Spawl lining on the M1A2 SEP V2

[mydogisscooby-psn]

So basically why does the M1A2 Sep V2 not have spawl lining even though the T-90 gets spawl lining, bags, ERA etc. I call BS on gaijin cause im tired of getting one shotted crews, just ad the kevlar before documents get leaked baby girl.

[tripod2008]

@mydogisscooby-psn

So basically why does the M1A2 Sep V2 not have spawl lining even though the T-90 gets spawl lining

Because the spall reduction mechanism in the M1 isn’t an independent final liner placed on the inside of the fighting compartment. So it doesn’t meet Gaijin’s arbitrary definition that they use for “spall liners”

It’s part of the actual NERA array.

@tripod2008

As it is known that Chobham, that formed the basis of the first generation of US NERA Developments includes a Plastic strike face & backing layer, and the limited cross-sections we do have of the M1’s arrays don’t delineate between Non-Conventional, Conventional, and Homogeneous armor and said description is broad enough to include plastics.

Would it be a fair assumption to make that it is likely that The “Basic” M1’s Array’s(at very least, as it is specified in the document that the M1A1 uses a different configuration) also contain a similar layer.

Relevant excerpts

Also is it just me or does the quality of the scans, and the reference [PDF page #12]
to the “Tri-plate” (?Three element? ) assembly mentioned in the definition of the Special armor make it look like the middle layer of the composite element that forms each layer is encapsulated, potentially the same way they are as outlined in the Chobham excerpts, which is known to be an unspecified plastic.

I’d report this but using Gaijin’s definition of a spall liner, it doesn’t count.

"First up, let’s take a look at what the spall liner is in reality. The spall liner is part of the structural protection of an armored combat vehicle, designed to reduce the damaging effect in the main compartment once a tank is penetrated. To do this, liners are attached inside of the main compartment. Material such as fabrics made from aramid fiber are most often used, but other materials are also used occasionally too.

In the game, the effect of a spall liner is implemented as follows: inside the main fighting compartment, directly after the main portion of a tank’s armor, a module is present that imitates spall liner material."

This is in the sense the issue, where it probably wouldn’t count due to the definition they are using itself, since in effect The Strikeface / Backface encapsulation of the Plate element in the armor would cause some reduction to Spall generation, due to how shock gets transmitted though a dissimilar boundary layer(s).

[pooqich]

@tripod2008

It’s part of the actual NERA array.

how would it stop the last layer of steel from generating spall?

[TheArcticFoxxo]

It doesn’t, he has no clue what NERA is.

[J-16D_PLA]

Yea I agree

[Cloudzy26160]

Yeah, even ignoring the fact that it’s the spall from the last layer of armour that is detrimental to crew health, those armour diagrams have the plastic on the outer side for shockwave refraction, not the inside for spall reduction.

[TheArcticFoxxo]

This car’s tire is made of rubber! That must mean that the seat is protected from static buildup!

[tripod2008]

@pooqich

how would it stop the last layer of steel from generating spall?

It’s not intended to stop it entirely, but reduce the mass of ejecta entering the fighting compartment, failing that reduce the impacted volume as best it can, and failing adjust the mass ratio of the spall to favor larger (lower velocity for an equivalent energy) fragments. so it’s more like a few chunks than a shotgun blast.

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The backing layer is a dual-hardness Steel, not typical Armor RHA, so is optimized to produce less small fragments comparatively.

More can be read about it in the following papers;

• AD759506 Structural Properties of Dual Hardness Steel Armor

• The Mechanical Metallurgy of Armour Steels

@TheArcticFoxxo

It doesn’t

Where did I claim that it stopped it entirely?

@TheArcticFoxxo

he has no clue what NERA is

So why include, plastic at all?

@Cloudzy26160

diagrams have the plastic on the outer side for shockwave refraction

Yes, and what does reflecting the shockwave do, if not reduce net stresses; by diverting the shockwave at a boundary?

@TheArcticFoxxo

This car’s tire is made of rubber! That must mean that the seat is protected from static buildup!

So would you expect such a design to produce less than a similarly effective monolithic block of RHA under the same conditions?

We know that the exemplar “Green Grape” array is proof against 115mm APFSDS (?3BM-21?), I’m not making any aspersions that the Baseline M1’s arrays are kinetically underperforming.

[Cloudzy26160]

@tripod2008

So why include, plastic at all?

To cause shockwave refraction

@tripod2008

Yes, and what does reflecting the shockwave do, if not reduce net stresses; by diverting the shockwave at a boundary?

Refracting, not reflecting, It redirects the shockwave into the backing plate to cause it to deform and either deflect the round or even break it apart.

@tripod2008

So would you expect such a design to produce less than a similarly effective monolithic block of RHA under the same conditions?

Yes. However ERA tends to be bad for nearby troops (hence why you don’t see Russian soldiers providing close in screening for their tanks the way NATO troops do), and each block is destroyed after a single impact. NERA has much better multi-hit survivability.
But neither ERA or NERA reduces internal spalling from a pentation as the spalling into the crew compartment is from the last layer of armour, that armour will stop everything from the outer layers, that’s why a spall liner has to be on the inner face of the armour.
Now there are types of metal as you mentioned that are soft on the inner face to reduce spall. but that was not what we where talking about. and if you have and UNCLASSIFIED info on the Abrams using such material than I’m all for it getting a spall liner.

[tripod2008]

@Cloudzy26160

if you have and UNCLASSIFIED info on the Abrams using such material than I’m all for it getting a spall liner

Well, I’d point to the fact that MIL-A-46099C is still classed as “active”. and with the Bradley and Stryker’s not being constructed using Steel, but aluminum there are few other options to keep it active.

And besides very little is actually known about the composition of the M1 anyway, let alone the structural components and their certifications.

[Cloudzy26160]

@tripod2008

still classed as “active”.

Which is a problem for all top tier vehicles in the game, which is why for better or for worse you need publicly available photos that show anti-spall lining. There are also a lot of references to the 2S38 being built from anti-spall aluminum alloy, yet that is not implemented in game either.
But regardless anti-spall either as a separate material or a deferentially hardened metal must be on the back of the armour to catch spall while not producing it’s own fragments.
One thing I think should be implemented is ballistic vests for the Abrams crews to increase their “HP” against spall, there are plenty of public photos of them wearing them.

[TheArcticFoxxo]

@tripod2008

Where did I claim that it stopped it entirely?

“Where did I claim that spall liners stop spall?!?!?” is quite possibly the most idiotic response I’ve ever received.

Believe me, I’ve dealt with some absolute troglodytes.

@tripod2008

So why include, plastic at all?

As an absorbent layer backing a hardened plate that prevents said plate from shattering? Do you have any idea how unbelievably thin those HHRA plates are? What might you imagine would happen if two plates placed extremely close to each other were to be hit by 7MJ of depleted uranium?

@tripod2008

So would you expect such a design to produce less than a similarly effective monolithic block of RHA under the same conditions?

No? The primary generator of spall in the array is the backing plate, which itself is an extremely brittle 570HB in the HAP packages.
Compared to RHA, this would spew debris like no tomorrow.

@tripod2008

We know that the exemplar “Green Grape” array is proof against 115mm APFSDS (?3BM-21?), I’m not making any aspersions that the Baseline M1’s arrays are kinetically underperforming.

It isn’t “proof against” any ammunition but domestic 829. At most it was projected to protect against 3VBM13, and none of its design choices have any influence on spall generated in the crew compartment.

That’s uh… Sort of what body armor is for.

[tripod2008]

@TheArcticFoxxo

is quite possibly the most idiotic response I’ve ever received.

Can you point it out please, I have a feeling your not exactly reading what has been written. nor being very constructive.

@TheArcticFoxxo

As an absorbent layer backing a hardened plate that prevents said plate from shattering?

Yes and so reduces the quantities of produced spalling vs a similar plate sans backing.

@TheArcticFoxxo

Do you have any idea how unbelievably thin those HHRA plates are?

If pixel measurement is to believed somewhere between 1/4 and 1/2", sans liners.

@TheArcticFoxxo

What might you imagine would happen if two plates placed extremely close to each other were to be hit by 7MJ of depleted uranium?

I would only have to ask, how close, abutting one another or a short distance.

@TheArcticFoxxo

which itself is an extremely brittle 570HB in the HAP packages.

You got a source for this?

@TheArcticFoxxo

It isn’t “proof against” any ammunition but domestic 829.

I’m not exactly sure how an amour array is supposed to be proofed against ammo that didn’t exist at the time, the FSD XM-1’s testing regime began in '75, 120mm M829 only begins validation & testing in late '79(FY’80), with the conclusion of the final set of the series of Tri-partite gun trials, which concluded with it’s selection over the Tungsten variant (M827) in '84 and subsequently entered production alongside the production of the 120mm M256 cannon beginning on US soil.

“Protection of the crew compartment against the Soviet 115mm FAPDS at 800~1200 meters”

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“Its frontal armor would be defeated at all battle ranges by the current 125mm Soviet FAPDS. This round is assessed as being capable of of penetrating 445mm of solid rolled homogeneous amour (RHA) at normal at 1000 meters (Tungsten penetrator) and 460mm (Depleted Uranium penetrator) at the same range where as the XM1 is protected against a round assessed as being capable of penetrating 325mm of solid RHA at the same range.”

Also see “table three” mentioned in the first excerpt for the 105mm surrogate rounds (XM579E4 & XM744) used as threat simulators and their performance.

Relevant Excerpts

@TheArcticFoxxo

That’s uh… Sort of what body armor is for

It’s not like a bespoke PPE system was issued to tankers, and injuries to limbs and extremities will take a station out of the fight just as easily as those to the vitals. As it’s fairly hard to grasp things if you are missing fingers(grip strength drops significantly), or manipulate hand controls missing an arm for example.

It’s why the M1IP was spun off as a pre-planned product improvement since the baseline array was overmatched by emerging threats and so backported the array of the M1E1, which is very likely to be better proofed against 125mm threats, but then there is still the HA & HA+s’ arrays.