bowersr@urubu.cs.orst.edu (Robert Mark Bowers) (04/10/90)
From: bowersr@urubu.cs.orst.edu (Robert Mark Bowers) In the discussion of the DU rounds, the Navy's Close-In Weapon System has somehow escaped mention. The CIWS uses the M61A1 gun, a six-barreled 20mm Gatling gun. Of course, its targets are typically less heavily armored than the targets previously alluded to in the discussion, but the streamlined shape of missiles and aircraft makes penetration pesky, hence the use of DU. Besides increasing bullet mass, the hardness of DU recommends it as bullet material. The earlier reference to "kinetic energy" is not quite sound. The kinetic energy of any projectile shot from a gun is determined more by the amount of powder used (and its burning characteristics) than by the mass of the bullet: Given identical powder charges, identical guns, and two projectiles of identical shape and size, the kinetic energy imparted will be identical. Note that the mass of the projectile doesn't affect the kinetic energy; if one of the projectiles was heavier than the other, it would have a lower muzzle velocity, in keeping with the one-half mv squared formula from elementary physics. I've already referred to DU's hardness, but I'm surprised nobody's mentioned it before: What good is a soft penetrator? That DU rounds can pass all thess way through a tank is due as much to DU's hardness as to its density. =============================================================================== Bob Bowers | "Time is Nature's way of keeping everything from bowersr@urubu.CS.ORST.EDU | happening at once." --Unknown -------------------------------------------------------------------------------
root@uunet.UU.NET (Superuser) (04/10/90)
From: grumbly!root@uunet.UU.NET (Superuser)
->>What can anyone tell me about ammo using depleted uranium?
->
->The GAU-8 cannon in our A-10 aircraft uses it. This is a 30mm gatling gun,
->basically, mounted in the nose of the airplane.
[...]
->I laugh hysterically. I have a tape that has a shot of an A-10 diving
->on a tank, and firing 4 bursts from the cannon in rapid succession. (bursts
->about 1/4 second long, and 1/2 second between bursts, approx.) Then they
->show what happens to the tank. The tank gains quite a number of
->perforations in it's armor. Then sparks begin to fly. Then there's a real
->nasty explosion that makes a VERY visible displacement of it's main gun.
->
->Basically what happens is the rounds have so much kinetic energy that they
->literally punch right through the armor and keep on going. Usually the
->rounds will punch right through to the fuel tanks or the magazine. At
->that point, it's all over for the tank.
What happens when it is used against reactive or other modern armor?
--
/// - - - - - - - - - - - - - - - - - - - - - - >
0 0 Richard Ducoty ..uunet!grumbly!root
> Capitola, Calif root@grumbly.com
` steve@uunet.UU.NET (Steve Nuchia) (04/10/90)
From: nuchat!steve@uunet.UU.NET (Steve Nuchia) In article <15306@cbnews.ATT.COM> sysmgr@KING.ENG.UMD.EDU (Doug Mohney) writes: >Of course (not to put on a GreenPeace(tm) hat), nobody knows what leaving >depleted uranium laying around all over future battlefields will do to >the environment on a long-term basis... I wish I could remember where I read this, but I can't. In india there are groups of "untouchables" living on the edges of artillery and bombing ranges who make their living collecting shell fragments and the occasional dud for sale as scrap metal. Their desperation is such that they sometimes go out before the shelling has stopped, and in any case unexploded munitions are dangerous. They suffer a lot of casualties, but it beats starving. I'd guess that in most scenarios that include a lot of DU slugs in the ground outside of designated ranges, there will be refugees or others who will "mine" the metal for its scrap value, which will be high as long as the fighting continues, and non-zero afterwards. Of course the slugs in the ranges in most of the world aren't being collected, and probably contribute to the heavy metal content of the runoff water from those areas. I wonder if it is any worse than the lead runoff from all the military and private small-arms ranges all over the world?
gwh%headcrash.Berkeley.EDU@ucbvax.Berkeley.EDU (George William Herbert) (04/10/90)
From: gwh%headcrash.Berkeley.EDU@ucbvax.Berkeley.EDU (George William Herbert) In article <15264@cbnews.ATT.COM> pfloyd@wpi.wpi.edu (The Floydian Slip) writes: > >>From: mathers@trlsasb.trl.oz (Steven Mathers) >>What can anyone tell me about ammo using depleted uranium? >>Would an m16 using such ammo seriously worry a tank for instance? >>What actually happens when the bullet/shell/missile hits the target? > >The depleted uranium rounds are only used in the A-10's GAU-8 Avenger >30mm rotary cannon. > > [mod.note: DU rounds are also provided for the 105mm and 120mm > guns mounted in the M1 Abrams. Does anyone know if they're > also available for the Bradley ? - Bill ] Weapons I am aware of that use DU in their ammo include all the above [just about all tank main weaponry too] and also the Vulcan 20mm [the ammo was developed for the Phalanx CIWS on ships, but has been back-qualified on all other models of M-61 vulcan, including the 3-barrel helicopter variant and all ground mounted AAA variants. The Bradley;s 25mm M242 cannon can fire a DU round also, though I am not sure if that is the standard AP round deployed. >The upshot of using depleted uranium is that, because it is so dense, it will >penetrate both the top armour, any spalling protection inside, and the bottom >armour of a tank. Quite a few of the pilots would rather use the pratice rounds >for the Avenger, because they won't go through the bottom armour-- they'll just >stay inside and bang around for a while. >I believe they can also ignite on contact with the armour. >It's a waste to produce rounds of this sort for, say, an M-16 rifle. The TP rounds also won't penetrate a MBT except for a really-high angle attack, and the AF is trying to keep the A-10's as low as possible. They all will fly with the AP rounds in combat. The 'igniting on contact' is a misunderstanding. Uranium is pyrolitic and will ignite very easily [like but not as extreme as phosphorus]. It is in no way a waste to produce AP small arms rounds. They are extremely useful in many situations, and DU ammo has been made for small arms. A lot of snipers will use AP in special situations, and it's becoming more likely that the next generation infantry weapon will use AP ammo to defeat personal armour. ******************************************************************************* George William Herbert JOAT For Hire: Anything, Anywhere: My Price UCB Naval Architecture undergrad: Engineering with a Bouyant Attitude :-) ------------------------------------------------------------------------------- gwh@ocf.berkeley.edu <= prefered [also gwh@soda.berk.. and maniac@garnet.berk..] Give me a billion dollars and two years and I'll build you a space station you'll never forget. "Pull up! NO, NOT THAT UP!" CRUNCH
tek@CS.UCLA.EDU (Ted Kim (Random Dude)) (04/11/90)
From: tek@CS.UCLA.EDU (Ted Kim (Random Dude)) In article <15379@cbnews.ATT.COM> grumbly!root@uunet.UU.NET (Superuser) writes: > >What happens when it [Depleted Uranium] is used against reactive or >other modern armor? > Reactive armor is quite effective against shaped charge warheads (HEAT, self-forging, etc.). But reactive armor has little effect on rounds that rely on their kinetic energy and hardness to penetrate. (eg "normal" AP and DU rounds). -ted Ted Kim UCLA Computer Science Department Internet: tek@penzance.cs.ucla.edu 3804C Boelter Hall UUCP: ...!{uunet|ucbvax}!cs.ucla.edu!tek Los Angeles, CA 90024 Phone: (213) 206-8696
sysmgr@KING.ENG.UMD.EDU (Doug Mohney) (04/11/90)
From: sysmgr@KING.ENG.UMD.EDU (Doug Mohney) In article <15380@cbnews.ATT.COM>, nuchat!steve@uunet.UU.NET (Steve Nuchia) writes: > >I'd guess that in most scenarios that include a lot of >DU slugs in the ground outside of designated ranges, there >will be refugees or others who will "mine" the metal for >its scrap value, which will be high as long as the fighting >continues, and non-zero afterwards. Very few countries drive off to the range and pop off Depleted Uranium rounds for practice; usually it's too EXPENSIVE. I'm not even sure if anyone outside of the "First World" uses depleted uranium rounds. >Of course the slugs in the ranges in most of the world >aren't being collected, and probably contribute to the >heavy metal content of the runoff water from those areas. >I wonder if it is any worse than the lead runoff from all >the military and private small-arms ranges all over the world? You miss the point. Uranium burns, and when it travels through the tank it will splinter and burn and break up into little bitty pieces which can be inhaled. As (I suspect) a low grade alpha emitter, you're talking guaranteed lung cancer if mixed in with smoke. The lead from bullets and small arms tends to stay in bullets and is not in a soluble form which will leach into the watertables. At least that's what I'd be willing to bet. Where are the chem people when you need 'em? [mod.note: The lead can form salts which are water-soluble. - Bill ]
drickter@BRL.MIL (04/12/90)
From: drickter@BRL.MIL In article <15380@cbnews.ATT.COM> nuchat!steve@uunet.UU.NET (Steve Nuchia) writes: > >Of course the slugs in the ranges in most of the world >aren't being collected, and probably contribute to the >heavy metal content of the runoff water from those areas. >I wonder if it is any worse than the lead runoff from all >the military and private small-arms ranges all over the world? not true. military proving grounds which fire du ammunition are required by license to "collect" slugs which are fired down range. also, there are specific ranges which allow du to be fired and when firing, the number of rounds (ie. round counts), must be submitted to range control. therefore, the firing of du for test purposes is highly controlled. also, du is NOT used for practice rounds ... this means that soldiers don't go around spraying du over the country side - here or in germany. this goes for army testing. i'm not sure about the other services.... donna hartka standard disclaimer applies .....
c162-bv@zooey.berkeley.edu (Iain McClatchie) (04/14/90)
From: c162-bv@zooey.berkeley.edu (Iain McClatchie) In article <15374@cbnews.ATT.COM> you write: > I've already referred to DU's hardness, but I'm surprised nobody's mentioned >it before: What good is a soft penetrator? That DU rounds can pass all thess >way through a tank is due as much to DU's hardness as to its density. It takes about 600 Calories per gram to vaporize water from room temperature, and water has an enormous heat capacity. The same heat per gram will heat steel 3000 degrees Celsius. This amount of heat corresponds to 2240 m/s impact, or 7350 ft/s. The M1 tank fires it's DU rounds about that fast, doesn't it? [mod.note: I think the MV for the APFSDS-DU ammo is about 5000 fps. - Bill ] My point here is that it seems the energy converted into heat on impact is going to melt the penetrator. Hmmmm.... [mod.note.2: First, not all the energy is converted; the projectile retains some velocity. Second, most of the lost energy is absorbed in the deformation of the armor, and would heat the tank, not the projectile. - Bill ] Could you clear something up for me? The M1 has a BIG (> 150mm) gun to shoot its round through the armor of an enemy tank. I think the M1 round is something like 3 pounds. The A-10 has a much smaller gun (like 30mm). It seems to make up with quantity. I can understand how quantity can mitigate bad accuracy, but it's not clear to me how a bunch of little bullets can get through armor that can stop each one. If the armor can't stop them, then why does the M1 need such a big gun? [mod.note.3 (this is getting to be a habit 8-): The M1 mounts a 120mm gun (105mm on the original version). The A-10 wins by not having to penetrate as much armor; attacking from altitude allows it to hit the much thinner deck armor, and defeats the slope of the frontal armor, which is inclined to nearly horizontal on modern tanks. - Bill ] -Iain McClatchie c162-bv@zooey.berkeley.edu