Shaped Charges – Sheet of copper going through 1ft of solid steel (2010) [video]

530 points19
hunter-gatherer14 hours ago

In the US/Iraq war such contraptions were commonly referred to as EFPs (explosively formed penetrators). My platoon was once hit by a four-array EFP that was hung behind a cement wall (US forces would often line streets with barricades like this) so we couldn't see it. It went through the concrete wall, the humvee, and took some legs with it. Brutal things they were. We avoided prolonged truck excursions, but I remember we used to always sit with our arms and legs as staggered as possible--The thought being that if an EFP went through, you might get lucky and only lose one arm/leg instead of two. Of course it probably didn't help... but whatever.

hedgehog11 hours ago

Devious. The assassination of Alfred Herrhausen is I think the textbook example of this technique:

sofixa8 hours ago

Interesting, thanks for sharing.

A few things stand out (spoilers of course) - the Chairman of Deutsche Bank had an armoured convoy with two vehicles with bodyguards. It makes sense seeing that someone was trying to kill him, but outside of that context it seems a lot. Most European politicians, including heads of state and government, have less today.

Second, he bled to death. I wonder what circumstances led to this, was the car too badly mangled and nobody could come to his aid? It's not something that happens instantaneously, i think, so there's some time to react. But maybe the blood loss couldn't be stopped ( severed legs, is there something that could be done? Would a tourniquet help?). No idea

conradev3 hours ago

You have about three minutes for an arterial bleed. Perhaps less for two arterial bleeds. The proper technique would indeed to be tourniquet the legs, which you can do with anything (like strips of cloth) as long as you can make it tight enough.

spiffistan8 hours ago

Also rather interesting that Vladimir Putin is thought to have been involved as the RAF handler, if those sources are veritable.

zeristor7 hours ago
brazzy4 hours ago

> if those sources are veritable.

Those sources are pretty shit, honestly. One says the Red Army Faction claimed responsibility (this is not disputed). The other cites an (unnamed) "former Red Army Faction" claiming they had meetings with Putin, but makes no connection with the Herrhausen assassination.

earthbee9 hours ago

EFPs are similar but distinct from shaped charges. Shaped charges use a conical liner that forms a jet that is only really effective over a limited range, the liner on EFPs is usually flatter and is designed to form a projectile that is effective over much wider ranges.

Retric2 hours ago

EFP’s are a type of shaped charge:

“An explosively formed penetrator, 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 armor effectively.”

magicalhippo2 hours ago

The dad of a childhood buddy was in our version of the rangers and mentioned they had made improvised shape charges (in his words) using a helmet filled with plastic explosives and a metal dinner plate as liner to form a shape charge.

When I got older I was thinking maybe he was telling some tall tales, but I guess this could work as an EFP.

sandworm10149 minutes ago

That would totally depend on the metal. Some would just shatter. Too brittle a metal or too violent a charge and the 'penetrator' just becomes a shotgun of shrapnel flying out in all direction.

root_axis13 hours ago

That sounds pretty scary. I hope you made it out ok.

jade-m10 hours ago
bottled_poe8 hours ago

The politics are important to understand, but it’s insensitive to bring this up in the context of an individual soldier’s account of this situation. Like, great work with the virtue signalling, you’re very clever and informed. Maybe try reading the room a bit and being a bit more compassionate toward people who have no influence in these politics?

jade-m8 hours ago

I understand where you're coming from. But as an Iraqi who have lived through the "war" and having several family members and close friends who were killed in the war (all civilians), I can't help but consider the objectivity in naming here as insensitive to the half-million Iraqis who were killed in the war. Not to mention destabilizing the middle east forever.

user_78324 hours ago

(Not replying to you but in general to the others)

> as an Iraqi who have lived through the "war"

This is why it's never a great idea to assume anything and interested better to try to keep things neutral and reasonable.

1274 hours ago
4gotunameagain8 hours ago

I'm sorry, but when somebody tells you "we will ship you 7000 miles away to fight in a different continent" and you accept, you share at least some part of the responsibility.

There would be no wars without greedy politicians, but there would be no wars without soldiers too.

bottled_poe8 hours ago
InCityDreams4 hours ago

I understand 'I'm sorry...' is a turn of phrase but it's absolutely not necessary here.

smokey_circles7 hours ago

None of that is salient.

Propaganda is an effective drag net. We're all susceptible to some form of it. Outright lying works more effectively than it should.

You're just looking for a morale high ground, no need to pretend otherwise.

jakear10 hours ago

Vouched for this. Names are important, it’s disingenuous to suggest US and Iraq played an equal role in initiating the engagement.

Do we call it the Russia/Ukraine war or the Russian invasion of Ukraine?

IMTDb9 hours ago

We call them : The Iraq War ( and the Russo-Ukrainian War (

This is a discussion about a special kind of explosive and a first hand story on how it is used in a conflict. Leave politics aside.

account-59 hours ago
gpm1 hour ago

Flagged this, I agree names are important, but the tone and context make this flamebait IMHO. I do think it's borderline.

I also don't quite buy the argument - see jhgb's reply - but that's definitely not why I flagged it.

jhgb8 hours ago

Both, since one is a part of the other. The way I get it, the major asymmetry between the two cases is that the US invasion of Iraq was the initial phase of the Iraq war (which had already ended), whereas the Russian invasion of Ukraine is the terminal (and current) phase of the Russo-Ukrainian war (which hasn't ended yet).

So if you're talking about these things today, it makes perfect sense to talk about the invasion in progress as it's the current event. If you bring up the Russo-Ukrainian war in a conversation, it's unclear about what part of the events since 2014 you're talking about, since presumably if you were talking about the current events, you'd be more specific. If you talk about the Iraq War, there can be no confusion with current events since it ended a decade ago.

kodah9 hours ago

Is it disingenuous to speak authoritatively on a subject that one doesn't bother to google? Is it also disingenuous to vouch for someone making an inflammatory comment intended on derailing discussion, especially when that discussion is threaded from someone reliving their experience with explosive projectiles?

12ian346 hours ago

I think you mean the US invasion of Iraq under completely false pretences

tomcam9 hours ago
nostrademons15 hours ago

The Wikipedia article on shaped charges is fascinating:

The penetration distance is proportional to the diameter of the charge (counterintuitive; you'd expect the height), and can be up to 7x as large. So a ~5 inch charge shown in the film can penetrate up to about 3 feet of solid steel.

Also, all of our known defenses against shaped charged rely on the assumption that the same spot won't get hit twice. Composite armor breaks and deflects the geometry of the jet through its deformation; reactive armor relies on a mini-explosion to defeat the jet. This has interesting implications in a world of drones and precision-guided munitions, and in fact the Javelin missiles we've been shipping to Ukraine have double warheads, the first to destroy the armor and the second to destroy the vehicle.

Terry_Roll14 hours ago

Alot of things were developed during WW2 like an Earthquake bomb and in the 50's the first of these were developed, a Tsunami bomb

A scaled down model of the Möhne dam where the bouncing bomb was used can be found at the BRE site in Watford on your way to the lunch canteen.

infofarmer15 hours ago

There are many more types of active defenses other than reactive armor:

bglazer13 hours ago

I recently learned that active protection systems have really significant electronic signatures. I’m no expert but I believe that they rely on vehicle mounted radar systems to detect incoming fire.

Take a look at this graphic:

The source for this is an advertisement for a Rheinmetal brand APS. So treat it like you would any marketing material.

Nonetheless, if it’s even remotely accurate, I would not want to be part of a tank crew that is visible to surveillance aircraft multiple countries away.

I get the impression these APS systems were designed with low intensity “anti-terror” operations in mind. They’ll do a decent job killing an RPG fired from across the street but they light you up like a Christmas tree. Not a problem if you’re battling ISIS but a significant liability against opponents with modern surveillance capability. Also they’re useless against top attack munitions which seem to be remarkably effective in Ukraine.

tootie14 hours ago

Great video on the engineering of the Javelin and why it's so simple and effective:

The Javelin has multiple tricks up its sleeve to defeat sophisticated armor and Russian armor is just behind the curve. It's a literal arms race to add more layers of defense and more layers of attack and right now, NATO is far ahead.

nyolfen12 hours ago

this is compounded by the fact that much of the armor on the ground in ukraine does not actually seem to feature the advanced defenses developed during the soviet era, like ERA. i've seen several photos of what appears to be decoy ERA on destroyed t-72's, which was nothing more than a hollow brick of steel. i suspect graft or a weak economy is the reason.

MertsA9 hours ago

Forget decoys, some of the videos coming out of Ukraine were showing plenty of Russian tanks with the bags for the reactive armor sagging down clearly only holding the spacers and no ERA plates. It's like the troops believed the cover story that they were only going near the border for a training exercise.

avereveard8 hours ago

the source of these pictures are all from ukraine. it's not far fetched to think they removed era and planted inert spacer to demoralize the enemy. in general, while the fog of war is in full effect, I wouldn't trust any one-sided intel.

sofixa7 hours ago
mensetmanusman4 hours ago
mauvehaus13 hours ago

You know, a theme of From the Earth to the Moon by Jules Verne is the longstanding rivalry between weapon makers and armor makers. 150 years after it was written, that bit still seems to hold true.

User2313 hours ago

Training with shaped charges made my father grateful he ended up in the infantry. They are clever, but seriously nasty.

amai29 minutes ago

„Electric armour is a type of reactive armour proposed for the protection of ships and armoured fighting vehicles from shaped charge and possibly kinetic weapons using a strong electric current“

supernova87a13 hours ago

I amuse myself by thinking that Sidney Alford (the expert in the video, who by the way appears to have passed away last year) looked like, and was, the modern Grand Maester, conjuring up magical (but yes, destructive and terrible) explosives for the use by kingdoms against each other. He should've been given a cameo part in Game of Thrones...

I got onto the topic years ago when watching the Dambusters. Related to this, he also has a video showing how putting a simple tube/bag of water behind an explosive charge magnifies its force incredibly. I believe he started a company that built and sold explosives with such a water-fillable jacket that could be used to knock down doors by police forces.

edit: here's the water filled explosive knocking down a door:

dEnigma6 hours ago

  >here's the water filled explosive knocking down a door
Seems more like it's blowing a hole into a wall.
andai3 hours ago

What wall? ;)

giantg218 hours ago

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.

dvtrn18 hours ago

"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

ethbr016 hours ago

"Hey look, buddy. I'm an engineer: that means I solve problems.

Not problems like 'What is beauty?' Because that would fall without the purview of your condundrums of philosophy.

I solve practical problems..."

jimnotgym7 hours ago

It strikes me that if you work with modern explosives and follow sensible procedures like retiring to a safe distance, the risks to you are not that high. The risks in a demolition are huge, but not to the life of the explosives guy. I can imagine the job of weakening the structure, (by removing parts of it) prior to the explosives carry more risk to the operator

mensetmanusman4 hours ago

I don’t know. I’m a trained chemist and after enough years, you have that one day where you might’ve went to sleep too late and where you use the wrong type of glass, and a boiling vat of sulfuric acid etc. fails quickly and melts a bunch of stuff.

Sometimes I’m glad I’m in this field though, because I hear about the researchers working on prions that have started dying off, and I know it’s one of those one and 100,000 events that you inevitably experience.

bawolff15 hours ago

Survivorship bias personified

sophacles14 hours ago

But... in a field where being bad at your job is fatal, is it really a fallacy?

Serious question - just like quoting an expert in the relevant topic isn't an appeal to authority, etc.

bawolff14 hours ago
panqueque9 hours ago

> just like quoting an expert in the relevant topic isn't an appeal to authority, etc.

The credentials of the expert don't determine whether or not the statement is an appeal to authority.

matheusmoreira15 hours ago

The bad demomen had to be glued back together. In hell.

mhh__16 hours ago

The younger guy in this clip actually ended up retiring because he got brain damage in a contraption he designed for this show.

matheusmoreira15 hours ago

> The injuries happened when Mr Stansfield, who was 42 at the time, filmed a Bang Goes The Theory feature about the relative safety of forward and rear-facing child car seats.

> The episode saw him "strapped into a rig like a go-cart which was propelled along a track into a post".

I'm sorry but to me this reads like something out of Darwin Awards.

htk14 hours ago

That’s why he was awarded around half of what he demanded, because BBC shared the responsibility by accepting the stunt, but he was also responsible for doing it.

supernova87a13 hours ago
robocat14 hours ago

> That’s why he was awarded around half of what he demanded

Which is why he asked for 4x what might be fair? I’m being facetious: I have no idea. I am just saying there is little constraint on how much damages you can reasonably ask for.

stjohnswarts15 hours ago

Exactly, this is what dummies (the inanimate ones), cameras, and sensors are for O_O

itsyaboi16 hours ago

This is bizarre. He knowingly, purposefully took the place of a crash test dummy? Why?

sacrosancty13 hours ago

Apparently they used to do that. Here are people demonstrating the safety of seatbelts by crashing their car

kayodelycaon13 hours ago

I assume he was focused on doing the experiment he (and dozens of other people) lost sight of the consequences.

As we say in America: “Hold my beer.”

Edit: Or more charitably, they underestimated the consequences.

noneeeed8 hours ago

Pretty much the latter.

This wasn’t Jackass, it was a science programme and he was the resident engineer. In theory he knew what he was doing but underestimated the risks and paid the personal consequences.

green-eclipse13 hours ago

"Hi, I'm Johnny Knoxville and this is crash test humans"

h2odragon18 hours ago

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.

IncRnd16 hours ago

There are old people who use explosives. There are bold people who use explosives. But, there are no old, bold people who use explosives.

ethbr016 hours ago

Reading Ignition! convinced me that there's more than raw intelligence to experimenting with energetic chemistry.

function_seven14 hours ago
Vladimof18 hours ago

This type of explosive is very stable... nothing like nitroglycerin ...

giantg218 hours ago

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).

jwhitlark1 hour ago

They used to burn c4 in Vietnam to heat coffee/food. Just don't step on it, as it suddenly remembers it's an explosive...

Vladimof18 hours ago

> (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

aurizon15 hours ago
ILMostro716 hours ago

I assume it helps to narrow down the list of suspects if/when the (guarded/secret) knowledge is used for nefarious purposes.

giantg218 hours ago
chemeril15 hours ago

Nitrocellulose is not a high-order explosive and used nowhere in this experiment. Deflagration != detonation.

relbeek213 hours ago

The calmness comes from really knowing and understanding what you are working with. I used to frequently work around hundreds of thousands of pounds of class 1 explosives. Once you understand that the primary risks of dry explosives are impact, shock, and impingement. You can protect yourself against those risks and get comfortable working around the material.

fortran7716 hours ago

And he still has 10 fingers! Unlike, for example, Mark Pauline (

swayvil16 hours ago

A bit of a nervous twitch perhaps.

anfractuosity18 hours ago

Dr Alford also designed water-lined shaped charges for disrupting IEDs -

StringyBob16 hours ago

Am I reading this right? That section also says he made shape charges out of cucumber that could cut steel!

GravitasFailure16 hours ago

You read that right or we're both reading it wrong. I'm guessing the cucumber was an early prototype of the gelled water shaped charges, or he has a very...energetic...hatred of salads.

dylan60415 hours ago

No, not salads. Spas.

londons_explore9 hours ago

Cucumber is basically water that you can cut to shape with a knife.

1274 hours ago

If you look just at how small the shaped charge inside the NLAW is, and how the weapon works, I wonder why you wouldn't just put that shaped charge inside a $50 drone and fly it directly above the tank.

ycombinete4 hours ago

They are already doing that. There are many videos of Ukraine using modified anti tank grenades. They remove the little parachute, and attach a 3-d printed tail. This is then fitted to a commercial drone.

Examples (NSFW-ish, Thermal imagery of tank cook-offs):



There are also a lot showing anti-personnel grenades, and even RPG rounds being dropped on people, and regular cars etc. too.

hasperdi4 hours ago

They do actually equip largish hobby class quadcopters with anti tank grenades. You'll find plenty videos of them on YouTube.

tshubbard14 hours ago

Shaped charges are also used to create the holes (perfs) in wellbores prior to fracking. The shaped charges blast through 1/2 inch of steel pipe and then a foot or two of rock. Sand and water are then pumped through the holes to prop open the rock and allow oil, gas, and water to flow out with less resistance.

daenz18 hours ago

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?

davesque17 hours ago

Here's a vid I found that seems to show a simulation of the effect:

BurningFrog16 hours ago


So the shape is such that all parts of the cone converge at the center, so the full energy of the explosive is focused in that thin column.

JumpCrisscross17 hours ago

It appears to rely on the copper’s ductility. Curious if a gold or silver shaped charge has been modelled.

nostrademons15 hours ago

It's been used for plutonium. The explosive lenses used in implosion-type nuclear weapons are extremely-precise shaped charges, and work by focusing all the explosion's energy into compressing the plutonium down to critical mass:

shirleyquirk16 hours ago

I found which has this to say about gold:

>Hypothetical shape charge liner. High density is a benefit but equally low speed of sound indicate s that it may be no better than uranium. An advantage may be found in its ductility, if it leads to greatly improved jet formation relative to its cost.

It seems that sound speed and density are considered more valuable, so tungsten, zirconium, molybdenum.

daenz17 hours ago

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.

jvanderbot17 hours ago

iirc, nothing is rigid, it's just very high energy jets, so they don't deform much. like particles in water jets cutting steel.

itsyaboi16 hours ago
jacquesm3 hours ago

The time scale on those is very interesting.

daenz18 hours ago

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.

lamontcg17 hours ago

The mental image which is working well enough for me is a series of tightly packed bullets with each one digging the hole a little deeper than the last one.

Of course the shaped charge isn't a gun though and the stream of copper doesn't travel for hundreds of meters/yards. If you need to stand off from the target you'd want to mount it as the payload of a rocket and fire towards thine enemies.

EDIT: this is of course a better description:

So the rod is traveling so fast that it and the target act like liquids, even though it isn't molten.

colechristensen15 hours ago

Imagine a picture of the jet coming out of a black hole.

Something very roughly similar is happening here. The shape of the cone as the detonation wave goes through the explosive forces copper into the center and the only (or lowest resistance) way out is a straight jet through the target material.

askvictor14 hours ago

I'm impressed (and a little confused) at the idea the explosive is essentially sitting untethered on the target. I would have thought the entire contraption would shoot up with the explosive force being reflected off the ground, but I suppose there's enough energy in the initial blast (before the reflection) to form the copper 'bullet'. =

lazide12 hours ago

The reason it works is nothing has time to get out of the way - all this is well past the speed of sounds for all materials involved. So the action/reaction is happening - the gas from the explosive is recoiling for instance - but it only has time to go a few inches and the forces and counter forces are immense.

ycombinete4 hours ago

It functions more like a jet of water. The speed that the solid copper moves at pushes the steel aside as if the were both liquids

yread17 hours ago

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.

emmelaich16 hours ago

A major part of it is that the copper is going extremely fast.

But also see other explanation, about being renewed.

trhway18 hours ago

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 ( 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.

Someone17 hours ago

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.

KennyBlanken18 hours ago

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.

jacquesm3 hours ago

You can use an abrasive component but you don't have to, pure waterjet cutting works. And depending on the materials and the nozzle shape might actually be the optimum.

nabla916 hours ago

The velocity of the jet is typically around 10 km/s. There is enough pressure to get trough.

nine_k18 hours ago

Update: this is incorrect.

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.

WhitneyLand18 hours ago

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_White17 hours ago

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?

foucalt-apathy14 hours ago
chemeril15 hours ago

Yes, that's reasonable. By the time the jet hits the target the explosive provides no motive force whatsoever: it's purely a momentum game.

throw_away16 hours ago

What would happen if you just started with a slug?

sacrosancty13 hours ago

I don't think you could deliver as much energy to it because it has such a small surface area normal to the direction of travel.

lazide12 hours ago

It’s really hard to get a slug Moving like that without tearing it apart. It’s easier to use the explosive to spread the force over a wider area initially but in a way that the projectile is formed by the concentration of the explosive forces mashing it all together. Weird.

raldi18 hours ago

The video specifically says it’s not molten.

causality018 hours ago

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.

Vladimof18 hours ago

> much like a jet of hot water melts through a block of ice

cold water can cut through steel also...

Nextgrid18 hours ago

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_stealth17 hours ago

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.


daenz17 hours ago
Vladimof18 hours ago

you learn something new everyday

nullc16 hours ago
walnutclosefarm18 hours ago

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.

postalrat18 hours ago

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.

GartzenDeHaes15 hours ago

A plasma technically. And it doesn't exactly penetrate, it pushes the steel atoms aside very literally like sticking your finger in butter.

Edit: obviously it penetrates, but not in the way that you would expect.

chemeril15 hours ago

Certainly not a plasma. It's a coherent spear of hydrodynamic copper, not a bunch of charged ions floating around.

GartzenDeHaes10 hours ago

As far as I know, it could be little qanons in there stealing the steel atoms to build jfk jr's moon rocket. However, the principle physicist for the nuclear emergency search team described it using the butter analogy.

samlader17 hours ago

Interesting simulation of a shaped charge:

staticassertion14 hours ago

Slow Mo guys using shape charges.

scotty7911 hours ago

What's pretty surprising is that explosively formed projectiles can have quite a range and can be aimed precisely.

Explosion of PTKM-R1 anti-tank mine that destroys the tank by targeting it from above:

I also read about some antitank missile that basically has two such auto-aiming charges and just releases them when it's above the targets and they aim and detonate forming projectiles that hit the tank(s?).

Animats19 hours ago

That's a nice explanation of how anti-tank weapons work.

kinjba1116 hours ago

There's a great recent video from Real Engineering showing how Javelins work to annihilate tanks.

Schweigi17 hours ago

If you want to know more - for example how the fuze even knows when to trigger and how it actually triggers the explosion - there is a good (lengthy) video about the M58 hollow charge rifle grenate and fuze design:

Vladimof18 hours ago

I wonder if that's how Ukraine killed so many tanks

JumpCrisscross17 hours ago

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.

toomuchtodo18 hours ago

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.”

sbierwagen17 hours ago

All design is compromise.

The autoloader is a design decision: it replaces a crew member, so Russian tanks operate with a crew of 3 instead of 4. This makes Russian tanks smaller and lighter. Here's a size comparison of the T-72 with the Abrams:

For the massed tank-on-tank actions it was meant for, this is good! Smaller targets are harder to hit, and T-72s were supposed to be fighting gun duels against M60s while crossing West Germany, so all the armor is in the front plate. Lighter tanks are cheaper, so you can build more of them, going from 4 crew to 3 means your limited pool of tankers can operate 33% more vehicles in the field. Classic cold war-era doctrine, hard lessons learned from WW2. (It makes regular operations like tank maintenance or replacing damaged tracks way harder, but oh well, nobody ever said being Russian was easy)

Separately, there is no particular reason to think Abrams tanks wouldn't be vulnerable to the same weapons, if the Russians had that tank today and were fielding them in the same way they're operating their own tanks. Abrams also has light top armor and no ERA tiles on the roof. An anti-tank grenade dropped by a drone on an Abrams ammo compartment would mission kill it instead of killing the crew, but it would still be out of operation. AFAIK, no Abrams are equipped with Trophy in significant numbers, so it would be just as vulnerable to Javelin or other top attack ATGMs.

Tanks are vulnerable from the air, so you need air supremacy; vulnerable to artillery, so you need counterbattery suppression; vulnerable to man-portable AT weapons, so you need dismounted infantry combined arms; vulnerable to AT mines, so you need demining combat engineers, perimeter security so UKR spec ops can't cross lines and plant them, and military police so enforce civilian curfews. Russia is doing none of this, partly due to incompetence, and partly because they just didn't have a big enough force. (Desert Storm took just a hair under a million troops!)

If Russia had Abrams, but held all else equal, we'd still be seeing hundreds of flaming wrecks on the nightly news.

AdrianB118 hours ago

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).

nradov16 hours ago

This Chinese TV news video shows a wild example of the Jack-in-the-box vulnerability. A Russian tank in Ukraine gets hit and the turret takes off like it's headed for orbit.

swimfar15 hours ago

The actual footage starts at 2:26

KennyBlanken17 hours ago

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 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 makes for a very, very motivated, united, angry enemy.

AdrianB118 hours ago

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.

berkut17 hours ago

HEAT warheads (what NLAW has) is completely to do with shaped charges.

AdrianB117 hours ago
blip5432117 hours ago

Question: Is there a way to play with these things at home? Any pointers to DIY stuff?

belval17 hours ago

You can find it by Googling around, but you won't find it on chemistry YouTube channels as YouTube cracked down hard on those. Even videos on making precursors to RDX or HMX (which can be used to make C-4) are banned.

Spooky2313 hours ago

The materials are monitored and retailers have relationships with police, nationwide.

If you, a non-farmer, shows up to buy some fertilizer, etc, calls are made.

chemeril15 hours ago

Yes and no. It's simple enough to construct a shaped charge from things you buy at Home Depot, assuming you have the right explosive. The explosive needs to be conformal (either plastic or castable) and capable of achieving true detonation. Secondaries like C4 and TNT are not easy to synthesize at home, and the primaries that are easy to synthesize at home are difficult to phlegmatize and handle safely at the necessary volumes.

Explosives are terribly fun but please do not try messing with them at home.

blip5432113 hours ago

I'd like to mess with them at home, but not at "the necessary volumes" to go through a foot of steel as in the video.

You know those little bang snaps you throw at the ground and they make a popping sound? For DIY, ideally, I'd do things in that kind of volume. I'd probably need a smidgen more, but I wouldn't want to do more than e.g. make a pinhole in 29 gauge sheet metal.

What I'd really love to make -- but I don't think I ever could safely -- is a little 1/8A or 1/4A rocket engine (of the that cost a couple bucks at the local hobby store).

This is science lab with kids, not bomb-making 101.

h2odragon30 minutes ago

Fireworks level explosives are fun and doable at the garage level. I don't think you can do real "shaped charge perpetrators" but you can do some really fun things like explosive welding and such.

lazide12 hours ago

Small rocket engines can be made with some pyrodex, dowels, and cardboard tubes.

Most high explosives involve nitric acid of decent concentration.

It’s hard to make them in quantities small enough to be actually not dangerous, especially since many of the compounds will react with all sorts of normal everyday substances (like aluminum, copper, etc) to form even more unstable compounds.

Some of them can even explode on exposure to light.

The two are not in the same ballpark. I wouldn’t recommend high explosive synthesis without a solid grounding in organic and inorganic chemistry.

Even a pea sized portion of these compounds can remove a finger or part of a hand, or blind you.

If you still want to know more ‘The Chemistry of Powders and Explosives’ is a good read.

Vladimof17 hours ago

any kind of explosive would probably be a good start... might want to check laws first though

throwaway74213 hours ago
KennyBlanken18 hours ago

"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.

a9h74j17 hours ago

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.


Someone17 hours ago

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.

KennyBlanken11 hours ago
AdrianB118 hours ago

It is just saying it is so stable and safe, it can be transported on a plane.

ncmncm12 hours ago

No. The explosives do not fly. The equipment is such as not to alarm airport people.

etaioinshrdlu18 hours ago

Is there a diagram of the setup? I find the video pretty confusing to watch.

emmelaich16 hours ago

Appears to be from a series

mhh__16 hours ago

The show was called bang goes the theory.

somat12 hours ago

Got to admit, I was hoping they would dig the copper jet out of the sand.

pueblito18 hours ago

Now I want to look into 3d printed explosives

a9h74j17 hours ago

Pro tip: you'll want to splurge on that second overtemperature limit on your heated bed.

chemeril15 hours ago

Several US national labs have been developing 3D-printed explosives technology for a bit now. Pretty crazy business that is (surprisingly) safer than doing large machining operations on bulk HE.

puskavi15 hours ago

I feel like this is really all about acoustics

stjohnswarts15 hours ago

lol I think I'm on a list now for watching that :)

swayvil16 hours ago

Bad ass.

Momentum trumps substance.

holly7618 hours ago
londons_explore18 hours ago

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.

alkonaut18 hours ago

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.

dragontamer18 hours ago

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.

AdrianB117 hours ago

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.

dragontamer17 hours ago
sudosysgen15 hours ago

Antidrone warfare is very very difficult. They are small and go slow and are thus difficult to shoot down. See how Iraqi militias fly drones into US bases and how Hezbollah regularly flies drone into Israel unpunished (sometimes Israel even has to resort to fighter jets to shoot them down).

ChuckMcM18 hours ago

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.

a9h74j17 hours ago

It's all fun and games until you realize your country has no deniability about being at war with Russia.

blip5432117 hours ago

I think the line is when your troops shoot their troops.

Providing weapons has been a US-Soviet past time for the whole Cold War.

In this case, I think the US could have even moved in troops without being at war, early in the invasion. It just needs a pretext. By far the best response a week in, when Russia claimed chemical weapons, Nazis, etc., would have been to send in a multilateral force to investigate Russia's claims. It's face-saving for the Russians and ends the war.

Tensions are too high for that now.

londons_explore16 hours ago
secondcoming16 hours ago

The CIA gave stinger missiles to the Taliban when the Soviets were in Afghanistan. The Russians gave military hardware to the North Vietnamese when the USA was there.

Arming your enemy's enemy is nothing new.

nradov14 hours ago

The Soviet Union never hesitated to supply weapons to North Vietnam when our country was at war with them. Turnabout is fair play.

qbasic_forever18 hours ago

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):

jltsiren16 hours ago

Drones are effective, but nothing is ever cheap on the battlefield. While the warhead that ultimately kills the target is often cheap, the real cost comes from the system that picks the right target and delivers the warhead there at the right time.

Cheap commercial drones have a short range. In order to use them effectively on the battlefield, each drone needs an operator, who must also be on the battlefield. Those operators then need other people for watching their backs, coordinating their actions, and handling the logistics. Those 1000 cheap simultaneously launched drones are now an entire brigade on the battlefield, which is definitely not cheap.

denton-scratch5 hours ago

I envisage a swarm of say 50 cheap-ish drones with a "swarm leader", intercommunicating using some kind of short-range mesh radio. They'd be disposable, single-use. They could be launched by a squad of say, 10 men.

The swarm leader could be human-piloted or autonomous. Autonomy would be a matter of software and sensors; once you've invented it, it would be dirt-cheap to implement. A swarm of 50 would be enough to baffle air-defence systems capable of tracking multiple targets.

I have no idea if this exists, but it seems an obvious idea; if it doesn't exist, it must have been tried and found wanting.

ncmncm11 hours ago

The most effective use of drones so far in Ukraine has been to direct artillery fire, converting what was an area weapon to a precisely targeted weapon.

Just a couple of days ago, a single artillery brigade eliminated an entire tank battalion at a river crossing.

Generally, if you can wipe out the fuel trucks, they have to abandon the tanks. An ordinary grenade suffices to blow up a fuel truck.

formerly_proven18 hours ago

UA is literally dropping anti-tank grenades and other explosives from commercial/civilian drones as we speak.

ThrowawayR217 hours ago

Then then drones meet or for which each round is even cheaper than the cheap drone it's aimed at and, snap, crackle, pop, no more drones.

Vladimof18 hours ago

Did you just upgrade the Slaughter bots?

actually I think that you didn't because slaughter bots are trying to not cause any collateral damage

natly18 hours ago

Not sure why you'd use drones rather than just tiny remote controlled model airplanes.

denton-scratch5 hours ago

What's the difference?

javert18 hours ago

If you were wondering what inspired the accents of fictional pirates and witches in movies and TV shows, now you know.

Maursault19 hours ago

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.