[HN Gopher] Shaped Charges - Sheet of copper going through 1ft o...
___________________________________________________________________
Shaped Charges - Sheet of copper going through 1ft of solid steel
(2010) [video]
Author : Vladimof
Score : 117 points
Date : 2022-05-14 21:01 UTC (1 hours ago)
(HTM) web link (www.youtube.com)
(TXT) w3m dump (www.youtube.com)
| holly76 wrote:
| londons_explore wrote:
| This is just a few dollars worth of copper and explosives.
|
| Attach it to a few tens of dollars worth of drone. (The cheapest
| drones are under 10 dollars now).
|
| A country could release 1000 of these and direct them at any
| military target, and they'll do massive amounts of damage at very
| low costs.
|
| Most anti-drone defences can be defeated simply with a redesign
| of the drone (eg. Use UWB for Comms, and have dual gyros and use
| a camera for location instead of GPS).
|
| I think the only reason we haven't seen this on the battlefield
| yet is that we haven't yet had a war between the right countries.
| But we will.
| qbasic_forever wrote:
| Loitering anti-tank munitions are basically just that--a drone
| with shaped charges that fire down. Russia actually has a mine
| that detects the seismic profile of a tank rolling nearby,
| launches a drone (of sorts) into the air, and shoots a shaped
| charge right down into the tank (where there's very little
| armor compared to the sides):
| https://www.youtube.com/watch?v=zqtFhqSNubY
| alkonaut wrote:
| Something that carries say 1kg for any distance, is a pretty
| significant drone. The Dji Mavic pro can carry 1kg and is
| around $1k.
|
| > I think the only reason we haven't seen this on the
| battlefield yet is that we haven't yet had a war between the
| right countries. But we will.
|
| There are videos every day of Ukrainian drones dropping shaped
| charges like the Russian RKG-3/1600 from drones.
|
| Ukraine even has special troops specialized in it, the
| Aerorozvidka (Google for the videos).
|
| The reason they apparently aren't bothered by anti drone
| efforts is because the Russian forces don't seem to have the
| training and equipment for it, so regular drones work well
| enough (with selection bias of course - we don't see the videos
| of the failed attacks).
|
| It's clear from that footage what an advantage it is to be able
| to drop 2 or 3 munitions since you can correct for wind if you
| miss the first, something you can't do with a single drop.
|
| The larger octocopters that can carry 5kg or more is probably
| what you want for the job. Some range, and at least 2 charges
| to drop.
| dragontamer wrote:
| 1kg is similar to smaller warheads in the AT4 anti-tank
| weapon.
|
| But AT4 is not reliable, only 400mm of penetration and tanks
| can have 500mm or 600mm of armor. (Or really, equivalent to
| 500+mm once special materials or geometry is factored in).
|
| To reliably kill a main battle tank requires a larger
| munition. Javelin is a 8kg warhead IIRC. This is because
| Javelin is tandem: two warheads. First warhead destroys
| reactive armor, 2nd warhead actually kills the tank with
| 900mm of penetration.
|
| ---------
|
| For drones to be optimized on the battlefield will require
| specially designed drones and special warheads designed to
| fit in the cargo-capacity of drones.
|
| Switchblade 300 is nice for example but is too small to
| reliably kill a tank.
|
| Switchblade 600 can kill a tank, but no longer has the small
| and lightweight form factor that I'm sure the soldiers who
| have to carry this crap care about.
| AdrianB1 wrote:
| You ignore that AT4 is fired at the main armor, while drone
| dropped munitions hit the top armor that is just a few
| centimeters. The impact point makes all the difference.
| formerly_proven wrote:
| UA is literally dropping anti-tank grenades and other
| explosives from commercial/civilian drones as we speak.
| ChuckMcM wrote:
| And you have just described the AeroEnvironment Switchblade 600
| drone. According to Drive they haven't actually been deployed
| in Ukraine yet but they are on the list apparently. The smaller
| 300 has been deployed apparently but it doesn't carry a shaped
| charge, instead it carries an antipersonnel charge. More of a
| flying hand grenade kind of deal.
| a9h74j wrote:
| It's all fun and games until you realize your country has no
| deniability about being at war with Russia.
| natly wrote:
| Not sure why you'd use drones rather than just tiny remote
| controlled model airplanes.
| Vladimof wrote:
| Did you just upgrade the Slaughter bots?
| https://www.youtube.com/watch?v=HipTO_7mUOw
|
| actually I think that you didn't because slaughter bots are
| trying to not cause any collateral damage
| giantg2 wrote:
| If you're going to play around with explosives, an old
| knowledgeable teacher is best. I imagine incompetence gets weeded
| out early. The guy in the video has been in quite a few others
| too. It's fun to see how the hosts are usually a little nervous
| and he's calm as can be.
| h2odragon wrote:
| Count the fingers. More than 8 is probably OK. age may be a
| drawback, one gets too old to meddle with some of the more fun
| things eventually.
| Vladimof wrote:
| This type of explosive is very stable... nothing like
| nitroglycerin ...
| giantg2 wrote:
| The explosive is stable (small cubes of most plastic
| explosive can even be lit on fire and act as fuel). But there
| is still danger in correctly handling/connecting the
| detonator. I'm not sure, but I thing the acceleration charge
| might be a less stable type as well (obviously they aren't
| going to give us step by step instructions).
| Vladimof wrote:
| > (obviously they aren't going to give us step by step
| instructions).
|
| nitrocellulose is very simple to make and detonate... and
| is also very stable.... I don't see why we need secrets...
| I played with that stuff when I was a teenager
| giantg2 wrote:
| Is that what they are using for the acceleration charge
| (not the main charge!)?
| dvtrn wrote:
| "What makes me a good Demoman? Well if I were a _bad_ Demoman,
| I wouldn 't be sitting here discussing it with you, now would
| I?"
|
| One of the silliest, hilarious but on point thing I've ever
| heard uttered from a video game character
| anfractuosity wrote:
| Dr Alford also designed water-lined shaped charges for disrupting
| IEDs -
| https://en.wikipedia.org/wiki/Sidney_Alford#Early_Inventions
| pueblito wrote:
| Now I want to look into 3d printed explosives
| [deleted]
| a9h74j wrote:
| Pro tip: you'll want to splurge on that second overtemperature
| limit on your heated bed.
| formerly_proven wrote:
| https://3dprintingindustry.com/news/uk-defence-agency-plans-...
| Animats wrote:
| That's a nice explanation of how anti-tank weapons work.
| Vladimof wrote:
| I wonder if that's how Ukraine killed so many tanks
| kube-system wrote:
| Yes: https://en.wikipedia.org/wiki/FGM-148_Javelin#Warhead
| KennyBlanken wrote:
| Poor training, poor tactics, poor supply/logistics, poor
| operational security. And despite Russia's supposed doctrine
| of having very tight infantry/mechanized unit integration,
| their mechanized forced have been very vulnerable to
| Ukraine's infantry. Especially early in the war, Russia's
| mechanized units were running out of food, water, fuel, and
| ammunition.
|
| Russia used Ukraine's mobile network and cell phones, then
| when they realized Ukraine was just targeting where they saw
| lots of Russian phone numbers, they stole Ukrainian phones
| off civilians...so Ukraine started accepting reports of stole
| SIMs/phones and tracking those.
|
| Turns out that surrounding yourself with people who tell you
| what you want to hear (and who are siphoning off every ruble
| they can into their own pockets) isn't that great for having
| a strong armed service.
|
| Also, you've got a force with a lot of conscripts who were
| lied to about what they were doing, versus a force which has
| watched their friends and family get butchered. That's one
| reason you don't go around slaughtering civilian
| populations...it makes for a very, very motivated, united,
| angry enemy.
| JumpCrisscross wrote:
| We've also seen credible reports that where the reactive
| armour is meant to have explosives, instead one finds egg
| cartons. Corruption, through and through.
| toomuchtodo wrote:
| My understanding is that it's poor design, storing ammunition
| in a ring within the turret which turns out is a poor
| location from an integrity perspective. The "Jack in the box"
| vulnerability.
|
| > The fault is related to the way many Russian tanks hold and
| load ammunition. In these tanks, including the T-72, the
| Soviet-designed vehicle that has seen wide use in Russia's
| invasion of Ukraine, shells are all placed in a ring within
| the turret. When an enemy shot hits the right spot, the ring
| of ammunition can quickly "cook off" and ignite a chain
| reaction, blasting the turret off the tank's hull in a lethal
| blow.
|
| > For Russia, "the people are as expendable as the machine,"
| he said. "The Russians have known about this for 31 years --
| you have to say they've just chosen not to deal with it."
|
| https://www.washingtonpost.com/world/2022/04/30/russian-
| tank...
| AdrianB1 wrote:
| The design is responsible for the catastrofic explosions
| that blow the turret off the tanks, not for the tank being
| penetrated. The penetration is achieved by making the
| missiles explode on top of the tank, defeating the thinnest
| armor versus frontal armor that has 60-100 cm equivalent in
| RHA steel (they are composite, so thickness is different).
| AdrianB1 wrote:
| No, it has nothing to do with shaped charges; they are using
| missiles that explode on top of the tanks. Most armor of the
| tank is frontal arc, some on the sides, top armor is minimal,
| just a few centimeters, so it can be easily penetrated by
| explosions of these missiles or by aircraft cannon fire from
| platforms like A-10.
| berkut wrote:
| HEAT warheads (what NLAW has) is _completely_ to do with
| shaped charges.
| AdrianB1 wrote:
| Yes, but it is not how it is used in Ukraine. Quote:
| "Against tanks and other armoured vehicles, the overfly
| top attack (OTA) mode is used; the missile flies about
| one metre above the line of sight, detonating the warhead
| above the target's weaker top armour".
|
| It has dual-mode: direct attack and OTA. The many tanks
| in Ukraine are killed in OTA, that does not use the
| shaped charge effect.
| KennyBlanken wrote:
| "I designed this, for, well, filling by the user. It means it can
| travel on airplanes and such"
|
| Presenter: "DIY shaped charges, _of course_ "
|
| "Mmm yes"
|
| I get that he likely meant it can be _shipped_ on airplanes and
| local explosives used for easier logistics, but it 's amusing to
| hear an explosive munitions expert brag about designing something
| so it can be carried on airplanes.
|
| "This box, I'm pleased to tell you, is full of explosives."
|
| Oh man, this guy is a hoot.
| a9h74j wrote:
| YT brought me this[1] next, another jolly bunch with
| explosives.
|
| One of them before an attempt with water between the explosive
| and the target wall: I predict it will either go through or the
| wall will be really clean.
|
| [1] https://www.youtube.com/watch?v=rUKTIt5GQrM
| Someone wrote:
| I interpreted that as him being able to bring everything except
| for the explosives anywhere easily by regular airlines, where
| he expects his client to provide the explosives.
| AdrianB1 wrote:
| It is just saying it is so stable and safe, it can be
| transported on a plane.
| javert wrote:
| If you were wondering what inspired the accents of fictional
| pirates and witches in movies and TV shows, now you know.
| Maursault wrote:
| In principle, I think this is how we defeat invading aliens.
| Production value of this piece is interesting. It kind of seems
| like an infomercial for PE4.
| etaioinshrdlu wrote:
| Is there a diagram of the setup? I find the video pretty
| confusing to watch.
| Jabbles wrote:
| https://makeagif.com/gif/shaped-charge-NMFryy
| daenz wrote:
| I'm not sure I fully understood the explanation. So the copper
| cone is turned inside out and turns into a pointed wire that
| drives into the target? How is it that this wire can continue
| through the 1ft of steel? Is the force of the explosion flowing
| through this wire/tube, like liquid in a straw? And somehow it
| can sustain this through 1ft of steel?
| trhway wrote:
| due to the copper cone shape and the explosion wave propagation
| from the back the copper, which at those pressures is flowing
| like a liquid, is formed into a jet and pushed forward like a
| water in a power washer hose. Water at 3000bar would cut
| several inch steel
| (https://www.youtube.com/watch?v=quL14Csmi_Y). The copper in
| that explosion gets accelerated to the speeds of like 10km/s
| and as a result cuts through everything in its way.
|
| A bit of current context - beside deep penetration the jet
| isn't that destructive to surroundings. And here comes design
| flaw of Russian tanks - getting inside a Russian tank such jet
| frequently hits the tank's ammo which in those tanks is stored
| in a carousel around/under the turret and thus it results in
| the whole tank ammo explosion which even throws the multi-ton
| turret several stories up into the air (you can see a lot of
| the tanks blown up in that way - 'lollypops' - in Ukraine). To
| compare - US Abrams tank has ammo stored in separate
| compartment in the back of the turret.
| KennyBlanken wrote:
| FYI, waterjets cut by using water to carry an abrasive media
| which is injected into the stream at/near the nozzle, not by
| the action of the water alone.
| Someone wrote:
| Also crucially, the munitions compartment is weaker on the
| outside of the tank than on the wall between it and the crew,
| so if it goes, it blows out of the tank (search term "blowout
| panels")
|
| Fireworks and ammunition factories and storage facilities
| tend to have strong walls and relatively weak roofs for the
| same reason: if a building goes boom, you don't want it to
| make neighboring buildings go boom, too.
| nine_k wrote:
| The cone becomes very hot stream of molten copper. It melts
| through the steel plate, much like a jet of hot water melts
| through a block of ice.
|
| This happens fast enough that much heat does not have the time
| to escape from the impact site, despite high thermal
| conductivity of metals. The high pressure created by the
| explosion keeps the jet compressed from sides, too, so it does
| not fragment easily.
|
| Various kinds of "active armor" trigger the munition by a
| thinner layer of metal well ahead of the real thick armor
| plate, then produce counter-explosions to break the jet.
| raldi wrote:
| The video specifically says it's not molten.
| causality0 wrote:
| It's not actually liquid, it only behaves like one on impact
| due to the magnitude of the forces. It's more accurate to say
| it erodes through the armor instead of melting.
| Vladimof wrote:
| > much like a jet of hot water melts through a block of ice
|
| cold water can cut through steel
| also...https://www.youtube.com/watch?v=v0NVOThRooE
| Nextgrid wrote:
| Waterjet cutting uses water to propel a powder which acts
| as an abrasive, like an infinite stream of sandpaper. I
| don't think water by itself will achieve much.
| climb_stealth wrote:
| Huh, thanks for mentioning this! I always thought it was
| just water with enough pressure.
|
| It looks like pressure cutting with pure water exists but
| it is limited to softer materials. This page [0] has a
| fair bit of detail on it all.
|
| [0] https://www.machinemfg.com/waterjet-cutting-
| guide/#Classific...
| daenz wrote:
| Sounds like pressure washing vs sand blasting. Only
| difference between the two (aside from drastically
| different effect) is sand blasting has an intake tube to
| suck sand into the water jet.
| Vladimof wrote:
| you learn something new everyday
| walnutclosefarm wrote:
| Water is not doing the cutting there. Water is just the
| carrier for garnet abrasive, which does the actual cutting.
| Garnet is roughly three times harder than steel, so at high
| pressure cuts it very effectively.
| postalrat wrote:
| Maybe that's what happens but the video explains it as a
| stream of copper (not molten?) that pushes the steel out of
| the way.
| WhitneyLand wrote:
| It's not molten, and heat plays no role in the penetration
| ability. This is a very common misconception.
|
| It's simply focused kinetic energy that does it. The cone
| focuses the copper into a slug like object, and the slug
| becomes similar to an extremely powerful bullet.
| Brian_K_White wrote:
| So it's like that old picture of the grass straw driven
| through the telephone pole by nothing but hurricane wind?
|
| The flimsy straw could do it simply because of how fast it
| was moving. The strength of the straw doesn't matter,
| simply it's mass, moving that fast, carries itself through,
| ie the leading edge is not being pushed from behind like a
| nail, more like a bullet with a string attached?
|
| Setting aside the simplification, that probably the mass of
| the rest of the straw does play _some_ part not absolutely
| zero, is that a reasonable way to conceptualize it?
| davesque wrote:
| Here's a vid I found that seems to show a simulation of the
| effect: https://www.youtube.com/watch?v=CpVVGk2OfQQ
| daenz wrote:
| Great find @ 0:40. The only thing it doesn't convey very well
| is the older man's explanation of the copper spear curling
| outward on itself. From the simulation, it seems like it is
| just punching through and maintaining its rigidity somehow.
| JumpCrisscross wrote:
| It appears to rely on the copper's ductility. Curious if a
| gold or silver shaped charge has been modelled.
| yread wrote:
| It's not molten but it could be and it would still work as the
| guy in the video invented water-lined shaped charges (for
| disabling mines and IEDs without making them explode). What's
| important is the force/pressure that pushes steel to the side.
| daenz wrote:
| Sorry to answer my own post, but I watched it again and picked
| up on the key idea at 2:09.
|
| The inverted apex of the cone drives into the steel, pushing
| the steel aside, but then the apex opens up and flows back
| along the outside of itself. In other words, any given part of
| this copper "wire" interacts with the steel only long enough to
| push it open, then it is replaced by new copper.
|
| From this explanation, it sounds like the tunnel that has been
| "bore" through the steel would be completely coated from start
| to finish by the inverted copper cone.
___________________________________________________________________
(page generated 2022-05-14 23:00 UTC)