Talk:Kinetic energy penetrator
|WikiProject Firearms||(Rated Start-class)|
- 1 See Also RussianArmor.Info
- 2 Etc.
- 3 Adiabatic?
- 4 How does this weapon actualy kill?
- 5 Depleted Uranium
- 6 Comparable kinetic energy
- 7 KE vs CE Misleading?
- 8 First Tank using APFDS and smoothbore gun = T-62?
- 9 975m/s?
- 10 Merge Discussion
See Also RussianArmor.Info
See also: http://russianarmor.info/Tanks/ARM/apfsds/overview.html -- Pelavarre (talk) 16:43, 17 November 2007 (UTC)
Someone needs to look at the force of the projectile in the beginning of the article. The units don't make sense to me. Also, to determine an impact force, you need to assume a deceleration rate. I see the acceleration due to gravity in that equation, which I do not think is relevant. Someone needs to delete that or make it correct. —Preceding unsigned comment added by 188.8.131.52 (talk) 12:37, 11 June 2010 (UTC)
Just a quick addition: not all sabot rounds are fin stabilized. Most rifled weapons use an APDS (Armor Piercing Discarding Sabot) rounds. Fin-stabilized rounds are common because many anti-tank guns are smoothbore (i.e. non-rifled) so as to optomize performence of shaped charge or HEAT (High Explosive Anti Tank) rounds.
I'm pretty sure the reason that most KEPs are fin stabilized and shot out of smooth bores is two fold. 1) A long thin projectile made out of dense materials (when shot with a sabot) maximizes the internal ballistics (highest muzzle velocity), external ballistics (less velocity lost to drag), and terminal ballistics (maximum KE spread over the least area on impact). And 2), there is a functional limit to the proportional length of projectiles that can be spin stabilized (see the article on Rifling). Many VLD rifle bullets already have to be spun very aggressively for them to stabilize, and most of them are no more than 7 or 8 calibers in length. Someone may want to edit the smoothbore section. — Preceding unsigned comment added by 184.108.40.206 (talk) 22:33, 13 July 2011 (UTC)
I removed the sentence stating that the British Army prefers HESH rounds. Certainly we developed them, but it appears we mainly use DU penetrators in our anti-armour rounds. We fired just 88 such rounds in the first Gulf War, but I understand we fired far more in the 2003- conflict. Can't find a reference for that right now though, sorry. Dan100 20:06, Mar 8, 2005 (UTC)
- I understand that the British army uses DU for heavy armoured taregts and HESH for every thing else. Apparently HESH is very verstile secondary round and quite cheap. That is why the British army wants to keep it. Why you cannot fire HESH from a smoothbore is not clear to me. David.j.james 15:21, 26 May 2007 (UTC)
- You can fire HESH from a smoothbore - it's just that firing it from a rifled weapon is more accurate and it doesn't suffer any adverse effect from being spun (unlike HEAT and APFSDS). AFAIK Rifling remains the preferred method of stabilising a round and the smoothbore tank gun only appeared because of the problems spin-stabilisation caused with HEAT and long-rod APDS. —Preceding unsigned comment added by 220.127.116.11 (talk) 11:31, 15 October 2010 (UTC)
Umm, yeah, there's a whole bunch of KE-penetrators apart from APFSDS: APDS, plain old AP, Gerlich squeezebore, and self-forging fragments.Securiger 11:56, 14 Mar 2005 (UTC)
- I recently read the USA expended over 750 tons of DU munitions since the invasion... -- Geo Swan 14:24, 2005 Mar 14 (UTC)
- You have a cite? It seems rather unlikely, since DU is used in anti-tank munitions and they haven't been fighting any tanks, and 750 tonnes is an enormous amount. (Since the 120 mm APFSDS round has only about 18 kg of DU, 750 tonne would amount to some 40,000 heavy anti-tank shots. There is also a DU round available for the Bradley 25 mm gun, but it's 100 times lighter still.) Securiger 17:21, 14 Mar 2005 (UTC)
The 750 tons number is from Iraqi propaganda and refers to the use of DU in tank munitions alone (an estimated 14,000 rounds - yes: they made an order of magnitude mistake :o) during 1990 and 1991, training in Saudi-Arabia included. Also the weight of the penetrator itself in the various rounds is about a quarter of the number you stated (3-5 kg). Never forget however that the USAAF too is using DU and that it's also used for HEAT-liners.
MWAK--18.104.22.168 10:43, 24 Mar 2005 (UTC)
Giving some more exact numbers: in 1991 6700 M829 and 2348 M829A1 rounds were fired; in 2003 2650 KE-rounds containing about 12 tons of DU, which again is about 10% of all DU, the vast majority (93,4 tons) of which was used by the USAAF. And 121,000 Bradley rounds were fired :o)
MWAK--22.214.171.124 11:02, 31 Mar 2005 (UTC)
- What's "USAAF"? Are you referring to the United States Air Force (USAF)? McGehee 17:55, 3 July 2006 (UTC)
- Well, to be more precisely to the United States of America AirForce ;o).--MWAK 16:57, 19 July 2006 (UTC)
"A uranium rod is also self-sharpening on impact due to its adiabatic properties: it doesn't "mushroom" like unjacketed tungsten does." I don't understand this. What part of the impact is adiabatic? Does it mean that the process of mechanical deformation upon impact occurs without the DU heating up? How does that prevent mushrooming? Tom Harrison (talk) 15:54, 31 December 2005 (UTC)
Adiabatic means that as the pressure increases the volume decreases while the heat remains at a constant. Since the volume decreases mushrooming does not occur and the round effectively sharpens its self as the cross-sectional area to which the pressure is applied decreases with the volume.
- Thanks; I've tried to incorporate this, but I wish someone who understands it better than I do would rewrite it. Tom Harrison Talk 00:10, 11 January 2006 (UTC)
Rewrote DU adiabatic stuff
After reading a handful of articles I do not fully understand, I believe the term "adiabatic" refers to adiabatic shear bands. These regions are termed adiabatic since there is no significant heat transfer to material outside the shear band. Temperatures within the band increase greatly due to shear deformation. In DU penetrators, heat transfer is limited since the deformation process is extremely rapid. The self-sharpening effect occurs because bits of DU break off along these shear bands. This prevents the formation of a mushroom head. Or so I've been led to believe. Is there a doctor of materials science in the house? --Ryanrs 13:23, 15 January 2006 (UTC)
- I know a few and they assure me that you are basically right. Optimising this effect is an important line of research, despite foul play by the tungsten lobby, which is behind most of the scare stories.--MWAK 16:57, 19 July 2006 (UTC)
Ames Lab research results for DU replacement
I read an article which gives some insights on new trends, and it mentions the Uran vs. Tungsten issue. To make a long story short, "nanolayers of tungsten and metallic glass" were used as material for kinetic penetrators to achive same performance (no "mushrooming") as with DU, without the negative side-effects associated with the use of DU in ammunition. Research was done at the Ames Laboratory. I got two references for this, one in German (this news site is rather "liberal" or "left", hence the biased comments) http://www.heise.de/tp/r4/artikel/24/24598/1.html the second being the original Press Release (atm only available in the Google Cache) http://126.96.36.199/search?q=cache:OIgzLcD1dxsJ:www.external.ameslab.gov/final/News/2007rel/KEP.htm+metallic+glass+tungsten&hl=de&ct=clnk&cd=1&gl=us Maybe someone could review this information and incorporate it into the article if he things it's useful. I think it is, especially due to the use of this new "class" of materials, metallic glasses. 188.8.131.52 14:38, 28 April 2007 (UTC)
How does this weapon actualy kill?
The objective of any weapon is to neutralize the opposing threat. We are specifically talking about the anti-armour weaponry. They go about their various ways to achieve this penetrating power and is always well documented in the Wikipeda articles. Although they always lack description of where the actual kill comes from. What does it do once it penetrates the armour? How does it disable? --Turbinator 18:23, 11 January 2007 (UTC)
- Transfer of kinetic energy and putting a "big ol' hole" in it. ;) --Falcorian (talk) 18:31, 11 January 2007 (UTC)
- That would take a few shots to get someone in it. After it makes a hole, does it continue moving inside? Seems like there is something more to it. For a good example of what I am looking for in the description of the actual kill effect look at this Thermobaric weapon article. --Turbinator 19:32, 11 January 2007 (UTC)
I guess if you were sitting in a tank and a projectile hops in you wouldn't be asking that question :) Not saying I have personal experience, but... In my opinion, the projectile just drills the armour. In the process, a lot of heat is produced, and it may even cause a fire. It would surely ignite the fuel if it penetrates the tank. -Adamantum-
After penetration the round will release high velocity fragments (or break apart itself ?) which will bounce around inside the vehicle destroying equipment and crew. There are also variants that will ignite interior of the vehicle (by plasma stream as in shaped charge). Hulkur
This information should be added to the article.
Talking to various ex-tankers it was suggested that the pressure generated as it goes in one side out the other kills the tank crew. — Preceding unsigned comment added by 184.108.40.206 (talk) 12:04, 18 July 2013 (UTC)
There is a mistake in units. 1.4 m/sec = 5 km/hr is not an impressive velocity. It should probably read 1.4 km /sec --Gerhardm 12:43, 19 March 2007 (UTC)
"Few countries use DU ammunition despite its lower cost compared to tungsten, because of adverse environmental and health effects, but mostly because it is difficult for nations without an active uranium enrichment program to acquire the necessary quantities of DU. Battle sites where DU rounds have been used typically have residual uranium dust in and around battle-damaged vehicles. This dust is only slightly radioactive, but it is toxic, and many are concerned by its lingering effects on public health."
I will say it bluntly: depleted uranium (specifically the staballoys used in this application) have no "adverse environmental and health effects". Disagree? http://www.who.int/ionizing_radiation/pub_meet/en/Report_WHO_depleted_uranium_Eng.pdf the World Health Organization says so. Argument over. If you disagree, independently look into DU. You can confirm for yourself that it wouldn't have "adverse effects". DU is exactly the same as lead - a dense metal that will make you sick if you ingest too much of it. The presence of expended ammunition nearby will not make you sick. It cannot. The only people who need be concerned about the health effects of DU ammunition are those on the receiving end of the projectiles when they're fired. I'm removing this section. —Preceding unsigned comment added by 220.127.116.11 (talk) 12:47, 17 April 2008 (UTC)
- i have read the report. the key points of it were:
- 1) depleted uranium is officially not-as-bad-as-real-uranium (duh.)
- 2) no problems yet were found, but the country is so backward that there is no reliable information
- 3) let's wait and see what happens in the future
- let's get the facts straight
- depleted uranium is still an alpha emitter, albeit 40% weaker than natural uranium. while alpha radiation is not dangerous because it is not penetrating, it is 20 times more dangerous than gamma radiation.
- depleted uranium is also poisonous, as every heavy metal is.
- and as most heavy metals, depleted uranium is subject to bioaccumulation, and that is the worst because that way it can be easily ingested and that is where alpha emitters are deadly.
- Dunkelfalke (talk) 21:49, 23 April 2008 (UTC)
Comparable kinetic energy
- I think the penetrating rod might weigh about 5kg, and maybe 1750 m/s velocity (Those figures are estimates, if someone has better figures please provide them). That would I think be over 7 1/2 million joules. (For comparison a .50 BMG round has about 15 to 20,000 joules of energy). A locomotive engine weighing 200,000 kg, and traveling at 30 m/s would have about 90 million joules of energy and that's only counting the locomotive engine not the whole train. OTOH the APDS round has all that energy in a relatively tiny frontal area. The force per area is massive. twfowler (talk) 17:50, 9 July 2009 (UTC)
- Yes, calculations of kinetic energy and force density can easily be made for various objects (truck at 50mph, medieval cannonball etc). Two questions :
- 1. Would that be WP:OR ?
- 2. Comparison should also be made with chemical energy content of HEAT/HESH rounds, how to do that ? TGCP (talk) 22:13, 17 December 2010 (UTC)
KE vs CE Misleading?
There's a topic of discussion I would like to raise. Is there anyone else out there who finds the traditional dichotoly between "Kinetic Energy" penetrators (APDS etc) and "Chemical Energy" Penetrators (HEAT) annoying and just plain wrong? So called called Chemical Energy rounds penetrate armor the same way that Kenetic Energy rounds do: they concentrate a large amount of kinetic energy in on a small area. Ineede, broadly speaking, KE and CE warheads work the same way: the conversion of chemical energy into kinetic energy. The difference is WHERE the conversion of chemical energy to kinetic energy takes place. For APDS rounds and the like, the conversion takes place in the chamber of the gun, where the chemical energy of the propellant is turned into the kinetic energy of the round. For HEAT rounds, the conversion takes place when the round hits the target, and the chemical energy stored in the explosive is released by the explosion and is used to impart kinetic energy to the particles of explosive and the liner material, if any. —Preceding unsigned comment added by 18.104.22.168 (talk) 15:50, 24 December 2010 (UTC)
Actually, HEAT rounds are flying bombs, while a KE round is a flying metal rod. See the difference? — Preceding unsigned comment added by Ninja Igoo (talk • contribs) 14:58, 25 October 2011 (UTC)
First Tank using APFDS and smoothbore gun = T-62?
Wasn't first tank using this kind of ammunition and smoothbore gun (105mm) T-62A of soviet army? I think soviets were the first to see advantages and other countries followed them afterwise. — Preceding unsigned comment added by 22.214.171.124 (talk) 07:54, 3 June 2011 (UTC)
The lead paragraph suggests that 'the' fin round (not specified which one...) has a velocity of 975m/s, which is rather slow. There is a cited figure later on describing a projectile with nearly twice that velocity. Jellyfish dave (talk) 11:52, 24 June 2011 (UTC)