Early 1980S Armour Comparisons ?

[EasyE]

For reference on the M1E1. It looks like 3 x 2' or 50.8mm steel plates for weight simulator for the armor package of the M1A1. 

The IPM1 and M1A1 seem to be a bit of a mystery with regards to protection. Are they the same array ? Is BRL-2 as tested in the late 1970s what was eventually fitted to one or both of these tanks? Was it incrementaly improved over the ~5 or so years? 

BRL-2 as tested in the 1970s seemed to be sufficent against German and UK 120mm tugnsten designs at ranges over 1000m. Also seemed be more then enough against the monoblock DU XM774. 

M833? 

115mm BM-28?

BM-32?

BM-42?

No clue. I suspect that "if" the M833 failed against the turret of the M1A1 that it may have been sufficent against the        BM-42.

My reason for this line of thinking is that the 105mm DU M833 proved much better in testing against complex armor arrays then the W XM829. 

On the flip side the BM-32 performed much better then the BM-42 against spaced target arrays so perhaps the M1A1 would be defeated by one and not the other.

 

[Przezdzieblo]

BRL-2 was used as a special target in 1976. It was fired at with 105 mm M735, XM774 model 28 and XM774 model 26, 120 mm FRG APFSDS (WHA, proto-DM13) and HEAT (proto-DM12) and 120 mm UK APFSDS (XL22, WHA). No penetrations, but the UK projectile made the biggest bulge.

BRL-2 was also used as special target in 1977. It was penetrated by 120 mm UK APFSDS (XL22, WHA) at point blank, and by 120 mm UK APFSDS (C24) and FRG APFSDS (proto-DM23?) at 2000 m. It was also defeated by potential growth projectiles: 120 mm UK two APFSDSs (DU variant of XL22 and C21) at 4000 m and 105 mm APFSDS (SB-60-24 of Silver Bullet project, DU, predecessor of XM833 and XM829) and 120 mm UK APFSDS (C31, DU) at 6000 m.

 

[methos]

The idea that BRL-1 would be identical to M1 Abrams' armor and BRL-2 to the M1A1's seems to be solely based on statements made by Damian Ratka on Twitter and in the SteelBeasts forum. As already stated by Przezdzieblo, these were targets used in the US Army's evaluation of 120 mm guns for the M1E1 tank.

The BRL-1 target was described to be "roughly the same" as the XM1's armor and to provide "similar" protection to the XM1 tank. The BRL-2 target was said to be "heavier" and "tougher" than the XM1's armor in the US Congress hearings on the topic. It provided protection "beyond" the XM1. However there is no evidence that the M1A1 actually ended up using BRL-2 or an armor. BRL-2 was specifically designed to showcase the performance difference between 105 mm and 120 mm APFSDS rounds.

 

The M1IP's new armor increased its combat weight by 2,000 lbs compared to the M1 Abrams; however it was stated in front of Congress, that a hypothetical tank with BRL-2 would be about 3 tons (6,000 lbs) heavier than one with BRL-1. This was one of the arguments against adopting a 120 mm gun ASAP ("they just need to make their tanks 3 tons heavier").

The German growth potential rounds provided the highest penetration against BRL-2 (1,200 m further than the best-performing British round), but suffered from core break-up during hot firing. The British noted that both 120 mm guns "outclassed" the American 105 mm gun.

14 hours ago, EasyE said:

For reference on the M1E1. It looks like 3 x 2' or 50.8mm steel plates for weight simulator for the armor package of the M1A1. 

Doesn't really look like 2 inch thick plates, specifically given that the plates clearly have different thicknesses.

14 hours ago, EasyE said:

The IPM1 and M1A1 seem to be a bit of a mystery with regards to protection. Are they the same array ?

As per Hunnicutt, yes.

 

Edited January 14, 2021 by methos

[Lesley]

On 7/27/2017 at 12:40 PM, methos said:

Well, the original Leopard 2 design with spaced armor (protection against 105 m APDS at 800 m distance along a 30° frontal arc) was obiously worse, but the relatively late armor re-desgin (three years after the US adopted Burlington armor) + a second redesign after US tests of the Leopard 2AV) seems to have paid 

From a German document used in the Netherlands army for evaluating the Leopard 2 it is stated;

Beschusssichterheit Leopard (protection) (no subtype mentionedl)). Since NLD signed the contract for the Leopard 2 in June 1979 it is probably a (very) early block from the time of Ben Hur. The Leopard 2A4 were identical to the German Block 2 and 3's but later on modified (at least the turret) with better armour. Krauss-Maffia Maffei workers came to the units and replaced the modules in the turret and welded the hatch on the left side of the turret. During this process no-one was allowed to look and view of the work was blocked by tents and tarpaulins.

Frontal turret 

I  ab 100 m (from 100 mtr) 

II ab 1000 m (from 1000 mtr)

III ab 0 m (from 0 mtr)

IV ab 200 m(from 200 mtr)

V ab 200 m (from 200 mtr)

VI ab 0 m (from 0 mtr)

Upper part of the frontal hull

Wie Turm (like turret)

I - VI

Lower part of the frontal hull

V ab 1600 m (V from 1600 mtr)

The explanation of the Roman numbers is;

I 120mm rak Sagger HEAT (120mm missile Sagger HEAT)

II 115 mm APFSDS

III 115 mm HEAT

IV 100 mm APDS

V 100 mm AP

VI 100 mm HEAT

regards

[methos]

Are you sure that turret armor was replaced during the upgrade to the Leopard 2A4 configuration? The ammunition hatches were welded shut on the earlier Leopard 2 models of the German Army aswell, but it appears that new armor modules were not adopted.

The protection levels are more or less identical to the Leopard 2AV's, which is expected given their similar weight (weight reductions applied during the transistion from Leopard 2AV to series model were meant to retain protection level) and era.

 

 

[EasyE]

On 1/14/2021 at 5:23 AM, Przezdzieblo said:

BRL-2 was also used as special target in 1977. It was penetrated by 120 mm UK APFSDS (XL22, WHA) at point blank, and by 120 mm UK APFSDS (C24) and FRG APFSDS (proto-DM23?) at 2000 m. It was also defeated by potential growth projectiles: 120 mm UK two APFSDSs (DU variant of XL22 and C21) at 4000 m and 105 mm APFSDS (SB-60-24 of Silver Bullet project, DU, predecessor of XM833 and XM829) and 120 mm UK APFSDS (C31, DU) at 6000 m.

That is so very interesting. Any idea about the constuction nature of the  "SB-60-24"  APFSDS?  The performance of a 105mm DU "proto" XM833/M829 vs  more primitive 120mm WHA rounds is very interesting to say the least. 

 

On 1/14/2021 at 6:24 AM, methos said:

Doesn't really look like 2 inch thick plates, specifically given that the plates clearly have different thicknesses.

It looks like I made an error in my measurments by assuming the welds are consistant thickness and that the top plate looks a bit raised, when they are not it may or may not be. The perspective of the shadow if those assumptions are wrong suggests they are differnt thicknesses.  

 

Safe to say that no one really has much a clue about what the armor of the M1A1 is or how it performs? Thinking out loud that against contemporary threats, it performs better then the Leopard 2 with Type B but worst then Type C vs KE and better then both vs CE threats. 

[methos]

16 hours ago, EasyE said:

Safe to say that no one really has much a clue about what the armor of the M1A1 is or how it performs? Thinking out loud that against contemporary threats, it performs better then the Leopard 2 with Type B but worst then Type C vs KE and better then both vs CE threats. 

  ...

On 3/6/2018 at 8:11 PM, methos said:

M1A1 armor protection according to another CIA document:

 

 

[Lesley]

On 1/15/2021 at 12:56 PM, methos said:

Are you sure that turret armor was replaced during the upgrade to the Leopard 2A4 configuration? The ammunition hatches were welded shut on the earlier Leopard 2 models of the German Army aswell, but it appears that new armor modules were not adopted.

That is what they told, it was absolutely not allowed to look at the work on it. A complete tent around the turret was a little over the for welding an ammohatch was a little over the top IMO.

But, honest, I didn't see it with my own eyes.

Regards,

Lesley

 

 

 

[EasyE]

11 hours ago, methos said:

  ...

 

 

I thought this document was proved to have been inauthentic. 

Assuming it is it seems rather sloppy and unreliable. 

I mean what is a ADPS? Who has T-80s in the Middle East, with a 90km/ hr road speed? Same goes for the M60A3? 

The source is assumed to be from from the early 1990s correct?

[methos]

This table from a 1987 issue of the CIA's Near East And South Asia Review that has been declassified thanks to the Freedom of Information Act. It can be directly downloaded from foia.cia.org, i.e. the official CIA website. The table is an article discussing the possible sale of M1A1 Abrams tanks to Egypt - including the reasons for this deal, impact on industry/political relations, alternatives considered by the Egyptian military and potential adversaries. Unless you believe that some trols/shitposters have managed to hack the CIA's website, I would assume that this is authentic.

 

At this time it was believed that Lybia would purchase - within the next decade - a number of T-80 tanks in an unknown configuration. As the true capabilities of the T-80 (specifically future versions) remained unknown, the values for the T-80 are all over the place.

Given that APFSDS can also be described as fin-stabilized APDS, using the term "APDS" in the table isn't that bad. The protection levels are apparently valid for a certain frontal arc (hence the 143 mm hull armor for the M60A3, which is basically the side hull being hit at 30° impact angle), so this is not further explained in the declassified texts; parts of the text are redacted.

Edited January 17, 2021 by methos

[EasyE]

On 1/17/2021 at 3:44 AM, methos said:

This table from a 1987 issue of the CIA's Near East And South Asia Review that has been declassified thanks to the Freedom of Information Act. It can be directly downloaded from foia.cia.org, i.e. the official CIA website. The table is an article discussing the possible sale of M1A1 Abrams tanks to Egypt - including the reasons for this deal, impact on industry/political relations, alternatives considered by the Egyptian military and potential adversaries. Unless you believe that some trols/shitposters have managed to hack the CIA's website, I would assume that this is authentic.

I tried to get the origional document and for some reason wasn't able to. There are CIA documents floating around that has had some of the  redacted edited back into areas with technical details about western equiptment. Perhaps I am getting some different documents mixed up. 

Just based on CIA documents it appears likley that the 400mm KE 750mm CE describes the M1 against early APFSDS designs while the British estimates of 325-340 refer to  more advanced WA ones. 

The value of 380mm for the M1A1 seems very close to the performance of the M833 against flat RHA at about 1000m. It would not surprise me if the M1A1 was protected against the M833 at a certian range and that RHA value is extracted from it. The 380mm value also seems rather close to early estimates of a 115mm DU APFSDS, so it may also refer to that protection criteria. 

Using RHA to try an determine actual protection against the rapid evolution of KE threats in the early to mid 1980s is an intersting black box. 

[RETAC21]

Here, page 47: https://www.cia.gov/readingroom/docs/CIA-RDP05S02029R000300950003-7.pdf

[DB]

"... poor to fair quality... ". Now that's praise.

[Mistral]

On 1/17/2021 at 3:45 AM, EasyE said:

I thought this document was proved to have been inauthentic. 

Assuming it is it seems rather sloppy and unreliable. 

I mean what is a ADPS? Who has T-80s in the Middle East, with a 90km/ hr road speed? Same goes for the M60A3? 

The source is assumed to be from from the early 1990s correct?

Don't know about the 90 km/hr but Cyprus has T80Us since 1996. Not that we are a threat to anyone😀

[RETAC21]

44 minutes ago, Mistral said:

Don't know about the 90 km/hr but Cyprus has T80Us since 1996. Not that we are a threat to anyone😀

The article mentions the T-80 as a possible acquisition by Libya, but the CIA's T-80 mey refer to the T-72B too

[EasyE]

On 1/19/2021 at 2:17 AM, RETAC21 said:

Here, page 47: https://www.cia.gov/readingroom/docs/CIA-RDP05S02029R000300950003-7.pdf

Thanks so much! 

 

On 1/17/2021 at 3:44 AM, methos said:

 

Given that APFSDS can also be described as fin-stabilized APDS, using the term "APDS" in the table isn't that bad. 

 

I think that it was a typo ADPS vs APDS that caught my eye

[bojan]

7 hours ago, RETAC21 said:

The article mentions the T-80 as a possible acquisition by Libya, but the CIA's T-80 mey refer to the T-72B too

Libya negotiated with Yugoslavia for M-84s. All Slovenian ones are actually first batch produced for Libya, delivery delayed due the embargo toward Libya, then held as a reserve for JNA.

Edited January 21, 2021 by bojan

[EasyE]

For context. 

Points to note that the M774 out performs the WA M829 (XM829E1) against the Nato tripple heavy target. 

From the same paper the XM833 was able to defeat a what was defined as the most difficult "complex" target at 3.3 km

The WA XM829E1 appears to have failed at even very short range. 

No information that I could find as to what this " complex" target was. Further development of BRL-2 ?

More evidence I think to support that the M1 in 1980 was protected from older APFSDS designs and little else with regards to KE threats. 

Also that if the CIA document is correct and the M1A1 protection listed as 380mm vs KE that if these KE rounds were something like the DU M833, that this represents a very  large jump in protection vs the M1, albiet not enough against 125mm BM-32. 

[TTK Ciar]

In that era, "complex target" usually (but not always) referred to NATO Triple Heavy.

[EasyE]

On 1/23/2021 at 4:16 PM, TTK Ciar said:

In that era, "complex target" usually (but not always) referred to NATO Triple Heavy.

In this case it appears to fall under the "not always". 

I would be very interested in knowing what these targets were. Are BRL-1 and BR-2 in that mix? 

Also that their toughest target in these test were able be defeated at greater then 3km by a 105mm APFSDS may have been very concerning from a protection point of view. 

 

 

[Tim Sielbeck]

What "Penetrator Material" is WA?

[EasyE]

3 hours ago, Tim Sielbeck said:

What "Penetrator Material" is WA?

Tungsten Alloy so "modern" long rods

WC is tungsten carbide. The core of early APFSDS like BM-22.  

[methos]

On 1/21/2021 at 8:56 PM, EasyE said:

More evidence I think to support that the M1 in 1980 was protected from older APFSDS designs and little else with regards to KE threats. 

Also that if the CIA document is correct and the M1A1 protection listed as 380mm vs KE that if these KE rounds were something like the DU M833, that this represents a very  large jump in protection vs the M1, albiet not enough against 125mm BM-32. 

I would say that is possible, but then again it is only speculation. The question remains whether the US Army believed that the Soviets were going to field an APFSDS round with monoblock penetrator within the relevant time frame.

Previously the XM1 was required to only stop sheated steel penetrators with brittle tungsten alloy cores (i.e. the XM579E4), because the US Army assumed that the Soviets would only field such a round in the mid-1980s.

 

It is also worth mentioning that during the SAIFV program (hypothetical alternative to the Bradley IFV based on a XM1 Abrams' drivetrain components) the option was investigated to stop a potential 115 mm DU APFSDS round (simulated using the XM774 APFSDS). According to the relevant document, the XM774 was capable of penetrating 189 mm steel armor sloped at 60° (378 mm LOS) at 1,000 m distance. Hence it seems more likely that the "380 mm" figure might be based on the M774 round rather than the M833.

 

Soviet 125 mm APFSDS such as 3BM-26, 3BM-29 and 3BM-32 probably still could defeat the M1A1's armor at ranges in excess of one kilometer.

On 1/24/2021 at 1:16 AM, TTK Ciar said:

In that era, "complex target" usually (but not always) referred to NATO Triple Heavy.

The FRG already used more complex targets already in 1974, such as six different spaced arrays formed each out of six steel plates, one six-layered composite plate array and one eight-layered composite plate array.

15 hours ago, EasyE said:

Also that their toughest target in these test were able be defeated at greater then 3km by a 105mm APFSDS may have been very concerning from a protection point of view. 

Well, given that the XM774 managed to defeat BRL-1 ("similar to M1 Abrams") at 4,000 meters, this isn't really that new. Soviet tanks with their heavier armor would be a lot harder to defeat...

[KV7]

What are the BRL targets ?

[methos]

1 hour ago, KV7 said:

What are the BRL targets ?

Special armor arrays designed by the Ballistics Research Laboratory (BRL) for the US Army's evaluation of the British and West-German 120 mm guns in 1976-1977.