TL9 Heavy Tank

[Verjigorm]

Originally Posted by Fred Brackin

Why are you skeptical and where did you gain this highly specialized knowledge.

All I know is from searching the internet but that tells me (from here

https://iopscience.iop.org/article/1...0190.11%C2%B0C. )

For five types of nitrocellulose with different nitrogen contents and different qualities, the lowest spontaneous ignition temperature is 188.12°C and the highest spontaneous ignition temperature is 190.11°C.

You know somehow that what's important for nitrocellulose ignition is the size of the molten metal jet rather than its' temperature?

My simple opinion is that flammable things can ignite even from small sparks.

I gained my knowledge largely from reading technical data about these weapon systems over the past few decades and listening to subject matter experts. Compared to what was available when I was in high school(FAS was about the best free source) and what is available now and the ease of which that information can be accessed(for example Nicholas Moran's youtube series and blogs), at this point there's not really much excuse for somebody who wants to talk about these subjects to have atleast a basic understanding of the vehicles and the weapons systems, other than wilful ignorance and obstinacy.

For example, there are cut-away diagrams of the T72 that are widely available these days, and these will show us that the auto loader is located under the turret ring, which requires the jet to traverse approximately a meter of space that is cram packed with equipment and crew. Nick Moran has a video on the autoloader vs manual loader debate, and he explicitly states that the top of the carousel for the t72 has some amount of armor, which may not protect it from a powerful, deeply penetrating hit, but would likely provide some decent protection from incendiary effects.

This then leads to the issue that the 40mm HEDP is rated to penetrate 2 inches of RHA(e) or about 50mm. HEAT effects can have penetration around 150% of their diameter, up to about 700% at the most before the jet begins to disassociate under strain. This is largely based on the geometry of the round, and depends greatly on stand-off: modern HEAT rounds often have very pointed nose caps that increase the stand-off distance to around the optimal and maximum distance of around 6-7x the diameter. A 40mm M433 HEDP round does not really have that sort of stand-off, limiting it's penetration. So the size of the jet *is* extremely important when talking about the penetration of a shaped charge. You can find this information on FAS or Wikipedia, if you were so inclined or interested. This is also based on a 0 degree angle of incidence, which is something really weird to deal with as you're having to figure out the ballistic arc of the round and the slope of the armor being struck, though it's been noted that HEDP fired at M113 would penetrate better at long ranges as the higher angle of the fire would result in hit closer to 0 degree than a shorter, flatter trajectory would have to go through more armor due to slope.

Incidentally, the top armor in the turret ring area is only 20mm thick, but is probably the hardest to hit, as the frikken turret sits on top of it. A 40mm grenade isn't really going to be penetrating that, though it is remotely feasible that a lucky round could impact right in the sweet spot to penetrate that thin armor and ignite rounds in the carousel. However it should be noted that the t72 has had a nearly 50 year service history, involvement in over 40 conflicts, and I am sure thousands have been been destroyed in combat. And I am aware of 2 accounts of a 40mm HEDP being used to catastrophically destroy them, both of which apparently targeted abandoned vehicles with open hatches. So, it appears to be a really, really unlikely event, rather than an almost assured result.

Notably, while the side armor is fairly low, actual t72s from the battle of Grozny in the 1st Chechan war survived multiple RPG impacts to the sides, without reactive armor. Several tanks that were destroyed remained operation for over a quarter of an hour, allowing their crews to both fight back and to eventually escape and survive.

I would suggest that, considering the notable and impressive armor of the t72, that the "jack in the box" secret weakness is quite possibly over played, and indicative of tanks caught in positions where they were subjected to low shots to their hull sides from lethal anti-tank rounds. This suggests bad tactics, rather than a notable vulnerability. Similarly, while the M1 Abrams has a reputation for toughness, improper tactics in Yemen by the Saudis resulted in massive losses compared to in US service, suggesting that the M1 when properly employed in combined arms operations(especially against poorly trained, equipped and motivated sub peer forces) is not as vulnerable as when employed poorly.

As others have noted: the "jack in the box" vulnerability seems to be showing up more often in russian tanks tanks, rather than Ukrainian tanks of the same or similar make. Are Ukrainians employing better tactics, are they using different operational methods that enhance survivability? Quite possibly. But it's also quite possible that there is selective reporting, and Ukrainian tank losses(and losses in general) are downplayed for political reasons. This may also be related to the imminent collapse of the Russian war effort that has been a few days or weeks at most away for over a year.

This isn't really that surprising, as there's plenty of times that one side will report really good kill rates, and later on it will turn out that as few has half of those kills can be independently confirmed after the conflict.

[Fred Brackin]

Originally Posted by Verjigorm

. This suggests bad tactics, rather than a notable vulnerability. t.

I would describe it more as good tactics exploiting a technical vulnerability. If I were designing a TL9 Heavy Tank I would try and avoid technical vulnerabilities. Luck and/or skill could turn those into real vulnerabilities.

Shifting over to aircraft for a different example, designers of 1960s jet aircraft would have scoffed at the possibility of losing such aircraft to rifle fire and yet in Vietnam with what became known as the "golden BB" principle exactly that happened. Hands could be waived over how this wasn't going to be a "real" threat in the future but it's probably good that other persons arranged to change over to a less flammable hydraulic fluid (among other measures of course).

Ignore vulnerabilities that are only "technically" possible in "expert" judgment and you'll find some of those technical possibilities becoming actual.

[Verjigorm]

Originally Posted by Fred Brackin

I would describe it more as good tactics exploiting a technical vulnerability. If I were designing a TL9 Heavy Tank I would try and avoid technical vulnerabilities. Luck and/or skill could turn those into real vulnerabilities.

Shifting over to aircraft for a different example, designers of 1960s jet aircraft would have scoffed at the possibility of losing such aircraft to rifle fire and yet in Vietnam with what became known as the "golden BB" principle exactly that happened. Hands could be waived over how this wasn't going to be a "real" threat in the future but it's probably good that other persons arranged to change over to a less flammable hydraulic fluid (among other measures of course).

Ignore vulnerabilities that are only "technically" possible in "expert" judgment and you'll find some of those technical possibilities becoming actual.

Considering how much high caliber artillery was used in Vietnam by the NVA, I'm leery about the golden BB being an AKM round. In Iraq in 2003, the iraqis published a picture of an iraqi farmer who allegedly shot down an apache(almost intact) with a brno rifle. Considering that the apaches were deliberately ambushed by a brigade level formation with lots of crew served weapons ranging from 7.62s up to 57mm auto cannons, I have my doubts that small arms were the killers, and especially that a farmer with a bolt action was responsible for any kills.

Auto-loaders are absolutely the wave of the future, and using an obsolete design from fifty years ago as an basis for arguing against them is absolute madness. Modern auto loaders can and have addressed many of the survivability concerns, and offer substantial benefits over manual loading. The largest advantage is that by getting rid of a crew member, you can make the turret and hence the tank much smaller, which means thicker armor for a given weight. If survivability is what you're looking for, then thicker armor is the way to go.

All tanks have the same technical vulnerabilities: in order to manage mass, they have to concentrate as much of their armor to one facing as possible, which makes their sides, rears and tops vulnerable. This has been the state of affairs for over a hundred years, because physics is a harsh mistress, and you can't cheat her. Proper employment of a tank requires protecting it from it's vulnerabilities, usually with supporting forces such as infantry, IFVs, SPAGs, SPAA, and, intelligence. If you screw these up, then you're tanks are likely to have a bad day.

[Fred Brackin]

Originally Posted by Verjigorm

Auto-loaders are absolutely the wave of the future, and using an obsolete design from fifty years ago as an basis for arguing against them is absolute madness. .

When did I argue against autoloaders? I said the T-72 is a death-trap and there are plenty of statistics to back that up. So you don't use the T-72's design. Start with one that doesn't have the crew and the ammo sharing quarters. The OP did that. I'm just a little dubious of some of his other choices.

On the other hand, it's hard to forecast anything about future tanks if we exclude all data from 50 year-old designs. There are few designs that aren't fifty years old (or modest upgrades of such designs) and most of the ones that aren't that I've seen are bargain products from second tier powers.

[Rupert]

Originally Posted by Fred Brackin

I would describe it more as good tactics exploiting a technical vulnerability. If I were designing a TL9 Heavy Tank I would try and avoid technical vulnerabilities. Luck and/or skill could turn those into real vulnerabilities.

It's impossible to remove all those vulnerabilities and still have a tank of reasonable weight and cost. Tanks have to carry a great deal of highly volatile fuel and ammunition (and even switching to a gauss weapon of some kind just changes 'chemical ammo' to 'highly energetic batteries and capacitors'), and they also need to be compact, so penetrating hits inevitably have good odds of hitting something flammable and/or explosive. Even if they don't, it's hard for them to not hit something mission critical. The cases where they don't are noteworthy - that's why they end up on youtube (alongside the really spectacular explosions).

[Verjigorm]

Originally Posted by Fred Brackin

When did I argue against autoloaders? I said the T-72 is a death-trap and there are plenty of statistics to back that up. So you don't use the T-72's design. Start with one that doesn't have the crew and the ammo sharing quarters. The OP did that. I'm just a little dubious of some of his other choices.

On the other hand, it's hard to forecast anything about future tanks if we exclude all data from 50 year-old designs. There are few designs that aren't fifty years old (or modest upgrades of such designs) and most of the ones that aren't that I've seen are bargain products from second tier powers.

The t-72 is not really any more of a death trap than any tank designed and fielded in the 70s. And by comparison, at the time, the t72 possessed very good frontal armor and a very good gun with good penetration against western tanks. And modernized t-72s such as the B3M are really pretty good. Which might be why the Ukrainians use any of them they capture. Because used correctly, they're still very effective tanks. This is rather like that old myth about shermans being death traps, compared to the uber-panzer of the unstoppable whermacht. Of course, if you only read the memoirs of an ordnance tank who pretty much only ever saw destroyed shermans, you would get a biased view.

Or the commonly cited idea that steel plates are gonna get you killed as body armor, because of ze spalling. Somehow, taking a bullet fragment to the face that has less KE than a rifle round punching through your chest is "worse".

the T-72(and t-80s and t-90s, and most soviet tanks since ww2) all had conscious design decisions that result in the "death trap" conditions: they're as heavily armed and armored as comparable western tanks, but much lighter. When the M1 came out, it was already outclassed by modernized T-72s in Wpac service, which is why there was almost an immediate improvement program to fix those glaring weaknesses, and the M1 and M1iP were still about 20 tons heavier than the t72.

The Armata series, if it wasn't vaporware(being a broke "super power" is a bummer) certainly seems to be the direction of the future: Put the crew in a separate fighting compartment from the gun itself, make the turret smaller and even more heavily armored, and compartmentalize the tank.

And this all ignores the most poignant fact of any weapons system: it can only be as good as the men and women who operate it, and the doctrine and commanders who order them into combat. A t90 or M1A2 in the hands a badly trained crew, badly maintained, without adequate planning or co-ordination with supporting arms, is a death trap. A t72 with decent upgrades, a good grew and sound leadership and tactics will be a battle winner, within the limits of the platform and it's adversary systems.

[Verjigorm]

Originally Posted by Rupert

It's impossible to remove all those vulnerabilities and still have a tank of reasonable weight and cost. Tanks have to carry a great deal of highly volatile fuel and ammunition (and even switching to a gauss weapon of some kind just changes 'chemical ammo' to 'highly energetic batteries and capacitors'), and they also need to be compact, so penetrating hits inevitably have good odds of hitting something flammable and/or explosive. Even if they don't, it's hard for them to not hit something mission critical. The cases where they don't are noteworthy - that's why they end up on youtube (alongside the really spectacular explosions).

There's a goofy little game called Cross-out, that has a gameplay loop of battling, salvaginging and designing fighting vehi cles, can be really good about teaching how hard it is to make a compact fighting system that doesn't loose large amounts of critical components when damaged. It's not...exactly realistic, but iss a neat little experience in AFV design.

There's only so much you can bend the rules of physics, and the triangle of mobility, protection and firepower is always a balancing act, hoping you made the right choices.

[Nightrider_88]

Originally Posted by Verjigorm

In Iraq in 2003, the iraqis published a picture of an iraqi farmer who allegedly shot down an apache(almost intact) with a brno rifle. Considering that the apaches were deliberately ambushed by a brigade level formation with lots of crew served weapons ranging from 7.62s up to 57mm auto cannons, I have my doubts that small arms were the killers, and especially that a farmer with a bolt action was responsible for any kills.
.

Idk about Apaches, but back in the 80s, at least one Soviet Mi-8 was **** down with a Lee-Enfield. According to official Soviet data, no less.

[Rupert]

Originally Posted by Verjigorm

The t-72 is not really any more of a death trap than any tank designed and fielded in the 70s. And by comparison, at the time, the t72 possessed very good frontal armor and a very good gun with good penetration against western tanks. And modernized t-72s such as the B3M are really pretty good. Which might be why the Ukrainians use any of them they capture. Because used correctly, they're still very effective tanks. This is rather like that old myth about shermans being death traps, compared to the uber-panzer of the unstoppable whermacht. Of course, if you only read the memoirs of an ordnance tank who pretty much only ever saw destroyed shermans, you would get a biased view.

Until the M1 came along the US was using M60s, and they used a hydraulic fluid that was highly flammable, and when an oil line was nicked, it'd spray an aerosol of this stuff into the crew compartment, at which point there was a high chance of everything now being on fire. Compared to that the T-72 isn't any worse, and might be better.

Or the commonly cited idea that steel plates are gonna get you killed as body armor, because of ze spalling. Somehow, taking a bullet fragment to the face that has less KE than a rifle round punching through your chest is "worse".

When it comes to body armour that's one of the reasons why every decent design these days has a backing layer. Steel has an advantage over ceramic for body armour in that near-penetrations don't weaken the whole plate the way they do for ceramics. OTOH, steel has disadvantages, but spalling isn't one of the major ones.

[Rupert]

Originally Posted by Nightrider_88

Idk about Apaches, but back in the 80s, at least one Soviet Mi-8 was **** down with a Lee-Enfield. According to official Soviet data, no less.

A bullet hitting just the right part of even an 'armoured' main rotor hub, or the tail rotor can cause a crash if the helicopter can't land quickly enough. There's only so much protection you can give those components without making the craft too heavy or compromising the function of the component.

The trick is landing that 'just right' hit.