETN?


[Edited on 12-2-2009 by grndpndr]

[Edited on 12-2-2009 by grndpndr]

Microtek - 12-2-2009 at 13:49

1.6 gram. The charge was the size of a 9mm casing.

grndpndr - 13-2-2009 at 18:03

Impressed!

DNA - 16-2-2009 at 02:21

I know of the experiment of AXT, but I mean is there any info about the glass thickness from AXT himself maybe?
I don't see him replying here or answering to a U2U message...
It would be a waste of time to test all kind of different glass thicknesses and angles and diameters while maybe that info is already available.
If not then I'll test these conditions and parameters and post them here. I'm curious about what a perfectly shaped cone of glass will do compared to a improvised martiniglass cone.

Different Target!

SAM4CH - 16-2-2009 at 06:45

If I have copper lined cone "I meant same cone-same explosive charge" but different Targets! Is there simple relation between penetration depth in each Lead Target, Aluminum Target, Copper Target, Steel Target?
I like to get simple equation which has density and tensile for each taget.. I am so tired in this simple equation unless now!!

gnitseretni - 16-2-2009 at 08:01

Has anyone here ever wondered why we're so obsessed with trying to find a way to make perfect cones(or hemispheres for that matter since they both just make holes)? I mean, suppose you do find a way to make perfect cones/hemispheres, all they're good for is blow tiny holes in metal plates. I mean I know its fun and all, but.. in the end it's just a hole, ya know?! I mean, if you ask me, LSC have the potential to be alot more fun because you can get different results just by changing the design.
Anyways, I for one hope to see more LSC posts.

grndpndr - 16-2-2009 at 17:33

I on the other hand I wonder whats the attraction with LSCs

I dont see what real advantage they have over a tamped line charge or cutting torch.

Each to our interests is what s important I dont dis anyones interest unless it infringes on my own rights or anothers.
Be a real boring,backward, stagnant enviroment if we all had similar interests.If im not mistaken there have been many posts here dealing with all SCs, LSCs included.All ya gotta do is post:)

Im sorry but the last sentence of your post may reveal why you dont find CSCs interesting there are as many variables in cone SC if not more than LSC designs.:)

[Edited on 16-2-2009 by grndpndr]

gnitseretni - 16-2-2009 at 19:00

It's not that I'm not interested in CSCs, it's just that this afternoon it suddenly hit me in that all I can do with CSC's is either widen the hole or go deeper(or both but that would require a rather large amount of HE). With CSCs the results are always the same: a hole. Big, small, wide or narrow.. doesn't matter, in the end it's still just a hole. With LSCs you can get a little more creative as to what the result will be, I think.

I'm not arguing, I just hadn't looked at it like that before ;) But the fact that I haven't been able to construct perfect cones probably doesn't help :P

grndpndr - 16-2-2009 at 23:34

I would hazard a guess that the complexities of all SCs are such there all a technical problem and if Im not mistaken this is what makes all SCs conical,linear,EFPs so fascinating to the majority.Witness the length of this thread as compared to most others.
I have a practical interest in CSCs and EFPs having spent a good amount of time with the 82nd abn in a combat support unit.The battalions heavy weapons company as an antitank gunner on a tow missile system.As well as ABN Inf in panama.So what interested me first about SCs was the incredible coherency of the jets produced from early 70s devices by trial and error w/o benefit of todays tech.30 years prior to that they still exceeded the best were able to improvise.Thats a challenge difficult to ignore.

DNA - 17-2-2009 at 04:55

You also need to look into what you want to achieve, in a very hard material it is hard to drill a hole so you can easily blow a deep hole in there with a shaped charge.
If you need to cut something then you can saw it or use a blow torch but if that takes too long a linear shaped charge will help.
It just depends on what you're doing, in my view conically shaped charges make deeper holes then linear shaped charges do with the same amount of HE. The LSC just need a lot more HE because the force is devided over the whole length of your SC, while in a CSC all the force is directed into one little point.

grndpndr - 19-2-2009 at 00:59

Ive had no luck with copper cone construction either.But it seems AXTs experince with glass funnels with a thickness of 1mm and seemingly more precise construction than cheap martini glasses would have to be a bit more successful.On the other hand the thickness of the less dense glass would seem to indicate athicker liner is needed to compensate for denser copper.

If size werent a consideration imp steel EFPs offer the most bang per buck if internal damage is a criteria.with 1/2lb he/platter @6100 plus /minus mps AN/NM HE the results of an imp efp from a garge junk pile and equipment are frightening.

Other than linear charges for demolition.perforation of oil field casings and explosive welding i cant think of any commercial applications where HEs are precise enough.
All extremely important in thier own right but i think w/o the most recent, explosive welding of dissimilar steels there wouldnt be composite armor for tanks capable of resisting atgms and energetic warheads.Actually a nazi idea some 60 years old and intended for the same application improved armor through the use of armor with dissimilar propertys similar to casehardened armor but on a grand scale.Impenetrable panther tanks?:(

[Edited on 19-2-2009 by grndpndr]

[Edited on 19-2-2009 by grndpndr]

gnitseretni - 19-2-2009 at 10:45

Made a LSC but didn't work as well as I'd hoped. It was made from copper sheet that was I believe only .025" thick, so not thick. May be that was the reason? Used 50g PETN. (amount in pic was 100g. Mixed 87g PETN with 13% vaseline)

Pics:
http://img207.imageshack.us/img207/7926/im000622ef2.jpg
http://img13.imageshack.us/img13/9430/im000623op2.jpg
http://img145.imageshack.us/img145/1483/picture002yw6.jpg
http://img13.imageshack.us/img13/9649/picture004rv8.jpg


The LSC was made by pretty much wrapping the copper sheet around two 1/8" thick 3/4" angle iron pieces on top of each other. The edges overlapped at the top and glued together with 5min epoxy, so not a strong bond. Could that, in addition to the thin liner, have been why the charge performed so poorly? It's hard to see but penetration was at most 1/4" deep. And that was at the top; I placed the charge in such a way that the charge was leaning against the target at the bottom with standoff gradually increasing towards the top where the standoff was about an inch.
Any thoughts?

grndpndr - 19-2-2009 at 18:26

Im not understanding your constructionn method.look at AXTs linear SC on page 1 should give a good idea of proper construction.The idea of varying the standoff to help optimize standoff distances with one charge is clever.

still looking for the optimum diameter/radius of an EFP.Almost like state secrets although the cost of a proper steel or copper EFP would be prohibitive at least for me. But for the sake of knowledge it would be interesting, though not absolutely nescessary for an effective device unless size is an important consideration.:(
Has anyone else heard that the addittion of a thick steel mesh in front of a single dish efp will produce many smaller
efps to deal with multiple armored targets.Though factory made multiple efps have seperate lenses incorporated to accomplish the same more efficiently in arty delivered top attack submunitions
I dont know the reliability of this claim but ive heard of manhole covers being converted to efp like devices!:o

[Edited on 19-2-2009 by grndpndr]

[Edited on 19-2-2009 by grndpndr]

[Edited on 19-2-2009 by grndpndr]

octogen - 5-3-2009 at 10:57

It seems by increasing the liner thickness, and charge length, which have been used in some powerful AT mine
like ATM-7,some magnificent result can be achieved.this design capable of projecting a EFP that can penetrate 70 millimeters of armour at 80 meters range, producing a hole approximately 120 millimeters in diameter. It uses heavy copper disc with apex approximately of 120 degree, and 9 kg of composition B.

octogen - 5-3-2009 at 11:00

Quote:
Originally posted by octogen
It seems by increasing the liner thickness, and charge length, which have been used in some powerful AT mine
like ATM-7,some magnificent result can be achieved.this design capable of projecting a EFP that can penetrate 70 millimeters of armour at 80 meters range, producing a hole approximately 120 millimeters in diameter. It uses heavy copper disc with apex approximately of 120 degree, and 9 kg of composition B.


atm-5.jpg - 126kB

grndpndr - 6-3-2009 at 14:35

Quote:
Originally posted by DNA
You also need to look into what you want to achieve, in a very hard material it is hard to drill a hole so you can easily blow a deep hole in there with a shaped charge.
If you need to cut something then you can saw it or use a blow torch but if that takes too long a linear shaped charge will help.
It just depends on what you're doing, in my view conically shaped charges make deeper holes then linear shaped charges do with the same amount of HE. The LSC just need a lot more HE because the force is devided over the whole length of your SC, while in a CSC all the force is directed into one little point.

I agree with the above as in th instance of the large 40lb
military engineer shaped charges.Often used to make the initial hole later widened with perhaps a dozen lenghths of mil strenght det cord widening the hole enough for the 40lb
an/al etc (nitramon) cratering charges.other methods can be used but speed dictates as well as availability of equipment.
LSCs for mil/civilian demolition are nearly indespensable.

Other SCs we havent mentioned yet still fall into the category of a SC such as saddle charges,diamond charges,used mainly to cut large diameter steel shafts. Possibly other demolition methods, line charge/pressure charges,Breaching,cratering and ditching may fall into a SC or perhaps a demolition method or both.The last 3 mentioned could be called purely demolition methods but the sadlle and diamond charges are surely SCs?

The LSC and the quick and dirty line charge accomplish the same end but I expect the advantage of economy of HE/ ease of placement(no tamping) going to the LSC.However practical experience has shown me at least a tamped line charge with a moderate HE (AN/NM
70/30) provided more than ample brisance to cleanly cut 5/8 mild steel using just a bicible inner tube 1.25 dia. IIRC lightly pressed w/#6 cap.I could crudely extrapolate the amount of HE but exact amounts Im afraid I kept no notes from a very old experience but Im quite sure the amount didnt exceed 6 to 8 oz for an 8 x5/8 plate.Is that then a shaped charge even though its not nearly as precise as the LSC?

My apologys, I dont have a method to illustrate theses various charges particularly interesting the saddle and diamond, possibly line charges as SCs. (FM 5/25 Explosives and Demolitions)

[Edited on 6-3-2009 by grndpndr]

[Edited on 6-3-2009 by grndpndr]

[Edited on 6-3-2009 by grndpndr]

grndpndr - 17-3-2009 at 20:06

As fascinating as saddle charges diamond charges etc are
The notion that laminated glass may be the key to defeating copper platter efps
is at least eaqually fascinating (to me anyway)The idea that layers of laminated glass may destabilize the EFP redirecting its KE along the glass laminations.Since Im in no way qualified to explain the phenomena ill direct you to the site \i discovered the info at.

Article title, "New Defense against explosively formed Penetrators" (EFPs)?
search the site "Defense Review"
Sorry I cannot provide a direct link.


The more I look at Octogens EFP the more I see a cone shaped charge? with a very shallow cone angle of 120 deg,
Is it a type of combination of the 2devices?The relatively shallow penetration with a large hole are ideal for a shaped charge intended for demolition work particularly that of quickly making a hole for a cratering charge effectually hampering access to bridges damaging rumways etc.:)

[Edited on 17-3-2009 by grndpndr]

[Edited on 17-3-2009 by grndpndr]

[Edited on 17-3-2009 by grndpndr]

octogen - 18-3-2009 at 06:26

I have uploaded, very intresting manual, which is about general rules of design of sc. its old but useful.link:http://rapidshare.com/files/209561357/manual_of_sc.pdf.html

octogen - 18-3-2009 at 06:41

Is it possible to use no metal liner in sc? the answer is yes.and the result is not actually very bad,just you will get shallower and wider hole.take look at:http://www.havoc.com.au/linear_charge.html.
intresting, isnt it?

octogen - 18-3-2009 at 06:45

It seems the website,has been broken.http://rapidshare.com/files/210721707/point_focal_charge.html

[Edited on 18-3-2009 by octogen]

[Edited on 18-3-2009 by octogen]

[Edited on 18-3-2009 by octogen]

grndpndr - 18-3-2009 at 07:07

From the information Ive gotten thats how the Monroe effect was discovered blocks of nitrocellulose incised with US navy were detonated on steel plates leaving a perfect impression of the impression in the HE.In an emergency its accepatable to simply carve a cone in a block of C4 as some penetration will result.Sometimes its preferable to make a wider shallower hole such as a pipeline engine block etc.From what I was told the cylinder charhge is the one to use for those purposes however the very large efp/slight ly conical charge you posted made a very wide hole as \i suspect not to primarilypenetrate armor but for demolition prep.Quickly make holes for cratering charges.Octogen Id still likt to know the source you posted the sc from!?

[Edited on 18-3-2009 by grndpndr]

gnitseretni - 18-3-2009 at 18:41

The link has a dot after the html. Just click on the link and get rid of the dot and hit your refresh button and the page should come up.

Btw, those LSC casings look just like the ones i tried to make.

octogen - 19-3-2009 at 07:44

I have the sc manual from www.dtic.mil

[Edited on 19-3-2009 by octogen]

octogen - 19-3-2009 at 07:59

Just look at another sample: MIACAH F1 mine is powerful and contains 6 kg of HEXOLITE. see how wide and thick liner is;this is certainly EFP rather than SC. source is http://ordatamines.maic.jmu.edu/.

[Edited on 19-3-2009 by octogen]

[Edited on 19-3-2009 by octogen]

[Edited on 19-3-2009 by octogen]

MIACAH F1.jpg - 35kB

grndpndr - 19-3-2009 at 10:39

Thanks for the image and the link.What little I know of efps is that the platters(i thought) are always conical even multiple efps by thier description would seem to be conical or a geodesic like construction as thier desribed with individual 'lens' being formed into penetrators or sometimes imp multiple penetrators having a heavy steel meshover the platter producing the individual penetrators?I wish i could recall the source but Ill surely run across the same method(s)
if I search enough sources/patents

The liner yor referring to is obviously not made for any CSC Im aware of but that leaves alot of ground to cover as complex as some SCs have become .
Thanks ,
again,regards:D

Looks like some sort of adjustable aiming mechanism atached to the efp with a possible fold down site on top?

[Edited on 19-3-2009 by grndpndr]

octogen - 20-3-2009 at 07:46

EFP Liners also can be hemispherical ,but again their depth are shallower when you compare them with hemi spherical liners for SCs. and hemispherical liners easier to make(i think).

497 - 23-3-2009 at 09:53

I'm curious, does anyone know if it would be possible to use a pyramide or tetrahedron shaped liner? If they worked, it might be quite a bit easier to construct compared to a conical or hemispherical liner. Simply cutting triangles out of the end of a piece of heavy walled steel tube/pipe and bending the remaining triangles of metal together. The seams could be welded, or maybe it would function with seams..

grndpndr - 23-3-2009 at 11:27

That very subject came up somewhere else iirc.Iwill look to see if I can find it again but my gut says if it were successful to any degree it would be patented/more info published on the subject. regards.

Deceitful_Frank - 23-3-2009 at 11:34

Sounds plausible. Copper sheet could be cut in to triangles and soldered in to the shape of a baseless tetrahedron. I have never heard of this before but I am sure some penetration could be achieved.

Just trying to visualize in my head how such a liner would plasticly deform and collapse.

It would be much easier to keep the liner geometry within acceptable tolerances than trying to form a cone or hemi by hand using copper foil or sheet.

EDIT:

Would a baseless terahedral pyramid liner produce a hole resembling a three pointed star if standoff was not judged perfectly. Obviously the more sides the pyramid has the closer it is geometrically to a cone.

Would a twelve sided pyramid be that hard to construct and solder using 0.5mm Cu foil? ...maybe not :)

In theory a twelve sided pyramid is nearer to a cone than a three sided pyramid

But the three sided is structurally perfectly sound and is impossible to flex along the soldered hinges.

Our twelve sided option, or any other for that matter does not share this property. If I as to investigate this I would try it with the baseless tetrahedron.

One downside though with this design if a cylindrical case was used would be wastage of explosive so for this reason right off the bat, efficiency is compromised.

Quote: Originally posted by grndpndr  
That very subject came up somewhere else iirc.Iwill look to see if I can find it again but my gut says if it were successful to any degree it would be patented/more info published on the subject. regards.


Not necessarily. A multifaceted liner is never going to be as efficient as a professionally spun cone or hemisphere and anyone with the money or means and a half decent metal shop can realize this.

I think that we amateurs often have to make compromises within our hobby and we are bound to be happy taking a 5-10% loss of performance to save ourselves a few grand of a lathe.

The big boys don't need to make these compromises so why would they even investigate a lesser technology?

[Edited on 24-3-2009 by Deceitful_Frank]

grndpndr - 26-3-2009 at 13:29

Ive seen the attemted cones by lathe turning etc Commercially likely some type of die and press are used,maybe way off base.But another idea occurred, in HS back in the day when machine tools didnt frighten and it was acceptable for kids to use lathes etc
w/o much fear of lawsuits we had access to all types of machine tools.But what seems to me the most useful for the linear charges linear cone would be a sheet metal brake
and shears.Not something a guy would run out and buy just for the one purpose but a machine shop particulary the one where you bought your copper would perform the needed shearing and bends to precisely duplicate up to a 90 degree linear cone.As for the conical shaped liners the accepted name of the machine escapes me but essentially its a large roller capable of making various angle cones or tubing looking at a tool catalog i see a sheet metal tool called a shear,press brake, slip rolls and while I never learned to operate the roller with any proficiency the capability was there to make a precision conical liner of various diameters from different gauge metal.

Again the tooling would cost the individual several hundred dollars for either tool but a machine shop with some specialty in sheet metal such as an air conditioning and cooling company should have the needed tools. Im curious as to what Axts 50mm device would have been capable of if a precision copper liner were used in place of the mod. glass funnel as well as what would occur with the linear Sc with precision formed copper liner rather than angle AL? Likely substantial given the correct thickness copper stock as simple rolling wouldnt compromise the liner thickness unlike lathe turned cones besides the rolled cones being much more precise and repeatable.Every machine shop a potential munitions factory.Makes me wonder the veracity of US claims precision copper efp
'platters' were imported.Im sure given the blueprints for an effective copper platter nearly any machine shop could accomodate.The only problem I could envision would be the raw casting with adequate material or precise enough casting obviating the need for an oversized casting.casting copper would be no trick at all for a competent machine shop.in HS shop we often cast aluminum pieces of larger sizes than the platters seen in the photos,copper would have been more expensive but would likely have better casting characteristics. The raw casting along with the lathe
could make repeatable platters slowly compared to punch presses but still effective.IMO

Also wanted to reiterate my sentiment that diamond charges
even saddle charges and line or tubular charges,squash head are shaped charges.Not as complex most of them excepting perhaps the diamond charge but it seems all work on the principle of concentrating shock waves.Possibly even including pressure charges.probably impossible to include all of them as a shaped charge in some fashion or another but
all it seems engineered placement of explosives( effectively controlled demolition) results to some degree in what we'd call a shaped charge IF the defenition is concentrating the shock waves of the explosive?

Excuse all the edits simply additional thoughts rather than a punch press for EFPs modern precision casting could easily duplicate copper or steel EFP penetrators en masse w/great precision-minimal hand finishing.

[Edited on 26-3-2009 by grndpndr]

[Edited on 26-3-2009 by grndpndr]

[Edited on 26-3-2009 by grndpndr]

grndpndr - 27-3-2009 at 16:45

I believe the lost wax process of casting is within the capabilitys of the garage fabricator particularly the simple shapes of the hemisperical copper efp or the slighty angular
120 degree apex EFP platter could be roughly duplicated with a lost wax, sand cast mold at the garage or lathe equipped garage machine shop equipped with a crude coal or gas fired forge to melt the copper.I know crude forges made with castoffs will melt through the steel leaves used in
a leaf spring suspension I was forging knives from.Far more than enough heat than needed for copper simply a hole lined with brick and a reversed vacum connected to a steel pipe with spaced holes to allow escape of an air stream to feed 02 to the forge.Actually a large vacum is far to much! for a small forge a hand held vacum supplied excessive oxygen to my forge heating it to very extreme almost unusable temps which had to be shut down regularly or the steel melted with unnesscesary coal use.The sand castings are the most difficult but can be done likely with less effort than expected and with repeatable results using the same pieces to form the wax mold.
Possibly even usable as is with some hand finishing to remove flash etc.. Just exploring some Ideas for fabrication
of various munition components. Including the very obvious copper linear cones and more difficult but very doable copper cones using common sheet metal forming tools. In fact in lieu of the very expensive sheet metal brake a very inexpensive steel tool i believe added to the larger vise accomplished similar results at a cost of some $9.accuracy will suffer but far better than some improvised copper linear copper cones ive seen using angle Iron as the form and it appeared from the post allso part of the liner!? Copper sheet linear cone of sorts hammered over a piece of 1/4 in steel angle iron with the total used as the liner .no wonder results were nil.Also as copper flashing for the roofing trade becomes more common copper stock of varying gauges and widths are commonly available at better hardware /building centers.Good source for copper stock for these devices.

As is becoming painfully obvious w/o far better precision cones along with a HV castable or liquid ,slurry HE and precision assembly were just stuck in a rut and our results with CSCs,LSCs,and copper EFPs just cant improve despite a better explosive etc.It seems adequate simple HEs abound.
the problem is precision manufacture of copper cones and platters along with precision assembly.Next! tantalum efps
formed from punched 'pucks' of powdered tantalum heated and pressed.Maybe much for the garage,LOL but at this point it seems baby steps to produce even obsolescent CSCs/EFPs:)
tantalum.LOL
[Edited on 28-3-2009 by grndpndr]

[Edited on 28-3-2009 by grndpndr]

octogen - 8-4-2009 at 05:36

It is possible to use pyramid, i have the pdf file in this regard: http://rapidshare.com/files/218887409/pyramid.pdf.html enjoy it.

[Edited on 8-4-2009 by octogen]

grndpndr - 9-4-2009 at 15:19

Please post a pic of your hand fabricated tetrahedron liner
when its completed.Id be fascinated by the result.No disrespect but I dont think you realize the difficultys involved with fabricating a miltifaceted liner tetrahedron or pyramid.
I think youve seriously underestimated the diifficultys in constructing what you propose.
As for the linear sc liners I saw a $38 sheet metal brake that will form the copper liner for the linear SC with great precision with up to a 90 degree angle or anything in between and is repeatable.Same cataloge featured a sheet metal roller, shears,etc for $130 for conical SC cones.I do wish you the best but I believe the majority of SC failures are due to inconsistent,mishapen liners as well as construction.I think AXT's devices using off the shelf materials carefully assembled proves the point.


A precision assembled pyramid or tetrahedron shaped liner may be" possible" but practical's another matter.




[Edited on 10-4-2009 by grndpndr]

[Edited on 10-4-2009 by grndpndr]

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