Burning bullets - melting your way into a tank

[Jacks Complete]

New Scientist
6th September 2005

Burning bullets

A bunker-busting shell that gets so hot on impact that it burns its way through concrete and steel is being developed by the US Navy's Warfare Center in Virginia.

The shell contains a mixture of aluminium polytetrafluoroethylene (PTFE) and perchlorate oxydiser, moulded together into an aerodynamic shape. To prevent the mixture from disintegrating as it travels through air at high velocity the shell is wrapped in a soft Teflon tape, which is wound tight under high tension, heated and topped with epoxy glue to prevent unravelling.

Its high-velocity impact acts as a catalyst, forcing the two chemicals together in a red hot reaction. The projectile gets so hot so fast that it should instantly burn its way through armour plating or other defences.

And the burning shell would avoid the environmental pitfalls of radioactive depleted uranium - currently the most common material used in armour-piercing shells.

Read the burning bullets patent at http://tinyurl.com/cgopd

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Sounds like fun, & certainly one up from Thermite!

[malzraa]

I like that idea. Seems like it would be easily defeated by an ablative or reactive armor. The Reactive armor would be an explosive that detonates upon the impact of one of these burners, throwing the burning material away from the target to burn harmlessly on the ground. Very inventive, though.

[nbk2000]

Reactive fragments are a good thing. Perhaps the implementation, as described in the patent, is flawed on purpose? After all, the government knows that foreign nations read patents too.

[meselfs]

I like that idea. Seems like it would be easily defeated by an ablative or reactive armor. The Reactive armor would be an explosive that detonates upon the impact of one of these burners, throwing the burning material away from the target to burn harmlessly on the ground. Very inventive, though.
It'd probably work only for burning bullets.

It doesn't seem plausible to me... in order to repell a regular (HE or KE) bullet off, your explosives would create a reactive force that would at the very least throw the bullet back. This results in a big momentum transfer, bigger then if the bullet jsut hit...

If I encountered a tank with such silly armor I'd fire HE/KE bullets at it and exploit this sensitivity.

[malzraa]

Yeah, that is true. The point of these bullets was to melt through armor though, not to destroy by the transfer of momentum, and that could be defeated through reactive armor. only problem with reactive armor is that is gone after you use it.

[Jacks Complete]

It'd probably work only for burning bullets.

It doesn't seem plausible to me... in order to repell a regular (HE or KE) bullet off, your explosives would create a reactive force that would at the very least throw the bullet back. This results in a big momentum transfer, bigger then if the bullet jsut hit...

If I encountered a tank with such silly armor I'd fire HE/KE bullets at it and exploit this sensitivity.
Which is why reactive armour is only found on tanks. You can't exploit it, because if you knock on the door, they send a 155mm round to see who's there. They know where you are - it's a modern tank with reactive armour, a thermal imager and a shot direction finder of some type.

Your first shot sets off a non-directed block of C-4 (or whatever) and this goes bang. Without compression or direction, the vast majority of the force goes outwards, rather than doing much to the foot or so of tank armour behind it. It does a great job of fucking up anything incoming, though, like an RPG or a HESH round.

Anyway, the idea of burning your way through at supersonic speeds is almost insane. The composition in the patent must burn faster than most low explosives!

[FUTI]

I agree Jack it look very awkward to me...seems like someone looked upon a space shuttle crash movie and got up an idea. That mixture will ignite and make a lot of heat, but did anyone tried to figure out how this can drill a hole? I believe that heat is slower transfered to an object this projectile hits that the projectile itself smash into the object...so I couldn't call that a melting. It seems this two forces work combined (if this actually work and isn't a hoax generated in some obscure secret agency)- like in "beating the plowshares into swords" the more you beat it the warmer it gets;) I got a similar idea few years ago but I was thinking about cheap armor-piercing ammo, but since this didn't needed a termite of any kind to work I didn't planed it that way(why would I use a cannon to kill a fly?).

[Chris The Great]

What happens when molten metal/stuff hits something hard at high speed? It splatters.

More well spent government money on something that couldn't possibly work.

[malzraa]

I suppose this all could be proven effective/ineffective mathematically (aside from the arguments relating to the actual mechanics of the bullet). In order for the bullet to burn through the armor, it must be travelling fast enough so that the entire armor surface doesn't absorb the heat (high temperature gradient around the impact area), but slow enough for the metal to boil away and not merely splinter and deflect the bullet. It also must burn quickly and hot enough to boil the target armor very rapidly, but not so quickly as to burn out before reaching the center of the target. All this seems to be WAY to much "if"s just to make a novel armor-piercing bullet. Way to many potential points of failure.

[meselfs]

I'd say a burning bullet isn't a bad idea at all (unlike that reactive armor...).

The bullet would have to be rather long, and it may work best as a rocket or with mass in the back to keep it moving as it burns.

The fuel would also need to be heavy & insensitive, so that the molten/vaporized material could go around it withough messing it up.

If a burning bullet could work, then what about some sort of burning "clam" ? You could stick it onto a tank, ignite it, and run; assuming you could approach the tank without being perforated. It would look like a daddy longlegs spider, with the centerpiece doing the burning.

[malzraa]

That's a good idea. It would either need to be placed directly on top of the tank, or have some sort of propellant to push it into the tank.

[Chris The Great]

Heat seeking thermite carrying kamikazi robots? :cool:

In terms of reliability and effectiveness, shaped charges seem to work quite well. Unless they have reactive armour, that is actually VERY effective, it can cut penetration down to 1/4 normal. The problem is it is single usage so if they shoot you again in the same spot you aren't going to be a happy tank.

[Flake2m]

Well an M1 abrams fires projectiles that are about 2-3ft long, so theres the long projectile that you need.
Given the sound of this technology, There is likely to be a tungsten penetrator associated with it. Tungsten can be pyrophoric in certain conditions.

Don't the DU round kill tanks because the amount of heat and energy the round has get transferred over to the armour and cockpit? I did see pictures of tank turrets being blown off the tank and landing many metres away from the tank wreckage.

My train of thought is;
This composition is used to coat a standard tungsten penetrator. So when this round hits the armour, it enhances the effects of the actual penetrator itself, this would make the round more effective at penetrating armour. Also the tungsten is nessecary to give the round some weight and momentum.
The other effect this would have is killing crew and disabling vital systems, because 300*°Cparticles and human flesh,fuel tanks and ammuntion don't mix too well.

[teshilo]

Other nice stuff.Bullet created from these composition after shot none any traces for forensic.All self destruct.And if created bullet composition incendiary explosive type as PTFE perchlorate outer, inner rubber azide mix around hard steel needle?

[Jacks Complete]

Other nice stuff.Bullet created from these composition after shot none any traces for forensic.All self destruct.And if created bullet composition incendiary explosive type as PTFE perchlorate outer, inner rubber azide mix around hard steel needle?
Like the "ice bullet" that melts inside the victim... (Edit: Yes, I know! :roll: )

I think that using a burning bullet on a person would make the target more likely to survive than less, since the heat would help stop the bleeding.

There would be far more to go on forensically than normal, just no rifle marks on the slug. The barrel would have traces of the burning composition on it unless saboted, and then it would be rifling free anyway.

Energetically, I doubt anything can burn fast enough to put the heat into the metal fast enough to make much difference to the rate of penetration without actually deflagrating. However, it seems like it might work after millions of dollars (and rounds) of testing. I'd do that job!

Heat seeking thermite carrying kamikazi robots?Why not? Ever played Red Alert 2? Imagine a steel spider that tracked heat, was quite tough to kill, man sized or large dog sized, and armed with an oxygen lance or a plasma cutter, and some thermite to pump in once the hole was cut. Good vs. tanks, I think.

Now the DARPA Grand Challenge is complete and won (by five different teams!) I can see these things being five years away, tops. Of course, the tanks won't have a crew either...

[ShadowMyGeekSpace]

What about HEAT rounds?

http://en.wikipedia.org/wiki/HEAT

[Jacks Complete]

A HEAT round doesn't use heat, it uses the explosive shockwave to form a molten jet that travels very rapidly, and that bores through.

This idea is a bit different, in that it doesn't try to punch through with a small jet, it tries to burn through with the entire round, without the explosive acceleration.

I can see a two inch wood slab stopping one of these rounds, with a layer of something underneath. The water/steam outgassing will disrupt the forward travel, and the carbon layer would resist the heat rather well.

[Chris The Great]

The jet isn't molten... but basically it's a shaped charge with a rocket strapped to it. Completely different than this idea, as JC says.

[Gollum]

There's some more ways to kill tanks. You can kill a T80 as well as M1's by using a smoke grenade.. Both the tanks use turbine engines. Turbines die when they ingest stuff they're not supposed to. So throw a smoke grenade on the air intake and let the engine choke to death. Sometimes the turbine will catch fire and the crew will have to evacuate. Other times the turbine will just die and the tank will be stuck motionless for a while until the gunk clears out of the compressor stages.

FYI, HEAT rounds are terrible antitank rounds because they do not penetrate armor very well. They are better for very old tanks (Like 50's and 60's equipment) or APC's. A heat round from an M1 probably wouldn't kill a T72 except if it hit the turret ring or the back. Sabot are much better for anti tank stuff.

And yes the HEAT round is basically a shaped charge, look at one if you can, it's clearly a conical shape with a single spike in the middle. When it is fired and hits a target, the whole unit heats to a molten form, reverses shape and the center of the unit penetrates the armor then breaks up into thousands of pieces (spalls) which is what kills the crew inside (at least initially, before any ammo or fuel explodes). Most new armor has a spall liner to stop this from happening.

[Jacks Complete]

The spall liner was originally designed for protection from HESH rounds, which were the forerunner of HEAT. They used a block of plastic explosive, and were designed to hit the arnour, then squash against it. It was then detonated from the rear, which coupled the shockwave into the armour, causing bits to fly off the inside, killing the crew without actually defeating the armour.

HEAT is very, very effective, and is used in most man-portable systems, where the energy required to launch a KE kill warhead would be too high for a man. The copper dart from an RPG9 has killed more tanks, even relatively modern tanks, than you have probably ever seen. However, against a non-linear density armour such as Chobham (a secret steel sandwich of carbide and tungsten bits with an inert filler) and even the WWII emergency ship protection of steel bread with gravel and tar (tarmac) filling, it is very much less effective. A quite modern and unfielded as yet development is a highly charged capacitor and two steel plates with an air gap, which when bridged by the copper is instantly blown apart by the current surge, much like a fuse.

The latest way to stop anti-tank rounds is with an electronic system that fires an anti-anti-tank missile to intercept. Lots of info at http://www.defensetech.org/archives/002230.html

I know that the Axis powers tried to use an ozone generatoing bomb to stall tank engines in WWII, but that failed. I also find it unilkely that a smoke bomb would kill an M1 tank's engine, when standard ops. call for huge continuous smokescreens over huge areas for a long time, generated and spread by the tanks themselves.

[Chris The Great]

The most recent warheads use an EFP since it is not affected by countermeasures for the HEAT round. Since HEATs are the most common thing in the world thanks to the RPG-7, tanks are soft targets for an EFP warhead.

OTOH, EFP warheads are a little more complex, since they need a much larger standoff.

[Jacks Complete]

I'm just pondering, it's possible that you could kill a turbine engined tank by reacting with the jet fuel more aggressively than air. I don't have any real experiance of turbine engines, but I do know that they can suck in huge volumes of air, they are very high powered yet quite quiet, and they take a while to spin up. If an M1 is sat there, it takes a few moments before it can start moving, as the turbine suffers from, effectively, "turbo lag". However, there's no way that you could flood the engine with sand or grit, due to the filters, and no way you could really use a regular liquid. It would have to be a gas, and quite a high volume of it.

[Gollum]

>take a while to spin up.<

In my experience I have not found that to be the case on either the american or russian tanks. The turbines are supposed to run at high rpm's so that torque is instantly available when needed. My understanding is that it's adjusted downward when needed for fuel economy. In modern jetliners and military aviation, it's standard procedure to do your final approach with the engines set to high thrust settings so that if something goes wrong like a windshear, you don't have to wait ages for the engines to spool up. It's not good for fuel economy and it requires a higher angle of approach, but it makes more sense maneuverability/safety wise.

As I mentioned a few posts above, the best way to do it is with a few smoke grenades, or if you can find any chemical that reacts violently on contact with jp1 then that would be another ok substitute.

Other easy tank killing methods are just the old basics stuff. Blowing up the tracks of a tank really puts it in a jam for about 30 minutes. Killing the TC or fucking up the periscope on the m1a2 would make things more difficult for the crew, so would blowing up external fuel tanks. The russians have all kinds of flammable shit on the back of t72's.

probably the best realistic method of killing a tank is the IED method and the towelheads over there already know this and use it to good effect. The underside is generally the weakest part of all military vehicles.

[FUTI]

I'm just pondering, it's possible that you could kill a turbine engined tank by reacting with the jet fuel more aggressively than air.

I have no idea about those engines but taking your idea into consideration cheapest idea I can thought of is NOx. Now we all know how to make it...but quick and enough when needed. I had somewhere description how to make liquid N2O3 I think. To much trouble if you ask me but who knows...

[Sausagemit]

I know that the Axis powers tried to use an ozone generatoing bomb to stall tank engines in WWII, but that failed. I also find it unilkely that a smoke bomb would kill an M1 tank's engine, when standard ops. call for huge continuous smokescreens over huge areas for a long time, generated and spread by the tanks themselves.


But that's acctually caused by dumping diesel fuel into the hot exhaust, completely different than a red phosphorus smoke gernade. I also find it somewhat hard to believe that a RP smoke gernade would stall a m1's engine too. But using the right kind of smoke, mabye something thats water or oil based might do the trick.

And don't DU rounds pretty much do the same thing. Correct me if I'm wrong but DU when put under extreme stress (such as being fired at high velocities into something solid) heat up a lot, enough to melt it's way through armor.

The only drawback is the radiation, but it's so little that nobody cares except those environmentalists who don't realize that in order for it to be harmfull it has to be ground up and injested, so pretty much the only people who have to worry about it are either too stupid because they were chewing on a chunk of DU and deserver to die or the people with two heads because they were on the recieving end of a DU round.

++++++++

Improve your grammar and spelling ASAP. NBK

[Chris The Great]

The penetrator is caused by the combination of extreme velocity, density and strength of the DU round, concentrated onto a very small area. It has nothing to do with how hot the round may get.

Once inside the tank however, the DU ignites into flame. This is why DU rounds cause enviromental effects, because they are blown into fine uranium oxide dust once they penetrate a tank, and this uranium oxide is easily absorbed into the enviroment.

[Jacks Complete]

If you can find some way of getting that much smoke there fast enough, and then making it persistant for long enough to stall the engine/turbine, go for it. I seriously doubt that it will work. Burning deisel doesn't do much, and red and white phosphorus had been used in war for a while now. The fine Iraq dust storms killed a lot of the UK tanks because they decided to save £7million by not fitting them, but that problem has gone now they fitted them. (Cost a lot more than the original £7mill. though!) You can put a cigarette out in JP1 now, you know? It's going to take something really special.

As for the M1 series taking a while to get moving, my point was that the troops have said that it is an issue, because the turbines aren't always spooled up, and they can't be because you need to have enough fuel to do what you are doing and get home again, and running at 100% all the time means you run out hours before.

[Sausagemit]

Once inside the tank however, the DU ignites into flame. This is why DU rounds cause enviromental effects, because they are blown into fine uranium oxide dust once they penetrate a tank, and this uranium oxide is easily absorbed into the enviroment.


Oh, so it's a pyrophoric material, I did not realize that. I guess I should have done a little bit of research before posting.

But you still have to ingest/inhale/be shrapneld (not a real word but it should be) by DU in order for it to be harmful as it emits very little gamma radiation and the alpha and beta particles (its main source of radiation) are blocked by skin and clothes respectively. So as long as your not licking an exploded Iraqi tank, I think you will be fine. And the old T-64's used a lot of asbestos so I think the DU would be the least of your worries if you see a T-64 shot up by it.

And as for modern JP-1, it's pretty much kerosene with a detergent additive (it used to be almost straight kerosene) to give it a very high flash point. It's different than most modern jet aircraft fuels in the fact it doesn't ignite as easy as JP-5 (the kind used on aircraft carriers to cut down on the fire hazard), and even JP-7 (fuel used in supersonic aircraft).

The reason JP-1 isn't used for aircraft anymore is because of its slow burn rate compared to other superior kerosene based mixtures. Pretty much the only use for JP-1 in modern aircraft anymore is for scramjets, which are still in the working prototype phase of development. But as for a tank fuel it works great for the above stated reasons.

[sparkchaser]

Tanks these days use JP-8, which is fairly similar to diesel. All U.S. military vehicles run on this stuff to help in logistics.

DU is pyrophoric, which causes a massive overflash inside the troop compartment after the round has penetrated and left a cloud of DU dust inside.

The way it defeats armor is two-fold. One; as it penetrates, it self sharpens by non linear fracture. Two; it has incredible density which gives it the energy to keep travelling through steel at the massive velocities which it is fired at (gotta love sabots!).

Heat rounds are shaped charges which work very well for thinner armor, but don't have the penetration to defeat armor on most facets of the tank. Tanks are faceted to deflect the majority of frontal or side attacks by most weapons.

I think the teflon/aluminum/perchlorate rounds *could* work, if only they had the density to cary any sort of velocity at range, or penetrate for that matter.

The U.S. is considering the replacement of it's 30mm anti tank DU rounds with tungsten because the tungsten carries it's velocity better, and is able to penetrate at a greater distance. Added to the carcinogenic effects of tungsten fragments, but no radioactivity (DU does infect the graound water with radiation quite badly), and it's a winner. DU's only advantage comes in the shorter ranges (if you consider 4,000m to be short), and the advantage is slight.

The dense smoke of a few smoke grenades may work to stop the engine, if enough was ingested. The A-10 thunderbolt II initially had flameout problems when firing it's main gun at certain angles of attack, due to the engines ingesting the large amounts of smoke that 30mm rounds make when fired at 6,000 rounds per minute.

The aircraft's fuselage had to be completely redesigned to deflect the smoke into the slipstream below the plane.