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APFSDS design vs Heavy ERA


EasyE
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How does steel beasts model the interaction between heavy ERA like K5 vs APFSDS. From my research it appears there are many factors that go into the effectiveness of ERA in defeating an incoming long rod. Like Speed rod width and angle of penetration. For example rod diameter for K5 is optimal at around 40-45mm with initiation being unreliable with rounds that have a smaller diameter.

 

One thing that is very clear is that modern rod design has several methods of defeating ERA like K5 and Relikt. Rounds like the M829A2-A3 seem to both have different tip designs to defeat ERA. Other Rounds like the Dm-53/63 have segmented rods as well as complex tip design.

 

So while the DM-53 is on par with M829A1/A2 vs RHA it can defeat armor packages protected by ERA with a much much higher RHA equivalent and I have read statements from German officials, (not from primary sources) that suggest that the Leopard 2 tanks and L55 120mm feel comfortable defeating T-80U and T-90/90A tanks from any  practical range they chose to engage at.

 

How does Steel Beasts incorporate this knowledge or do they not accept it as true.

 

Thanks

 

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2 hours ago, EasyE said:

How does steel beasts model the interaction between heavy ERA like K5 vs APFSDS. From my research it appears there are many factors that go into the effectiveness of ERA in defeating an incoming long rod. Like Speed rod width and angle of penetration. For example rod diameter for K5 is optimal at around 40-45mm with initiation being unreliable with rounds that have a smaller diameter.

 

One thing that is very clear is that modern rod design has several methods of defeating ERA like K5 and Relikt. Rounds like the M829A2-A3 seem to both have different tip designs to defeat ERA. Other Rounds like the Dm-53/63 have segmented rods as well as complex tip design.

 

So while the DM-53 is on par with M829A1/A2 vs RHA it can defeat armor packages protected by ERA with a much much higher RHA equivalent and I have read statements from German officials, (not from primary sources) that suggest that the Leopard 2 tanks and L55 120mm feel comfortable defeating T-80U and T-90/90A tanks from any  practical range they chose to engage at.

 

How does Steel Beasts incorporate this knowledge or do they not accept it as true.

 

Thanks

 

Rumor has it that the DM53 fired from the L55 can penetrate 900+ mm RHAe point-blank.

Edited by lavictoireestlavie
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59 minutes ago, Ssnake said:

 

Depending on type, there's a fixed value by which the penetration power of the attacking projectile will be reduced.

 

The APFSDS are classified by type?

 

What metrics are used?

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6 hours ago, EasyE said:

 

I can't see how, that is 20% or more RHA then rod length. 

Some Finnish "tank commander"  and an unrelated German retired soldier told me that it was 900+ mm point-blank.   I am surprised by this figure as well. I would expect the penetration of the DM 53 round  to be around 750 - 850 mm for the L55.

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6 hours ago, lavictoireestlavie said:

Some Finnish "tank commander"  and an unrelated German retired soldier told me that it was 900+ mm point-blank.   I am surprised by this figure as well. I would expect the penetration of the DM 53 round  to be around 750 - 850 mm for the L55.

Never trust a crew when they say what their vehicle can penetrate, there is always a level of wishful thinking and errors when explaining it, so the first dude got the info "900mm at BEST conditions EVER" and after 5 years and 30 re-tells its "superior 900mm or more" suddenly.

 

Its like when I was on the PBV302 I had a captain that thought that shooting more then 1 20mm round on an enemy APC was wasting ammo as a 20mm had such good penetration and behind target effect that it was a solid kill with one hit.... 

 

/KT

 

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On 4/18/2017 at 2:34 AM, lavictoireestlavie said:

Some Finnish "tank commander"  and an unrelated German retired soldier told me that it was 900+ mm point-blank.   I am surprised by this figure as well. I would expect the penetration of the DM 53 round  to be around 750 - 850 mm for the L55.

 

I think that explaining things in terms of the ability  of a segmented tungsten alloy long rod to defeat a passive Steel-NERA-Ceramic/Backing passive array covered by ERA with two thick steel flyer plates equal to 850mm RHA, to soldiers is seen as overly complex. So everything is just scaled up in Terms of RHA.

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Perforation limit of long rods is not only sensitive to hardness, but also to angle of impact. From the Odermatt form:

The typical values given seem to be reasonable* for high obliquity impacts (where the perforation LOS is maximum just before the onset of ricochet), but could be 17% lower near the normal impact condition into RHA targets.
* That is that the penetration values quoted are met with the best estimates of the penetrator dimensions, while at lower angles the penetrations are much lower...

A 1:1 penetration limit to penetrator length at the normal impact is consistent with a 1.2:1 perforation limit to penetrator length at 65 degrees, going through a plate with thickness of 51% the maximum penetrable.

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4 hours ago, EasyE said:

 

I think that explaining things in terms of the ability  of a segmented tungsten alloy long rod to defeat a passive Steel-NERA-Ceramic/Backing passive array covered by ERA with two thick steel flyer plates equal to 850mm RHA, to soldiers is seen as overly complex. So everything is just scaled up in Terms of RHA.

 

I'd term it more in terms of at the tactical level we just don't care.

 

We are issued ammunition and its what we use.

 

No one stands on the back of the ammunition truck and says "I want this instead of that because its Odermatt numbers are better" - you get what you are issued, not necessarily what you want. :)

 

The R&D  / Capability Development guys do the number crunching and purchase on behalf of all of Army.

 

Also we tend to be more focused on where to shoot (to an extent). So even if its "sub optimal" ammunition, you are still taught to manoeuvre to positions of advantage.

 

Shooting into the flank as opposed to the glacis plate tends to make up for relative abstract performance differences, even if you are aiming for "centre of mass".

 

Edited by Gibsonm
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what you could do is take already existing rounds with known penetration, then ask: 
is the DM53 longer, denser, and flies faster than the known round? 

if all of the above is true, then it likely has a higher penetration than that known round. 

there used to be values on the KEW and KEW-A1 rounds out there, but it seems like this is no longer the case. 

in any case, here's some blurb on the KEW-A1

 

http://www.gd-ots.com/download/120mm KE-W A1 APFSDS-T.pdf

 

from this diagram, you can make the assumption that each "block" is about 200mm penetration, since M829 has a penetration of around 600mm. 

so KEW-A1 would have 700mm + penetration at 0 meters, and in the sub-600s at 2km. 

 

http://defense-update.com/products/digits/120ke.htm

 

DM-53 is 745mm long, projectile weighs 8.35kg with sabots, muzzle velocity is 1750m/s fired from the L55 gun, and it's tungsten.

 

KEW-A1; length ?? projectile weight 4 kg with sabots, muzzle velocity 1740m/s and it's tungsten. 

 

from this we can make the assumption: since the DM-53 is heavier, and has a higher muzzle velocity than the KEW-A1, it's penetration power should be higher than KEW-A1. 

750-850mm range is a reasonable guess. 

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On 4/21/2017 at 0:54 PM, dejawolf said:

what you could do is take already existing rounds with known penetration, then ask: 
is the DM53 longer, denser, and flies faster than the known round? 

if all of the above is true, then it likely has a higher penetration than that known round. 

there used to be values on the KEW and KEW-A1 rounds out there, but it seems like this is no longer the case. 

in any case, here's some blurb on the KEW-A1

 

http://www.gd-ots.com/download/120mm KE-W A1 APFSDS-T.pdf

 

from this diagram, you can make the assumption that each "block" is about 200mm penetration, since M829 has a penetration of around 600mm. 

so KEW-A1 would have 700mm + penetration at 0 meters, and in the sub-600s at 2km. 

 

http://defense-update.com/products/digits/120ke.htm

 

DM-53 is 745mm long, projectile weighs 8.35kg with sabots, muzzle velocity is 1750m/s fired from the L55 gun, and it's tungsten.

 

KEW-A1; length ?? projectile weight 4 kg with sabots, muzzle velocity 1740m/s and it's tungsten. 

 

from this we can make the assumption: since the DM-53 is heavier, and has a higher muzzle velocity than the KEW-A1, it's penetration power should be higher than KEW-A1. 

750-850mm range is a reasonable guess. 

 

Perhaps, that is a good way at looking at the problem. Of course do measures that enhance performance against complex armor arrays increase or decrease performance against a standard RHA target (hypothetical steel plate)? Something to look into I suppose.

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Another thing is, that some penetrators designed to defeat targets protected by heavy ERA, are designed to use a certain feature of ERA to their advantage. ERA is designed in such way that hits of projectiles below a certain diameter will not detonate them. So for example M829A2 have a specially designed tip that will create a hole in ERA without detonating it. 

I suspect that M829A3 and M829A4 might use similiar trick among possible other solutions.

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On 4/26/2017 at 3:27 AM, Damian90 said:

Another thing is, that some penetrators designed to defeat targets protected by heavy ERA, are designed to use a certain feature of ERA to their advantage. ERA is designed in such way that hits of projectiles below a certain diameter will not detonate them. So for example M829A2 have a specially designed tip that will create a hole in ERA without detonating it. 

I suspect that M829A3 and M829A4 might use similiar trick among possible other solutions.

 

I would suspect this is the case. The American defense industry since the 1980s has a rather large track of trying to provide a 95% solution when a 75% would be sufficient. When you have the money to spend I suppose. Much easier when you have a greatly inflated threat. IIRC The HAP on the M1A1 Abrams was a top funding priority and received billions in the early 1980s because it was felt that a new Russian tank with a 135mm gun firing a mono-block APFSDS was perceived to be just around the corner. The reality was that most tanks in the USSR would be shooting sheathed and segmented APFSDS until about 1988 when the 3bm-42 reached wide distribution to front line units, its self falling far short of what was needed.

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On 18/04/2017 at 7:12 PM, Gibsonm said:

Well if you are only issued one, you have to hope that its all you need.

 

Two might create waste. ;)

 

 

Personally I use the philosophy of:

 

"Keep hitting until it changes shape and/or colour."

 

Granted, it is SB ammo so doesn't cost anything except time to replace.

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On 5/1/2017 at 10:40 PM, EasyE said:

 

I would suspect this is the case. The American defense industry since the 1980s has a rather large track of trying to provide a 95% solution when a 75% would be sufficient. When you have the money to spend I suppose. Much easier when you have a greatly inflated threat. IIRC The HAP on the M1A1 Abrams was a top funding priority and received billions in the early 1980s because it was felt that a new Russian tank with a 135mm gun firing a mono-block APFSDS was perceived to be just around the corner. The reality was that most tanks in the USSR would be shooting sheathed and segmented APFSDS until about 1988 when the 3bm-42 reached wide distribution to front line units, its self falling far short of what was needed.

 

3bm-42 is a sheated and segmented apfsds. 3BM32 is the monoblock DU penetrator. 

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4 hours ago, dejawolf said:

 

3bm-42 is a sheated and segmented apfsds. 3BM32 is the monoblock DU penetrator. 

 

Yes sorry typo, 3BM-32 is how it should have read, both the 32 seemed to have had a DOI in the mid 1980s but not reached any real distribution until the very late 1980s. It appears that a few different methods for manufacturing the rod were being run.. Uranium and tungsten are actually were  very quirky things to alloy and manufacture, with it being very difficult and expensive to achieve uniform tensile strength in a high LD  alloy rod because of fracturing during fabrication and heat treating of the materials. The 3BM-42 being a quick solution to the problem and the 3BM-32 being another. There was no inexpensive solution to this problem available to the USSR  to mass produce longer rods until the late 1980s, where they were a decade behind the USA and Germany at this point.

 

 

I suspect that the USA didn't know this, and assumed that the USSR had worked out how to cheaply alloy heavy metal long rods with out very serious manufacturing defects. From what I can gather in available public information, the BRL-1 armor package would have been effective against the most common APFSDS steel with tungsten slug designs of early 125mm ammo like the 3BM-26, with the NERA array breaking apart, yawing and causing misalignment the interior components to then fail against the backing compoenents. The rush to introduce 3 armor packages a little over 8 years suggest to me that this was the case.   

 

On another note, the USA and Germany conducted a great deal of research in the late 1980s on vastly improve the tensile and yield strength of heavy metal alloys. In some cases gaining improvements of 300-400% through some methods that caused  dissolution uniform recrystallization of ultra fine powders of various metals mixed with the main heavy metal. I suspect this may be one of the ways the M829A2 was improved over the M829A1. It could also be a way of improving the heavy metal alloys in armor packages such as HAP-2 and Burlington.

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