Primer: Statistical Armour

https://www.tanknology.co.uk/post/statistical-armour

178 89 4 years ago

tanknology.co.uk

Super helpful and well documented article, thank you!

So why are the Russians using the very specific small and flat turret-mounted type 'Javelin' cages? The article says they're not-designed for that and would be ineffective anyway and of course RPG has no top-attack (unless you're firing from a building, which as we've seen is tricky to get it to arm in time)... so why are they doing it?

Goronmon• 4 years ago

One easy answer is that something being ineffective doesn't mean people won't try it anyways.

blamazon2• 4 years ago

In the /r/NonCredibleDefense subreddit, it's been called the "cope cage" among other similar mocking terms.

https://old.reddit.com/r/NonCredibleDefense/comments/t9i7q2/...

dragontamer7• 4 years ago

You can't stop a Javelin. Its too sophisticated. If a Javelin is launched your tank is dead.

and of course RPG has no top-attack (unless you're firing from a building, which as we've seen is tricky to get it to arm in time)

These tanks were planning to assault Kyiv. The assumption was that cheaper RPGs (such as the AT4) would be used against these tanks. The AT4 isn't designed to be used vs main-battle-tanks (AT4 has penetration of 450mm), the frontal-armor is too thick (500mm to 700mm effective frontal armor, depending on the tank, depending on the angle the attack hits from... Largely due to geometry, not physical thickness). But the "cope-cage" might be strong enough to deflect an attack against the turret (especially if the AT4 is "top down", because it was fired from an urban building).

There's many, many, many weapons of war. There are many different types of "anti-armor" weapons.

The Russians also know that the turret has the critical weakpoint of the tank: the autoloader. If the autoloader is hit, the entire tank's munitions blow up simultaneously (aka: cooks off), and everyone inside the tank dies. Protecting the turret with a "cope cage" (even if ineffective vs Javelins) to try and mitigate damage from other RPGs (AT4, RPG7, Panzerfaust 3) just makes sense.

----------

Javelins are the most expensive man-portable anti-tank weapon. There's relatively few of them (yes, I know USA sent thousands of Javelins, but we also sent far more simpler anti-tank weapons as well). Javelins are $170,000 per shot, and the AT4 is $1500.

The other man-portable weapon discussed, NLAWs, are like $40,000, much cheaper than a Javelin but still an incredibly sophisticated and expensive weapon.

Media ignores the cheap stuff (AT4, RPG7) because they're not really interesting. But those are probably the workhorses and the more common weapon in the battlefield.

chrisseaton5• 4 years ago

I wonder who started calling them 'Javelin cages'?

blamazon2• 4 years ago

Also in use in Ukraine presently are the Stugna-P, a domestically produced antitank weapon [1] as well as the German Panzerfaust 3 [2]. In the footage available online, the infantry are carrying a surprising quantity of all these types of weapons - It's a quirky group of antitank weapons from a bunch of different countries. There are videos circulating in Ukraine on how to use the more foreign systems. [3] [4]

[1] https://en.wikipedia.org/wiki/Skif_(anti-tank_guided_missile...

[2] https://en.wikipedia.org/wiki/Panzerfaust_3

[3] https://www.youtube.com/watch?v=rQThjNgoQRY

[4] https://www.youtube.com/watch?v=LUDrLFrfr_s

PeterisP• 4 years ago

I think that out of all the weapons only the javelin strikes from the top of the tank while flying over it, everything else is a direct fire missile that will hit the tank from the side.

So a 'cage device' on top of the turret seems to be intended solely for Javelins, since every other weapon simply won't strike from that direction.

abra02• 4 years ago

Javelin rockets are $80k-$100k a piece, $170k figure is the launcher and the rocket together. Unlike NLAW the launcher is reusable (and even useful on its own because the targeting unit is detachable and has thermal vision)

xarope• 4 years ago

That's a good point. Just like the best tool to use is the one you have at the time, mobile infantry would be more than likely to have AT4s only. I vaguely remember a section of 9-12 men would carry only two AT4 equivalents, and we were supposed to use both against the same target.

Once the tanks get bogged down, then anti-tank platoons would be deployed with the heavier gear.

frickinLasers• 4 years ago

nitpick--The AT4 is a recoil-less round with the propelling charge in the launch tube--not a Rocket-Propelled Grenade. I imaging firing one from inside a building would be a regrettable decision.

ChuckNorris892• 4 years ago

Those aren't javelin cages, they're called "cope cages"[1], because they're just a psychological coping mechanism for the troops inside, but offer no protection against modern smart munitions like NLAW or Javelin.

They're a relic since Russia's war in Chechnya where those cages could protect against ancient RPGs fired from buildings in narrow city streets.

[1] https://i.kym-cdn.com/photos/images/original/002/324/004/043...

dragontamer7• 4 years ago

They're a relic since Russia's war in Chechnya where those cages could protect against RPGs fired from buildings in narrow city streets.

USA sent IIRC 3x as many "dumb" RPGs (the AT4) as Javelins, assuming that the Ukrainians would be fighting in narrow city streets.

Turned out that urban warfare didn't really happen much. But... I think everyone's plan was for urban combat, and then everybody turned out to be wrong. On the USA side, not a big deal, we sent the wrong mix of weapons but we're fixing that with lend-lease / additional aid packages.

bee_rider• 4 years ago

Perhaps it is pedantic, but in case someone reads your comment and doesn't click on the image, the name "cope cage" is a meme based around making fun of them. I think these things don't have convenient a real name because they are improvised. "Improvised top attack armor" or something like that is probably what a journalist would call them. And they probably won't get a real name because they apparently they basically suck.

trhway• 4 years ago

They're a relic since Russia's war in Chechnya where those cages could protect against ancient RPGs fired from buildings in narrow city streets.

Actually even in 1945 facing Panzerfausts in European cities Soviet tankists tried to similarly bolt/weld onto the top of the turret the spring metal bed frames. It didn't work well if any. While at the same time it showed the precise position of the tank while in bushes, far in the field/etc. Ukrainians have been joking about those "chicken coops" showing the tank position as another sign of a Russian fail and lack of thinking through in this war.

baud147258• 4 years ago

the same author did another article on that subject, btw: https://www.tanknology.co.uk/post/russian-turret-cages

vpribish• 4 years ago

in urban environments an RPG could definitely be coming down from above.

chrisseaton5• 4 years ago

As I said - it's tricky to get them to arm in time. We've seen that problem in practice in videos from Ukraine.

Decabytes• 4 years ago

It's clear that the writer is very passionate about this topic. I didn't realize that the idea was for the RPG to get stuck in the bar. I always though it was so the explosion was outside of the vehicle. This article doesn't paint a particularly good picture for the armor. Which makes me believe that the person who came up with this got a lot of good money, but the value for the soldiers isn't there.

burnished2• 4 years ago

How did you come to that conclusion?

meatmanek• 4 years ago

Indeed. The author of the article came to the opposite conclusion:

Is bar armour worth it? It depends, but broadly yes, it is cheap, simple, and adds a layer of increased protection against a common and widely proliferated threat that would otherwise be very likely to do significant damage to a vehicle, particularly lighter classes of vehicle like protected patrol and utility vehicles (MRAPs in old money) that are vastly overmatched by the threat.

laichzeit0• 4 years ago

The reality of this myth is actually more significant - detonating the warhead on the bars can be at least as bad as if it had hit the defended vehicle and, in some cases, actually a worse result for the defended vehicle.

Probably from this paragraph. It confused me as well. Throughout the whole article he’s building a case for how bad the armour is, if not worse than no slat armour, then concludes the article with “well broadly, it’s probably still better”.

aidenn0• 4 years ago

I don't know; I get the sense that it was "Someone shoots an RPG-7 at your MRAP; you're definitely screwed. Someone shoots an RPG-7 at your MRAP with bar-armor, you're only maybe screwed"

Seems like "maybe screwed" is a big improvement over "definitely screwed"

LambdaTrain• 4 years ago

Multiplying the saved cost by probability of a defeat (which is ineffective mentioned by writer) does not seem bad considering the grid is low-cost design.

But placing timer/accelerator in RPG as a backup plan for fusing in case the warhead is shortcircuited also seems low-cost. I must be missing something here.

mrguyorama2• 4 years ago

Good luck retrofitting your extra fusing system into thousands and thousands of RPG-7s.

h2odragon• 4 years ago

Says a lot that the folks employed to be inside the tanks are reaching out for enhanced armor however they can.

nomilk2• 4 years ago

Hopefully the effect is becoming obvious - by impacting the statistical armour and detonating at that point, the armour has given the RPG a free c.300+ mm of free standoff extension. The armour just amplified the threat capability by a good 20%, making life worse for you inside that vehicle.

For an APC with ~5cm of armour, pretty much any garden variety shaped charge will penetrate it with ease. If the chance of penetration is already 100% it doesn't matter if the charge is 20% stronger. But having the cage at least gives a small chance of stopping the charge from ever detonating.

Different story with tanks though, where the extra 20% could mean the difference between a badly damaged hull and the complete destruction of both tank and crew.

littlestymaar• 4 years ago

Different story with tanks though, where the extra 20% could mean the difference between a badly damaged hull and the complete destruction of both tank and crew.

This kind of additional armor is usually on the rear, which is much less protected. In fact it wouldn't make sense to put them in front of a piece of armor thick enough to survive and RPG shot by itself. So in practice this extra 20% would never change anything?

picture2• 4 years ago

I'm quite interested about military technology like this, are there any good books or resources HN would recommend to learn more about anything from engineering to tactics?

nomilk2• 4 years ago

Military History Visualised is great: https://www.youtube.com/c/MilitaryHistory/videos

These two playlists by Ryan McBeth (a SWE, former anti-tank infantryman) are very interesting:

Military equipment, tactics and strategy: https://www.youtube.com/watch?v=r2s0Szx-kVs&list=PLt670_P7pO...

40 short Q&A videos about Ukraine : https://www.youtube.com/watch?v=M8mJ7hG9xM8&list=PLt670_P7pO...

openasocket• 4 years ago

In addition to military history visualized (mentioned by another commenter), I recommend:

* The Chieftain: https://www.youtube.com/c/TheChieftainsHatch . He has a series on the development of Armored doctrine for various nations prior to WW2 which is a very interesting dive into what military doctrine is and how it is formed.

* Battle Order https://www.youtube.com/c/BattleOrder covers how troops are organized and divided into squads/platoons/companies/battalions/etc in various countries and at various times.

* If you are interested in World War 2, the World War 2 in real time series on YouTube is also fascinating: https://www.youtube.com/c/WorldWarTwo .

* For getting the perspective of national security experts dealing with current events, I would take a look at https://warontherocks.com , which has a mix of articles and associated podcasts. The war on the rocks podcast has been doing weekly updates on the state of the war in Ukraine with Michael Kofman, director for the Russia Studies Program at CNA. I've found those very informative.

* Arms Control Wonk (https://www.armscontrolwonk.com/ ) the blog and podcast are interesting for looking at the military from the point of view of strategic stability.

* https://acoup.blog/ is run by a professor of military history. He covers a variety of topics; he does several series analyzing the historical realism of video games and movies for example. But he also discusses some of the fundamentals of military theory, and tends to focus a lot on what the popular imagination gets right and wrong about the military and warfare throughout the ages.

* There are think tanks like the RAND corporation, CSIS, and CNA that publish papers on a variety of topics in military theory and policy. With a little effort, a lot of them are fairly readable to the layman

* For the deepest dive, the US Army field manuals are publicly available if you search around. Skimming through them gave me a much better understanding of how an officer goes about planning an attack, preparing a defense, setting up an ambush, etc.

simonebrunozzi2• 4 years ago

Acoup.blog is amazing. I just don't have time to read everything he writes, but highly recommend it.

dragonwriter2• 4 years ago

openasocket has made good suggestions in a sibling comment. I would add that one thing that can be illuminating is works by professionals (whether current or past) recommending new directions; reading about arguments for paths not (or not yet) taken can provide a broader perspective.

(It's been a while since I’ve spent time with this; one which I remember finding interesting was Breaking the Phalanx: A New Design for Land Power in the 21st Century. [0])

[0] https://www.goodreads.com/book/show/1597250.Breaking_the_Pha...

deepspace• 4 years ago

If you are interested in the field, almost everything written by Richard M. Ogorkiewicz will be a worthwhile read. He was THE go-to compiler of military engineering information in the 80s and 90s.

While the technologies he describes are a bit dated, his presentation is very comprehensive. Only problem is that many of his works are out of print.

hemloc_io• 4 years ago

Haven't seen this channel recommended yet, so checkout Perun.

I found him through the youtube algo, used to be a gaming youtuber but seems to have a day job in defense and started talking about the Ukrainian war. Hour long data dense powerpoints about what's going on over there. Easily my favorite source.

https://www.youtube.com/channel/UCC3ehuUksTyQ7bbjGntmx3Q/vid...

donavanm• 4 years ago

If youre interested in the organization and operations aspect, especially of russia and other warsaw pact countries, check out lester grau. I recently read over https://www.armyupress.army.mil/Portals/7/Hot%20Spots/Docume... as a refresher. His translations of USSR after actions in afghanistan were also worthwhile in the past.

sorokod8• 4 years ago

Given the apparent vulnerability of MBTs (main battle tanks) as demonstrated in Ukraine to cheap-ish weapons, is this the end of the road for MBTs?

ceeplusplus• 4 years ago

I'm guessing we're going to see more active protection [1] that tries to detonate incoming projectiles at a distance to nullify the effectiveness of shaped charges.

[1] https://www.youtube.com/watch?v=iKeuVHKc92U

picture2• 4 years ago

Good lord.. While I know about existence of APS especially on Merkava tanks, this video really shows how modern warfare can brush right up against science fiction.

We're able to detect an incoming round and automatically kill it with a directed explosion, all faster than you can blink. What, are we going to see munitions that has submunitions of its own to counter the countermeasure next? (That might be a reasonable development actually)

Either way I'm fortunate that these things aren't used around me, and I'm not in any danger. I would love to one day see those C-beams glitter, as a spectator in safety

cwmma3• 4 years ago

Not really, everybody has known that tanks on their own, unsupported by infantry are incredibly vulnerable to anti-tank missiles since, at least the Yom Kippur War (50 years ago) probably longer. The Russians for various reasons didn't and the results were predictable. So no MBTs aren't obsolete they just are very easy to break if you use them wrong.

Also there are newer active protection systems that can defeat missiles like the ones being used, the Russian tanks in the invasion either don't have them or don't have the ones that can detect threats from above.

sorokod8• 4 years ago

Actually Yom Kippur war went well for Israel's armour in the north (Golan Heights), the largest tank battle ever if memory serves.

Can you reference the relevant active protection systems?

ranger207• 4 years ago

Well, what would an MBT be replaced with? You'll still need a vehicle carrying heavy weapons to take out bunkers, enemy vehicles, etc. Maybe you can have an ATGM carrier with a bunch of missiles. But missiles are expensive, so maybe if you fit a specialized fire control system to a gun you can get the same accuracy as a missile but cheaper. That's going to be heavy, so you'll probably want tracks to spread the weight[0]. Then you'll want to protect your big and heavy vehicle too so it can't be killed by say someone with a common RPG-7. And now what do you have? A tank.

Certainly things are going to change in the future. Active protection systems (APSs) are going to be basically required, and I wouldn't be surprised if APSs became the main armor. After WWII the effectiveness of HEAT made designers believe armor was ineffective, so many post-war designs sacrificed armor for speed, such as the Leopard 1, so something similar could happen again.

But an important part of the equation is tactics. A very similar question to "why do we still need MBTs" is "why do we still need infantry" and the answer is the same: they synergise[1]. Infantry need tanks to blow up hard points, and tanks need infantry to keep an eye on the surroundings, suppress and occupy potential firing points, take buildings to prevent them from being used to fire ATGMs and to use to look out for enemy ATGMs, etc. Infantry itself doesn't do anything to reduce the threat of missiles, but infantry-tank coordination tactics do.

[0] For example, the Stryker MGS is a wheeled vehicle carrying a gun. It's widely regarded to suck badly, but in principle there's no reason you couldn't have a good wheeled gun carrier.

[1] Also you need infantry to go places tanks can't go and root out defenders, plus actually do the work of holding enemy territory like talking to local leaders, clearing the radio station of hostile DJs, etc

sorokod8• 4 years ago

Well, what would an MBT be replaced with?

Don't know, but that is a different question.

BTW some/many of the MBT in this war are already equipped with active protection systems e.g Shtora ( https://en.wikipedia.org/wiki/Shtora-1 ).

See the T-80 and T-90 sections here: https://www.oryxspioenkop.com/2022/02/attack-on-europe-docum...

rectang• 4 years ago

Well, what would an MBT be replaced with?

For taking out hard targets: precision artillery firing guided munitions from further behind the front lines, with minimal armor but protected by APS, and highly mobile to shoot and scoot?

YeGoblynQueenne• 4 years ago

> Well, what would an MBT be replaced with?

Powered armour?

mcguire• 4 years ago

Tanks have always been vulnerable to cheaper weapons, whether that's an anti-tank gun hidden in rubble or a NLAW. This is why tanks require infantry support---to locate and deal with those threats while the tanks deal with things the infantry cannot.

Many of the videos from Ukraine have been ambushes (sort of a separate matter) or of AFVs operating without close infantry support. That's not a good way to do things.

sorokod8• 4 years ago

Is your assumption that the Russians do not know that "tanks require infantry support" or just ignore this fact?

dogma11383• 4 years ago

No.

Both the US and Germany bought Trophy, the Dutch bought Iron Fist (another Israeli APS), a few other NATO members are evaluating Trophy and also working on their own APS.

So MBTs are going no where, APS would become more common and more important and the doctrine of now not having your tanks alone without infantry and ISR proving support would be even more solidified.

sorokod8• 4 years ago

I suppose that by APS you mean hard-kill systems such as Iron Fist and Trophy. As far as I know they are not effective against "top attacks".

nosianu• 4 years ago

I thanked my good star that when I was drafted into the German army (1991, freshly reunified) I got to be a Leopard 1A5 electronicd and weapons systems mechanic (EloWaMech), instead of having to fight in one.

Closer on topic, that tank had an additional no-holes layer of armor in front of the actual armored turret mostly on the two sides, and in the back with much more distance. Here is a model that nevertheless shows it pretty well:

https://www.super-hobby.at/zdjecia/0/7/3/35478_rev03320-4.jp...

If "detonate at a distance" does not work I wonder what the function of that kind of add-on armor was, on the sides specifically?

It should have worked fine against RPG from the back because as you can see it extended quite a bit there, creating external storage space and probably providing ample room that an RPG detonating there would not have done anything to the main unit. But on the sides it was just a few centimeters of space between the additional armor layer and the main armor.

I do remember it was really good steel. We had to replace one of those armor plates, and the new ones had the holes slightly different than the tank we were working on. Getting a new hole drilled into the armor plate proved to be impossible with the drilling tools we had.

mrguyorama2• 4 years ago

If "detonate at a distance" does not work I wonder what the function of that kind of add-on armor was, on the sides specifically?

It depends on the shell/threat you expect to come at you. I don't know if "capped" armor piercing shells were still a concept when those tanks were built. In that case, an initial, small amount of spaced armor is designed to "decap" the shell, because the shell under the cap has significantly less armor penetrating capability.

nonrandomstring• 4 years ago

Well written. Sad how misunderstanding the function of cage armour makes the AT warheads more effective. Who'd want to be in a tank? An armour guy told me they call them "iron coffins". A bit off-topic, but wrt statistical defences and tanks - I read an old Home Guard manual about how to stop a tank column using dinner plates. You need a few anti-tank mines too, which look similar. One of every 200 dinner plates covered with dirt is an actual AT mine. Infantry sweepers have to check each one. Another in every 200 dinner plates is booby trapped with an AP device. Infantry want to check each one really slowly and carefully.

jacobn• 4 years ago

I'm wondering why tank armor is (appears to be) basically flat, when the AT warheads appear to be based on creating that super-heated jet, optimized for striking a flat surface?

Why not stack a few layers of corrugated steel/ceramic plates to try to split the jet apart?

Basic theory would be to present the projectile with a surface that has drastically different amounts of resistance across the front of the projectile, in the hope of destabilizing it & the jet it creates.

I guess it would make the armor quite thick, but with varying density/composition it may not end up that much heavier?

(And maybe it just wouldn't work ;)

jiggawatts• 4 years ago

You basically invented composite armour, which is a thing already, and actually somewhat outdated.

The problem is that at such high velocities, during the impact everything acts like a fluid. Tensile strength and shape is almost irrelevant. You can think of the atoms in the armour not as a solid but as individual particles just hanging in space. Their mass — and hence inertia — is more important than anything else!

Modern armour design is about trying to have moving components that present “fresh” volume/mass to increase the effective thickness. Either via rubber layers that can distort, moving steel plates, or explosive reactive armour that do the same thing but faster.

chipsa4• 4 years ago

Not super heated jet. It's still roughly room temperature. It's being moved fast enough that it acts like a fluid more than a solid.

Terry_Roll• 4 years ago

Its a metal version of cricket nets!

gfd• 4 years ago

Statistical armour is exclusively for defeat of shaped charge munitions using a double-skinned nose as conductive path for a piezoelectric-based fuzing system.

Is there a reason for this to be a common design for RPGs? If it turns out everyone is using statistical armor, shouldn't RPG designers "catch up" by redesigning them to trigger when any part of the tip is collapsed, instead of just the tip, thus defeating this entire category of defense?

chipsa4• 4 years ago

A piezo based fuse in the nose is an easy way to construct the fuse. It's also easy to construct a safety for it: stick a cap to protect the piezo from getting hit.

That said, the safety cap doesn't help if you accidentally trip and fall after taking the cap off. Most western single use AT designs use a different safety that deactivates on firing.

greedo3• 4 years ago

The thing that is really dooming Russian armor in Ukraine isn't really the ATGMs and RPGs being deployed, it's the complete lack of functional thermal gear. Other than IR spotlights on most of the tanks I've seen, they're lacking in the high quality thermal sights found on most Western tanks and IFVs. If they use the IR spotlight, it's like shining a flashlight in a dark room. Everyone knows exactly where you are...

This means two things. First the UA owns the night to a large extent. This gives their SOF and TDF troops the ability to hunt the Russian vehicles at night and survive the encounters. It also helps them during the daytime as well; thermal sites are very handy in low light conditions. A hot tank engine stands out a long ways to a thermal site.

Even the Javelin CLU used by the UA has incredible thermal sites. This give troops armed with it much better situational awareness. I believe the NLAW has a good thermal sight as well, but it's disposable.

simonebrunozzi2• 4 years ago

I'm sure yours is a great comment, but too many acronyms for an average reader to be able to follow.

stickfigure• 4 years ago

Not sure if I'm an average HN reader or not:

* ATGM - anti tank guided missile

* RPG - rocket propelled grenade

* IR - infrared

* IFV - infantry fighting vehicle

* UA - Ukranian army

* SOF - special operations forces

* TDF - territorial defense forces

* CLU - (I did have to look this up, though I understood it from context) command launch unit ie the screen+trigger

* NLAW - next generation anti tank weapon

Primer: Statistical Armour

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