Having conducted enough experiments with the Munroe effect over shaped charges, Zoz decides to try diamond charges and a blast suppression technique.So I feel good about shaped charges, but there’s one other charge I wanted to try, which is a diamond charge (see right-hand image). The EOD folks use these a lot for cutting. What you do is you create a flat high explosive and you cap it at both sides, and when you set it off the shockwave comes in from both sides, meets in the middle and turns 90 degrees. And you get a jet that comes out either side and cuts through whatever you want to cut through. And what I wanted to use for this was this stuff – it’s detasheet, it’s kind of like a high explosive ‘fruit roll-up’ (see left-hand image). I’ve used it before, and we had some, so I wanted to use this on the shoot. But it’s difficult to transport. You have to be placarded to transport this stuff based on the original packaging. No matter how much you actually have, it’s just what’s written on the packaging. So we had a small amount, but the package said it was a huge roll, like a kitchen roll. And so we couldn’t move it. We could get it but we couldn’t transport it. Instead, I 3D-printed again a container and filled it full of FELIX, and we capped it from both sides with det cord (see right-hand image). So here it is set up, 60 grams of FELIX, and there it is good to go on the drive. And on this shot (see left-hand image), the diamond charge is underneath the big steel plate, and we’re also getting rid of some surplus perforators under the big steel plate at the end of the day. That’s a half-inch steel plate. There’s, I think, three of the small perforators under there. You’ll need to know that for this video (watch below). That’s the big plate coming down. The heavy plate is not in that shot. But it is in another shot – once again, this was, I think, our last shot of the day. Wait for it. There’s the quarter-inch steel plate, and there is the half-inch one. The good thing is we didn’t need that anymore, because it was gone. There’s the drive (see right-hand image). It didn’t actually do too much, it just acted like a platter charge. You can see the edges of the diamond in it, didn’t cut it. Total failure. Anyway, it was interesting. I’d like to try that again with a detasheet, because I know that works. So, blast suppression (see left-hand image). We had fun blowing things up, but can we actually make this work inside equipment? So we’ve got to couple the blast to the drive, but we want to decouple it from our equipment. So we have the explosive against the drive and some kind of a damping material between the explosive and the equipment shell. What are we going to use to damp it with? It would be great if we could get some kind of a nice substance that was an alternating compressible and incompressible matrix, maybe like some kind of liquid and gas foam. It would be great if it was inexpensive and that we could actually inject it into the equipment when we wanted to so that we don’t have to have our equipment full of foam.
Where could we get such a wonderful hi-tech magic thing? Shaving cream! We learned this from the explosive engineering instructors. They actually use this when they explosively punch out lock cylinders. They’ll put a big cupful of this stuff over the explosive and just punch out a cylinder, and the shaving cream damps the noise and the frag.
So, I said I’d return back to this shot (see right-hand image), the single 100-grain det cord shot, plus the shaving cream, inside a box. Let’s see how that did (watch video below).You can see the A camera there to the left of the shot. So, alright, you know, this was a shot in which the drive was really shredded, and stuff definitely flies everywhere. But let’s take a look at some still frames from our two cameras on this shot.
That on the top left is the first detonation frame of the shaving cream shot with the 100-grain det cord (see right-hand image). To the right of it is the first frame without the shaving cream from a charge that was 40% the size of the left one.So the left one is 2.5 times the explosive as the right. On the lower images, that’s it from the other camera. So if nothing else, we’re definitely damping the flame and heat pulse that’s coming out of that. That’s pretty interesting to me. So we tried this again with a kind of a simulator of a 1U rack (see left-hand image). Here’s 75 grams of FELIX, it’s the annular shaped charge thing again. This is our 1U rack simulator, the steel plate with the angle pieces welded to it. Set up here, coated in shaving cream. And then with the other plate on top of it with a sandbag (see right-hand image). So we’re just kind of getting an idea about, you know, stuffing the 1U and what’s going to happen I personally think that’s pretty impressive (watch video above). Here’s the FS700 shot. Stuff goes flying, but markedly different from all those other undamped shots that we did.
Here is the steel plate (see left-hand image). And yep, it made a dent in the steel plate.That’s where the drive was, and that’s the other side of the steel plate. So it’s dented, but totally non-perforated. On the other one, you can see it didn’t clear quite so well. We did actually unfold the angle iron and split it a little bit, but you can also see the drive imprinted on the plate there.
But the summary here, after damping stuff: with enough engineering effort, the high explosives just might fucking work.
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