It's not about light armor, it's about it being a drone. At that point it's not really a tank, just an armored autonomous fighting vehicle. It's like making a BMP completely automated. >Isn't that true of all armour then?
No, armor & its placement is meant to be balanced against mobility & resource viability, that's the reason 3rd generation NATO tanks have fairly low numbers compared to Soviet counterparts, they're far too resource heavy. This is also the reason that starting from mid WW2 & after the main, thickest armor on tanks sat in the frontal 30-45 degrees on the hull front & turret front. Roof, sides & rear are less targeted in direct combat, & no amount of armor is going to protect the top from an aviation bomb (BUT improved upper armor can fight off top-attack HEAT & suicide drones). Point is armor placement reflects the main threats to an AFV & the expected requirements. That's the reason heavy APCs like the Puma are retarded, they're still no match for a tank or ATGM, so uparmoring them for anything past 30mm/155mm airburst is moronic. A tank should be able to take a hit & even a penetration yet keep going as long as the armor manages to protect the key features. You're never going to ensure crew protection at 100% because that's just not possible, placing them all in a capsule isn't removing the problem of the electronics & hydraulics in their place being open for damage & needing protection too, thus up-armoring there occurs, negating the entire point. The point of improving roof armor in current combat is because a slightly thicker roof + ERA is going to be able to help dissipate HEAT warheads even if they penetrate so internal impacts are minimized. That's the reason the Abrams ought to uparmore its bustle, because it is easy to penetrate & even if it leaves the crew alive, the tank is nigh-unarmed & open to consecutive attacks. This happened in the Gulf, a Type 69 (Chinese T-62) penetrated an M1A2 in the bustle, leaving it ammunitionless, if it hadn't been for the constant air support, allied tanks & god's luck that they had one shell in the barrel, that Abrams would have been taken out utterly. Hell this has happened to many Saudi Abrams. >That's still going to involve making the tank taller
Not if you shift the gun mantlet up in the turret, but not the actual turret itself. Essentially the gun is a bit higher in the front of the turret, there's plenty of space left over & turret dimensions aren't even necessary to change much. The height increase is going to be at most 10 centimeters, insignificant in todays combat environment. I'm going to try an Oekaki this if I can. >a track from getting shot off
Ah but a track is an easy field repair, even a single man can jury-rig a fix, unlike internal components. The Engine block being used as armor in the Merkava is because it's armor is trash & the tank is a glorified, heavy IFV, almost no other tank in the world uses this set up for a reason. Getting your engine taken out is a death sentence for any tank not surrounded by friendlies & so condemning the crew too. The reason BMP-1s & 2s had frontal engines (besides the need to let troops come out the back) is the fact that a more thinly armored AFV can afford to be taken out, because unless it has a tank level of armor, the penetration can kill the crew otherwise so you can either bail or die. A tank isn't permitted that.>The internal volume of the tank isn't agnostic towards which dimension you're giving space
True, but in a tank you forget THE HULL. You can lean back, forward, to the side etc. & you must be able to push the hatch up using your head in cases of emergency. The IS-3 also isn't that cramped. The T-72 early versions are a bit cramped (although not by much even compared to the Leo-II) because of the electronics/sights/fire-controls, that sit on the horizontal axis to the sides & front of tanker. Height isn't a big issue, that's just an old wives tale from anti-Soviet Cold Warriors, the same morons that said that T-72 autoloaders rip the arm off the gunner. >Javelin still penetrates hundreds of millimetres of steel
Good thing modern COMPOSITE armor isn't just steel, & can be thinner yet equate to much thicker steel. That's the reason the T-64 was so groundbreaking - the composite armor permitted it to have the protection of a heavy tank, yet far less weight & actual armor thickness. The same can be applied to Roof armor. Moreover the Javelin's penetration is overrated. The overfly HEAT is limited because the 2 modes of attack mean that a tandem charge (necessary against ERA) is impossible to utilize in a large enough calibre to properly hurt the vehicle. Most Javelin kills have been against softer targets. Against tanks using ERA it's notably failed to induce catastrophic penetration (i.e. hitting ammunition or key components. A notable incident from early 2022 had a javelin hit a T-72B3. The attack penetrated but because it lacked the ability to go through, only caused a fire. The tank continued to keep going, still battle-capable. Improving the roof armor a bit already makes it even more survivable against such attacks. >hard-kill active protective systems
Yes that is also true, but those have a risk of harming nearby troops, making it impossible to use on a 360 angle unless they seek to operate alone.
TL;Dr: I'm not saying slap on a ton of armor, but improving its thickness by about half + ERA is going to improve survivability against top-attacks & the increase in height is going to be negligible.