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Posted
I used our (TANKNET) modified Anderson equation (I believe Paul is the one most responsible for this) with a "super-DU" modifier of 1.2.

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This is the C.E. Andersen Equation for semi-infinite penetration. Two home-brewed modifications were added for scaling and back-surface effects. I think Paul had indicated that there were several folks involved with the two home-brewed modifications.

 

Your numbers are presumably for 0-degree obliquity? What sort of numbers would you estimate for say 68-degrees to 70-degrees? A common attack angle for alot of glacis configurations.

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Guest pfcem
Posted (edited)
This is the C.E. Andersen Equation for semi-infinite penetration.  Two home-brewed modifications were added for scaling and back-surface effects.  I think Paul had indicated that there were several folks involved with the two home-brewed modifications. 

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Yes (with a DU modifier as the basic equation is for Tungsten penetrators). So it basically gives a ballpark estimate against "semi-infinite" RHA based on the basic physical properties of the penetrator.

 

Of coarse, MBT armor is not all RHA but their protection esimates are also estimated as RHAe. And we all know that different penetrator vs different armor will in reality produce results different that their respective RHAe. If we ever are able to get more than just ballpark estimated figures, then doing a separate calculation for each & every combination would be worth doing, but for now, ballpark figures for penetration & protection normalized to RHAe at least gives us values to work with.

 

 

 

Your numbers are presumably for 0-degree obliquity?  What sort of numbers would you estimate for say 68-degrees to 70-degrees?  A common attack angle for alot of glacis configurations.

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Yes, 0-degree obliquity (straight on).

 

For oblique non-zero degree (straight on) hits I personally just simplify it by multiplying by the cos of the angle. It is obviously more complicated than that but we are only really able to "estimate" ballpark figures anyway.

 

common angles (ones I know the values of "off the top of my head")

30 degrees = 0.866

45 degrees = 0.707

60 degrees = 0.500

 

For glacis specifically, the RHAe estimates for the protection they provide already takes the angle into account.

Edited by pfcem
  • 3 weeks later...
Posted

Just one question, based on short note in Polish "RAPORT WTO" 12/2004 (my translation, not the best but I hope you`ll catch the idea):

 

"At Annual AUSA Meeting 2004 there was presented the newest projectile by ATK Alliant Techsystem - new long rod 120 mm round. For better penetration at the end of rod there was installed small rocket engine, which increase projectiles muzzle velocity to 1555 m/s, what result also in increased range, flatter trajectory and faster hit. Round are already high-scale produced for US Army"

 

There was also small photo of round just after leaving the muzzle, with sabot discarding and `jet` flash at the end of long rod.

 

 

 

And now...

1555 m/s is MV of M829A3. Possible mistake of author of article who confused M829A3 w/tracer with new long rod w/rocket?

At ATK site I found no information about new tank round (MRM-KE is another round, and still tested). I remember no thread about such round with "afterburner" (or something similar to Base Bleed).

One more round in US tanks?

What do you think?

Guest pfcem
Posted

Either the author is confusing the tracer for a booster rocket (more likely) or it is new APFSDS (likely based on the M829A3) that does have a rocket booster.

 

The US had tested rocket-assisted rounds for the A-10 GAU-8 decades ago so it is not beyong the ralm of possibility that it coulb be applied to an APFSDS.

 

The question is, would the added terminal velocity from such a comparatively small rocket make up for the mass lost from replacing that amount of penetrator material (DU or Tungsten). I would tend to think not.

 

Could you post the photo?

  • 1 month later...
Posted

Rheinmetall dubbed it "WHA IV" with the ability of adiabatic shearing.

Posted

All I can say is taht all western rounds of french, german and other origin have about the same penetration. As for the 829A3 it proved to be very inaccurate during the trials in Turkey.

Posted

M829A3 isn't approved for export and was not tested in Turkey. I highly doubt it's even being issued in Iraq.

 

Perhaps you mean KEW-A2 which IIRC is the tungsten M829A2 analog. S/F....Ken M

Posted

Why would the Americans try and sell a round to the Turks that they know would be hopelessly inaccurate? That is not something that can be swept under the rug in trials.

Posted
Why would the Americans try and sell a round to the Turks that they know would be hopelessly inaccurate? That is not something that can be swept under the rug in trials.

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Don't take such comments too seriously. Until we actually see test results that we can all reference too its just more useless rumor mill material. Even commentary is irrelevant.

 

Now knowing that the DM-53 uses '"WHA IV" with the ability of adiabatic shearing', is useful . But we don't know how much better such alloy does than the WHA alloy they use. We could tentatively give it the same performance bounce as DU alloy does. However thats a tentative assumption for now.

  • 4 weeks later...
Posted (edited)
So how about some estimates on Modern 125mm APFSDS?

 

eg: Tapna, Pronit, Mango, Svinet.. ...

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Czech 125/EPpSv-97

(by 05 Explosia Pardubice-Semtima, penetrators probably by IMI)

500 mm RHAe/2000 m

- this one??

http://www.army.cz/scripts/detail.php?id=6539

 

Polish 125 mm APFSDS

(Developed by WITU, made by ZPS Pionki (former Pronit) with cooperation FPS Bolechowo)

500 mm RHAe/2000 m

http://www.bumar.com/eng/pdf/125mm_Rounds_...nk_Gun_2A46.pdf

 

 

I guess 500 mm RHAe/2000 m is certified penetration.

Edited by Przezdzieblo
  • 2 weeks later...
Posted

Another thought on the possible penetrator length of the M829A3 penetrator.

 

The M829A1 projectile is 780mm long & the penetrator is 684mm long. If the M829A3 penetrator is the same 96mm shorter then it would be 828mm (924-96) long! Without going back through the posts, I believe someone had indicated that it could be as much as 830mm long.

 

A 828mm x 25mm penetrator would calculate to 776mm@2km RHAe penetration (vs 750mm for a 800mm long penetrator).

Posted

LOSAT pic from Army S&T Overview .... Objective Force Munitions (NDIA 2001 Munitions Executive Summit, 13 February 2001) by Dr. A. Michael Andrews, Deputy Assistant Secretary of the Army, Research and Technology / Chief Scientist.

I estimate the Penetrator Length is 950-1000mm, the Penetrator Diameter is 30-35mm, so Penetration is 40-44inch.

post-2716-1157081966_thumb.jpg

  • 11 years later...
Posted (edited)

Please pardon the topic necromancy :-)

 

I had reason to revisit the part of this thread where folks were helping me sort out the implementation of Anderson's penetration formula, and it occurred to me that it might interest some to review the collection of ballistic formula implementations (including Anderson) I submitted to CPAN last year:

 

https://metacpan.org/pod/Physics::Ballistics

 

Some of these are definitely works in progress and leave something to be desired.

Edited by TTK Ciar

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