Challenger 2 Blog inaccuracies

[Legwolf]

In the recently released blog about the Challenger 2 ([Development] Discussing reports related to the Challenger 2 MBT - News - War Thunder), There are several inaccuracies regarding the side armor of Challenger 2 TES and OES, while quoting me as the author.

Here is a plain text summary of the issues:

ISSUE: Blog claims the side armor is “Armor Shield R”
The side armor package of Challenger 2 TES (2008) and Challenger 2 OES are the same as the Mk.3 Bulldog, which is ASPRO-HMT

(source: Tankograd No.9009 - British Next Generation Armour, written by Carl Schulze.)
At no point did I say it was Armor Shield R in my quoted report. This is a long since debunked theory.

ISSUE: Blog claims the side armor is ERA
The side armor package of Challenger 2 TES/OES is ASPRO-HMT, which by the manufacturer Rafaels own description is a “Hybrid Reactive/Passive Armor Protection”

(Source: Rafael ADS ASPRO HMT brochure).
In the book “Images of War, Challenger 2, the British main battle tank” by MP Robinson and Rob Griffin, the ASPRO-HMT blocks are described as having “Chobham Type” (in other words, literally Chobham or Composite Armor) protection as well as reactive armor, layed out in a series of layers to give maximum protection against kinetic rounds and modern ATGMs. This armor package is both ERA and NERA in one block, not one large explosive armor as modelled in game and cited in the blog.

ISSUE: Blog claims the current side protection does not contradict documents in my report (KE)
ASPRO-HMT is rated to STANAG 5 Protection on Rafaels own brochure and data sheet, and as such should be able to defeat any threat up to 25MM Autocannon APFSDS at 500 meters.

The requirements set out in STANAG 4569, state that it must defeat the 25MM APFSDS from a frontal arc to centerline of 30 degrees plus or minus. This means the projectile can be hitting the strike face of the brick anywhere between -30 degrees offset to 0 degrees (head on) to +30 degrees offset and any impact angle in that reverse cone and be unable to penetrate.

The best analogue for 0 degrees 25MM APFSDS in game, is Italian IFV “Dardo” with its PMB-090 APFSDS which can penetrate 83mm of RHA. To defeat this and thus satisfy the STANAG 5 requirement, ASPRO-HMT must have at LEAST 84mm of KE protection. Furthermore, my previous report on the matter has employee TrickZZter show in the Protection Analysis screen that the game already satisfies the criteria, however this is a VERY common mistake.

(screenshot by TrickZZter in Protection Analysis, taken from my report)

The protection analysis tool in game factors in the hull, airgap, composite screen and other armor elements behind the block, that are not just the ASPRO-HMT block itself. The protection values I have mentioned are JUST the ASPRO-HMT bricks, nothing else, I make no mention of the composite screen behind the bricks, the baseplate, hull or any other elements contributing to the STANAG rating of ASPRO-HMT, nor would I. The protection analysis tool will not accurately show the protection provided by a single, lone block. The blog itself also relies on this as proof it currently meets STANAG 5 requirements in game, which it absolutely does not.

ISSUE: Blog claims the current side protection does not contradict documents in my report (CE)
As of the current implementation of the game, the side armor is given just 400MM CE (Chemical) protection. At these yet to be sourced and unverifiable values, TES and OES’ side armor cannot defeat even a basic PG-7VL Single Stage Anti-Tank shaped warhead, fired from an RPG-7. The very weapon system Rafael mentions in their brochure of defeating completely. Using Rosoboronexport’s own values as a primary source for the penetration values of PG-7VL (This is the official Russian arms export website making these claims- Anti-tank Rocket PG-7VL | Catalog Rosoboronexport) PG-7VL penetrates 0.5m (500m) of homogenous armor. Our side armor provides up to only 400MM of Chemical Protection RHAe. This means, even a basic, single stage RPG round from 1977 can blow through the ASPRO-HMT brick and still penetrate. In the aforementioned book “Images of War” The ASPRO-HMT bricks are described as being designed to give maximum protection against MODERN ATGMs. By 2008 standards, a modern ATGM is the Russian 9M133 Kornet, in service since 1998 - A TANDEM WARHEAD anti-tank launcher capable of penetrating up to 1000MM+ of RHA and defeating modern ERA. For futher example, the PG-7VR (c.1988) is an RPG-7 fired, tandem shaped charge anti tank missile, existing far before the TES’ 2008 era adoption era. Given the ASPRO-HMT is designed to stop these threats, it can be safely said that 400MM CE protection is not accurate to the evidence, either. Remember, this is NOT one giant explosive brick, it is layered passive AND reactive armor. Layers which can stop a breaching end of a tandem warhead, and still have layers behind it, to stop the warhead proper.

ISSUE: Blog states mounting plate is aluminium.
This is false and is documented in “Tankograd - British Special No 9021, Challenger 2” where it explicitly states in reference to the TES “…Consists of tiles containing a low-burning-rate insensitive explosive filling, mounted onto a massive STEEL baseplate”. The photographed TES it references is also circa Octoba 2008, which is what our TES is based off.

Please correct your blog post or issue a follow-up corrective blog rectifying the mistake. I put a lot of work into this research and I would appreciate it being at least interpretted correctly, especially when being openly named in the blog itself.

Thank you,
Legwolf.

[John_Sneeeeeeeew]

Gaijin should hire you :)

[MDC5000]

Stellar job !

[duckmartin]

Absolutely spot on mate !!

[DevilO6]

Here is my effort

[Development] Discussing reports related to the Challenger 2 MBT

Ok, so as we can see on the Brochure [image] [image] It talks about hybrid add on armor that combines reactive and passive elements, so something like that [image] It never talks about any backplate. And as it can be seen, it can be aplied to multitude of things, such as APCs, IFVs and MBTs. If the STANAG 5 protection was achieved only with help of 40mm backplate, it would had to be stated. If that is the case, and it is not stated, the company would be making false advertisement, and could…

[Development] Discussing reports related to the Challenger 2 MBT

At close to 0 it pens like nothing was there https://streamable.com/cs4hju At 58 it stops on the backplate https://streamable.com/oq7k81 And at 64 the block by itself stops it https://streamable.com/xnjlp9 unlike what STANG 5 says [image] WIth that it should provide that level of protection from angle 0, and 30 degree to both sides, so 60 degree arc at the front of the block. Not like what we have in game. [image] Here is a different product showing how stopping thing that fits in STAN…

[Lolman345]

Good to see more compendium posts debunking the BS present in these recent “we are right” gaijin dev posts.

Its time correct information is presented and recognized by gaijin.

[Men_of_Harlech]

I increasingly think it’s ridiculous that gaijin relies on player research to fix vehicles in the game, we’re not even developers, and gaijin doesn’t pay us anything. It is entirely the developer’s job and responsibility to conduct detailed research on the vehicles in the game. We just love the game and spend our time and our money in exchange for an incredibly arrogant attitude that is really dismissive. Sometimes players don’t even expect gaijin to fix their problems right away, they just need the dev team to admit that they got it wrong and they need time to work on them. I really don’t know what the business logic is like in Russia, the vast majority of players are even consumers of this game but in exchange for such an arrogant attitude.

[Nuckerball]

Only glorious russia is capable of producing effective applique armor. It doesnt matter that russia has fallen behind in every conceivable metric of technology, contact 1 is still better than anything the united kingdom could produce, including these massive composite blocks which are like 4 times thicker. Dont you know the soviets already hit the limits of material science? Igla is the absolute best manpad possible, no western alternative can maneuver better. No western era can do better either

[StepBomber]

@Legwolf

The requirements set out in STANAG 4569, state that it must defeat the 25MM APFSDS from a frontal arc to centerline of 30 degrees plus or minus.

The disconnect between what you and Gaijin claim seems to be how “±30° from centreline” is interpreted. You claim that it should apply to the individual ASPRO-HMT blocks themselves, Gaijin, as indicated by the screenshot by TrickZZter and what they write in their latest Devblog about this, seems to think this means from the centreline of the vehicle. If your interpretation is correct it would probably help if you could provide documentation that supports that.

My knowledge of this is limited, but what I’ve read so far seems to indicate the latter interpretation is correct. I’ll attach what I found on it:

• STANAG 4569 is specifically about “protection levels for occupants of armoured vehicles”, not individual armour subsystems.

• PROCEDURES FOR EVALUATING THE PROTECTION LEVEL OF LOGISTIC AND LIGHT ARMOURED VEHICLES; Page 12
  The image speaks for itself, I think. The document talks at length about evaluating the protection level of vehicles. Maybe there is something similar for individual armour systems?
  

• This Armor Shield R from Rafael on a Bradley. It is rated for STANAG 4569 Level 6. As you can
  see the front and side tiles are not idential, which makes it more likely that the protection level rating is for the vehicle as a whole.
  

[DevilO6]

@StepBomber

The image speaks for itself, I think. The document talks at length about evaluating the protection level of vehicles. Maybe there is something similar for individual armour systems

Here the example is a vehicle. If you want to apply it to a block, you replace the vehicle model with block. Done

[StepBomber]

@DevilO6

Here the example is a vehicle. If you want to apply it to a block, you replace the vehicle model with block. Done

Why does the document not mention that? It only talks about vehicles as a whole. So does STANAG 4569. Why are Armor Shield R blocks on the front of the Bradley about a third of the thickness as the ones on the side when they’re supposedly rated on their own, without taking vehicle configuration into account?

[Legwolf]

Hey there!

I’ve looked into this pretty extensively and you’re right - There’s two interpretation of the “±30° from centreline to frontal arc” One for the angle of attack to the brick itself as seen below:

If you use this interpretation, then the bricks in game are NOT STANAG 5.

Full penetration can be achieved by 25mm Autocannon at 500m and 30 degrees angle.

The other interpretation as you’ve outlined is the heading of the vehicle / centreline of the vehicle.
Gaijin’s official stance is this interpretation. However, this does not hold water i’m afraid.
Firstly, the official data sheet for ASPRO-HMT (The bricks on TES) makes no mention of being applied on a specific vehicle, position or angle. Just that it overall meets STANAG 5 requirements. This interpretation also completely throws roof mounted ERA and any non-side mounted ERA out the window, as you’d be shooting into their sides (STANAG level 5 requires 0 elevation. You cannot adjust to fire at the front/strike face and would therefore be shooting into the brick sideways if mounted anywhere that isn’t sideways.)

The other major issue with this interpretation is that again: it is not reflected in game:

Here’s 30 degrees from centreline, rather than angle of attack. The angle of attack here is something akin to 70 degrees. I’m using Dardo’s PMB-090 APFSDS, at 500M distance, 0 degrees elevation, and firing at 30 degrees from centerline as Gaijin suggests.
While the protection analysis tool will show you that it cant penetrate - it is taking into consideration the back plate, the airgap and the hull as well. Firing the round and following it top down shows complete penetration of the ASPRO-HMT block, failing the STANAG 5 requirement yet again.

In BOTH interpretationso of the STANAG 4569 document, the TES/OES applique armor fails to prevent 25MM darts from penetrating under the set conditions.

Furthermore, here’s some actual footage of STANAG 4569 testing. You can see here, it’s being shot at with a 0 degree angle. An angle ONLY possible if you follow the “Angle of attack” interpretation of the document. You cannot fire from 0 degrees offset when considering the vehicles heading/centreline as standard.

STANAG 4569-1

Hope this explains it :)

[SlowHandClap]

I’ve never witnessed a gaming community who puts in so much effort to support the developers…

…and also never witnessed a game developer who shuns help from the community as much as GJN does.

@Legwolf

SOURCE3828×1146 171 KB

Worth noting that in the main carcrash devblog I posted two images in game of Russian 14.5mm AP MG rounds going straight through the OES ERA at 90 degrees. So it isn’t even achieving STANAG level 4 protection according to those charts.

I’ve emailed Rafael to ask about the angles of attack on their blocks. ± 30 degrees frontal arc including sides does sound like GJNs definition, but as you’ve already pointed out it doesn’t even meet those requirements.

All of this is mentioning ballistic performance of the ERA too. GJN haven’t even really commented on whether the effectiveness against chemical rounds is performing correctly (it isn’t).

[Legwolf]

Their interpretation is based solely off of protection analysis which is a flawed narrator.
I’ve shown in all my reports and writeups it’s not making STANAG 5 requirements and the 30/400 protection values are not right

[StepBomber]

@Legwolf

Firstly, the official data sheet for ASPRO-HMT (The bricks on TES) makes no mention of being applied on a specific vehicle, position or angle. Just that it overall meets STANAG 5 requirements.

The same is true for Armor Shield R on the Bradley, despite using two significantly different blocks for its front and sides. Advertisement brochures rarely go into configuration details. They also single out CE projecticles for 360° protection and 14.5 mm AP (STANAG Level 4, angles not specified in your image) for some reason. If it can stop 25 mm APFSDS at any angle you’d think they’d advertise that? Certainly more impressive than 14.5.

@Legwolf

Here’s 30 degrees from centreline, rather than angle of attack. The angle of attack here is something akin to 70 degrees. I’m using Dardo’s PMB-090 APFSDS, at 500M distance, 0 degrees elevation, and firing at 30 degrees from centerline as Gaijin suggests.
While the protection analysis tool will show you that it cant penetrate - it is taking into consideration the back plate, the airgap and the hull as well. Firing the round and following it top down shows complete penetration of the ASPRO-HMT block, failing the STANAG 5 requirement yet again.

In BOTH interpretationso of the STANAG 4569 document, the TES/OES applique armor fails to prevent 25MM darts from penetrating under the set conditions.

At 30° from vehicle centreline 25 mm APFSDS stops within the ERA. Yes, it goes through two blocks and whatever is between them, but it doesn’t make it to the backing plate. If you go with the “±30° from centreline” it should thus meet STANAG Level 5 specification as it does not penetrate. That’s the only thing that matters for the specification.

@Legwolf

Furthermore, here’s some actual footage of STANAG 4569 testing. You can see here, it’s being shot at with a 0 degree angle. An angle ONLY possible if you follow the “Angle of attack” interpretation of the document. You cannot fire from 0 degrees offset when considering the vehicles heading/centreline as standard.

STANAG 4569 Level 1 specifies a 360° Azimuth against 7.62x51 Ball. So they would of course be testing at the worst possible angle. It doesn’t have the “±30° from centreline” ambiguity.

[Legwolf]

@StepBomber

If it can stop 25 mm APFSDS at any angle you’d think they’d advertise that? Certainly more impressive than 14.5

ASPRO-HMT actually advertised 0.3 AP (30mm) at 90 degrees. I didn’t include this in my research yet but…why say 25MM when you can advertise your higher calibre?

@StepBomber

The same is true for Armor Shield R

I’d be really careful drawing conclusions between ASPRO-HMT and Armor Shield R. One is an explosive reactive armor, the other is a hybrid Passive/Active armor hybrid. They’re not really comparable products and was never used by the UK. The blocks themselves are what the data sheet are referencing, and thus the STANAG 5 claim on the data sheet is exclusive to them as a whole. No configuration details as the tests are standardised in 4569.

@StepBomber

At 30° from vehicle centreline 25 mm APFSDS stops within the ERA. Yes, it goes through two blocks and whatever is between them, but it doesn’t make it to the backing plate.

You’re mistaken here, the blocks themselves are STANAG 5. Not the backing plate. that’s a custom solution made by the vehicle operators, not Rafael. They penetrate right through the blocks and hit the back plate before failing pen. This means they failed to meet STANAG 5 requirements. The blocks are STANAG 5. Not the plate or vehicle they’re mounted to.

[quote=“StepBomber, post:15, topic:67919”]
STANAG 4569 Level 1 specifies a 360° Azimuth against 7.62x51 Ball. So they would of course be testing at the worst possible angle. It doesn’t have the “±30° from centreline”

@StepBomber

STANAG 4569 Level 1 specifies a 360° Azimuth against 7.62x51 Ball. So they would of course be testing at the worst possible angle. It doesn’t have the “±30° from centreline” ambiguity.

I was more trying to show, the materials are tested based on the projectile angle of attack, not the vehicles heading/centerline.
You would end up with wildly different metrics for what makes a product STANAG 5 if you tested using the vehicle centreline method, rather than testing the bricks themselves.

[zuadao]

ok so first of all the stanag level CANNOT take the vehicle into account. aspro only makes the era/nera block and just because they say it provides a certain stanag level it doesnt mean you will have that level of protection in every vehicle. vehicles are diferent and as such the protection levels are different.

secondly the protection against 25mm apfsds is on a full 30º angle from the center 0º, that means it protects at 30º at 25º at 10º and at 0º, its not that hard and they provide a coloured picture for ppl who cant compreend angles.

[cortbowan]

Thank you for your post and your extensive work @Legwolf

This is some great and detailed research, I hope Gaijin recognizes that and implements the findings accordingly.

[Flame2512]

@Legwolf

ASPRO-HMT actually advertised 0.3 AP (30mm) at 90 degrees.

I’m pretty sure that in this context 0.3 AP means 0.3 inches. AKA .30 cal / 7.62mm

[Legwolf]

It’s a bit ambiguious hence why I omitted it from my research and just went with the STANAG 5 claim :P