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Comment by greedo | Hacker News Reader

Just because it's classified doesn't mean it's valuable. Lots of stuff is classified for bureaucratic reasons. Also, there's little about the Challenger 2 that opposing forces couldn't have researched. The tank itself has been around for more than 2 decades, and the Soviets/Russians have been consistently able to penetrate British security for the last 70 years.

The gun is nothing special, and it's performance is well known. Chobbham/Dorcester armor has been around for quite awhile, and isn't unique. The US has sold M1s to Egypt, Iraq etc with Chobbham armor.

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Chobham armour is the informal name of a composite armour developed in the 1960s at the British tank research centre on Chobham Common, Surrey. The name has since become the common generic term for composite ceramic vehicle armour. Other names informally given to Chobham armour include "Burlington" and "Dorchester." "Special armour" is a broader informal term referring to any armour arrangement comprising "sandwich" reactive plates, including Chobham armour.

Although the construction details of the Chobham armour remain a secret, it has been described as being composed of ceramic tiles encased within a metal framework and bonded to a backing plate and several elastic layers. Owing to the extreme hardness of the ceramics used, they offer superior resistance against shaped charges such as high explosive anti-tank (HEAT) rounds and they shatter kinetic energy penetrators.

https://en.wikipedia.org/wiki/Chobham_armour

It sounds like it's basically chainmail for tanks.

it sounds like it's basically unlike chainmail in all possible ways!

I believe you were thinking of brigandine.

Actually, there are no ceramics in Chobham armor.

https://below-the-turret-ring.blogspot.com/2016/03/chobham-a...

While an interesting read: it's fairly clearly stated that they believe there were no ceramics in early Chobham armors. And some newer ones might, though probably not most, and that it's not particularly relevant to the effectiveness (i.e. it's an armor structural pattern, ceramic is orthogonal).

So it mostly supports your claim, since Wikipedia is rather focused on the ceramic aspect, but it's in a somewhat different context.

Ceramics and metals can "cross over" so to speak. Structurally distinct, but in the margins can share properties. They have a relationship. So it might pay not to fixate on the words implications. Chobham armour is a composite, and exploits the properties of different materials.

Out of curiosity: suppose a modern tank was (magically) transported to WWII. Would it be essentially invincible against the weapons of that era?

(Addendum: I do appreciate that repeated weapons impacts will degrade any type of armor over time.)

Yes and no.

If the Germans had some well-fortified position only to see a T-72B3 fitted with explosive reactive armor and an active protection system roll in? Yes, in that case, the Germans are toast. In practical terms they would not be able to damage the tank.

It isn't invincible, though. The tracks on any tank are vulnerable and the engine is (relatively) fragile. A lucky HEAT shot or a well-placed anti-tank mine could disable it, though I don't they could score an outright kill.

I suspect they would be invincible for sure. Keep in mind that modern main battle tanks are typically heavier than WW2 tanks, carry guns that are almost twice in diameter (76mm for the late war Sherman's vs 120mm for M1A1/2/3 Abrams) are much faster, have vastly improved electronics and night vision, counter measures, etc.

> 76mm for the late war Sherman's vs 120mm for M1A1/2/3 Abrams

And the Shermans were notoriously undergunned. The Germans had 88mm guns on tanks since 1942 with the Tiger I, and had anti-tank guns up to 126mm (which was even mounted on the Jagdtiger tank destroyers ( of course as everything late war German, in pitiful numbers)).

The Soviet KV-2 had a 152mm howitzer in 1939, and anti-tank guns up to 100mm. The IS-2 had a 122mm gun, and was used since 1944.

Today's main battle tanks are closer to heavy WW2 tanks ( in terms of size, armament, protection, etc.), so compare apples with apples, shall we :p

I am guessing you already know this, given all the information that you have posted, but "caliber parity" alone would not be sufficient to penetrate an Abrams/T-90/Chally/whatever.

Today's 120mm rounds are kinetic-penetrator sabot rounds* (link below if someone really wants the details and naming conventions). The point is that this round is way longer than WWII tank rounds and functions completely differently. None of the tanks you listed would penetrate a modern tank from the front (100%), I would guess they are unlikely to penetrate from any aspect, but I am not ready to provide data proving that. Note that even T-72s are currently being updated specifically to be able to use LONGER rounds, and every developed country has chosen to BYPASS 150+mm cannons in favor of using longer 12x rounds.

We can also get fancy and talk about active protection systems (APS), which would defend against slow WWII rounds as well as they protect against RPGs since the 90s. Though, no one but Israel has really fielded APS in serious numbers since the USSR pioneered the concept.

* https://en.wikipedia.org/wiki/Armour-piercing_fin-stabilized...

The only thing a WW2 era tank could do to an M1 would be a mobility kill. Treads, optics or engine. Eventually the M1 would run out of 120mm rounds, then there becomes a more realistic chance of disabling it.

No---an effective anti-tank weapon is a ditch: https://en.wikipedia.org/wiki/Anti-tank_trench

You might need to make a bigger one for a modern tank than a WWII tank, but the tools to make big holes have been around for a while.

You'd need an awful lot of ditches, since tanks have high mobility. And were actually designed to counter trench warfare tactics.

MBTs have standardized dimensions.

Trenches have flexible dimensions.

You show me an MBT, and I'll design a ditch it can't cross.

(Which is the entire point of combat engineers. But as you point out, given the speed of modern MBTs, it's easier to flank static anti-tank defenses like ditches)

The role of combat engineers isn't to stop tanks, but to funnel tanks and AFVs into kill zones. Since WW2 era gear can't really kill a tank, it's pointless. The best a CE could do would hope for a mine to damage a track.

Turn it the other way around.

The role of modern combat engineers is to get MBTs (and infantry) through obstacles.

A ditch isn't very effective if the far side is dynamited into a slope.

Potato Potahto. Sure on offense engineers are tasked with clearing obstacles, that's a given. On defense, the role is reversed.

https://www.youtube.com/watch?v=WNmLFTSq-TE

I guess you'd have to dig quite a deep trench for modern tanks.

Not WWII, but how about tanks, helicopters versus Samurais? https://www.youtube.com/watch?v=An3t39SGSUE

No, a modern main battle tank would still be vulnerable to arty, a leg with a grenade, poor crew decisions, etc. depending on a favorable setup (no adversary air or arty, able keep distance from dismounts) it would dominate for a couple hours and then laws of logistics take over.

Your question reminds me of Rome Sweet Rome: https://www.reddit.com/r/RomeSweetRome/

It started out as someone on AskReddit asking how modern military would fare against ancient Roman military. The full story is on the right side of that sub-reddit under the section FAQ as a PDF, or here's the first section: https://www.reddit.com/r/AskReddit/comments/k067x/could_i_de...

A lot of people are still (after 9 years) waiting for the studio who acquired the rights to actually make a movie or a series based on the story (which Prufrock451 sold, good for him/her!). I for one hope Netflix/HBO/Amazon picks it up and makes a series out of it someday.

If you mean in tank-to-tank combat, then yes. Specifically, when deployed at night (thermals) on flats (firing out of enemy detection range) - it would be able to make its kills and retreat faster than it can be chased.

In direct combat, nothing short of a direct artillery hit (unlikely) could kill it or render it unable to defend itself in the short term. Let's say it got ambushed by 3 AT teams within 50 meters - the AT RPGs / recoil-less rifles of the time could do nothing to the armor, even rear.

In reality, any super-weapon, and its supply chain would be hit with massed artillery, bombing runs, and special forces.

It also has vulnerable optics and tracks as was mentioned earlier.

Furthermore, even if it took out 40 tanks (each round is a kill), it would not be significant in a major WWII engagement.

Btw, this topic has been discussed ad-nauseum elsewhere.

It wouldn’t last long without modern logistics to supply ammunition, spare parts, fuel etc. Very few people in modern armies actually do any fighting. The vast majority is logistics/support.

FWIW, the armor on the export M1 is different than the US version.

Yes, but all M1s have Chobbham/Dorcester armor. Some additionally have DU (Depleted Uranium) inserts. The DU inserts are generally limited to US Army M1s.

Export M1's do not have Chobham armor.

Do you have a source for this? My understanding was that DU armor was the only difference in armor on export versions (Kuwait, SA, Egypt).

Chobham armor is just an informal/generic name for composite armor. The actual designs vary from tank to tank and are highly classified. There's no singular style of 'Chobham armor'.

I remember growing up watching the "military vehicle shows" on the Discovery channel when they just output all the various specs of every vehicle.

I think a lot of the general operating specs and such are pretty well known.

Up to a point I recall some one who worked for RAE and was on Salisbury plain and their land rover was over taken at speed by a MBT (well over the listed spec BTW)

Tbf, anything can overtake those garage decorations.

I was a huge fan of these sorts of shows as well! Having talked with folks who had full access to the specs however, my understanding is that there are specs and there are specs. Basically the specs that give advantage or could be exploited as weaknesses on the battlefield were classified whereas the kind of stuff you could deduce just by watching one operate in the field was not. So for example, seeing how far a tank could shoot by watching one compete, not classified. But 'how many' shootable things and 'what kind' it carries might be classified.

There's also things like published max speeds, and then full military power speeds that are more closely held.

More likely, that operating it at the official full speed causes irreparable damage within an hour, and it's traditional for everyone to piss on the radiator to help cool it down.

How maintainable they are in the field and whether the Army has enough trained mechanics are more important than sexy specs like muzzle velocity and max speed.

Right, but when bullets are flying and it's time to high tail it out of Dodge, then pissing on the radiator doesn't seem such a high price.

Just because it isn’t valuable doesn’t mean it is legally allowed to be released.

I think this is understood. The issue is that these bureaucratic legalese nonsense needs to go.

This community well understands how individually innocuous details can be aggregated to produce very important insights. The governments and intelligence agencies of the world know this too.

Perhaps one could learn of a manufacturing deficiency / lack of understanding by getting enough details about enough vehicles the UK uses. Etc etc.

Just because its illegal doesn't mean that there was any harm done.

That is a bit more complex issue.

Well if the guy was a commander he should be smart enough not to share/discuss such things in gamer forums.

While yes technology on its own could be mostly understood by people you still expect commander even if not officer to keep his mouth shut.

Person did harm to himself while maybe not to the army. Just for being silly and not careful while you are being in the army there should be prosecution.

Now compare it with how much work goes into telling people that they should not click links in suspicious emails...

People still click those links, companies get ransomed.

At some point it is not "ALL FUN AND GAMES" but "WE ARE RESPONSIBLE ADULTS" - well no one died but I would not like to work with that guy on serious things.

Commanding a tank is a serious thing not "well no harm done, corporate bs".

"Customer" Tanks don't get all the sweet latest tech that the host country has.

an Iraqi T72 wasn't the same as the WP ones for example.

It doesn't matter if a technical person looking at it thinks it isn't valuable. If it has any marking other than "Approved for public release", the book will be thrown at someone intentionally releasing it - and rightly so.

If the MOD says it is classified, this person likely just ended their career and might go to jail. For a tank game's accuracy.

I mean sometimes people make bad choices, but Jesus, what a mistake.

Seems like this is only news for two reasons: 1. tanks are interesting. 2. people get excited about cancelling strangers on the internet over whatever loose pretext they can.

How else can you explain this profoundly mundane story ending up on the front page of a tech news site? What's next, we going to start chiming in on soldiers who don't renew their military IDs in time? Y'all are acting like he leaked plans for the Army's top-secret death ray, or a bunch of videos of helicopters killing civilians, not a boring piece of paper work nobody in the military cared about enough to declassify after decades of service.

Many people on this website work with governments. National security topics intersect with technology often: Snowden, Reality Winner, the OPM hack, SolarWinds, really anything involving the NSA. There's hardly a day we don't read about some state-backed threat actor.

Does it not seem reasonable, then, that a violation of fundamental classification policy catches interest?

The impact of the leak shouldn't be measured in the material revelations that might be in those documents, especially should they be so underwhelming as many seem to think. Rather, the impact is that a person of rank chose to execute such a violation for such an overwhelmingly trivial reason. Imagine, if you can, the impact that act might have on morale within that military, and on the capacity for the social pressures within that organization to maintain adherence in the future.

I don’t know what is news and what isn’t. But I know why I find it interesting.

There is a very human element in it. I can totally imagine what goes on in the leakers head: He really knows that tank. He worked with it since forever. And the game developers are wrong. They got some detail wrong. And not just any detail, but an important… no, not just important but a crucial detail! He can tell them, but they wont believe him. Why would they? He could be anybody. So he puts his credentials in his forum profile. But the developers might still be ignoring him. This might happen for a myriad reasons, but he decides it is because they don’t believe him still. Those fools! How could he show them? Ah, he will just upload this manual, that should prove he is right and the developers will be forced to accept defeat!

Super silly, but you can just see how one can walk themselves into this situation.

One can also imagine it from the developers side. They are probably at least a little bit interested in tanks and weaponry. At least some of them. It is possible that they even have aspirations to make a very realistic tank simulator. Some obnoxious loudmouth user drops a leak on them. Publicly! They can’t use this info now or their game might get banned for “national security” reasons. They can’t even let it be ambigous if they have used it or not. If they get banned in the west their business might as well shut down the next day. They have to distance themselves publicly and dramatically. ( Now of course this might not be how it went down. I can imagine many variants. But it is a sticky situation none-the-less.)

The third interesting bit here is the question of what makes a good game. Is a change which makes the tank simulator more realistic also always makes it more fun? Are there also game ballance considerations? Or maybe some detail would barelly change the player experience but would require a complete rewrite of their simulation engine. Is it worth implementing still?

These are the perspectives and questions which made this article interesting to me. I don’t even know what “canceling strangers” would even mean in this situation.

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