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1 hour ago, Sovngard said:

The T-14 was supposed to use weight-saving 44S-sv-Sh steel alloy.

 

20 minutes ago, LoooSeR said:

   That is a steel for thin armor, not for tanks.

 

IIRC the 44S-sv-Sh steel is meant for the protection of external modules (e.g panoramic sight and the turret's protective sheet) in vehicle applications. Otherwise it is marketed for use as body armor, as it is specialized for protection against small arms.

So no, it's not going to save any meaningful amount of weight on the T-14, but it still exists on the tank as well as any recent AFV that has external modules to protect.

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10 minutes ago, Mighty_Zuk said:

IIRC the 44S-sv-Sh steel is meant for the protection of external modules (e.g panoramic sight and the turret's protective sheet) in vehicle applications. Otherwise it is marketed for use as body armor, as it is specialized for protection against small arms.

So no, it's not going to save any meaningful amount of weight on the T-14, but it still exists on the tank as well as any recent AFV that has external modules to protect.

I never heard of this steel being used as protection for sights. 

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7 hours ago, Kal said:

0.615 (los steel) x 2.3 (width) x 0.8 (height, lessor guess) x 7.8 = 8.8tonne

 

0.663 x 2.3 x 1.0 x 7.8 = 11.9 tonne

 

So approximate range for front upper glacis armour is between 9 and 12 tonnes, using assumptions above.

 

That is heavy.

I guess that the main advantage of having a mostly unprotected turret is that you can have the luxury of using a super heavy hull front, having "just" 9-12 tons of heavy armor in a 50 ton tank and still being capable of withstanding anything the enemy can throw at you is quite remarkable.  By comparison, the Abrams turret weights about 20 tons, mostly because of the armor, and that was before they started using DU!

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This t72b/t90 derived armour would be equivalent to entry level heavy armour.  Its what a current t90 operator like india or egypt could use if they wanted to.  

 

What russia could do to improve it includes.

 

Steel - Special rolling techniques, presumably this is what upgrades the 44s sv sh to be 'ultrafine' Should be able to use approximately same steel (t72b/t90) but improve both hardness and toughness, thus the 15% weight reduction (less steel used). Still artic friendly.

 

Upgrade rubber interlayer to more energised compound, many options, an earlier israeli patent displays that highest decomposition but adequate stability is desirable. 

 

Upgrade the rear flyer plates to titanium.  Can also use similar advanced rolling techniques.

 

Make intitial front steel layer perforated steel, can save upto 50% weight.

 

These all maintain the current design, just upgrade individual elements (or reduce weight)

 

 

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32 minutes ago, Collimatrix said:

Everything I've read suggests that perforated armor does not work terribly well against APFSDS.  I buy the rest of what you say, more or less.  There have been substantial improvements to armor steel metallurgy over the past several decades.  But they are costly improvements.

Whose apfsds? Pakistans or india? For many operators this armour is simply overmatch anyway.  + russia really likes her ERA,  this t14 is going to have era postage stamps all over it.

 

I havent found a good paper comparing apfsds vs perforated armour.  My intuition is that perforated armour works best when its holes/slots are optimised against a design projectile caliber.  Also that the angle of the perforations can also have a large influence.

 

Some of metallurgy improvements are costly, others are low cost, others still reduce cost.  Obtaining fine grain by special rolling is not high cost at all, just specialised.  But the benefits dissappear upon further heat treatment or welding.  So its suitable for applications like bulging plates, covers and body armour, but NOT for applications involving wide re anealling. 

 

Would i design the armour to be like the t72b/t90 derivatives above? No.

But i sure would test ammunition against the t72b/t90 derivative above.  Its a baseline for simpliest technological progression for the armata t14.

 

 

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Question is: why would the russians include more expensive armor elements within an already expensive new tank that they are having problems buying?

 

The whole point of my estimation was to prove that even by using 35 year old armor, the T-14 would be meeting current protection needs without having to field a fancy new and expensive armor package. After doing the math i was truly surprised by the effectiveness of such armor even using the lowest possible estimate.

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I dont think russia would use the perforated steel for the leading steel plate, but it is a option.  Perforations are much cheaper now than historically.

 

I do think russia will use their new steel, if it the same/similar chemistry as the old steel, but ran through a special roller, then the cost increase is small, in particular, the cost is sunk anyway and the incremental costs of using special rollers is probably less than the the benefit of higher strength. 

 

I do think they will upgrade the rubber interlayer, cost is neglible and reward is great.

 

I suspect that russia would make the rear flyer plates out of titanium, just because its Russia, and its a suitable application.

 

In general, with 5 sandwiches, newer tech is probably cheaper than 6 sandwiches of the older tech.

 

With 6 sandwiches, newer tech can be thinner than the older tech.

 

Either way, they are going to use ultrafine steel in there.

 

 

 

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9 hours ago, Kal said:

Whose apfsds? Pakistans or india? For many operators this armour is simply overmatch anyway.  + russia really likes her ERA,  this t14 is going to have era postage stamps all over it.

  

I havent found a good paper comparing apfsds vs perforated armour.  My intuition is that perforated armour works best when its holes/slots are optimised against a design projectile caliber.  Also that the angle of the perforations can also have a large influence.

  

 

Perforated armor does not work particularly well against APFSDS in general.  Doesn't matter what country the factory is located in.  Perforated armor works by having an array of holes (thus the name) that are sized such that it is statistically likely that an incoming KE threat will catch one of the holes on the very edge.  This tends to mangle the KE threat and also yaw the penetrator so it hit slightly side-on.

 

APFSDS darts have a very high aspect ratio and a relatively small diameter, so they should be fairly easy to mangle and they should be enormously degraded if they rotate even slightly, right?  So far so good.

 

But APFSDS has a number of properties that also make it less vulnerable to perforated armor.  The biggest problem is that APFSDS is really, really fast.  If you impart a given amount of torque on an incoming projectile with a perforated stand-off plate, it will yaw less by the time it reaches the main plate if it's going faster.  A given amount of torque will impart a given angular velocity on a given penetrator, and with APFSDS the penetrators are moving so fast that they don't have much time to yaw before they strike the main plate.

 

On top of that, APFSDS has an extremely high moment of inertia about the yaw axes because it is so long.  A given torque applied to the rod will rotate it less.

 

Finally, APFSDS operates within a semi hydrodynamic regime, and the penetrators erode by design.  They're not like traditional, full-caliber AP rounds that live and die by penetrator integrity, and this makes it a lot harder to apply torques to them in the first place.

 

So, APFSDS is moving too fast to get turnt in time, it's resistant to getting turnt, and it's not easy to turnt it in the first place.  All my sources on the matter (e.g. Hazell 2016) say that armor arrays that try to yaw APFSDS don't work particularly well.  That said, a perforated array would work much better if the perforated array has more inertia.  So, a perforated array made out of, say, depleted uranium might work against APFSDS where steel would fail.  I have suspected in the past that this might be what the "DU mesh" in the Abrams' turret is, but @SH_MM has stated that he thinks a DU-based NERA array is more likely.  In any case, the design of the DU arrays in the armor have changed from model to model.

 

The T-14 almost certainly has ERA built in, and there is no reason to expect that future Russian ERA will look like 1980s vintage K1 "postage stamps".

 

9 hours ago, Kal said:

Some of metallurgy improvements are costly, others are low cost, others still reduce cost.  Obtaining fine grain by special rolling is not high cost at all, just specialised.  But the benefits dissappear upon further heat treatment or welding.  So its suitable for applications like bulging plates, covers and body armour, but NOT for applications involving wide re anealling. 

 

The grain size will only go down so much from a single rolling operation.  To get ideal grain sizes, the process needs to be rinsed and repeated a few times.  That costs.

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3 hours ago, Collimatrix said:

That said, a perforated array would work much better if the perforated array has more inertia.  So, a perforated array made out of, say, depleted uranium might work against APFSDS where steel would fail.  I have suspected in the past that this might be what the "DU mesh" in the Abrams' turret is, but @SH_MM has stated that he thinks a DU-based NERA array is more likely.

 

Building on this tangent: would a perforated DU equipped SLERA perform better against APDSFS than DU equipped NERA/NxRA? 

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Ive yet to see clear definitons of 'middling' reactive armour.  My understanding of SLERA is that it is essentially ERA, but the compounds/assembly make it technically not ERA.   Similary to how ANFO is not high explosive but is a blasting agent instead.  Or how a high explosive if stored at less than critical diameter might not be 'high explosive'.

 

Basically its a arbitary definition, according to a rule, so to prioritise storage and handling procedures and laws.

 

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The turret of the armata suggest to me postage stamps of ERA.  I was contrasting that to the block bricks of soviet ERA.   

 

Postage stamps being thin ERA.

There are demonstrations using just the explosive inserts, upon thick steel.  Something more akin to that.

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11 hours ago, Kal said:

Ive yet to see clear definitons of 'middling' reactive armour.  My understanding of SLERA is that it is essentially ERA, but the compounds/assembly make it technically not ERA.   Similary to how ANFO is not high explosive but is a blasting agent instead.  Or how a high explosive if stored at less than critical diameter might not be 'high explosive'.

 

Basically its a arbitary definition, according to a rule, so to prioritise storage and handling procedures and laws.

 

 

Not my intent to derail the thread, but when initially looking for more information on SLERA, I often came across contradicting descriptions, wherein the "energetic material" is either full-blown explosive (though either in small portions or the amount of movement imparted to the reactive components is physically limited by the SLERA container) or something "passive" by NATO standards. Either way, I view it as some sort of mild, internal ERA-NERA hybrid (where the gas-producing substance or rubber layer is mixed in with explosives). Dunno whether SLERA offers good multi-hit capability, though.

 

P.S. By the way, was the side armor of the Merkava 4 turret officially categorized as SLERA or pure ERA?

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Re: Merkava

 

It is an object of the present invention to provide a non-explosive energetic material suitable for NxRA which does not contain explosive material and fulfills its protective function (high efficiency and high survivability of the armor), whilst the non-explosive energetic material lowers the requirements of transportation and logistics according to various standards e.g. UN regulations as appearing in the Recommendations on the Transport of Dangerous Goods.

 

[0014] It is a further object of the present invention to provide an armor element fitted for such an energetic material and where the armor is of comparable efficiency to SLERA and of comparable survivability to NERA.

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5 hours ago, Konev said:

Except rubber,what materials were used in modern NERA and NxRA?

Thanks!

This is a list of materials I've found in the papers I have about SLERA, NxRA and NERA. It is by no means complete or containing only materials that are actually fielded, it's just what I've found:

  • Glycidyl azide polymer (GAP) hardened with Desmodur N100
  • GAP (hardened) with CaCO3
  • GAP (hardened) with Guanidinazotetrazolat
  • GAP (hardened) with varying amounts of RDX
  • "Rubber or GAP" with a layer of Dottikon
  • Perbunan
  • NBR
  • PU
  • FKM
  • SI
  • Dyneema HB26
  • Carbon reinforced rubber
  • Glass reinforced rubber
  • Kevlar reinforced rubber
  • PBO reinforced rubber

But there's probably more, this is all I could find in the grand total of three papers I have on this topic.

 

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On 12/7/2018 at 2:14 AM, Mighty_Zuk said:

The mantlet being reinforced with composite armor, perhaps to the point of being nearly as strong or as strong as the rest of the turret front, is neither unique to the Leopard 2A5-7, nor is it very uncommon. 

 

Other tanks like the Abrams, Merkava, and perhaps the T-tanks (barring the T-14), plus maybe the Challengers (though not too sure) have well protected mantlets.

 

I wouldn't agree with that statement. The gun mantlet is always a weak spot, even on the Leopard 2A5. However the amount of armor seems to differ quite dramatically between tanks, with many designers focusing on reducing the overall size of the mantlet rather than trying to add lots of armor to that.

 

For example on Abrams the special armor cavity at the front of the gun mantlet seems to be less than 300 mm thick, unless the soldiers in the following picture happen to be giants...



9MOIv.jpg87Sxj.jpg

 

The Merkava's design seems to also to be very much focused on reducing the size of the gun mantlet rather than focusing on providing it with thick armor. On the earlier models,  there isn't much of a question. For the Merkava 4, the mantlet is extremely small (one of the smallest one in use), but it still seems to be fitted with rather limited protection only:

Spoiler

QjEl9On.jpg

rl5ssod.jpg

 

 

The T-90A with welded turret seems to have a decent mantlet thickness based on drawings and exterior photographs, but the earlier Soviet-designed tanks didn't feature any special armor at the gun mantlet.

 

 

On 12/28/2018 at 1:38 PM, Mighty_Zuk said:

Officials claim 900mm (of what? ERA and armor, or armor after ERA?). I think it's definitely possible.

 

Russian language articles have claimed a protection level of 900 mm RHS vs KE, but I doubt that this is based on official claims.

 

On 12/28/2018 at 3:10 PM, alanch90 said:

When i get back home from work ill make a longer post about the issue, but ill say for now that i find highly likely that T-14 uses the same or very similar armor package as the one on the T-90A turret. In fact T-14 UFP could very well have the exact same LOS thickness as the maximum LOS thickness of T-90A turret from the front (about 900mm).

 

It seems highly unlikely that the T-90A's turret armor array or a similar construction is used in the T-14 Armata.

 

On 12/29/2018 at 4:57 AM, alanch90 said:

Years passed and nowadays the T-90 models still use that exact NERA array (granted, since A model, in a welded turret which increases the overall effectivenes by 10-15 percent). In other words, russian engineers don´t consider those "bulging plates" obsolete, nor sort of a "bottleneck" in protection performance.

 

Any source for these claims? The T-90 and T-90A were made as cheap main battle tanks to keep the industry alive, the Soviets already had better armor in development and proposed for all of their next-generation desgisn (both Kontakt-5 and the "bulging plates" main armor was therefore outdated in certain aspects).

 

On 12/31/2018 at 9:09 PM, alanch90 said:

Yep, the russians are totally using the 35 year old bulging plates array and getting away with it.


They are totally not and that was some very weird and questionable napkin math.

 

On 1/1/2019 at 11:06 AM, Kal said:

So approximate range for front upper glacis armour is between 9 and 12 tonnes, using assumptions above. 

  

That is heavy. 

 

That is way too heavy to be a reliable estimate. The complete special armor of the Leopard 2 from 1979 supposedly weighs between 5.4 and 5.5 metric tons - for a total weight of 55.15 metric tons; putting the weight of the tank without special armor at 49.65 to 49.75 metric tons. With 9 to 12 metric tons of glacis main armor (and the tank is also featuring special armor at the sides of the hull and roof) and additional ERA - the Kontakt-1 kit for the T-80BV weighed 1.2 metric tons; the T-14's heavy ERA covering a larger area (hull flanks, roof and glacis) should weigh a lot more - the T-14 tank without any special armor would have a weight significantly lower than 40 metric tons, which I'd consider impossible given its size. The unmanned turreet allows shaving a few metric tons away, but not that much.

 

On 1/1/2019 at 6:39 PM, alanch90 said:

By comparison, the Abrams turret weights about 20 tons, mostly because of the armor, and that was before they started using DU!

 

Unless you are mixing short and metric tons, your claim is incorrect. Only a relatively small part of the weight is special armor, as the steel construction, ammunition, gun and internal components are quite heavy. For example the weight of non-armor (neither steel structure nor composite armor) of a Leopard 2A4 turret is more than 6.5 metric tons. The T-14 Armata's turret is likely heavier than 10 metric tons (as it features a heavier gun than the old Rh 120 L44, has a basic steel structure, roof armor and ERA, an APS, a RWS, etc.).

 

On 1/2/2019 at 12:43 PM, Collimatrix said:

  So, a perforated array made out of, say, depleted uranium might work against APFSDS where steel would fail.  I have suspected in the past that this might be what the "DU mesh" in the Abrams' turret is, but @SH_MM has stated that he thinks a DU-based NERA array is more likely.  In any case, the design of the DU arrays in the armor have changed from model to model.

 

 

The main problem I have with perforated DU armor plates in the Abrams is that there is no source suggesting anything like that. All speculation regarding such a design seems to be related to a statement regarding a "DU mesh" on Wikipedia - it was never provided with a reference to a source and hence removed quite a while ago; yet it seems to still hang around in the minds and memories of lots of people.

 

Using DU as material for a NERA array was at least scientifically tested by the UK. It is the only known case of a DU armor array being tested (while Sweden did also test DU, we have no idea about what the specific armor arrays looked like).

 

On 1/2/2019 at 4:16 PM, Lord_James said:

Building on this tangent: would a perforated DU equipped SLERA perform better against APDSFS than DU equipped NERA/NxRA? 

 

SLERA is trading some multi-hit capability for a higher overall performance; so to answer your question: the theoretical DU SLERA would outperform the other types, but would withstand less consecutive hits in the same area.

BBleAeo.jpg

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On 1/3/2019 at 12:44 PM, Renegade334 said:

P.S. By the way, was the side armor of the Merkava 4 turret officially categorized as SLERA or pure ERA?

The only official info on the Merkava 4's armor is that it uses a "continuous (i.e high coverage) semi-reactive armor".

Rafael (who are among the producers of armor for the Merkava) are also strong believers in NxRA, deeming it optimal in a compromise between survivability of the armor module and its per-hit efficiency.

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@SH_MM i did state quite a few reasons for why its likely that the russians kept the bulging plates, both historical and practical ones. After that reasoning the next logical step was to try tests if said array would provide enough protection, if the estimates were to be too low, then that would have discarded my hipothesis. But not only in the LOS estimate the T-90A array fits almost too well but in the actual effectiveness estimation, the lowest possible result is high enough against currently fielded and near future threat weapons. On the other hand, the highest result kind of adds up to the claims made at the media ("900mm RHA"), and also i did clarify that the result could be even higher (than around 836-874mm) because of a number of variables that could not be taken into account with the calculation method that i used (meaning, the likely increased effectiveness of the NERA-bulging plates section of the array because of the higher number of sandwiches that could be fitted at an optimal angle and/or slight and small improvements in metallurgy and materials used).

 

As for the calculation method, there are 2 possible criticisms: the first one aimed at the method itselfs in which case any kind of "napkin mathematics" should not be aimed at myself but rather at the author of the article at tankograd. The second criticism which can be directed at myself would not be against the calculation method but its actual implementation, meaning that i screw up the numbers which i already admitted that is always possible, but the follow up to that criticism should be to remake the calculation.

After arguing for the feasibility of the bulging plates array being used, my conclusion is to ratify my hypothesis given the track record of the russians on using the same designs and methods until their potential is fully exhausted. Caution:  im not saying that the russians can´t or haven´t designed new armor packages in over 3 decades since the dissolution of USSR, its certain that they did BUT the reasons to keep using the bulging plates outweight the ones for fielding newer, better and more expensive packages.

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