In Gurps, how powerful do you need to fight a tank?

[Bathawk]

It's a slightly complicated question, first of all, to define "fight"...afterall, you don't need to be able to toss a Tank into the sun to "Turtle" it...or use insubstantiality to phase in, drop off some explosives and phase out.

I'm curious though in the "comic book" version of of defeating a tank...bending cannon barrels, tearing turrets off, taking a hit from the main gun and then wrecking it with a single punch or blast of laser vision

And I'm curious about how wide the gap would be between say a modern Abrams tank vs. say the 50 year old T series that Russia is using in the Ukraine

[whswhs]

In my version of GURPS Supers, I had a vignette of the Soviet superhero Stalina fighting German tanks during the Great Patriotic War, and an analysis of how her various abilities applied to the effort. I didn't provide a complete build of Stalina, but there are figures for her strength, aerial move, and damage reduction.

[Anthony]

If you want to just slug it out with a tank, going through frontal armor and absorbing hits from the main gun, requires being able to punch through 1500 DR and then rip through around 200 hit points. It also requires being able to take a hit that's on the order of 6d*30(3) piercing. This is solidly C-scale.

If you're willing to dodge the main gun and go after weak points, it's a lot easier -- you want damage in the hundreds, which is D-scale.

I-scale characters might be able to kill a tank, but they'll need to be creative.

[Bathawk]

Originally Posted by Anthony

If you want to just slug it out with a tank, going through frontal armor and absorbing hits from the main gun, requires being able to punch through 1500 DR and then rip through around 200 hit points. It also requires being able to take a hit that's on the order of 6d*30(3) piercing. This is solidly C-scale.

If you're willing to dodge the main gun and go after weak points, it's a lot easier -- you want damage in the hundreds, which is D-scale.

I-scale characters might be able to kill a tank, but they'll need to be creative.

Not a big fan of "different scales"..."Heroes Forever" tried something similar, and it just felt off. Kind of like Batman and Super-Man being able to stand in the same room.

Not too worried about "taking the hit" 1/1000 damage reduction with a -10% modifier is "only" 405 points, and not sure how easy a tank cannon can track a man sized target

[Ulzgoroth]

Originally Posted by Bathawk

Not a big fan of "different scales"..."Heroes Forever" tried something similar, and it just felt off. Kind of like Batman and Super-Man being able to stand in the same room.

Not too worried about "taking the hit" 1/1000 damage reduction with a -10% modifier is "only" 405 points, and not sure how easy a tank cannon can track a man sized target

GURPS doesn't have different scales with different rules really, it just has them as a descriptive tool that some find useful.

[Ulzgoroth]

Bending cannon barrels: IDK, bend bars isn't a rule I've ever looked hard at.

Tearing turrets off: I think you just need enough strength to lift the turret? The main thing holding them down is gravity.

Taking a hit from the main gun: You can find T-72 gun stats in HT.

Wrecking it with a single punch: You can find DR/HP/HT there too. Realistically it's hard to say how you could wreck a tank with a punch that isn't targeting a key component, in the same way that putting your fist through a car door panel doesn't really do anything to disable the car. (Unless it's a fly-through punch, in which case sure go ahead and split the thing in half.)

New vs. old: honestly, probably not all that much. The DR would be better, at least against actual anti-tank weapons though only incidentally about unstoppable fists or optic disintegrators, the gun damage might be a bit higher. Abrams are around 50% heavier, so they've got a bit more HP. A lot of the improvements have more to do with sensors and accuracy than raw gun power.

(Incidental note, the original Abrams is almost the same age as the T-72. Both have gone through a lot of modernizations...depending on whether a particular tank got those or not.)

[Varyon]

Originally Posted by Bathawk

bending cannon barrels

A brief bit of online research indicates GURPS Supers has rules for bending bars (and a cannon barrel is basically just a hollow bar), although those aren't really meant to be realistic, just emulate four color supers to a certain extent. That would be a good place to start. The entry about it on the GURPS Wiki indicates it's a contest of the character's ST and the higher of the target's HT or HP. Wikipedia's entry on the Rheinmetall Rh-120 states at least one version of the barrel weighs in at 2,620 lb - the barrel would be considered homogenous, so that's around 110 HP; with ST 110, you have a 50% chance of being able to bend it (if it's just a straight contest; I don't have that particular book to see if there are modifiers in play - or how much of a bend that is, as there's a difference between bending the barrel slightly and turning it into a pretzel).

Originally Posted by Bathawk

tearing turrets off

This depends on how well-attached the turret is, but for simplicity I'd probably treat this as requiring as much Injury as tearing an arm off (if the tank had arms, anyway). But a turret isn't likely to give you much leverage (grabbing the barrel with just bend - and eventually break - it), so I'd probably use Wrench (Limb) but with thr rather than sw damage. The only modern tank in HT is the T-72A, which has 176 HP, so you need 356 HP of Injury to tear off the turret (89 HP to cripple an arm, for twice that to sever it with a cutting attack or 4x that to sever it with a crushing attack). It's up to the GM if the turret's DR protects it here (RAW is that rigid armor protects fully against Wrench (Limb); I'd use the Side value, here) - if so, that's DR 420 to also contend with. Thr that can reliably deal more than 420 damage can eventually tear it off, but to do it all in one go you need to deal 776 HP Injury at once; that calls for about 222d to do somewhat-reliably, which in turn calls for somewhere around ST 2210 if I'm not mistaken. Note that gives a BL just shy of 500 tons, and over 10x what you need to simply lift that T-72A - indeed, you could grab the tank and throw it 5,525 yards (a bit over three miles).

Originally Posted by Bathawk

taking a hit from the main gun and then wrecking it with a single punch or blast of laser vision

Taking a hit calls for high DR (possibly Hardened if the tank uses HEAT or the like) and/or IT:DR - how much depends on the weapon. That T-72A, above, typically deals 6dx7(10) cr ex with HEAT, for average penetration of 1470 DR. Hardened will reduce this, potentially down to 147 DR with Hardened 4 (which negates that (10)) or higher. Wrecking it with a single hit requires you to be able to deal at least twice the target's HP in Injury (and doing it reliably calls for 6xHP in Injury, to get it to -5xHP in one go). If you want the character to be able to do that against the most-armored part of the tank, on a T-72A that's DR 1,375 - but you can reduce the amount of damage needed with an Armor Divisor. Innate Attack 400d burn (Armor Divisor (5) +150%) [5000] would reliably 1-shot that T-72A, for example.

[mlangsdorf]

Originally Posted by Bathawk

I'm curious though in the "comic book" version of of defeating a tank...bending cannon barrels, tearing turrets off, taking a hit from the main gun and then wrecking it with a single punch or blast of laser vision

The DF rules for bending bars can probably be applied to bending a tank gun's turret: it's a quick contest of bender's ST versus bendee's HP + DR. A modern tank gun barrel probably weighs 2,000 to 3,000 lbs for HP 35-46 and barrel walls that are 1-2" thick, for DR 70-280, depending on you assess it.

So on the low end such as a 1960s era T-62, a ST 110 can twist the barrels without much effort. On the upper end for a T-80 or M1 Abrahms, ST 200 should be sufficient but you could make the argument for ST 340.

A flying super can get above a T-72 and go through the weak top armor, needing to penetrate DR 90 and do around 180 HP injury to bring it below 0 HP, at which point it will probably stop working in a few seconds given that it has HP 9. Based on the Ukraine war, T-72s may be Fragile: Flammable and Explosive, in which case a mere 90 points of burning or explosive damage past DR has a 80+% chance of setting it on fire, followed by an ammo explosive and turret high jump. A 6dx7 (2) bu attack, average 147 damage and halving effective DR, would be sufficient.

[Rupert]

Originally Posted by mlangsdorf

A flying super can get above a T-72 and go through the weak top armor, needing to penetrate DR 90 and do around 180 HP injury to bring it below 0 HP, at which point it will probably stop working in a few seconds given that it has HP 9. Based on the Ukraine war, T-72s may be Fragile: Flammable and Explosive, in which case a mere 90 points of burning or explosive damage past DR has a 80+% chance of setting it on fire, followed by an ammo explosive and turret high jump. A 6dx7 (2) bu attack, average 147 damage and halving effective DR, would be sufficient.

That's because of extra ammo being stored all over the place, and would apply to any tank that doesn't store all the ammo in something like the M1's rear turret bustle with its blast-proof doors and blow-out panels. A T-72 series tank with ammo only in the carosel won't be brewing up from anything that hasn't already fried the crew on the way past if it's a top or high side attack.

Also, most of the brew-ups you see aren't instant - they're after the interior has already caught fire, the crew has bailed, and then the ammo has cooked off. The problem here isn't that they're more flammable than other tanks, but that the fire suppression systems often aren't good enough, though in GURPS' terms that can be treated as all part of the initial 'does it catch fire' check. I'd go so far as to say that of the crew of a T-72 series dumped all the non-carosel ammo (so they're only carrying the 22 rounds that the carosel carries), it should lose the 'x' on its health.

Funnily enough 'x' is probably less of a problem for a vehicle than 'c' - Explosive only triggers on critical failuires vs major wounds and instant death fails. Flammable means catching fire on any major wound's HT being failed, with a -3 on the check for burning and explosive attacks or vital hits (cumulative). Vehicles in general are probably Combustible, but with the HP10+ automatic fire being a HT roll (because otherwise it's going to be an automatic thing when using heavy weapons, and combat experience with tanks and ships shows that this is not the case).

[Fred Brackin]

Originally Posted by Rupert

s already caught fire, the crew has bailed, and then the ammo has cooked off. The problem here isn't that they're more flammable than other tanks, but that the fire suppression systems often aren't good enough, ).

They're not good enough because propellant is self-oxidizing. You can't smother it after it catches fire. You have to cool it below ignition temp (for small fires or very large quantities of suppressant only) or put out a more conventional fire that would then ignite the propellant.

The molten metal of a HEAT jet is really problematic. It blasted through the armor because of kinetic energy rather than temperature but it's a great ignition source after penetration.