Talk:Shaped charge

Error in "Liner" section re: usefulness of skirts today?

Paragraph 4 of the Liner section ends with the statements The use of skirts today would, depending on the warhead, probably increase penetration by providing a more optimal standoff distance. The new Stryker vehicle was recalled from Iraq specifically to fit it with slat armor, a form of skirt armor, to protect it against RPGs etc. I have removed this sentence until its accuracy can be assertained or clarified.

Good call. That sentence is nonsense. Riddley 10:50, 28 August 2006 (UTC)

There is no error is the previous text, abet maybe my poor grammar and spelling? The use of basic thin mild steel side skirts will, in many cases, improve a modern shaped charge (SC) warhead's effectiveness. It is only when the skirting is extremely thick, or armour arrays using ceramic, composite, explosive reactive armour (ERA), or non explosive reactive armour, will this be decremental to the warhead's penetration. It was found that in some cases the spacing provided by the skirting actually improved penetration by providing a more optimal standoff distant from the warhead to the tanks side armour (more below).

Shaped charges require a standoff for the jet to form correctly. Early warheads required about 2-3 charge diameters (CD), 2nd generation 70's era, 6-7 CDs and modern up to and above 10 CDs. Degradation to penetration (due to jet breakup and dispersion) happens after 4-6 CDs for WWII era SCs, 2nd gen after 16 CDs and for modern SCs the distance is mostly classified information. If you plug some numbers into that data, you get some interesting results. Here is an example attack: for a 75mm projectile with a 65 mm SC warhead, the spacing distance needed to make an appreciable drop in penetration would be 260-390mm for WWII SCs and over 1m for a more modern warhead. Most modern anti-tank missiles have a SC warhead diameter between 100-150mm, bringing the optimum standoff to 1-1.5m and the a degraded standoff up to a ridiculous 1.6-2.4m! You can see that the use of skirting in these cases, does in fact, do diddlely squat to distance the armour away from the shaped charge's jet before it has degraded, as the skirting is only some 300-500mm away from the tank's side armour!

The original use for the skirts (Schürzen) was firstly to defeat small calibre armour piercing (AP) projectiles and secondly to degrade, but not defeat, the larger calibre ones. For small calibre, by direct defeat or destabilisation and for large calibre, by a combination of destabilising the projectile and damaging the penetrating cap. On very small calibre, or the more crude of WWII SCs, the armour could also degrade the SC's penetration to some extent. The use of slat, chain, or bar armour in modern armoured fighting vehicles (AFVs) is to damage/short circuit the fuzing system on some shaped charge projectiles. The fuzing system on some RPG-7 (Ruchnoy Protivotankoviy Granatomet [Handheld Anti-Tank Grenade Launcher] -7) projectiles use the inner and outer nose cone (ogive) to transmit the firing pulse from the small diameter piezoelectric nose probe to the rear mounted fuze and detonator. If the inner and outer sections of the ogive are forced together, the fuze short circuits, the detonator at the rear cannot initiate the main charge, and the shaped charge jet cannot form. Slat/bar/chain armour is used on AFV's for this reason and not the reason stated before. It should be noted that if the nose probe hits a slat/bar/chain element, then the warhead will function correctly, the jet will form and on a poorly protected vehicle the armour behind will more than likely be penetrated. Another note is that the high speed impact of the RPG-7 projectile with the armour, may cause the projectile's filling to deflagrate (a low order subsonic explosion), not detonate, causing some local fragmentation and blast damage.NeilGibson 08:33, 1 October 2006 (UTC)

Having done a bit of reading, I accept that slat armour is primarily designed to disrupt the fusing mechanism rather than change the standoff, just goes to show you learn something new everyday. I still don't understand what you are saying regrading optimum standoff though - if modern HEATs need a standoff of say 10 or more CDs "for the jet to form correctly" then how could any impact-fused modern weapon achieve a correctly formed jet? Why not use proximity fuses to get the optimum standoff? Riddley 10:02, 1 October 2006 (UTC)

Well a standoff of 10 CDs may be the optimum for some of the most advanced warheads, but most are still only 5-7 CDs. Although there is an optimum standoff, you can lose a few CD here and there and still achieve good penetration, you’ll just not get the max capability out of the warhead. For some warheads, the cone angle may also be wider, this results in a thicker jet which improves lethality and lowers the standoff, but negatively, decreases the depth of penetration. Those warheads which do not use a proximity sensor, have to rely on some form of inbuilt standoff. The standoff can come from just the nose, a nose probe, an extending nose probe, or by placing the warhead as far to the rear of the missile/projectile and allowing the jet to travel along a channel in the centre axis of the weapon. Although proximity sensors are used on many heavyweight systems (HOT 3, Brimstone, Hellfire, BILL RBS 56, etc) and on more advanced lightweight systems (Javelin, NLAW, etc), the exact nature of the proximity sensor used (magnetic, laser, optical or radar) and it's capability is not normally released due to security reasons. NeilGibson 16:18, 1 October 2006 (UTC)

Shaped Charge (Munition) Image

Hi, what is the exact round in the new image? Checking the image, the name of the file gives the origin as French. It seems most likely to be of 90 mm calibre and for either the Giat 90 mm CN 90 F1, Cockerill or Engesa guns due to the length of the cartridge case. If for the CN 90 F1 gun this makes it a HEAT-T, OCC F1 and if for the Cockerill or Engesa guns, the NR478 HEAT-T. NeilGibson 18:54, 8 February 2006 (UTC)

This looks like another view of the same round, with some more markings visible: http://commons.wikimedia.org/wiki/Image:Mines_501607_fh000003.jpg BillFlis 16:31, 10 February 2006 (UTC)

Linear Shaped Charge Image

Oh I forgot to say thanks for the linear shaped charge image, but there are two problems. LSCs are not normally initiated in the way depicted in the image, e.g. by a detonator applied to the top of the charge. In general they are initiated from one end using some form of coupling between the explosive fill and the detonator, be it only a blob of PE. Also they tend to have a triangular top section, as the explosive to the sides is not used in the collapse of the internal apex. If this profile was used it would just raise the cost and enlarge the danger area. NeilGibson 19:28, 8 February 2006 (UTC)

You're quite right about my sketch not resembling the commercial product, a photo of which would be a good addition, but I'm reluctant to steal one from, say, Ensign-Bickford. My image looks like what I would have made in a machine shop, if I had to. The central initiation would give a symmetric jet. It also resembles Figure 63 of Walters's book.BillFlis 20:22, 8 February 2006 (UTC)

Yes I have contemplated 'acquiring' images from the above fore mentioned website, but have resisted the temptation. There a loads of other LCS manufacturers too which have images on their websites? Perhaps if we contact one of them and give a link to their website at the bottom of the article, they may be interested? Anyway for now it’s the best we have, I'll have a look around myself and see if I can find a more representative image. The profile in you image is used though, but not for LSCs in general. Your image profile is used to produce a linear self forging fragment, abet with a different liner cross-sections, the addition explosive being a bonus this time. I've seen a few of these in technical papers and reference books. NeilGibson 09:37, 9 February 2006 (UTC)

Additionally the lack of labelling makes it unclear whether the entire blue section or just the orange one is the actual charge. —Preceding unsigned comment added by 38.102.193.126 (talk) 17:49, 27 October 2010 (UTC)

Explosive lens

I think the section on Explosive Lenses should be moved to a separate article. It's not really a "shaped charge" as the phrase has come to be used. Granted, it's a charge of explosive and it's shaped, but that doesn't make it a shaped charge any more than heating up a dog turns it into a hot dog (frankfurter).

Also, I think an explosive lens is something that someone (reading, say, about nuclear weapons) might reasonably be expected to want to look up. So it deserves its own heading. Cross-referencing to Shaped Charges would be appropriate, because SCs-proper sometimes incorporate them (mainly for research purposes).BillFlis 22:54, 7 February 2006 (UTC)

Yes I quite agree that lens and plane wave generators should be in a separate entry. I did not move it myself as I had changed so much the first time I edited the article, I though someone might be offended. There is the point of view though that shaped charges share many of the aspects of explosive lens, especially shaped charges that use a barrier within the explosive to shape the detonation wave? I also though about starting an article on warhead mechanics, which all of these separate articles could fit within, but I haven't taken it further as of yet? NeilGibson 18:54, 8 February 2006 (UTC)

The terminology that has arisen for the "barriers" you mention is "waveshaper." No ordnance charge that I know of uses a true explosive lens, and indeed I think it would be an unnecessary and expensive complication. The lens analogy is a good one--as in an optical lens, the effect is based on a difference in wave velocities. A waveshaper affects the shape of a detonation wave rather by changing its path, rather than its speed.BillFlis 20:35, 8 February 2006 (UTC).

There are various ordnance charges that shape the detonation wave, whether by multipoint initiation or by using inert barrier materials. There may also be some that use active barrier materials (varying speed explosives). Some of the cross sections of these charges show different materials between the initiation point and the main explosive fill. Whether or not this is another explosive, or just some form of inert barrier tends to be classified. Either way feel free to set up another article on the subject as I think it’s a very good idea. For your info I didn't write the original nuclear weapons part of the article, just tidied up a few things. NeilGibson 09:37, 9 February 2006 (UTC)

Fluted Liners

Someone should add some extra detail re. fluted liners for shaped charges. --Nabokov 10:24, 6 May 2006 (UTC)

WPMILHIST Assessment

There really should be in-line citations, but your sources are listed at the bottom, and the material is lengthy, thorough, and well-written. LordAmeth 16:44, 3 February 2007 (UTC)

This article totally lacks a history section. Parts of the German language article could be used as it is excellent. --13:54, 15 February 2009 (UTC)

Commercial shaped charges

There is a commercial use of lined conical shaped charges that is not mentioned in this article. Oilfield service companies, e.g. Schlumberger and Halliburton, use small shaped charges to perforate the casing of a wellbore. See Oil well completion, Schlumberger, and AnaLog. Millions of these shaped charges are produced and used annually.

This article, being in a military category, is probably not the place for this information. I am not familiar enough with the practices here to make another article myself, though. Suggestions?

wysiwyg 15:39, 18 February 2007 (UTC)

Speed vs Velocity

Someone changed nearly every instance of velocity to speed. I don't ever recall anyone referring to tip speed or ignition speed, so I changed them back. —Travis^talk 02:32, 22 June 2007 (UTC)

Spun Shaped Charges

From wikipedia: "HEAT rounds are less effective if they are spinning, the normal method for giving a shell accuracy. The centrifugal force disperses the jet, so the warhead design needs to be modified for use with rifled guns, or fired from smoothbore weapons."

From this page: "Shaped charges are frequently used as warheads in anti-tank missiles (guided and unguided) and also gun-fired projectiles (spun and unspun), rifle grenades, mines, bomblets, torpedoes and various types of air/land/sea-launched guided missiles."

Seems like a slight contradiction, or at least, should be clarified. To be honest I've never heard of rifled-shaped charge weapons, for precisely the reason listed above. Of course, I'm not an expert, but I thought it was worth bringing up.

Combine wit HEAT Article

I reckon this article should be combin ed with the HEAT article (or vice versa). As far as I know tehre is no difference between a shaped charge and a HEAT warhead and there is not substantive difference int eh articles - there is a lot of duplication. I reckon the articles should be combined and then one should reditrect to teh other. —Preceding unsigned comment added by 122.49.150.39 (talk) 15:40, 29 April 2008 (UTC)

Plagiarism

Forgive me if this is acceptable on wikipedia - but the section on this page discussing Voitenko compressors is 50% plagiarised from the source (a NASA webpage). The same material is repeated on the Voitenko compressor page as well. Should this be rephrased? —Preceding unsigned comment added by 114.76.27.133 (talk) 08:20, 29 September 2009 (UTC)

Merge Munroe effect into Shaped charge

I think the Munroe effect should be merged into Shaped charge. There is almost 100% overlap, and I don't reckon that the phrase "Munroe effect" is used anywhere outside the topic of shaped charges. I think Munroe effect should just redirect here after the text is merged. --Kubanczyk (talk) 19:12, 21 August 2011 (UTC)

This seems to make sense and I would support this. What do others think? I am no expert in this matter, BTW.--TDurden1937 (talk) 20:46, 22 August 2011 (UTC)

I am no expert, but I tend to agree - I also propose merging Explosive lens since ther is no practical difference - It rather looks as if this area needs the attention of an expert, and maybe reformatting? Timpo (talk) 09:05, 5 February 2014 (UTC)

I am somewhat of an expert. There is an immense practical difference, and I oppose the merge. Georgewilliamherbert (talk) 17:16, 5 February 2014 (UTC)

Core Diameter (CD)

The article uses CD referring to Core Diameter. This is not explicitly defined. Exactly what measurement represents the CD, and where is it measured. At the place where the greatest CD is, or what? This needs to be known because penetration power is expressed as a multiple of CD.--TDurden1937 (talk) 20:52, 22 August 2011 (UTC)

Shaped Nuclear Charge

The citations given in this section are both speculative in nature. Neither actually discuss actual existing devices, merely hypothetical devices. — Preceding unsigned comment added by 71.179.5.25 (talk) 02:17, 16 February 2012 (UTC)

Whether burning is important

re "the shaped charge does not depend in any way on heating or melting for its effectiveness":

• not for the shaping
• burning DU is a contribution to military effectiveness
  • http://www.globalsecurity.org/military/systems/munitions/du.htm

Does this belong in the article? ArthurDent006.5 (talk) 08:17, 4 March 2014 (UTC)

It has nothing to do with penetration, but does contribute to destruction past tge armor package somewhat.

That said, superheated glowing hot liquid metal sprays at rifle bullet velocities are pretty bad, burning or not... Georgewilliamherbert (talk) 09:16, 4 March 2014 (UTC)

History of shaped charges: German & French versions

The German and French articles on shaped charges contain information that differs in some details from that contained in the English article. The articles also contain some information that's not presently contained in this article.

Problem: The French article contains no references and the German article contains only a few.

Translation of the French article on history of shaped charges

The hollow charge was the invention of Dr. Mohaupt, a Swiss citizen. In 1935 he presented his invention to the French army, but the staff laughed at him, denying the invention's utility and the danger of tanks. Nevertheless, Thomson-Brandt, recognizing the value of the invention, put it into production in the form of rifle grenades for the MAS 36 rifle, too late however for it to be distributed at the front in 1940. The invention reached the U.S. via diplomatic pouch, the U.S. paying the Brandt firm royalties on all hollow charges produced during World War II.

[Subsequent research: According to this source — David Lehmann (December 5, 2005) "1939-1940 French Armament", pp. 93–94 (available on-line at: Hit Pages ) — Mohaupt's shaped charge munition was developed by the French weapons firm of Edgar William Brandt. Brandt used Mohaupt's ideas to develop both an artillery shell and a rifle-launched grenade.

• The 75mm HEAT shell was tested at the artillery test range in Bourges, France in 1940. On 14th June 1940, the French war ministry authorized Brandt to give all this information to the USA and to the United Kingdom, including the exploitation licence for the Mohaupt patent. The inventor, Henry Mohaupt, via the Brandt company, filed for US patent on 10th February 1941. (Here is Mohaupt's patent: Henry Hans Mohaupt, "Projectile," U.S. Patent no. 2,419,414 (filed: October 3, 1941 ; issued: April 22, 1947)) On 7th March 1941 the patent was classified as "secret".
• At the end of 1939 Brandt developed also a 50mm HEAT rifle grenade. It had a range of about 100m and an armor penetration of 40mm (1.57 inches). It entered in production during May 1940 and was successfully tested at the Versailles–Satory test range on 10th June 1940, but they could not be issued to the combat units before the armistice. The documents related to this work were sent to the USA in June 1940 and were in some extent used as basis to develop the M9 AT rifle grenade and the HEAT rocket of bazookas. The Brandt HEAT rifle grenade was also secretly produced in France at 300,000 pieces in the free zone and issued to Vichy forces. Several partisans groups used them in 1944.

VexorAbVikipædia (talk) 21:32, 16 April 2016 (UTC)]

The first bazooka stemmed from a harpoon cannon that was intended for hunting whales; the Americans simply used it to launch a hollow charge. Charges with magnetic base plates were used at the start of World War II during the taking of fort Ében-Émael. At this time, only this type of munition was capable of handling modern armor. However, the charge's large size did not permit its integration into a shell or a rocket; they were brought to the site by gliders and placed manually on their targets.

However, this handicap was solved soon enough, and the hollow charge was to be found in the German Panzerfaust, the American bazooka, and the British PIAT. Later hollow charges are to be found in numerous anti-tank shells or in anti-tank rockets, under the name HEAT, in conjunction with AP (armor piercing) shells.

The Germans, having captured some of the first American bazookas, hastened to copy them in the form of the Panzerschreck, then towards the end of the war, in the form of disposable over-caliber launchers constituting the Panzerfaust family. It was also used in the Mistel, a modified Ju88 bomber, with the cockpit replaced with an enormous hollow charge and piloted by a fighter (first the Bf 109, then the Fw 190) attached to the bomber, which detached shortly before impact. This assembly was used with variable success against allied naval installations such as Gibraltar, Leningrad, and Scapa Flow, as well as bridges crossing the Vistula, a Polish river.

It was during World War II that the British invented a hollow charge in the form of a grenade. However, if the technology had seemed to show promise, the use of such grenades was soon abandoned.

At the start of the 1960s, hollow charges could penetrate 4 times their caliber in steel tank armor; in the 1970s, 8 times; and in the 1980s, 10 times using the most powerful explosive, octolite [a mixture of HMX and TNT (see: Cameo Chemicals)]. They lost their attraction in the course of this period due to the constant development of reactive armors, which consist of explosive tiles fitted on the tank's armor. The tiles explode invidually in response to the impact of an explosive charge, efficiently dispersing the perforating jet of the hollow charge. In contrast to penetrating shells, the effectiveness of the hollow charge is based on the power of the explosive. Its effectiveness is therefore independent of the speed of the projectile that carries it, which renders it more useful in missiles, rockets, and aerial anti-tank submunitions.

In order to counter reactive armor, certain munitions are now equipped with tandem hollow charges, such as the HOT missile. A small hollow charge is placed in front; it triggers the explosion of the tile, permitting the second, normal sized charge to penetrate the more conventional armor.

Translation of the German article on history of shaped charges

Discovery

Since the end of the 18th century, it was known that the geometric form of an explosive charge plays a decisive roll in the explosive's effect; for example, a hollowed out charge possesses an especially high penetrating power. In the year 1792 Franz von Baader was the first to write about this effect. An investigation of this phenomenon wasn't possible at the time. In the 1930s the Reichswehr secretly contracted out a series of developmental projects in this field. Thus at the Second Physics Institute of Berlin University under Prof. Erich Schumann, a series of dissertations on theoretical problems of the hollow charge were written. Also, in the USA, work had been done on the hollow charge principle since 1880, which during the 1930s was advanced by Heinrich Mohaupt and which led to hollow-charge hand- and rifle grenades as well as later to the development of the bazooka. This weapon was first used in November 1942 in North Africa during Operation Torch.

On the part of the German armaments industry, there were developed in 1938 tank-busting projectiles with hollow charges (abbreviated HL or Hl), such as the Gr. 38HL, which could be fired with a 7.5 cm KwK 37 tank cannon.

Conventional hollow charges

In Germany, Franz Thomanek of the Air Transport Research Institute in Braunschweig achieved a breakthrough in 1935. He developed the first hollow charge weapon, a 7 cm. anti-tank weapon. In 1938, Thomanek also discovered the liner effect, which would prove decisive to further research. The weapon's penetrating power was thereby more than doubled. Starting in the summer of 1942, the development of the Panzerfaust was completed by a development team under the leadership of Heinrich Langweiler at the Leipzig firm of Hugo Schneider Inc. Shortly after his second discovery, Thomanek joined Hubert Schardin at the Institute for Technical Physics and Ballistics at the Technical Academy of the Air Force in Berlin-Gatow.

[Note that in the German account, Thomanek discovered the hollow charge effect in 1938, whereas Kennedy states that it was discovered earlier, and the German account states that Thomanek discovered the liner effect before joining Schardin, whereas Kennedy states that Thomanek made that discovery while working for Schardin.]

Shortly thereafter Thomanek gave hollow-charge research a new direction: he suggested to Max Steenbeck, a scientist at Siemens, an investigation, via X-rays, of the gas discharge during hollow charge detonations. Subsequently the Ballistics Institute and Siemens' research laboratory developed an X-ray flash tube, with which more than 45,000 images per second could be recorded. Thereby the jet's formation during a hollow-charge detonation and its effect on armor plate could be observed and analyzed for the first time. Subsequently comprehensive improvements were made at the Army Weapons Office (HWA) and at the Air Force Academy by Schardin; these improvements found their application in the development of weapons, of which the Panzerfaust became the best known of all.

One of the first uses of the hollow charge was on 10 May 1940 during the storming of the Belgian fort Eben-Emael by German parachutists, during which charges of up to 50 kg were used for the destruction of the armored cupolas.

After Erich Schumann took over leadership of Army research in the Army Weapons Office, Walter Trinks was appointed in 1940 as director of the Wa Fl b department, explosion physics and hollow charges. By the war's end, Trinks' scientific team had filed at least forty secret patents regarding hollow charges.

Atomic hollow charges

Starting in 1942, the theoretical work of the fluid dynamicists Adolf Busemann and Gottfried Guderley gave impetus to a completely new direction for work in nuclear physics. Both worked at the Air Transport Research Institute in Braunschweig and concerned themselves with the focusing of shock waves. They showed how pressure and temperature jumps could be achieved in a small region at the center of convergence of energetic shock waves. Their investigations gave impetus to experiments to initiate fusion reactions by means of high pressures and temperatures.

At the urging of Carl Ramsauers, director of the research department of AEG, there began, in autumn, experiments with deuterium filled hemispheres at the HWA (Walter Trinks, Kurt Diebner) and the Naval Weapons Office (MWA, Otto Haxel). In October 1943 Trinks began at the Army Research Institute Kummersdorf-Gut a series of experiments [titled] Release of atomic energy by reactions between light elements. The experiments failed, according to his own statement; however, they were continued — obviously in secret.

Schumann, Trinks and Diebner explained in patents and publications after the war the scientific and technical way to produce atomic hollow charges. Of course only Diebner went into the details of the need for the addition of fissile material (U²³⁵, U²³³, plutonium). Author H. J. Hajek publicized in 1956 under a pseudonym an article on atomic hollow charges in the journal "Explosives" (Explosivstoffe) (issue 5/6, 1955, pp. 65 ff). Besides that, he referred in the article to work of the French nuclear ministry into atomic hollow charges, which remains inaccessible even today.

VexorAbVikipædia (talk) 23:11, 13 April 2016 (UTC)

Noble metal liners

The article claims that silver, gold, and platinum have been tested as liner materials. I can find a paper that references a paper (A. C. Robinson, “Multilayered liners for shaped charge jets,” Sandia National Laboratories, Tech. Rep. SAND85-2300, 1985) that summarizes a paper that tested gold-lined copper liners (Regan, J.M. and G. H. Jonas, The Generation and Penetration Characteristics of High Density Shaped Charge Jets, BRL Memorandum Report, AD370730, 1965). This paper is listed on DTIC, but not publicly available. I've marked the relevant sentence as citation needed. EnticingCanine (talk) 15:00, 28 September 2021 (UTC)

Misconception - by whom?

@User:Hohum, with ref to your revert and edits here [[1]] (about an alleged misconception) I wanted first to thank you for not inadvertently reverting the edit I made to a later part of the article. That would have been easy to do and it is a sign of your careful editing that you did not do that. My edit was based around being unconvinced that the alleged misconception was common - it certainly exists (in Forbes and ABC news for example). But we'd need a reliable source to say it was a common misconception, and I don't think WW woud be reliable for that judgement (he is clearly highly reliable for the technical aspects of the topic). There is another good - and actually clearer - reference to the misunderstanding in: - but from a quick look around I can't find more than a handful of the misinformed newspaper articles etc that William is so keen to debunk.

For the lede we don't need too much detail: I'd suggest something along the lines of:

The penetration effect is purely kinetic, rather than thermodynamic, but the process creates significant heat and often has a significant secondary incendiary effect after penetration.

Then lower down in the article - I suggest at the end of "Function" - to reflect the second ref:

The shaped charge concept is not well understood by non-specialists who may typically suggest that the jet is a cutting plasma of molten metal at 20,000C and several times the density of steel, which burns its way through armor. This is emphatically not the case.

What do you think? Springnuts (talk) 21:19, 5 April 2022 (UTC)

References