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

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

#161

Post by bawolff »

zhengyi13 wrote: post #138
bawolff wrote: post #134

Earlier quoted context omitted.

Its still a fallacy because some people are just lucky instead of being skilled, and its entirely possible to confuse the two. In the same way, an appeal to an authority is better than nothing, but its still a really weak argument. You can misunderstand authorities and authority can be mistaken or suborned. Its a reasonable argument if nobody knows much about the topic, but its never convincing if people are learned…

Luck eventually runs out. That's not to say you're wrong, only that I expect the distribution of the lucky amongst the skilled tends towards zero over sufficient time. "Beware old men in a young man's game."

The real question is what amount of time is sufficient. Its probably longer than you expect.

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

#162

Post by daxfohl »

bawolff wrote: post #134
sophacles wrote: post #130

Earlier quoted context omitted.

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.

Its still a fallacy because some people are just lucky instead of being skilled, and its entirely possible to confuse the two. In the same way, an appeal to an authority is better than nothing, but its still a really weak argument. You can misunderstand authorities and authority can be mistaken or suborned. Its a reasonable argument if nobody knows much about the topic, but its never convincing if people are learned…

Survivorship bias is more about believing a task is safe/easy because you only hear from the survivors/winners. Not about saying someone is better at a job because they haven't died/lost yet.

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

#163

Post by bglazer »

infofarmer wrote: post #129
nostrademons wrote: post #107

The Wikipedia article on shaped charges is fascinating: https://en.wikipedia.org/wiki/Shaped_charge 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…

There are many more types of active defenses other than reactive armor: https://en.wikipedia.org/wiki/Active_protection_system

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:

https://sites.breakingmedia.com/uploads/sites/3/2021/07/imag...

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.

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

#164

Post by Spooky23 »

belval wrote: post #73
blip54321 wrote: post #67

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

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.

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.

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

#165

Post by mauvehaus »

tootie wrote: post #139
nostrademons wrote: post #107

The Wikipedia article on shaped charges is fascinating: https://en.wikipedia.org/wiki/Shaped_charge 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…

Great video on the engineering of the Javelin and why it's so simple and effective: https://youtu.be/SUdHzKRiBX8 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.

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.

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

#166

Post by nyolfen »

tootie wrote: post #139
nostrademons wrote: post #107

The Wikipedia article on shaped charges is fascinating: https://en.wikipedia.org/wiki/Shaped_charge 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…

Great video on the engineering of the Javelin and why it's so simple and effective: https://youtu.be/SUdHzKRiBX8 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.

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.

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

#167

Post by nyolfen »

dragontamer wrote: post #68
AdrianB1 wrote: post #48

Earlier quoted context omitted.

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.

Sure, but Javelins (considered a very reliable weapon), is top-down AND 8kg of tandem charge of 900mm+ penetration. I think NLAW is ~500mm of penetration and top-down. Its not too hard to make a top-down weapon these days, but it does add weight to the device. -------- EDIT: I'm pretty sure that you can't just "drop" a mortar or AT4 warhead reliably either. You'd want to make it into the shape of... well... a bomb. S…

> EDIT: I'm pretty sure that you can't just "drop" a mortar or AT4 warhead reliably either. You'd want to make it into the shape of... well... a bomb. So that the "shape" of the shape-charge points in the correct direction.

they have been dropping 60's-vintage anti-tank hand grenades with 3d printed stabilizers: https://en.wikipedia.org/wiki/RKG-3_anti-tank_grenade#Histor...

"220 mm penetration of RHA" which is plenty for top armor

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

#168

Post by dragontamer »

nyolfen wrote: post #167
dragontamer wrote: post #68

Earlier quoted context omitted.

Sure, but Javelins (considered a very reliable weapon), is top-down AND 8kg of tandem charge of 900mm+ penetration. I think NLAW is ~500mm of penetration and top-down. Its not too hard to make a top-down weapon these days, but it does add weight to the device. -------- EDIT: I'm pretty sure that you can't just "drop" a mortar or AT4 warhead reliably either. You'd want to make it into the shape of... well... a bomb. S…

> EDIT: I'm pretty sure that you can't just "drop" a mortar or AT4 warhead reliably either. You'd want to make it into the shape of... well... a bomb. So that the "shape" of the shape-charge points in the correct direction. they have been dropping 60's-vintage anti-tank hand grenades with 3d printed stabilizers: https://en.wikipedia.org/wiki/RKG-3_anti-tank_grenade#Histor... "220 mm penetration of RHA" which is plent…

> "220 mm penetration of RHA" which is plenty for top armor

I seriously doubt that. Almost all modern tanks have reactive-armor on top.

There's a reason why NLAW has 500+mm penetration AND top-down. NLAW is single-charge (no-tandem), to punch-through reactive armor requires a lot more penetration.

Let alone lol Javelin with top-down, 900mm+ penetration, and tandem charge.

I don't think 200mm or even 400mm is considered reliable today.

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

#169

Post by lazide »

askvictor wrote: post #135
daenz wrote: post #16

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?

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'. =

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.

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

#170

Post by lazide »

throw_away wrote: post #102
WhitneyLand wrote: post #34

Earlier quoted context omitted.

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.

What would happen if you just started with a slug?

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.
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