Flexible armor with spacecraft

[the-red-scare]

Suppose I have a civilian spacecraft that uses a 6” layer of UHMWPE as radiation shielding. (I am unconcerned with expense or practicality for this example). Per “Cutting Edge Armor Design” in Pyramid this is ballistic polymer or maybe improved ballistic polymer. Let’s say it’s the former, and therefore has DR 288 against piercing attacks and 115 against others. Cool.

1. What if we come under fire by a Spaceships design? Kinetic weapons in Spaceships don’t have a damage type, but one would assume at least the smaller calibers are doing piercing damage. I know above a certain relative velocity (that nobody can really pin down) kinetics might better be modeled as explosive damage. Bottom line: should flexible armor get full DR vs. Spaceships-level guns or missiles, and does either relative velocity or proximity detonation change that?

2. The rules were designed basically for people wearing flexible armor. Vehicles might have far more than is practical for people and the rules may not apply. Is there a thickness at which the piercing / other distinction becomes meaningless? Where is the cutoff if any?

I’m actually planning to use some of these armors in a kind of homebrew Transhumance Space situation using modifications to the THS spacecraft design rules and the Spaceships combat rules, but I want to figure out how they work first.

[Varyon]

1) Kinetic weapons in Spaceships deal crushing damage.

2) I’m unaware if there’s a point where things get thick enough for there to no longer be a distinction, but I doubt it (and if it occurs, I’d honestly expect for it to be a loss of the bonus against cutting/piercing rather than loss of the malus against everything else). You don’t see tanks covered in Kevlar or similar, after all (you do see it as part of composite armor, but that’s the metallic laminate from SS1).

[the-red-scare]

Re: 1. I’m unable to find a reference for Spaceships kinetics dealing crushing damage. It certainly seems weird that a 2cm gun is crushing dmg when a real 20mm gun is pi++. I was under the impression that damage type for guns was just ignored since it isn’t really relevant to the Spaceships rules as is, but it is relevant to my particular interest.

[Rupert]

I would assume that kinetic damage from missiles is pi++ (which is x1 injury vs unliving). I'd also assume that flexible armour isn't really a meaningful thing at Spaceships scale.

[the-red-scare]

I don’t expect the armor to actually be flexible at a Spaceships-like scale, just that it’s made of a material that is classified as flexible in the armor tables — Kevlar, bioplas, whatever. At smaller scales though, it could be used for Bigelow or TransHab inflatables, which could be fun.

[Varyon]

Originally Posted by the-red-scare

Re: 1. I’m unable to find a reference for Spaceships kinetics dealing crushing damage. It certainly seems weird that a 2cm gun is crushing dmg when a real 20mm gun is pi++. I was under the impression that damage type for guns was just ignored since it isn’t really relevant to the Spaceships rules as is, but it is relevant to my particular interest.

Hmmm... you're right, I can't find any reference to damage type for them. Also, I could have sworn most of the cannons in LT did crushing damage, but now that I look they're all pi++. Of course, if the projectile's relative velocity is in excess of the speed of sound within the projectile's material, it is going to basically explode on impact, dealing crushing damage (technically, cr ex). For steel, this is around 3 mps; for other materials, it may be higher or lower. Treating everything as crushing for simplicity makes a good deal of sense, although if you want greater resolution, having some cutoff point where it goes from pi++ to cr can be interesting, particularly if you armor your ships with a material that treats those two differently. Something with dDR 100/30 (100 against pi/cut, 30 against everything else) is proof against up to 16cm projectiles at 1 mps (indeed, it's only 5 dDR shy of being proof against 20cm) and 10cm projectiles at 2 mps, but at 3 mps - when damage turns to cr - even 2cm projectiles can get through (only 1.5 points with an average roll, of course).