PDA

View Full Version : OT- Punching holes in steel



jeremy13
01-03-2010, 08:59 PM
With explosives!!! This is a military grade shape charge. Just the cone and shell the explosive is our binary. The target A 2.75" thick mystery steel. This stuff is hard!!! A 50cal armor piercing round will make it half way threw at 100yds and bounce out. We get the plates from an old train wreaking yard. The best guess of what they came from they called them bump plates. From what I under stand they are located behind the coupler and a spring sits on it and adsorbs the impact of the cars stopping and compressing the spring.
http://i50.tinypic.com/110y8ok.jpg
The impact hole, notice the metal pulled in the hole. We haven't figured this out yet with the commercial explosives the hole will be open. With ours the hole is blocked. almost like it is sucking in the molten steel around the hole.
http://i46.tinypic.com/vysbgl.jpg
The exit hole about 1/2" diameter and small radial cracks.
http://i45.tinypic.com/2rbz41c.jpg
The impact on the ground about 1X2" and 8" deep with a 4" diameter hollow spot at the bottom.
http://i45.tinypic.com/s3k9kk.jpg

jeremy13
01-03-2010, 09:00 PM
http://i49.tinypic.com/2vtaxae.jpg

Black_Moons
01-03-2010, 09:23 PM
Hahaha. Sure beats using a drill!

J Tiers
01-03-2010, 09:36 PM
I almost felt I should write my reply in arabic ........ looks like you are making IEDs there, which might be frowned on somewhat..... I might suggest being a little more discreet.......

It was fun, fun, fun, until Uncle sent the Feds to the door.........

jeremy13
01-03-2010, 09:52 PM
They can come out all they want. ATFE license to prove it and it covers manufacture of explosives and testing. We get UXO guys out and UN guys looking at the binary for de-mining in 3rd world countries.

The best part I get paid to blow stuff up!!!

Tony Ennis
01-03-2010, 10:04 PM
This sort of thing is why I am amazed tanks can exist on the battlefield.

Forrest Addy
01-03-2010, 10:23 PM
Feed must have been about a billion inches per minute

Boucher
01-03-2010, 10:27 PM
Be Carefull! The longest moment in my life was the time between when I dropped a tray of very sensative experimental detonators and the time they hit the floor. Fortunately nothing popped, but it completely redefined the known scale on pucker factor.

jeremy13
01-03-2010, 10:35 PM
We kind of drilled threw and nicked the table. The new tanks survive thanks to reactive armor. The armor plate itself explodes and helps cancel out the shock wave of the shape charge. The next gen shape charges use two explosions. The first one sets of the reactive armor and the second fallows the path of the first. Now there is no reactive armor in it's way.

jeremy13
01-03-2010, 10:37 PM
Bouncer I see your in Burnet wear you working for Slumber-J

jeremy13
01-03-2010, 10:44 PM
Lets see 24,000 FPS = 288,000 IPS = 17,280,000 IPM feed rate.:D

x39
01-03-2010, 11:01 PM
Interesting. Many years ago I read a book about manufacturing processes involving forming metal with explosives. Some very deep draws in sheet metal were accomplished using shaped charges with the workpiece under water.

doctor demo
01-03-2010, 11:19 PM
Feed must have been about a billion inches per minute
I thought You were a better machinist than that Forrest, You only missed the estimate by about 900 million ipm:D That will kill the tool life:D .


Steve

J Tiers
01-03-2010, 11:35 PM
They can come out all they want. ATFE license to prove it and it covers manufacture of explosives and testing. We get UXO guys out and UN guys looking at the binary for de-mining in 3rd world countries.

The best part I get paid to blow stuff up!!!

In that case, go for it.

On never quite knows who or what is posting, even here.

Boucher
01-04-2010, 02:14 PM
Jeremy13, I was in Phoenix working for Unidynamics Div. of Universal Match when the detonator drop occurred. The cockpit escape pod for the F-111 was to be cut from the airframe with linear shaped charge. We designed and built these detonators as part of that system test. When you work around explosives you are going to see bad things happen. It was fun for a while like riding motorcycles I decided to move on to safer pursuits.

camdigger
01-04-2010, 03:03 PM
The slug plugging the hole is formed from the shaped charge liner - no? Material selection for the liner may be the key.

Alistair Hosie
01-04-2010, 03:11 PM
Feed must have been about a billion inches per minute

Just as fast at eating as me:D Alistair

ckelloug
01-04-2010, 03:54 PM
If the material in the center is the same as the plate, it would seem that a cone shaped jet with missing center is eminating from the shaped charge rather than the solid lance I've seen in pictures.

If your explosive has a different detonation velocity than the commercial stuff it is replacing, your explosive lens design may be wrong for the explosive being used and as a result, the plasma jet isn't quite focusing.

For the record, I have never worked with explosives but I have read a couple books on explosives engineering in relation to research work I was doing on armor.

From the Peanut Gallery,
Cameron

Boucher
01-04-2010, 08:09 PM
The velocity on most of this kind of material is around 7000 meters /sec.

jeremy13
01-04-2010, 09:25 PM
I find it hard to believe that the plug is actually part of the cone. The cone is defiantly some kink of powdered metal. Some times we can find what we assume is the cone in the bottom of the hole in a teardrop shape. But the plug is loose, you can wiggle it with your finger witch points back to not being part of the target. Best guess so far is the cone is getting torn in half. The top of the cone forms the jet and punches threw. The other half folds and gets stuck in the target. The shape charge was defiantly made for C4. We haven't had the binary tested for speed yet. But most of the UXO guys will tell us that C4 wont do that on a lot of deferent tests. One is we take one pound and make a mound on 1/2" plate. The mound looks like a firm C cup but smaller. And fire it off. It will punch A 3" hole with very little distortion to the plate. I have hung the plate with a piece of chain same result. And on the ground just puts the cut out section 24" deep in hard clay. Even when I use a piece of 5"X1/2" bar it will leave the thin wed on the sides un broke and still flat.