So, based on the various descriptions in the core and in some supplements, I get the picture that Footfall is a series of large asteroids from a pre-existing asteroid field, all of which have been both hollowed out and added onto with conventional masonry and made into a series of asteroid bases. I also understand that some of these asteroids are securely tethered to each other with massive void-chains.

The only thing is, the practicalities of that construction seems a bit odd. I mean, a bunch of asteroid bases in one place is fair enough, it's easy to imagine, but the tethering thing is a bit odd. How do you tether a bunch of asteroids together without them slamming into each other? And why? After all, they can drift in all different directions, and sooner or later they're going to tug on each other and send one careening off into one direction or another, or just straight yank one of the chains out of it's moorings or something like that.

This is how it's playing out in my mind, at least. Something like a bunch of floating islands held up by chains hung from much more stable structures is pretty cool, but because space is 3-dimensional, the physics of it are weirding me out in trying to picture it.

A few attitude thrusters in key positions should be enough to give the place a basic level of stability. If you're on some piece of rock that no one cares about and isn't threatening pieces of rock anyone cares about, said thrusters may be absent or malfunctioning, however.

AkumaKorgar said:

Consider that the chains may be more complex than many Tech-Priests will admit. Perhaps they maintain the formation by adjusting the tension through various lines across the pieces. Combine this with attitude thrusters and it's possible (at least to the same degree as other WH40K tech) to have a 'variable configuration' that doesn't pull itself apart (or together) while drifting in space.

Sounds a bit like the Magog World-ship from that schlock scifi show Andromeda.

Errant said:

That was the one where Hercules shot aliens with his high tech dildo, right?

Yup, that's the one.

As I remember it, the asteriods/rocks are clustered around a huge statue of the emperor (praise his name). That might imply a shere-like or cylindrical structure chained together. To avoid too many crashes you could put a spin on the structure, thereby creating outward tension.

That would work fine with a cylinder, but a sphere would have "poles" with little tension. Perhaps these parts drift more?

Just some thoughts...

AkumaKorgar said:

You are questioning architecture designs in a universe where gigantic 500-meter tall Titans have a Cathedral for an upper body. Yes, it's impractical. Yes, there is no real world metal we know of that could possibly stand the torsion involved with keeping a bunch of objects with the mass value of Manhattan in place. And yes, it's made possible by the magic of Unobtainium™ metal.

Best not to cogitate too much on it.

Maybe the asteroids do bounce off each other on occasion, just slowly enough that most of the bumps are too small to even be felt.

The way to expand the settlement would be to tether new asteroids (more unobtainium and some extensive bolting and welding) on to the inner asteroids. A bit like an expanding 3D spiders web. Would be hard to navigate with large craft. The outer asteroids would have to be docks/cargo handling.

Likely they are chained together so they can provide a united perimeter for defense in case of attack. That way they don't have to put point-defense guns all the way around every asteroid, just on the sides that face outward from the rest.

Bilateralrope said:

Nothing in space moves slowly.

Bilateralrope said:

Not one - never one - to vie for the position of an omniscient scholar in physics, but (after briefly refurbishing my perfunctory knowledge of Nu-tonz lawz) I assume that in a universe where "F= m*a", a gargantuan Scylla of an asteroid merely brushing another Charybdic giant of an asteroid would mean more than a mere bump: a cosmic clap the worth of a million Nutonz. Yes.

Naturally, one would have to assume that in the 40th millenium the cosmos has not flipped over to Oldtonian physics that are based on the rule of Qhul. No?

Its 40k - 10,000 men on each asteroid strip to the waist, cake themselves in soot and then pull the chains on each asteroid to maintain perfect spacing and distance.

Fitting asteroids with thrusters should be enough to avoid calamity. Until of course someone starts shooting at footfall (and there are a few people who have done so in the cannon) at which point it becomes the universes biggest executive toy, with asteroids smashing into each other and swinging back and worth on chains and all the puny humans squished like goo.

I suppose when I really think about it, the attitude thrusters would be enough. Although really it makes me wonder what the chains are even for.

Perhaps the really large asteroids, the central hubs, like the macrostatue of the Emperor, have the primary attitude thrusters and the smaller ones just have minor attitude thrusters to keep them in place, and the chains are a failsafe to prevent them from drifting off. The chains are probably, like Fortinbras said, made of unobtainium and maybe even reinforced with some kind of Mechanicus device. I guess at the moment I'm picturing a series of smaller asteroids chained to a big one, like spokes around the hub of a wheel, as opposed to a large network of asteroids that are chained together in one long mass or belt.

I was reading just yesterday in Dark Heresy: Blood of Martyrs about how a lot of the biggest Ecclesiarchal cathedrals have architecture which is only possible because of anti-grav generators installed in the soaring heights of the structure.

If the chains were always taut and the entire arrangement was at least semi-rigid the whole thing makes a bit more sense. Think of the chains like a spider's web with the various bits being dew drops suspended in it. The whole thing could spin slowly from a central axis to maintain form. The total mass is so large that even a cruiser ramming into it is unlikely to disrupt things too much except at the point of impact.

HappyDaze said:

Yeah, that's very much how I pictured it as well.