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

[Anaraxes]

Originally Posted by Varyon

Do you know if there's anywhere in the tracks where you could just shove your arm in and get it stuck (and mangled if you're a normal human), akin to the spokes of a tire? If you've got enough DR to tank (heh) a cannon to the chest, the tracks would probably break

There's certainly places to get your arm caught. Here's a picture of some soldiers doing field maintenance on an Abrams.

(The long bar is, I believe, a socket wrench. When they said torque it down, they meant it. This pic gives you an idea of the sort of force that's considered routine maintenance, not damaging the equipment. This one gives you a good look at the inside of the track; looks like these soldiers are replacing a damaged link before wrapping the tread back around the wheels. Not an Abrams, but an M88 Hercules recovery vehicle. The track design is close enough, though.)

But, I meant to point out the row of "teeth" down the middle of the track on the inside that run through slots on the wheels. Suppose Indestructible Man lays his arm between those teeth and lets the track carry his arm between the track and a wheel. The road wheels can move a bit; they have a suspension system. Idler and drive, not so much. It seems to me that this action would stretch the track a bit as the arm goes around between the two tank parts. On the bright side, Indestructible Man doesn't have to exert any force. (He blew all his points on DR, and has only ST 10...) The tank engine is the thing stretching the track. On the down side, that force is going to be spread among many of the track shoes and their pins, so it will be more difficult (for the tank) compared to a focused effort targeting on one pin.

But given that tanks really do manage to break their own tracks, I'd say it's at least possible.

You might also break or bend those teeth on the inside of the track. If enough of those are damaged, the track will likely slide off the wheels as the tank maneuvers. Not quite as cinematic as tearing the turret off or wrapping the gun barrel into a spiral around your arm. But that attack might suit a more stealthy super that's content to sneak around the battlefield disabling enemy vehicles. (This sounds like a job for Mole Man!)

Do we even have rules for damage caused by a heavy weight? Not dropping it on someone, just sitting on them or slowing ramping up -- the goal being to calculate the DR needed for Indestructible Man. Pressure Support 3 makes you "immune to the effects of high pressure". But the pressure rules in Campaigns (B429, B435) are more concerned with breathing and atmospheric pressure than with mechanical damage. Maybe in Vehicles?

The inside teeth would be a very dull, slow chainsaw with a 1500 horsepower engine. Alas, I can't find the dimensions for the center guide tooth. It's a square cross section of about the same size as the track pins. You'd probably wind up bending both bars of a single tooth as the same time, so up to twice as hard as just bending one pin. (That's only +2 more ST with Super-Effort, though, equivalent to 3-6 tons BL. And since an Abrams can haul itself up a 60 degree gradient, the engine does have the ability to exert that much force via the tracks.)

(As long as I'm wandering off point with pictures, this mental image reminds me of the "VB 10000" ship salvage vessel, which was used on a 70,000-ton car carrier ship, the Golden Ray, which capsized off the Georgia coast a while back. It sawed the ship (and its contents) up into sections to be individually hauled away, using a "cutting chain" that wasn't as near as I could tell sharp in any way, but a fairly ordinary-looking chain. The chain was, however, driven by a 17,000+ horsepower engine.)