Underwaterdetonation

[Myrol]

This is my first own thread so i hope i dont get banned trough this :p My Question: Can anyone here provide a Video of a deep Underwaterdetonation? I have actually one with 150g APAN from Spydamonkee and his Vid with the 800g ANFO misfire! BUT I have no Movie with such a deep Detonation where you can hear the typical properties of a UNDERwaterexplosion. Spy's one is more a Surfaceexplosion because the Water was dusted into Fog! I asked this because i searched ALOT trough the web and the Forum but dont find any real Video (WITH SOUND!!). My E-Mail for other Questions: Mr.Nitropenta@gmx.de

[knoddas]

Have You seen this one?
2 kg's of an/nm/al detonated under 30 cm of ice. (http://earth.prohosting.com/andyboy1/2kgannmal.wmv)
found at: http://earth.prohosting.com/andyboy1/movies7.html

[Myrol]

Hey cool! Thank you for the Link its a nice Video and i can hear the difference between Underwater and "Underland". But something is really strange on Andyboyz movies...The Sound!!! 17ml NG makes no real loud BAAAMM and a 6,5kilo ANFO Charge with 1,3kg ANNMAl sounds only little like a BIG Explosion! His Microphone must be pissed off! Hopefully we can find a Vid with a Underwaterexplosion so deep that no Jet comes off the Surface!

[thepyrolooz]

Andyboy uses a plexiglass box, were theres drilled small holes for the mic. that could be one reason. Another could be the distance, the camcorder is away from the charge. Plus i know from personal experience that my camcorders mic. can't record very loud sounds, and therefore makes a "scratty" sound.. :(

[nuclearattack]

Well Myrol i'm searching for a small lake near my city to make this interesting test. I'm looking for a well isolated lake and i don't want a lake where live fishes and other kind of life form because i'm a naturalist and i don't want to damage the nature. I know that it can sound strange but it is a very important thing for me. When the test will be done i'll send to your e mail the video. I have also noticed the problem of the sound with the camera, its microphone is not able to capture well the mighty boom of explosions but i'll try to do my best.

[Myrol]

Wow Nuclearattack thats a very NICE Idea! A big thanks to you for doing this :D :D :D :D Today I ignited a 2,9g AP Charge in a 7,92mm Cartrigde and it was a fucking PAAMMM because it was only 8cm under Water........The Jet was 2m high and coool!

[Myrol]

Has anyone a good idea how to make real working Underwaterfuse? I have big trouble doing this because the normal sparklers are to sensitive against moisture and strong coatings! I've heard something about Fuses with Silicone KMnO4 and Sulfur who should work good Underwater but theres guaranted a dark corner with this Fuses :( Fine Blackpowder pressed in Straws and coated with NC-laquer should also work I think, but I could be terrible wrong :confused:

[chemistr1]

Underwater fuses.
I use a variation of what used to be known as a VC fuse which basically comprises of a thin diameter piece of bamboo cleaned out and tightly packed with fine blackpowder, apparently the vietcong used this type of fusing for improvised coke can grenades. Its basically an improvised version of the Italian designed spollette fusing used in aerial display shells.The fusing always works underwater or out after you have got used to producing them but for some reason everyone I have ever mentioned this type of fusing to always replies no way it will blow up. Which is damn strange as I have been using this type of fusing for well over 17 years now. I really should make some videos of the fuse working on and out of water to prove it though. When we used this technique as kids though we always had a rule that he who made the fuse lit it though as if the BP is not packed tightly enough it could flash through the tube.
Hope this helps. Will get some more bamboo tubing and film a couple of fuses in action for any non believers.

[Efraim_barkbit]

Try putting your fuse in a piece of shrinktubing, that should work.

Or lay your fuse on a wide enough strip of tape, fold over, and you gor yourself a water proof fuse.
Works with my homemade anyway, wich consists of silicone mixed with whistle powder and "rolled" to a string.
Its even "waterproof" in it self if it´s thick enough.
Use your imagination, and you´ll figure something out.

Anyways, you could simply use electric ignition, thats IMO the best when dong stuff underwater.

chemistr1, as a friendly advice, learn how to use the "ENTER" key.

[Skean Dhu]

I did my first underwater detonations the other day. I put AP into some M-80/M-100 sized cases taped a rock to them and set them off in 3-5ft deep water.
They made a nice quiet thump followed by bubbles and displaced water, but no jets were formed by either of the two I set off. This was done in a pond inhabited by fish and the like and none have gone belly up on me, but these were also rather small charges.

[Guerilla]

Or lay your fuse on a wide enough strip of tape, fold over, and you gor yourself a water proof fuse. Depending on the fuse, you may also get a very good quickmatch this way, that will burn in one whoosh once ignited.. :rolleyes:

Its better to just drop the idea of using some homemade fuse in underwater charges. You only get pissed off if it wont detonate, and you have to pull the 5kg charge that should be safe up from the water.

[Efraim_barkbit]

kind of OT, but nice to know:
I watched part of a nature program on tv yesterday blah blah, and they mentioned that only 1/1000 of sound created underwater can be heard over water level.
Of coarse, when dealing with underwaterdetonations, this can only be true when the explosion is deep enough that no water jet will form.

edit: k in know

[Myrol]

Wow if its really true....you can ignite kilos of HE without alerting people if you're do it in the right way :cool: Due to the fact that I have never found a Video with an Underwaterexplosion filmed UNDER Water I thin I WILL do it :D 500g APAN a nice lake a late time and a nice deep place under Water should be good to produce such a Movie! My Digicam should stand the pressure if I make no stupud mistakes! Packing it into a solid Plastic baggie and tamping the Baggie well enough to dive the Cam around 30cm under Water......THEN we can see the REAL effect of such an Explosion! How the hot Gasses produce a short flash and a expanding Gascloud with eruption of a sudden Jethammer...Mmmm seems to be nice but perhaps a risk for my cam :confused: :confused:

[Myrol]

Efraim Barkbit: I appologize for my swearing to you in the APAN-Tests thread! I was somewhat pissed off and angry about the "playing" with new forum members....Dont take it personally!

[spydamonkee]

if using anything over 500grams i really recommend using electrical detonation as it really sux to lose a reasonable amount of HE.

I know of a vid where 10kg was detonated a meter deep and about 2 meter's from the shore of a river... apparantly that was as far as the person could throw it :P
20m+ jet of water apparantly :D
will try and get it uploaded when the person finds a way to digitise it.

also 1kg of APAN under water looks very impressive

[aikon]

Maybe that's a silly question but if you detonate such a high amount of HE in a lake you probably kill the fish around the detonation,right? Wich lethal radius could one expect from about 1kg of APAN? Blast fishing seems to be a nice hobby:)
I found this article about homemade caps on the net:http://www.oneocean.org/overseas/200101/the_business_of_blast_fishing.html

[Myrol]

Yeaahh I NEED this Movie :D 10kilos under Water....THATS ABSOLUTELY worth a download also with "slow-motion" 56k :p Umm SpyDAmonkee.....did you remember that Guy who blewed up 100kilos ANFO and was arrested by the Cops? Are there some news from him?I know its a little off topic but whilst reading the lines from his "Project" I felt the Anger from all Australian Forum-Members who get big trouble since them buying AN-Fertilizer......

[Flake2m]

If you live near the coast why not set it off in the ocean?
Just ask a friend that has a boat and doesn't have a problem with you conducting "experiments" at sea. Just go out a relatively calm day and then sink the charge to A desired depth, use a float to mark where it is then tak the boat out a few hundred metres before setting it off. The boat shouldn't be in any danger because the shockwave will be mainly in the ocean. I wouldn't recommend being in the water (ie diving) anywhere near the charge because the water will amplify the shockwave.

[nbk2000]

Blast fishing pulverizes the internals of the fish, resulting in spongy and pulpy fillets, not nice and tender fillets. OK for survival, but gross for anything less than starvation.

[Myrol]

Umm Flake2m: It would be great if I live near the Ocean, but I live in the middle of Germany! I have only one "big" lake and some Rivers, ponds and puddles to ignite Stuff under Water! This saturday I will set of 200g APAN in the "big" lake (200m in diameter). Its my first real electric ignition because I had often misfires with Electricdets due to broken Bridges or "empty" batteries! But now....it MUST work with my new 12V rechargeable Batterypack :) (Its from a Drill). Hopefully are 10m Bell wire and some metres Water enough to deepen the Sound that It dont makes me deaf :p

[Myrol]

Last Friday I "tested" again a 4,5g APPN 50/50 Cartridge with a very loud success! I put the thing in a 8cm deep puddle and lit the sparkler....after 20secs.......PAAAMMMM...It was nice loud for me but too loud for the peoples in their houses so one comes on the balcony and screamed: "What was it for a F*****g loud Bang? I walked fast away and for my luck nothing happened "more"...My Expirience for the future: NEVER ignite any sort of HE in the visible near of houses or people....minimum range should be 500m if I fire flat under Water...because thats crazy :p ! Did you remember my 2,5kg APAN-ANNM test? An old friend told me yesterday as he looked to the hills he saw suddenly a Cloud of Dust and dont know whats the real reason of this "strange Cloud"...but after around 9secs....everything was clear after the nice thunder comes into his ears...(He said it was 8-10sec. delay from "flying Dirt" and Brrrommm:p )

[nuclearattack]

To Myrol:
a very nice test! AH! AH! You should be a funny and likeable man! I say this because i use to test some detos near my palace but for me is not a big problem because everybody knows me and they know that i am a little crazy!
If you are going to make a vacation/travel in italy send me a mail maybe we can make some tests together! I'll make you know some friends of mine that are HE "aficionados".

Let's talk about underwater tests:
i detonated 5 gr of AP in a plastic bucket. The charge was placed in the middle of the bucket at about 20 cm from the surface. It made a good "paaam" and the bucket was completely destroyed.
Now...i made this test to know how much water absorbs the detonation sound. The sound was absorbed a little, but not so much.
I'm impressed...i'm planning a test with 1200 gr of kinepak in a small desert lake and i really don't know how much the sound will be loud! This is an important factor because i want to test an underwater detonation but i don't want to alert people!
Maybe 2 or 3 meters underwater should absorb the sound?
The sound is attenuated when it passes from water to air, but what is the physical principle involved in this phenomenon?

[Myrol]

Ahh Nuclearattack, yes you're right! I love it to see Jets flowing meters over meters into the Air....Umm 2-3 meters water for 1,2kg Kinepak should be enough to deepen the Sound. But be prepared for a nicely huuuge Jet :D :D Today I had fired 3,5g AP under 15cm muddy water and the Jet was.....uhhh...9m high!!!!! I couldn't believe that so less AP can blow Water soooo high :eek: The Sound was a nice loud "Danggg" or like someone Bang an big Wood-door ;) But the Jet.....its really unbelievable..9metres!! He was around as same as high as the old oaks behing "him"!

[Guerilla]

3m sounds about the right depth for such a charge.. A few days ago, 560gr of PNNM was set off 2m deep in a small pond. The result was a thump sound and about a 4m high and 1½m wide water jet.

Because of the water, the detonation shook the surrounding ground quite noticeably, even the camcorder that was resting on the ground 20m from the detonation shook a bit.

The video can be found on the ftp, but here's some frames

[Myrol]

Its everytime nice to see how easy an Explosion thunders Water to such cool Domes, Jets, Hammers or plumes! Congratulation Guerilla :) How had you settted off the Charge? By Fuse or with an Electric Detonator? I made the expirience that 5mm thick Blackpowderstraws burn nearly without any problems Under Water. These ones were also my choice for the 3,5g test!

[nbk2000]

I wonder if there's a correlation between the optimum standoff for an SC and the maximum distance a water jet is ejected above the surface? Some kind of scaling applicable?

[0EZ0]

To my knowledge there shouldn't be any direct correlation between the jet formed in a shaped charge and the destructive jet formed from the collapse of a bubble produced from an underwater explosion. The jet witnessed in underwater explosions has alot to do with differing densities between water air and gaseous detonation products, boundaries and how bubble dynamics govern the situation.

It's all very interesting stuff. Quite fascinating. There is a little about it on the web and various militaries have experimented on it's use to destroy ships at sea.

http://www.eng.nus.edu.sg/EResnews/0603/rd/rd_12.html
http://www.fges.demon.co.uk/blast/underwater.html http://www.dt.navy.mil/sites/uerd/history.html

[Myrol]

Are there also some possible Calculations how deep a Charge must be to get the effect that NO Jet and no Dome appears? Yesterday I fired some Pentrinit (6,5g 70/30) 15cm Under Water and the Jet was very good! Better as the 3,5g AP Jet in the same "Puddle" and the same deepness :) (Heights are both around 9m!! but the Pentrinit-Jet was denser and thicker as the AP-Jet)

[Myrol]

Umm Guerilla, I'm absolutely not able to download your great 560g PNNM Video! If it does not to much work, can you please send me the Video via Mail? My E-Mail is: Mr.Nitropenta@gmx.de

[Ropik]

Back to waterproof fuses: Normal thin green fuse(sold in cheaper pyroshops etc.) isn't waterproof in it's basic form, but if you coat it with NC lacquer (acetone/ping-pong balls type works well), you have nice, waterproof, fairly break-resistant fuse (When you break the normal variety of this fuse several times on the same spot, it die on the break, but NC variety hasn't any problems with it), much cheaper than shrink-tubing variety (which works well also). I had many sucesses with this fuse. It never died in the water (nor in the air), regardless on the leght etc.
Hope somebody find this useful. Final hint: I can bought the "green fuse" in the hobby shop (for rockets) so cheap that I made my own fuse only once: when I was testing procedures from IMH. This has considerable influence on my invention. It might or might not works for improvised fuses. I didn't tested it.

[Bugger]

How could an "underwater fuse" or "waterproof fuse" possibly work, in the absence of air (except in an insufficient amount in an hermetically sealed container) for combustion? Some sort of electronic or mechanical clock timing device, set to deliver a detonating current from a battery or impact on a percussion cap at the end of a certain period of time, would surely, be far more practical.

Bugger.

[Marvin]

Err, John, pyrotechnic mixtures have fuels and oxidisers, you dont need air. Laquered fuse is generally a slowburning blackpowder core with some sort of fibre tightly woven around it. It'll work under water if you can avoid the core getting wet. Side spitting fuse, and I forget offhand if that is red or green, is probably much less suited.

[Mr Cool]

Side-spit is the green, which as Ropik said needs an extra coating for underwater work.

[Myrol]

I improved my Fuses now because the were to often killed after the charge reached more than 1,5m deepness. I take a 7,5mm thick straw an fill him with hand compressed blackpowder. Attaching to the detonator...bla bla....and then I wrap him with tape and Aluminiumfoil twice to make a heatresistant layer of metal. The Fuse burns perfectly under water also in bigger deeps because the hot gasses can only evolve upside, but I think more than 5m will kill nearly every fuse due to the "high" waterpressure. A good delay for depth charges is a straw with two bare wire-ends inside of him wich are cast in some hot melt glue. Put some DRY salt over the bare ends and fill the rest with a slow watersucking material out. Use this as a switch and prepare the rest like a normal electric fired depth charge. Function: You throw the charge in the lake etc. and the water will sucked up slowly by the towels for example.....the salt is getting slowly wet and after "the special point" the switch is closed because the solution of salt submits the electricity...BAAM.....The device looks then very close to the old WWII depth charges for killing submarines ;)
Yes I know my English is getting more bad as before...the Forum is my only chance to get a better english......it was down for more than a month so please dont flame me due this.. :o

[Myrol]

Huh, what a punch! On saturday I blewed up a 30g APAN Filmcanister 1,5m under Water and I was only 50cm from the edge away....summarized are this 2m from 30g APAN....If there would be no water....I had never done such a risky test (dont think I'm crazy) ! After the depth charge exploded I felt a very hard punch in my knees!, in my tummy and my foots are ripped under the ground away. The compression was so hard that my friend (he was even more closer!!!) was thrown 2-3cm high from the ground...I have noticed that and it looked very funny! :cool: The soil is nicely moist (like loam) so that the shock was not that much absorbed after it changed the media liquid-solid. I have such a luck that I have found this pit.....no fishes and a very steeply edge, 50cm after the water begins it is around 150cm deep, in the middle it reaches even more than 2,5m. :) The pit was an old open mining place, no matter what they really searched for but the water is uniform rusty! Now after my Fuzes work 100% under Water I will test some more chargesizes from 3g to 1,5kg.

[ShockWave]

This must be the right section to place a video of an underwater detonation.

Look at my site in video's

or click http://apanshock.tripod.com/Video/20aug2004ANNM.avi

[anchorpad]

This must be the right section to place a video of an underwater detonation.

Look at my site in video's

or click http://apanshock.tripod.com/Video/20aug2004ANNM.avi

"This file is hosted by Tripod, a Lycos®Network Site, and is not available for download. Please check out Tripod's Help system for more information about Remote Loading and our Remote Loading policy."

The link doesn´t work.
Is it me or is it my computer that doesn´t work properly? :confused:

[Myrol]

I thought a long time if it is necessary to post it here but I think someone could help me out! In August this Year I fired a lot of Filmcanister and so on in the "Pit Morl". The Water was on the edge 1,5m and in the Center 2,5m deep. Next Summer I will capture some more Detonations directly under Water and I will make some more big and fat Jets :) So now my question: I attached some Frames from my Videos. One with the under water bubble created by 3g APAl, one (the strange one!) with 40g APANAl 2m deep and one Frame where I made a Test with 100mg APAl in a 5Liter Jug on the Balcony. If you look clear enough you can see the Bubble and that whats strange the Jug is sharply shrinked together! In the second picture you can see lots of white rings on the Watersurface....I promise it hasn't rained that day!!! I believe it was the Shockwave wich hit the watermirror that way that it created that strange formations!

[croc]

If a big charge of explosives is detonated deep underwater doesnt it cause an implosion?
If a shockwave passes through you underwater it can fracter and bend your bones.

[nuclearattack]

After the detonation there should be an implosion because some water is ejected away but i don't know the proportions of this implosions relatively to the HE quantity.
It should be very usefull to take a camera capture directly in the water just like Myrol said, i thought a lot of times about it but i fear the shockwave effect on the camera.
You can put the camera in a tough lexan box well sealed but it's a risk for the camera. I don't have a camera and i don't want to destroy my friend's one!
What do you think about it?
Will a lexan box protect the camera from the shockwave?

To Myrol:
you started this thread with a little fear of being banned but it has been revealed very interesting! Good idea my friend!

[croc]

Get an old tape camera not an expensive digital one. It should cost you around $50 second hand. With this if you fail and wreak the camera the footage would still have been printed on the tape.

The deeper underwater the explosion happened the more pressure there is and your camera might not be able to withstand these conditions.

Shock waves can pass through anything even earth I don’t know much about a sonic boom but it happens when an object breaks the sound barrier (goes faster than the speed of sound) such as a HE.

In an implosion the shockwave would push all of the water out a bit then the deeper underwater the more pressure there would be to move the water back therefore the bigger the implosion am I right?

[nbk2000]

One of your pictures was pointless, the other too blurry, so the underwater bubble pic was the only one left.

[Myrol]

Oh man NBK, yes I know (you like it to flame people huh ;) ?). The Pictures are in a bad quality and I was scared to post them, BUT! One Picture has irregular strange rings on the Surface this is point 1 wich confuses me! The other picture (perhaps the "too blurry one") is my 100mg APAl test in a 5Liter Jug to show you all the Bubble wichwas on the ground of the Jug and has a shape more like an Egg as a Circle! Yes and then the Underwaterpicture, to all: Dont be to scared trough the Implosionpressure of the Charge! Whilst I was capturing this Video I felt a nice and hard blow in my Arms but it was not to uncomfortable that I must say: Oh my Lord, I'll never do this again....No no no, it was just a sharp and short strike. :cool: Next Summer or perhaps in the sooner time I will capture more Detonations underwater! My protection device for the Camera was a nicely cleaned GLASSCONTAINER!!! Yes Glass!!! It wasn't broken into pieces, it withstand the venomous pressure!! So if you capture something with a LEXAN or Polycarbonate conatainer under Water....it should be no problem even the Implosion risk if you dont place the thing to close to the "Bubble". P.s. The Shockwave has a nicely different shape of striking your Body if you feel her IN WATER. This does not mean you can swim close to the Explosion with your whole body and even listening it with your Ears (the Eardrums can rupture, PERHAPS, perhaps not!!). Stupidity is very unpleasant under Water ;) to Nuclearattack: thanks for your compliments :D Oh man, if I have a pool, I think it wouldn't intrest me to dirten the Water with VERY GOOD VISIBLE TESTS!!! :D

[nbk2000]

You're still failing to use the RETURN key to make paragraphs out of your endless sentences.

Failure to correct this IMMEDIATELY will result in the cessation of your existance here. :mad:

[THErAPIST]

Blast fishing pulverizes the internals of the fish, resulting in spongy and pulpy fillets, not nice and tender fillets. OK for survival, but gross for anything less than starvation.

While this is usually true, it's not always true.. 200g ANNC under 20 feet of water made absolutely no noise at all (did produce a bubble that was about 3 feet in diameter) and served this up about a year ago. made some nice filets ;)
http://www.experi-mental.org/pictures/fish.jpg

[Myrol]

PRE-EDIT:
Ahh, well. You make a Flat tire out of me :eek: .
Sure, my sentences are much to long,
so I just hope you dont kick me out :o of this PERFECT Forum.

POST-EDIT:

Is it so important for you to read short and compact paragraphs :confused: ?
RETURN
Well, I try to improve my posts to stay friendly with ALL!
RETURN
Is this post ok? Carpe Diem, back on topic.

++++++++++++++++

Let's not forget the RETURN between the lines, eh?

[Guerilla]

THErAPIST, hehe poor fish.. Do you know how far away roughly was it from the charge? I think I could try knocking out some pikes with similar sized charges as well, so to not raise any suspicion from neighbors or do any more harm to the fish population than is necessary.

Grandpa told they once tried fishing with hand grenades back in the war times, from his experience such small charges (100-150gr I would think..) in a river didn't do shit unless they happened to detonate very close to some random fish.

[Cyclonite]

Getting a little off topic but lets mine be the last...I knocked out about 10 fish from a 100g flash charge. It works great, you would be really surprised how much more power the shock wave holds in denser stuff (water earth) plus it travels much further..

[nuclearattack]

Yes Cyclonite, water (and denser material in general) transmits the shockwave at higher speed and i must say that observing this during my tests is very amazing.
I detonated two small charges of 5 gr AP in two differents tanks. The first tank was a plastic bucket 40 cm diameter and 40 cm high...it was completely destroyed in pieces.
The second tank was a big metallic can (like the ones used for oil or to put dangerous slags) 60 cm diameter and maybe 1 m high. The shockwave made to vibrate the can so loud that it was like a big hammer blow.
However i'm planning some others underwater tests to see the effect of the shockwave on submerged targets, it will be funny and interesting for sure.
I'm going also to test shockwave propagation in steel and the effects on targets placed in contact with the steel plate...but this is another topic so i will post in another place.

[Myrol]

Hi Nuclearattack! Would it be not great to test the precision of under water
demolition via blowing up some grams APAN in a small pond (without fishes
ore life wich could be damaged, because i KNOW you'r a naturalist :) ) and
watching how some Copperplates were bend into a special shape from
the Shockwave?

A unknown weekend I will do some controlled tests perhaps how a tightly
closed Marmeladejar implodes or a Airfilled thing like an old Toy if nothing more
is avilable :D The Pressure works under Water much more violent as in Air,
so you can really compress thing's if they are not totally filled with liquid. :cool:

[nuclearattack]

I'm thinking about a simple underwater ignition system. An electric cable is the best but sometimes (most of times!) you need to do it very quickly because of the too curious peoples and an electric cable is too slow to use and you need to remain in the det site during the test. I need a simple ignition system that can be thrown in the lake letting you the time to reach a secure point of view. I want to use a simple sparkle as a fuse, the wole charge with the detonator is placed in a tank, you ignite the sparkle, close the tank and launch it in the lake. Simple like drinking a water glass!
It should work fine but i'll test it on november when sparkle are sold in fireworks shops.

[Myrol]

Hi to all! To Nuclearattack: Umm, ok the thing with the sparkler can work. Perhaps its good to fill a Cokecan with 1kg ANNM or a better Explosive wich isn't that humid like ANNM's with more than 25% NM.

My favourite is with 35% NM and it has always a thin layer of unsoaked NM but your favourite with 40% NM seems to be obvius better more NM=more pressure. :D The only problem is to construct the device as a tight, stable and solid thing. I say.....there exist always some full idiots wich stick a sparkler in 400g AP lit and BAAAM were blown into compact Dogfood. Especially in a sealed area its important to ensure the Explosives CAN NOT fired accidentaly due to one damn spark.

Now another thing: My favourite media for Explosions is Mud from thick to thin consistency. The Crater has a very very uniform shape. Thick mud has the property to be blown in big chunks wich fly crown-shaped radial from the ground zero away. The pieces are often good propelled, in my attempts it took often more than 12sec. after all lumps had been fallen down. 230g ANNM had blown some lumps so far, they landed more than 70m behind us......+ our 40m inital length.... :D thats awesome!

Explosions in thin mud are more like a shallow under water detonation. You have a spraydome and just sometimes some bigger chunks of mud. Mud's pro for blasting is the good confinement so even a ziplockbaggie do the job to protect the Ex, the confinement comes from the Mud ;)

[The_Rsert]

I have just made an little underwater detonation.
120g KNO3+Sorbitol in a steel pipe under 3m water
I have only seen a flash an some huge bubbles :).
No loud bang, only a deep "bluuubbp" :)

[nuclearattack]

KNO3+Sorbitol is a low explosive, if you want a nice underwater det. you need a HE with a good brisance. With a good HE you will feel a nice shockwave like an earthquake!
Underwater detonations are very safe but i'm worried about you because you are using a steel pipe with this kind of mixture.
Beware using steel pipes, expecially with NC, black powder, KNO3+sorbitol,sensitive HEs and so on.
A steel pipe work well with ANNM but you should insert in it a plastic bag to avoid corrosion, the plastic bag is also usefull for KNO3+Sorbitol and the mixtures i mentioned because it is anti static.

[Anthony]

How is a plastic bag antistatic? In my experience, they are quite the opposite, and encourage static charges to form.

[Guerilla]

if you want a nice underwater det. you need a HE with a good brisance. Actually to maximize the underwater blast effect you want less brisance and more energy (by means of metal powders), its after all the bubble that does the greatest damage.

[nuclearattack]

To Anthony:
i use PP (polipropilene) bags to make HV capacitors, i use this capacitors in my tesla coil generators. I can say that PP is used a lot in this application because it is a very good isolator far more better then other kind of plastic, it is able to stop corona effect so it should be good to insulate an HE from static discharges.
However if someone uses insensitive HEs there is no problem but at least the plastic bag will avoid corrosion of the metal pipe from acidic HEs.

To Guerrilla:
i'm not fully agree with you. Well the expanding bubble makes a lot of damage for sure but a minimum of brisance is needed. You have a bigger shockwave with a high vod explosive and the water maximize the effect because it transmits elastics waves more faster then air.
I think that ANNM is a very good underwater HE because it is enough brisant and produces a lot of gas. I tested black powder underwater and it is pathetic also in big quantities, surely because it is too slow, on contrary ANFO is good because it has a bit of brisancy that optimize the effect.
If i remember well the military ships use Torpex in their underwater deep bombs for submarines, Torpex contains also TNT that is enough brisant.
This bombs damage the submarine with the shockwaves, do you think that is possible to damage a submarine with a very low explosive?
So if you have a good HE that produces a lot of output gas it's good...but if you have a HE that is also brisant you have a very good bitch in your hands to do a nice underwater detonation!
About the Al powder it surely increase the output power but in this case you should balance the Al quantity with the oxygen. I'm saying that too much Al will be wasted because underwater there is no oxygen. On contrary in air you have oxygen to burn and if you add a lot of Al you will have a thermobaric charge.

Is there anybody that has tested different kind of HE with different vods underwater?
What difference have you seen in these tests?

[Myrol]

Well, trough discussing about the sort of Explosive wich does the biggest Bang for your buck, I think a little about Potassium perchlorate/ Aluminiumflash. It's a Low Explosive....anf if Oxygen-balanced he produces not the slightest cubiccentimeter of Gas on Detonation. If I fire some ounces under Water......what will happen??? Normally there should be NO Gas wich can expand, but obviously there MUST be a bubble of a pseudo-volume.......I can't imagine that some ounces Flash can vaporize so much Water within an eye-blink that it creates a huge Bubble.

But who know's, arrggh damn.....I think the only way to solve this problem.....is to do it :D I thinkat night there can be a VERY significant flash INSIDE the Water......wich should look EXTREMLY strange. The Viva-Brainiacs do a lot of demolition, so they could be also so nice and show in on TV :cool:

P.s. my last Detonation was in putty-like Mud looked a little like not to liquid thin-shit wich was solid enough to stay in shape ;) Ok, 34g Aluminized NG/NC gelatin produced a Crater wich looked like a funnel-shaped cup!!!! A little curios if you're asking me, someone with such a result too here?

[Guerilla]

nuclearattack, its hard to argue with you as you defend your claims in terms of vague concepts.. well I try to prove my point anyways.

Of course the VoD dont have to be any lower than is needed to reach the desired balance between the explosive and energy additive in order get the maximum energy output, that is, to burn all the extra fuel completely. Naturally, you want an explosive with a high VoD and OB to start with, but you hardly can get both and even then, the influence of aluminum (or whatever) on VoD varies from explosive to explosive. Therefore a compromise between the energy output and VoD has to be made, and in this case the amount of energy should be favoured.

And the reason is, to cause the severest damage to a submarine one needs a great deal of mechanical force, in other words, to move as much water as possible. What else than a large gas output can do this? This applies to all kinds of targets, but ships etc. are particularly sensitive to this kind of massive and prolonged blasts that stress the structures widely first by the initial shock and then by their own weight when they fall down to the empty "crater".

The availability of O2 is not essential as the Al can burn in CO2, H2O, N2.. as well. The underwater explosives are oxygen deficient on purpose to cause lenghtened detonations this way.

[Darkness]

I think that both Guerrilla and Nuclearattack are agree and right.
They are both saying that brisance and ouput gas are important and should be balanced.

To Guerilla:
Underwater explosives are oxygen deficent to increase the volume of the bubble?! Can you explain this concept to me a little better? :( I haven't a lot of experience in underwater detonation but i want to go deeper in this business!
What kind of underwater tests have you made?

[nuclearattack]

Well Guerrilla! Now i'm fully agree with you! You are just saying what i was trying to explain with my last post.
The last concept you mentioned is interesting, i mean the fact that underwater HEs are oxygen deficent with the purpose to extend the bubble effect. With less oxygen the vod will be lower and you obtain a more extended bubble.
I always use ANNM with a bit more NM then 33% (this is the ratio for optimum ox balance), usually i use 40% NM for my underwater dets.
I use this ratio because it's very long storage stable (a bit more NM compensates the one eventually evaporating for bad sealing) but according to your explanation i should modify my ANNM.
I should try with less NM then 33% and add Al powder instead of NM, this should be a very good mixture for underwater dets.
What about this ratio: 20/20/60, NM/Al/AN?

[Guerilla]

I didn't mean oxygen deficiency itself improves the gas volume, but the metal powder which combust with the detonation products (and partly directly with the explosive, which is one reason the VoD goes down), lengthening the rise time of pressure and expanding the bubble, both of which are preferred. The explosive could as well be oxygen rich, but then you would need to abandon the use of the common brisant explosives (that military tends to prefer). I would think the depth charges composed of ammonium perchlorate, RDX and aluminium are more efficient greatly due to their higher OB's. Sorry for causing confusion.

I have made a few bigger underwater blastings, but not any kind of comparison between metallized and non-metallized compositions yet as I've just lately acquired some decent quality powders (German Dark Al, 25µm Al, <100µm Mg and some other coarser grades). I will carry out some tests as soon as I get more time..at the moment I need to take every effort in order to graduate in time, thanks to the attitude problems I've been having.

[Myrol]

Depth Charges are often made with Minol, Tritonal or Torpex (Hexotonal).
Hexotonal gives the best results to dent a Submarine or stressing some sweat-overstreamed submariners :D

Well, not very important but whats about "explosives" wich produce no gas on detonation but cause a significant Explosioneffect? For example Copper acetylide or balanced Chlorate-Magnesiumflash!

Water contains always some gas and I think the reaction products are also able to react a little with the water to produce a bubble! Thats my theorie, might be wrong I dont know!

Umm back to Mudblasting: I like Explosions in thin Mud very very very much! The confinement seems ideal and the power is very regular distributed! Fist-sized chunks fly absolutely perfect radial from the explosion point away! It look's like a crown :D , the Crater has also a very beautyful shape!

If someone can provide Pictures or Videos..............I'm open to everything :D

[xyz]

Myrol, in the case of an explosive that produces no gas, the bubble is water vapour that's been heated by the explosion.

Kinda like the way a nuke works underwater really... (Nukes are far more powerful in water than in air, they produce an explosion by making enough heat to expand the surroundings, and water expands to a much greater volume than air when heated by a nuclear blast)

[tom haggen]

Thats odd, because I saw some old military footage of a nuke going of in the ocean the other day. There were many ships surrounding the explosion that were still intact after the detonation. Of course, the explosion was on the surface of the water and not submerged.

[xyz]

The US military did a test sometime in the 1960s IIRC where they detonated 2 identical nukes at sea, using a load of old WW2 battleships as test subjects. One nuke was detonated several hundred metres up in the air, and one was detonated deep under the water. The underwater one caused many times more damage to the ships.

In the case of a surface blast, I'm unsure what would happen, but I think that most of the heat would end up being applied to the air. The nuke has to be several hundred metres underwater to get a real power boost.

[FUTI]

The water is a bitch when it comes to explosion. It makes more damage to the divers and living tissue then objects. It seems that inhomogenity of that fluid related to temperature and salinity can render submarines rather insensitive to nuke attacks...I read somwhere that detonation of nuke armed torpedo as close as 500m from submarine do not necesary mean it's destruction.

[nuclearattack]

That sound very strange to me! If a conventional charge is able to damage the submarine hull or the internals how can't a nuke make it?
Maybe that it depends from what is meant for "destroyed", if they meant only sink i think that a nuke will make a good job but if they meant "completely crushed" it is possible that the submarine hull will resist enough.
Sometimes it's hard to understand what is meant in an affirmation.

[FUTI]

The way I understand it, it looks like spread of explosion wave isn't uniform. It is the same way as with sound waves. Blast will spread more in the direction that makes less "resistance". But I agree that God knows what did they meant.

[FUTI]

In the light of the tsunami wave that hit south-east Asia this thread look interesting again. I talk to a friend from physics department and although he urge me to look in some geophysics book he thinks that this phenomenon people mistakenly call wave but in his opinion it is more like convection (not oscilation) caused by suden emerging/or droping of entire rif (sorry for spelling) and movement of mass of water to compensate this. Other oppinion I gathered say that this "wave" travel actually over ocean bottom and that it's high wavelength make little trouble to ships at the ocean as they hardly notice it, but when reach shore makes hell especialy in narrow bays.

It seems that others have dilemas about propagation of disturbancy made with mechanical energy through water. Have anyone researched this?

[Myrol]

About the propagation I'm very unsure! Well this summer I've made a lot of under water tests, especially such dimnished one's!

My Test Area was an old Pit for Ironoxide around 20m in diameter the small but deeper hole. I fired some 40g samples of APANAl 1-2,5m under Water and dipped my Hands at the other side in the water. Result: I felt a hard blow in my whole Hand but only where she was under water!

I would say that Waves, Tsunami or Shockwaves can be very good propagated under water....even if the compression pressure decreases rapidly! I'm also a little confused HOW MUCH water can be compressed......In 11. Grade wich is a little ago my Physics teacher told me that water can be compressed but just a tiny bit.

Would this play a role in under Water detonations? It's a fascinating thing to me.....I saw a picture in the web where a 2Ton dropbomb from the WWII was blown up 30m deep under Water and ejected a Jet nearly 200m high :eek: :eek: !!!!

If someone had seen "U-571" theres also a scene where you can see some VERY cool depth Charge Explosions, but it's not very important.

[The_Duke]

The mechanism of an under-water blast presents some interesting phenomena associated with a more dense medium than air. An underwater explosion creates a cavity filled with high-pressure gas, which pushed the water out radially against the opposing external hydrostatic pressure. At the instant of explosion, a certain amount of gas is instantaneously generated at high pressure and temperature, creating a bubble. In addition, the heat causes a certain amount of water to vaporize, adding to the volume of the bubble. This action immediately begins to force the water in contact with the blast front in an outward direction. The potential energy initially possessed by the gas bubble by virtue of its pressure is thus gradually communicated to the water in the form of kinetic energy. The inertia of the water causes the bubble to overshoot the point at which its internal pressure is equal to the external pressure of the water. The bubble then becomes rarefied, and its radial motion is brought to rest. The external pressure now compresses the rarefied bubble. Again, the equilibrium configuration is overshot, and since by hypothesis there has been no loss of energy, the bubble comes to rest at the same pressure and volume as at the moment of explosion (in practice, of course, energy is lost by acoustical and heat radiation).

The bubble of compressed gas then expands again, and the cycle is repeated. The result is a pulsating bubble of gas slowly rising to the surface, with each expansion of the bubble creating shock wave. Approximately 90% of the bubble's energy is dissipated after the first expansion and contraction. This phenomenon explains how an underwater explosion appears to be followed by other explosions. The time interval of the energy being returned to the bubble (the period of pulsation's) varies with the intensity of the initial explosion.

The rapid expansion of the gas bubble formed by an explosion under water results in a shock wave being sent out through the water in all directions. The shock wave is similar in general form to that in air, although if differs in detail. Just as in air, there is a sharp rise in overpressure at the shock front. However, in water, the peak overpressure does not fall off as rapidly with distance as it does in air. Hence, the peak values in water are much higher than those at the same distance from an equal explosion in air. The velocity of sound in water is nearly one mile per second, almost five times as great as in air. Consequently, the duration of the shock wave developed is shorter than in air.

The close proximity of the upper and lower boundaries between which the shock wave is forced to travel (water surface and ocean floor) causes complex shock wave patterns to occur as a result of reflection and rarefaction. Also, in addition to the initial shock wave that results from the initial gas bubble expansion, subsequent shock waves are produced by bubble pulsation. The pulsating shock wave is of lower magnitude and of longer duration than the initial shock wave.

Another interesting phenomenon of an underwater blast is surface cutoff. At the surface, the shock wave moving through the water meets a much less dense medium--air. As a result, a reflected wave is sent back into the water, but this is a rarefaction or suction wave. At a point below the surface, the combination of the reflected suction wave with the direct incident wave produces a sharp decrease in the water shock pressure. This is surface cutoff.

After the lapse of a short interval, which is the time required for the shock wave to travel from the explosion to the given location, the overpressure rises suddenly due to the arrival of them shock front. Then, for a period of time, the pressure decreases steadily, as in air. Soon thereafter, the arrival of the reflected suction wave from the surface causes the pressure to drop sharply, even below the normal (hydrostatic) pressure of the water. This negative pressure phase is of short duration and can result in decrease in the extent of damage sustained by the target. The time interval between the arrival of the direct shock wave at a particular location (or target) in the water and that of the cutoff, signaling the arrival of the reflected wave, depends upon the depth of burst, the depth of the target, and the distance from the burst point to the target. It can generally be said that a depth bomb should be detonated at or below the target and that a target is less vulnerable near the surface.

[The_Duke]

Well this thread died quick. :(
I found some cool pictures of nukes going off under water and figuered I'd add the link here.
http://www.cddc.vt.edu/host/atomic/nukeffct/enw77b2.htm

[Myrol]

Yes, this thread dried a little out. I think its just because under Water Blast are a lot more difficult to manage as on Land. I can't wait for the summer.

I have now some money on my account and can buy me a lot more chemicals and especially Ammonium Nitrate, because this coming summer I will do some BIG under Water Blasts. 5-20kg are waiting :D I will do for sure a big test to create a Jet and also a huge dimnished Blast to create a 8m+ wide circle of shallow splashed water.

BUT before I do this, I need a NEW camcorder :D Does somebody know whats up with SpyDAMonkee? He's a little quiet for a long time....Did he gave up with HE?? Well and does somebody know how much forum members are DEAD??? Because it's a little bad but I think we have some serious casualties since 1995, right?

[nuclearattack]

To Duke (Nukem?):
no the thread is not died, it is interesting and after all i think that underwater tets are more easy and safe to do because you do very low noise, no shrapnels or splinters, lot of fun.
Your post is interesting, i thought about it and i think that the bubble pulse should be very short and fast. I noticed something like this when i detonated 300 gr ANNM underwater, the detonation provoked the classic water jet but immediatly after it a huge bubble pushed a lot of mud (from the bottom of the lake) on the surface and this pulsing bubble continued for two times. However the last 2 pulsations were attenuated as you explained.

To Myrol:
Eh Eh! I like your plan! About the died members i don't think that a lot of members are died, probably their passion for HEs is finished. This is impossible for me because i have this passion since when i was a child!
The only member that we now is died (because of his stupidity) is Phone.

[The_Duke]

No, your right! This thread has not died. It slowed down and I was just being anxious.

I think what your explaining is the occurrence of another underwater blast phenomena similar to surface cut off. I can’t remember the name of this phenomena but I remember reading somewhere that blasts near the water bed surface reflect a weak shockwave back upwards which catches up with the pulsating bubble. Even though the reflected wave is weaker this still happens within a fraction of a second, depending on the distance from the bottom and the power of the initial shock wave. If the explosion is close enough to the bottom and in shallow water the initial shock wave disturbs the mud and the reflected wave helps to push the mud and muck to the surface following directly behind the bubble. I’m pretty sure the bubble does not create the disturbance of the mud but it does help to carry it to the surface. Can anyone back me on this or am I wrong?

And yeah nuclear attack, it’s Duke Nukem. I also like John Wayne. :D

[FUTI]

Just got this link from a friend, and since I mentioned the subject in this thread here I post it to be seen by hard working members of the E&W Forum:)
http://www.hinduonnet.com/thehindu/thscrip/print.pl?file=2004123000111600.htm&date=2004/12/30/&prd=seta&

to Duke: thanks your explanation is as good and thorough as the one Marvin gave in EMP thread.

[Myrol]

Some time ago, I've heard somethin' about a company from the netherlands called exploform wich forms sheets of metal into VERY accurate shapes via explosive forming under Water!

I saw them how they made a nozzle for a rocket with such a precision....ohhh dear.....Is somebody here wich formed metal under water too? I mean....some members like Axt have done tons of tests with metalpaltes on Land but not under Water?

My Idea is to attach a 40g ANNM Filmcanister to a 2mm V4A-Stainless Steelplate and blowing it up that the Plate will be propelled out of the water! Hope it won't be ripped into pieces but explosively forming of metal under water seems like a nice hobby :D I'll post my results including a picture if I'm ready then.

I think, if you compare the dent's with different explosives especially Aluminized ones, you'll see then the REAL difference between AP and Pentrinital, not?

[Myrol]

Some time ago, I've heard somethin' about a company from the netherlands called exploform wich forms sheets of metal into VERY accurate shapes via explosive forming under Water!

I saw them how they made a nozzle for a rocket with such a precision....ohhh dear.....Is somebody here wich formed metal under water too? I mean....some members like Axt have done tons of tests with metalpaltes on Land but not under Water?

My Idea is to attach a 40g ANNM Filmcanister to a 2mm V4A-Stainless Steelplate and blowing it up that the Plate will be propelled out of the water! Hope it won't be ripped into pieces but explosively forming of metal under water seems like a nice hobby :D I'll post my results including a picture if I'm ready then.

I think, if you compare the dent's with different explosives especially Aluminized ones, you'll see then the REAL difference between AP and Pentrinital, not?

[Myrol]

Some time ago, I've heard somethin' about a company from the netherlands called exploform wich forms sheets of metal into VERY accurate shapes via explosive forming under Water!

I saw them how they made a nozzle for a rocket with such a precision....ohhh dear.....Is somebody here wich formed metal under water too? I mean....some members like Axt have done tons of tests with metalpaltes on Land but not under Water?

My Idea is to attach a 40g ANNM Filmcanister to a 2mm V4A-Stainless Steelplate and blowing it up that the Plate will be propelled out of the water! Hope it won't be ripped into pieces but explosively forming of metal under water seems like a nice hobby :D I'll post my results including a picture if I'm ready then.

I think, if you compare the dent's with different explosives especially Aluminized ones, you'll see then the REAL difference between AP and Pentrinital, not?

[Silentnite]

I googled and found the website:

Exploform (http://www.exploform.com/)

http://www.exploform.com/images/products_001tn.jpg http://www.exploform.com/images/products_029tn.jpg

Its pretty amazing what you can do with our beloved explosives. Would there happen to be a CAD program with an explosive design tool?

As far as the underwater Demo goes, what about a shaped charge? Dont they cut ship steel under water with plasma jets? Something about preventing the metal from warping. I dont exactly know why that would be useful, as we are normally looking to make a hole, not a line. But who knows.

I wish I had a lake nearby with which I could do some testing. But I will have to make do with buckets, and maybe the little pond I dug out back. Pictures coming soon.

EDIT:
I am not sure how relavant to this page this is, but it is rather interesting and I couldnt find a better place for it. Some scientists were sitting around and playing with ethanol, and discovered that at very low Torrs it didnt splash. Dropped into a flat liquid, at a low atmosphiric pressure, it didnt splash. Just absorbed.
Better explained HERE: (http://www-news.uchicago.edu/releases/05/050322.splash.shtml)

[Silentnite]

I googled and found the website:

Exploform (http://www.exploform.com/)

http://www.exploform.com/images/products_001tn.jpg http://www.exploform.com/images/products_029tn.jpg

Its pretty amazing what you can do with our beloved explosives. Would there happen to be a CAD program with an explosive design tool?

As far as the underwater Demo goes, what about a shaped charge? Dont they cut ship steel under water with plasma jets? Something about preventing the metal from warping. I dont exactly know why that would be useful, as we are normally looking to make a hole, not a line. But who knows.

I wish I had a lake nearby with which I could do some testing. But I will have to make do with buckets, and maybe the little pond I dug out back. Pictures coming soon.

EDIT:
I am not sure how relavant to this page this is, but it is rather interesting and I couldnt find a better place for it. Some scientists were sitting around and playing with ethanol, and discovered that at very low Torrs it didnt splash. Dropped into a flat liquid, at a low atmosphiric pressure, it didnt splash. Just absorbed.
Better explained HERE: (http://www-news.uchicago.edu/releases/05/050322.splash.shtml)

[Silentnite]

I googled and found the website:

Exploform (http://www.exploform.com/)

http://www.exploform.com/images/products_001tn.jpg http://www.exploform.com/images/products_029tn.jpg

Its pretty amazing what you can do with our beloved explosives. Would there happen to be a CAD program with an explosive design tool?

As far as the underwater Demo goes, what about a shaped charge? Dont they cut ship steel under water with plasma jets? Something about preventing the metal from warping. I dont exactly know why that would be useful, as we are normally looking to make a hole, not a line. But who knows.

I wish I had a lake nearby with which I could do some testing. But I will have to make do with buckets, and maybe the little pond I dug out back. Pictures coming soon.

EDIT:
I am not sure how relavant to this page this is, but it is rather interesting and I couldnt find a better place for it. Some scientists were sitting around and playing with ethanol, and discovered that at very low Torrs it didnt splash. Dropped into a flat liquid, at a low atmosphiric pressure, it didnt splash. Just absorbed.
Better explained HERE: (http://www-news.uchicago.edu/releases/05/050322.splash.shtml)

[Guerilla]

Seems like using this exploform metal forming technique, one might be able to prepare sturdy and uniform metal cones for larger SC's without much of hassle. At least for our needs that's the most profitable task for this method I can now think of.. All that would be needed would be a strong die with either vent holes or vacuum space inside the cavity, a metal plate to be formed, a small explosive charge and a decent sized tank filled with water or other dense material like sand.

All kinds of other useful things could also be shaped with this method, but from an amateurs perspective the fact that the formed metal part can only be as complicated as the used die sort of beats the purpose. I mean unless you got access to a lathe, fancy looking rocket nozzles etc. parts seem all no-go's. Though I wonder if there would be some easily moldable die materials that would still be able to sustain the shock, some polymer or ceramic clay perhaps? Gotta try out, as soon as I can be arsed..
Some scientists were sitting around and playing with ethanol, and discovered that ... Hehe.. that was an interesting article. Good to see they research and question old theories around such common seeming phenomenons, too.

[Guerilla]

Seems like using this exploform metal forming technique, one might be able to prepare sturdy and uniform metal cones for larger SC's without much of hassle. At least for our needs that's the most profitable task for this method I can now think of.. All that would be needed would be a strong die with either vent holes or vacuum space inside the cavity, a metal plate to be formed, a small explosive charge and a decent sized tank filled with water or other dense material like sand.

All kinds of other useful things could also be shaped with this method, but from an amateurs perspective the fact that the formed metal part can only be as complicated as the used die sort of beats the purpose. I mean unless you got access to a lathe, fancy looking rocket nozzles etc. parts seem all no-go's. Though I wonder if there would be some easily moldable die materials that would still be able to sustain the shock, some polymer or ceramic clay perhaps? Gotta try out, as soon as I can be arsed..
Some scientists were sitting around and playing with ethanol, and discovered that ... Hehe.. that was an interesting article. Good to see they research and question old theories around such common seeming phenomenons, too.

[Guerilla]

Seems like using this exploform metal forming technique, one might be able to prepare sturdy and uniform metal cones for larger SC's without much of hassle. At least for our needs that's the most profitable task for this method I can now think of.. All that would be needed would be a strong die with either vent holes or vacuum space inside the cavity, a metal plate to be formed, a small explosive charge and a decent sized tank filled with water or other dense material like sand.

All kinds of other useful things could also be shaped with this method, but from an amateurs perspective the fact that the formed metal part can only be as complicated as the used die sort of beats the purpose. I mean unless you got access to a lathe, fancy looking rocket nozzles etc. parts seem all no-go's. Though I wonder if there would be some easily moldable die materials that would still be able to sustain the shock, some polymer or ceramic clay perhaps? Gotta try out, as soon as I can be arsed..
Some scientists were sitting around and playing with ethanol, and discovered that ... Hehe.. that was an interesting article. Good to see they research and question old theories around such common seeming phenomenons, too.

[Bert]

Re the splashing- I want to know more about that 47,000 frame per second digital camera!

[Bert]

Re the splashing- I want to know more about that 47,000 frame per second digital camera!

[Bert]

Re the splashing- I want to know more about that 47,000 frame per second digital camera!

[FUTI]

I read many years ago...I just realised I'm old...that someone claimed that Russians are using something like exploform to make keels of their submarines. Taking in consideration link kindly provided by Silentnite and that two of four metals used are aluminium and titanium which is the case with at least two class of Russian submarine Alpha and Typhoon...it can be true since I don't believe in coincidence.

[FUTI]

I read many years ago...I just realised I'm old...that someone claimed that Russians are using something like exploform to make keels of their submarines. Taking in consideration link kindly provided by Silentnite and that two of four metals used are aluminium and titanium which is the case with at least two class of Russian submarine Alpha and Typhoon...it can be true since I don't believe in coincidence.

[FUTI]

I read many years ago...I just realised I'm old...that someone claimed that Russians are using something like exploform to make keels of their submarines. Taking in consideration link kindly provided by Silentnite and that two of four metals used are aluminium and titanium which is the case with at least two class of Russian submarine Alpha and Typhoon...it can be true since I don't believe in coincidence.

[me234]

With regards to what nuclearattack mentioned earlier: he mentioned that Al in explosives underwater weren't much good if one used an explosive with a bad OB, fair enough I thought very plausible and most probable. Then I read the SM thread on Al/H2O2 explosives, and AXT posted something about Al/Mg in water or alcohols being pretty decent explosives.
http://67.15.145.24/~sciencem/talk/viewthread.php?tid=3214&page=1
Next I recalled a particular thermobaric mixture that went something like 75:25 Al:IPN which required a huge booster because the explosive itself was not present in sufficient quantity to sustain the explosion throughout the body of the TBmix, this is because there was too much Al, and the excess went on to combust in the air. So, if one were to take this mixture (along with huge booster) and set it off underwater, what would become of the excess Al?
Perhaps it might react with the water to further the explosion?
Considering that some of the water would be in gaseous form, it should make it require less energy to cause this Al/H2O secondary reaction to occur.
This could lead to a potentially powerful (I should think) and very useful explosive for underwater applications.
What say you, the devoted 10 000?

[me234]

With regards to what nuclearattack mentioned earlier: he mentioned that Al in explosives underwater weren't much good if one used an explosive with a bad OB, fair enough I thought very plausible and most probable. Then I read the SM thread on Al/H2O2 explosives, and AXT posted something about Al/Mg in water or alcohols being pretty decent explosives.
http://67.15.145.24/~sciencem/talk/viewthread.php?tid=3214&page=1
Next I recalled a particular thermobaric mixture that went something like 75:25 Al:IPN which required a huge booster because the explosive itself was not present in sufficient quantity to sustain the explosion throughout the body of the TBmix, this is because there was too much Al, and the excess went on to combust in the air. So, if one were to take this mixture (along with huge booster) and set it off underwater, what would become of the excess Al?
Perhaps it might react with the water to further the explosion?
Considering that some of the water would be in gaseous form, it should make it require less energy to cause this Al/H2O secondary reaction to occur.
This could lead to a potentially powerful (I should think) and very useful explosive for underwater applications.
What say you, the devoted 10 000?

[me234]

With regards to what nuclearattack mentioned earlier: he mentioned that Al in explosives underwater weren't much good if one used an explosive with a bad OB, fair enough I thought very plausible and most probable. Then I read the SM thread on Al/H2O2 explosives, and AXT posted something about Al/Mg in water or alcohols being pretty decent explosives.
http://67.15.145.24/~sciencem/talk/viewthread.php?tid=3214&page=1
Next I recalled a particular thermobaric mixture that went something like 75:25 Al:IPN which required a huge booster because the explosive itself was not present in sufficient quantity to sustain the explosion throughout the body of the TBmix, this is because there was too much Al, and the excess went on to combust in the air. So, if one were to take this mixture (along with huge booster) and set it off underwater, what would become of the excess Al?
Perhaps it might react with the water to further the explosion?
Considering that some of the water would be in gaseous form, it should make it require less energy to cause this Al/H2O secondary reaction to occur.
This could lead to a potentially powerful (I should think) and very useful explosive for underwater applications.
What say you, the devoted 10 000?