Bronezhilet

So basically blood, sweat, tears and a lot of screaming since I have around 20 of those pages.

@Jeeps_Guns_Tanks any tips on how I should clean something like this?

Come on @Collimatrix I give you a forum suggestion and this is what you do!? Nice.

I heard Tekky is making a walker as well. Soooo walker platoon when?

On the other hand, if it was reactive, wouldn't a single hit detonate a complete NERA layer? For as far as I know NERA isn't segmented in blocks like ERA, which suggests that it isn't reactive (or at least not self-sustaining).

Sorry, personally I have no idea, but @Militarysta does claim it, although I don't know his sources: And from the same post: According to Dynamit Nobel the precursor in the Panzerfaust 3-T is non-intitating, but there's photographic evidence of the Panzerfaust 3-IT-600 being an initiating percursor. That post also has a few nice pictures from simulations and tests.

At the request of @anwaralsharrad a topic about non-initiating precursor shaped charges. Basic principle of non-initiating precursors As the name implies, these are specialised shaped charges designed to not initiate something, which in this case is an ERA sandwich. The purpose of this is to punch a hole through the ERA sandwich for the main charge to go through, without setting the ERA off. Achieving this means that the detonation of the ERA sandwich cannot influence your projectile in any way shape or form. The explanation on how this works is fairly simple: Every energetic material (explosive) needs to be initated, if it isn't initiated it will act like any other material when hit by a projectile. In our case the initiation is done (or not done) via an impact. For an explosive to not initiate by impact, the impact energy needs to be lower than the critical energy* of the explosive. So you basically throw something at the ERA sandwich fast enough to punch a hole through it, but not fast enough to introduce critical energy in the explosive. This is usually achieved by using a special liner material, usually something lighter than copper (in theory you can make the jet slower to make it non-initiating, but then the main charge might catch up with your precursor jet, which you don't want). I've seen PTFE thrown around as a liner material for a non-initiating precursor warhead. The formula for kinetic energy is Ek=0.5*m*v2,, the kinetic energy of something is half the mass multiplied by the square of its velocity. So to lower the energy you can either go lighter or slower. * The impact/shock initiation point of explosives can be quantified by multiple units like J*cm-2, v2d, u2d, ρv2d, √ρv2d, Pd, and probably a whole bunch more. In this topic I will keep it simple and try to not use units. Things that influence non-initiating precursors However, it is quite tricky to get right since a plethora of factors influence the initiation point of an explosive. For starters, the type of explosive used in the ERA block is important: (Table from "A General Model for the Shock Initiation of Explosives" by F. E. Walker and R.J. Wasley) As you can see, explosives can have wildly varying critical energy points. Although these values are for pure explosives and not the desensitised explosives used in ERA, but this should give you an idea about not all explosives being equal. So a precursor might be non-initiating versus one type of ERA, but not versus another type of ERA simply because they use different types of explosives. A different graph showing the same thing: (Figure from "The Legacy of Manfred Held with Critique" by EV2 Florian Bouvenot) Furthermore, the impact velocity to initiate an explosive changes when the explosive is protected by a barrier of another material. The effectiveness of this barrier, which in the case of ERA is a flyer plate, depends on its thickness: (Figure from "The Legacy of Manfred Held with Critique" by EV2 Florian Bouvenot) In this graph everything above the line means "Boom" and everything under it means "No Boom". So to initiate an explosive protected by a barrier, you can either go faster, or go heavier. And again, this means that a non-initiating precursor might not be non-initiating because one type of ERA might have a thinner flyer plate than an other type. Even the material used for the barrier has an effect: (Figure from "The Legacy of Manfred Held with Critique" by EV2 Florian Bouvenot) Again, a non-initiating precursor might be an initiating precursor depending on the material of the flyer plate. There has been research about using glass or ceramic flyer plates. It might be that a precursor that's non-initiating versus a steel flyer plate, is initiating versus a glass flyer plate. Another thing to take into account, is whether or not the explosive is confined on all sides. For example, Nozh has a non-uniform confinement, so Nozh might react differently to a non-initiating precursor. The effect looks like this: (Figure from "The Legacy of Manfred Held with Critique" by EV2 Florian Bouvenot) But the most important one for us, is projectile material: (Figure from "The Legacy of Manfred Held with Critique" by EV2 Florian Bouvenot) As you can see, the lower the material density, the faster the projectile has to go to initiate an explosive. This is what we want, because we want to punch a hole without initiating an explosive. However, a lighter material also means that it has less penetration compared to a liner with a heavier material. ...but a lighter material can be accelerated to higher velocities, which means a higher penetration than a slower jet with the same density. So basically, whether or not a non-initiating precursor is actually non-initiating depends on a significant amount of variables, each of which influences the other. Basically it's a giant mess of variables to keep an eye on, but the desired result is clear: Punching a hole through a metal-explosive-metal sandwich without setting off the explosive. After that you can throw whatever you want through that hole without having to worry about setting off an explosive, which means that you can use the best penetrator you can make. ... @anwaralsharrad does this answer your questions? If not, feel free to ask anything.

I'll take that as a yes. I'll collect some data and make a new topic about it in a few hours.

@Militarysta had a paper about it, but I don't know its name. I can explain how a non-initiating precursor works, but that means you'd have to be okay with me being your source and not some sort of paper.

That would explain the warning about explosives on the Merkava NERA.

On the other hand, it does show how relatively easy it is to get close. Stuff a more off-road-y vehicle full of ANFO or whatever and you'll have a fairly decent SVBIED.

Sorry not sorry to all the Russians here

To clarify a little on the above post, the paper from which those screencaps are considers everything moving at a velocity less than 2 km/s not part of the jet.

For the Dutch CV90, a few reposts: Various thicknesses: ...Yes I know I posted it in the German vehicles thread, sue me. Driver station: Commander station: Gunner station:

Lets play a game of "Find a photo of an Arjun with rear view mirrors". Because I haven't been able to find one.

Yep, this works.

Picture doesn't work, host doesnt allow hotlinking.

Way to react serious to a joke, Sturg.

And then the coalition bombed roads and a bridge so they got stuck in Syrian territory (I don't know exactly where).

So, when laughing looking at the Arjun Mk2 I also read a few things about an 8x8 APC designed by Tata and DRDO. It's called the Tata Kestrel. And guess what. Aside from looking like hot garbage, look at the side armour where it says Kestrel. You see those lighter and darker spots on the armour? That's warping. You know what's really difficult to warp? Armoured plates. You know what's easy to warp? Sheet metal. There's no way that side plate has any significant thickness to it. And guess what, basically all the other prototypes have a dazzle camouflage. I wonder why. Also yes @Collimatrix, they are indeed firing ports: But it has elevated seats, so that's good I guess?

Did someone say... walkies? Thing has an underslung Equalizer.

For as far as I understand, no, they're not the same thing. They're being a little vague, but it seems they're using something like a multi-layer liner or something. They specifically say "these energetic components are transferred [...] together with the jet", with a reactive liner, the jet is both the reactive material and penetrator. With this charge the two functions seem to be separate. And while it does say "strong exothermic reaction" and "extreme pressure spike" it doesn't say it's an explosion. The function of the energetic material is to transport debris out of the tunnel and thus making it wider. With a reactive liner you'll also be making the tunnel wider, but you'll be doing that by blowing up the target, which will inherently create more debris. So while they are talking about "extreme pressure", it doesn't seem to be a 'proper' explosion, just a reaction which creates enough gas to produce an overpressure in the perforating channel to create a backflow. It also says "small fractures may be initiated" (emphasis mine), but you've seen the damage a reactive liner can do to concrete. But then again, it might be the same thing, just with a reactive liner with a lower RE factor, but I don't think it is.

I'm seriously doubting that claim about it penetrating about the same as a copper liner, since that goes against basically everything we know about HEAT jet penetration. But yes, it would blow up the internals of whatever it hits. And I guess that if it hits ERA, there won't be much ERA left. It'll either detonate from the impact or the reactive jet will blow it sky-high. In my opinion RLSCs will be quite effective as multi-purpose warheads. If you have something like a 40 mm autocannon with RLSC warheads you'll have significant destructive power versus a lot of different types of targets.

In the tests done by Wang et al., the Al/PTFE liner had slightly less penetration in steel than a copper liner. Which is interesting because a copper liner should have significantly more penetration than for example a pure aluminium liner. It appears that the charges were dimension-matched, and then it doesn't make sense that an Al/PTFE liner has almost the same penetration as copper. Someone should do some tests with dimension and mass matched shaped charges to compare Al/PTFE to aluminium and copper.

"Demolition Mechanism and Behavior of Shaped Charge with Reactive Liner", Xiao et al. But a 1 kg jet is rare. a (really) rough estimation on a liner with a diameter of 110 and an internal angle of 50 degrees gives me ~380 grams for a 2 mm liner, ~500 grams for a 3 mm liner, and ~750 grams for a 4 mm liner. And we know that not all liner material will go into the jet or slug and we know that the jet itself has a very low weight compared to the slug. Using the following info: (Liner material is copper) I'm getting an RE factor of 2.39. (500/50 = 10 kJ per gram for the total jet, TNT is 4.184 kJ per gram -> 10/4.184=2.39) Yes, you're wrong. It's so destructive because a reactive liner literally blows the fuck up, a normal liner doesn't do this.