Okay, since there haven't been any replies for a few days, as I understand the rules, "bumping" is fine now. Especially since I have more to contribute than just a "bumping" post by itself. ;)
First of all, thanks to @DaveC426913 for recommending "Braking Day" to me. I'm about a tenth into the book so far, and as I've expected, I could care less about the story and characters (even though this is almost a five-star-rated book). But we're mainly here for the setting anyway.
So let's do a quick comparison of the Archimedes and the Exodus:
| my ship (SFV Exodus) | ship from "Braking Day" (Archimedes) |
| overall length | 3 km | >20 km |
| number of rings | 6 | 8 |
| shielding | sphere shape | disk shape |
| number of decks per ring | 5 (3 on the public ring) | >30 |
| central section diameter | 100 m | 200 m |
| width of ring hubs | 64 m | 625 m (5,000 m : 8 rings) |
| gravity in the ring hubs | 0.2 g (since the hubs have 1/5 of the diameter of the rings, which create 1 g) | none |
| population | 500 - 1,500 | >30,000 |
A few other noteworthy things:
1) The Archimedes is described to have windows. I deliberately removed any windows from my ship, replacing them with digital screens instead that only pretend to be windows to people on the insight. The reason of course being that people could get bombarded by radiation through those windows.
I'm not sure if having the shield / spheres on both ends would be enough to prevent that now, so that windows would be okay again. But as
@DaveC426913 said,
you must not see any starlight through them. So what would you look at? The other ring in front of or behind your own?
The upside of having a screen act like a window is that such a
screen could simulate things like sunrise and sunset, too.
2) Like on the Exodus, the Archimedes has the lifts in the spokes, four of them, and the entrance to those lifts are through their ceilings, through the holes in the hubs. So it seems like my design idea was pretty much spot-on in this regard. ;)
In addition to the regular lifts, though, the Archimedes is also described to have
paternosters (constantly rotating lifts in which you can enter at any time; I know these from one particular building in Cologne). That sounds like a nice idea; though I would leave this as a specific feature of the Archimedes, rather than "stealing" it for my own design.
3) The four-elevator construction, one in each spoke, seems to make intuitive sense. However, while a cylinder with a 100 m diameter (the ring hub) only has a circumference of 314 m, so the way from one elevator to the next isn't that long: For somebody down on the ring, which has a circumference of around 1,600 m, the distance between two elevator shafts is about 400 m (=one lap around a standard sports court with a race track). That seems quite long, especially if you have to get somebody from a room into a lift in case of emergency.
Therefore, would two lifts for each of the four sections make more sense? Then they'd only be 200 m apart, i.e. half a sports court. Since the lifts have to be between the section doors, that would divide each section the following way:
section door --> 100 m --> lift 1 --> 200 m --> lift 2 --> 100 m --> section door
The same pattern would repeat in the next section, so that between lift 2 of one section and lift 1 of the next section, there would again be 200 m in total.
Naturally, this would require the rings to have 8 spokes, rather than just 4.4) Also, the central section of the Archimedes is indeed just one big empty room, with the hubs rotating around it - rather than being divided into sub-pipes. That was also my initial design. As epic as that might look, though, it sounds like a
waste of space: How much use would people have for a pipe of 100 / 200 m, respectively, into which you could fit an entire cathedral upright?
Having sub-corridors in a circular array around the pipe would allow these corridors to be smaller, separate civilians from tech transport etc., you'd have emergency routes for quick transport to the medical bay etc.
Heck, you could even have separate sub-corridors for vehicles (most likely, floating ones, not "cars"), without running the risk of colliding with a "pedestrian" floating through the pipe.
5) The claim that the ring hubs on the Archimedes rotate, but don't produce any (!) artificial gravity at all, seems like a comparatively "lazy" handwave on the author's part. Supposedly, they rotate "too slowly to make gravity". But how would the rings rotate faster than the hubs (=more rotations per minute) if they're connected by the spokes? That's precisely the reason why we need the hubs to rotate in the first place, isn't it? ;)
I don't know the ring diameter of the Archimedes "wheels", as they're called. But if they're also twice as large as the rings of the Exodus (given that the central section is twice as wide), with the same number of rotations per minute at 1/5 the diameter,
analogously to the Exodus, those hubs should be creating 0.2 g, shouldn't they? And that's already more gravity than on the moon (0.16 g)! So I wouldn't say that can simply be ignored.
If the Archimedes wheels themselves are only as wide as the rings on the Exodus, meanwhile, but the central section of the Archimedes is twice as wide, we'd be looking at a 500 m diameter for the rings vs. a 200 m diameter of the hubs, again with the same rotation speed.
At that point, the hubs should even be creating 0.4 g with their rotation, which is more than the gravity on Mars (0.36 g).6) The author in Braking Day always uses the words "up" and "down" (sic!) in airquotes. That's why I've introduced the terms "pipeward" and "ringward" for my setting (and, after the input from the people on the last thread, "spinward" / "anti-spinward", too). Solves this "shameful" way of narrating ("I know up and down don't exist in space, but I lack a better term, so just bear with me") and also adds to the worldbuilding on top of that. But I'm glad the author of Braking Day didn't do this - it's just one more way for our settings to stand apart, which is a win-win!
7) The population of the Archimedes is about 30 times as large as the population of the Exodus (30,000 vs. 1,000 to 1,500 at max), while the ship (20 km vs. 3 km) is less than 7 times as long. However, given the number of decks on the Archimedes (over 30 vs. just 5), as well as the assumed diameter of those rings (given that the central section is already 200 m in width), and the larger number of rings, that creates a lot more inhabitable surface. The majority of the Exodus's length is made up by the two 1-km spheres.
Overall that still has me assume that the Archimedes is even less densely populated than the Exodus?8) The Archimedes seems to travel a little more slowly than the Exodus: It's headed for Tau Ceti, which is only 11.9 light years from Earth (whereas Teegarden's star is 12.5 away). Yet, it takes the Archimedes over 132 years to get there, whereas it would only take the Exodus 125.
9) The quarters on the Archimedes all have the ability to turn by 90 degrees, for when the ship accelerates or decelerates at 1 g.
This looks like the most crucial point to me. Is this a feature my design, the Exodus, would reasonably need as well?
I already have my crew being obsessed with tightening any loose obejcts that might float around, bolting down every peace of furniture, students wearing seatbelts in class etc. But since we've established that the ship can't just "slow down suddenly", most likely this isn't actually (what's) needed?
We've also talked about when exactly the rings would dismantle - namely, after the ship has already come to a halt. At that point, they would also stop rotating.
However, Braking Day suggests the rings have to stop rotating for deceleration, and turn everything inside of them by 90 degrees on top of that. I can't just disassemble the ring and turn the entire ring by 90 degrees, since then, some quarters would be facing into other directions than others. Also, this would kind of require me to turn the whole central pipe by 90 degrees, while the ship itself turns by 180.
In short: Do we need this independent, "capsule-like" structure for the individual rooms on the rings?
You would basically be inhabiting a glorified elevator chamber, then, which is "hanging" on some sort of wires all the time, and has a larger, surrounding chamber around it, in which it could turn by 90 degrees.
The quarters on the Exodus have a square surface of 8 x 8 m. That's 64 m² for a couple, which is acceptable, but not much. With a ring circumference of about 1,600 m, this allows for roughly
200 rooms per deck. In reality, it's of course less, because you still have 0.18 m of wall between every two quarters, plus the doors between the sections, where there obviously can't be any rooms.
However, all of this of course assumes a standard ceiling height of 2.4 m (and a ceiling thickness of 0.2 m). If the rooms must rotate, it would make more sense for the rooms to have a cube-like shape.
But in order to maintain just a humble 64 m² of living surface, that would require a 8 m x 8 m x 8 m cube. (Who needs a quarter with a ceiling height of 8 m?
)
)
