Building Your Stanford Torus Station

[robject]

Ecological Niche: Between small (up to 4 million tons) space stations and O'Neill Cylinders.
Size Range: 1,600 meters and 4,800 meters diameter, plus or minus.
Population Digits: 4 and 5.

Using some quick math, as opposed to perfectly correct math, I come up with this rule of thumb:

Population of a Stanford Torus by "World" Size as Diameter.

"Size" is a diameter code from 1 to 3, where 1.0 = 1600m, 2.0 = 3200m, and 3.0 = 4800m diameter. Fractional values are okay.
Pop approx = "Size"^3 x 20,000 people
[FONT=arial,helvetica]TL = "Size" + 8

[/FONT] Therefore:

Size  TL Pop  Popul    Tons  Diameter Tube R
----  -- --- -------  ------ -------- ------
   1   9   4    20 k    5 mt  1600 m     120
   1   9   4    98 k   20 mt  2720 m     204
   2  10   5   160 k   40 mt  3200 m     240
   3  11   5   540 k  135 mt  4800 m     360
   3  11   5   972 k  240 mt  5840 m     438

Technological and Size Limits

Cirque assumes a TL of 10 and 11. Wikipedia notes that the original proposal can house "up to" 140,000 people. In Traveller terms, that's a Size 3 torus. Above that, other structures are preferable.

I propose that required TL = Size + 8. This allows "Size 0" tori at TL 8 (for the sake of the formula, they'd actually be fractional sizes, but fractions in World Sizes are always ignored).

Rings. Small rings (same diameters/size codes) may be buildable on this TL range. However, they are about 1000x larger in diameter and much wider. Benefits of the Stanford Torus over Rings have not yet been itemized. One in particular is that they can be built from a shipyard; Rings cannot.



Sloppy math follows

Size code equals ring diameter D, so Circumference C = pi x Size x 1600m.
Tube radius is estimated average of ring diameter D x 1.5 / 20, or Size x 120 meters.

Volume is therefore approx Size^3 x 72 million, in cubic meters,
Or Size^3 x 5 million tons.

Assuming 20,000 people per 5 million tons, based on numbers in Cirque, then:
Population = Size^3 x 20,000 people.


Cirque's Assumption

A 2000m diameter torus with a tube diameter of 150m can house 30,000 people.
V = 6280m (Circumference) x 75 x 75 x pi (tube section area) = 111 million m^3, or 8 million tons.
8 million tons for 30,000 people => 5 million tons for 18,750 people.
I round up to 20k because the error due to all of the various unknowns is absorbed.

 

[shaunhilburn]

I propose that required TL = Size + 8. This allows "Size 0" tori at TL 8 (for the sake of the formula, they'd actually be fractional sizes, but fractions in World Sizes are always ignored).

The baseline Stanford Torus from the 1975 NASA/Ames "Summer Study" was conceived and designed to be built using minimal new technologies ca. 1975. All the tech mentioned was already in existence. It would have required a lot of space infrastructure e.g., spacelift, construction "shack", and lunar mining outpost, but nothing that was considered bleeding edge.

When completed, it would be Size 1 in your table and mid-TL 7.

 

[rancke]

The possibility of having TL8 societies in asteroid belts implies the ability to build fairly large space habitats at TL8.

Of course, it's not absolutely required. You can have billions of people housed in 20,000 man habitats. There's room enough for them in an asteroid belt. Still, the size 1 at TL 7 (with correspondingly higher numbers at higher TLs) sounds better to me.


Hans

 

[robject]

I agree with TL 7. The TL I pinned to these charts uses the tech and setting assumptions from Cirque.

 

[shaunhilburn]

I agree with TL 7. The TL I pinned to these charts uses the tech and setting assumptions from Cirque.

Actually, they can all be built at TL 7. Larger sizes don't require more tech, just more money, material, and increased construction time.

At TL 8, the introduction of fusion power, grav vehicles, and orbital elevators means greatly reduced construction time and cost.

At TL 9, the introduction of manuever drives means further reductions in time and cost.

At TL 10, the introduction of artificial gravity obviates the need for centrifugal pseudo-gravity; rotating habitats are obsolete.

 

[Aramais]

Cirque's Assumptions

Cirque is based on the Stanford Torus material found online, which says that a single torus about two kilometers in diameter (wheel size) and 150 meters across (tube size) can support between 10,000 and 30,000 people. My text in Cirque is conservative, tending toward the 10,000 population for a self-sustaining single torus.

If you double the torus up, you can increase the population. There is an upper limit to the efficiency of this IF you are using mirrors to reflect natural sunlight for internal lighting. If on the other hand you assume millions of fluorescent light tubes powered by fusionplus....

There are multiple benefits to the "Standard Stanford Torus" I proposed in Cirque as a game element.

1. It's based on science available in the 1970's, with updates to materials.
2. It produces a fairly large structure for your PCs to visit -- despite my breaking it down into ten 440-meter "1-G-Level decks" I have yet to complete a single torus deckplan all the way around.
3. If you send enough money, you can get access to the deckplans prepared for Cirque.
4. It's not impossibly large to referee.
5. It's at least quasi-canon now. WHich Rob is just noticing...

 

[Aramais]

Actually, they can all be built at TL 7. Larger sizes don't require more tech, just more money, material, and increased construction time.

At TL 8, the introduction of fusion power, grav vehicles, and orbital elevators means greatly reduced construction time and cost.

At TL 9, the introduction of manuever drives means further reductions in time and cost.

At TL 10, the introduction of artificial gravity obviates the need for centrifugal pseudo-gravity; rotating habitats are obsolete.

AT TL 10, additional options become available. Those options do NOT make rotating stations "obsolete." I assume that not spending gazilllions on deck plates remains an advantage in both initial cost and power production. As Hans sometimes says, it has to make sense...and cheapskates will always exist.

However, I did toy with the idea of a different megastructure (as Rob calls them) at another stop -- essentially a giant, domed pie-plate around one of the high-TL worlds. By then, I had already begun "deck plans" for Old Station around Rhylanor, as well as other maps, and concluded that MOARN was actually a damned fine idea.

As to the use of these in asteroid belts -- I assumed that there would be many in asteroid belts. The material is there (metal for frame and rock for other structures); the technology I assumed (nano-tech extraction and weaving) would make the process somewhat easy; and it would be familiar.

Never underestimate the value of familiar, both in reality and in RPGs. Think about it this way: if you have Cirque, especially the CD version, you have enough elements of a single Stanford Torus to run multiple scenarios. And, if you're build habitats for people who collect small rocks as well as big ones in a belt, you can make many of them. Sure, SOME habitats will be carved out of asteroids, whether spun for gravity or not, but other forms will ALSO exist.

And this, if Hans will pardon my theft, makes SENSE.

 

[rancke]

AT TL 10, additional options become available. Those options do NOT make rotating stations "obsolete." I assume that not spending gazilllions on deck plates remains an advantage in both initial cost and power production. As Hans sometimes says, it has to make sense...and cheapskates will always exist.

That makes sense.


Hans

 

[shaunhilburn]

AT TL 10, additional options become available. Those options do NOT make rotating stations "obsolete." I assume that not spending gazilllions on deck plates remains an advantage in both initial cost and power production. As Hans sometimes says, it has to make sense...and cheapskates will always exist.

True, but obsolete doesn't necessarily mean discontinued.

I imagine rotating habitats will still be in use at TL 10, but by then engineering will have outgrown projects like the Stanford Torus and the materials will be up to the task of building much larger micro-ringworld structures like Bishop Rings.

 

[robject]

True, but obsolete doesn't necessarily mean discontinued.

I imagine rotating habitats will still be in use at TL 10, but by then engineering will have outgrown projects like the Stanford Torus and the materials will be up to the task of building much larger micro-ringworld structures like Bishop Rings.

Welcome to my current flounderings.

Seems to me that (O'Neill) Cylinder Habitats and small (Bishop) Rings are perfectly fine at TL 10. And maybe earlier.

I guesstimate that "ringmoons" -- rings encircling planets at 100D -- also start to show up at TL 10, but the larger ones are TL 16. The really big ones around Gas Giants are TL 19 or 20.

Finally real bona fide Ringworlds around real live stars starts at around TL 27.

 

[shaunhilburn]

Welcome to my current flounderings.

Seems to me that (O'Neill) Cylinder Habitats and small (Bishop) Rings are perfectly fine at TL 10. And maybe earlier.

What I'd like to see is construction times. I've seen figures of 12 years for the first Bernal Sphere habitat and 25 years for the first Stanford Torus. Each completed habitat increases the space infrastructure and industrial base so that each subsequent project takes progressively less time to construct. I'm guessing that the first attempt at an O'Neil "Island Three" cylinder would take at 50 - 100 years. Essentially, you have to construct 400 sq km of real estate, pressurize it with 1900 megatons of air, and furnish the interior with communities, business parks, roads, et al while terraforming it with meadows/woodlands.

I guesstimate that "ringmoons" -- rings encircling planets at 100D -- also start to show up at TL 10, but the larger ones are TL 16. The really big ones around Gas Giants are TL 19 or 20.

Finally real bona fide Ringworlds around real live stars starts at around TL 27.

This from my expanded TL spreadsheet (my own current floundering)
TL 21 Hexagonal Klemperer rosette, Dyson swarm, Dyson bubble
TL 22 Banks orbital, inverted gas giant ringworld
TL 24 M-dwarf ringworlds
TL 25 Habitable supramundane planetary shells, white dwarf dyson shells, classic G-dwarf ringworld
TL 27 Dyson shell, Kardashev Type II civilization

 

[aramis]

An O'Neil Island 3 has major construction issues - namely that, until it's fully shelled, it's useless, and secondarily, the only viable expansion is to either take it off-line for the expansion or to add a whole extra cylinder. Which means it's not going to have primary habitat until it's sealed, soil-stocked, and water-stocked. Expect delays galore as they seal it, too.

The O'Neill types, and the Stanford type are all TL 7 doable, TL9 affordable, and by TL12+, probably deprecated due to gravitics going cheaper.

 

[shaunhilburn]

An O'Neil Island 3 has major construction issues - namely that, until it's fully shelled, it's useless, and secondarily, the only viable expansion is to either take it off-line for the expansion or to add a whole extra cylinder. Which means it's not going to have primary habitat until it's sealed, soil-stocked, and water-stocked.

Also, they're wasteful. The entire interior volume between the livable deck space and the spin axis is wasted - just empty air. Much more air than is required to sustain the ecology. Gigatons of mass is used to fill that space with little yield in return.

In this respect, the Stanford Torus is superior.

 

[shaunhilburn]

I guesstimate that "ringmoons" -- rings encircling planets at 100D -- also start to show up at TL 10

Some else to consider: Worldhouses.

Paraterraforming of small Size 1 planets can explain the presence of these worlds with breathable atmospheres. Essentially this involves enclosing the world in a multi-faceted trusswork canopy to retain the atmosphere.

These projects can begin at TL 7 by roofing over craters of deep canyons, creating a pressurized dome habitat. Over time, these increase in size and number and begin to merge, eventually covering the entire surface piecemeal.

At TL 8, the project can be undertaken in toto. My house rule is timescale in years = 50 × (2×WorldSize)²; 50 years to roof over the smallest Size 1 planetoid and 450 years for the largest Size 1 planets. The time is one half at TL 10 - 13, one tenth at TL 14 - 21, and one-hundredth at TL 22+. A TL 15 society can tackle Size 2 - 3 worlds.

At TL 10, gravity generators become available. Emplaced at the world's core, they have to be powerful enough to generate a decent (0.5G - 1G) field from a distance of 200 - 500 miles. I haven't really thought that through; it doesn't seem plausible that they would be that strong at the introductory TL.

 

[robject]

Note: I'm using Traveller5 as my resource for technology (which tends to rely on CT and MT).

An O'Neil Island 3 has major construction issues - namely that, until it's fully shelled, it's useless

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The entire interior volume between the livable deck space and the spin axis is wasted - just empty air.

Traveller's version of the Cylinder is certainly not O'Neill's vision. To the point where it might not make sense to have it.

...Paraterraforming of small Size 1 planets...

There's a world like this in the Deneb sector, larger than Size 1 IIRC.

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[robject]

What I'd like to see is construction times.

These things are likely to be 'spun' in a manner not unlike how Forrest Bishop sees them built. Traveller is likely to use organic-based industrial technology in situ, but Bishop doesn't go into detail, and that's good enough for me.

While they require care to build, I can't see them as an order of magnitude slower than starship construction.

 

[Aramais]

Also, they're wasteful. The entire interior volume between the livable deck space and the spin axis is wasted - just empty air. Much more air than is required to sustain the ecology. Gigatons of mass is used to fill that space with little yield in return.

In this respect, the Stanford Torus is superior.

Well, I've become a fan of toruses, no doubt. However, I'm not sure that air above is inherently wasted. We have several miles of it here on earth. It can't hurt to have lots, and to have circulation of it. If only to be egalitarian about the air being scented by the garbage dumps...

 

[shaunhilburn]

Well, I've become a fan of toruses, no doubt. However, I'm not sure that air above is inherently wasted. We have several miles of it here on earth. It can't hurt to have lots, and to have circulation of it. If only to be egalitarian about the air being scented by the garbage dumps...

I think O'Neil, Heppenheimer, etc were enamored with the idea of wide open spaces and natural rain showers vs. sprinklers. By the look of the various illustrations, the designers also had a fixation with hang gliding in all of the colony designs.

Come to think of it, work is rarely depicted in that old artwork. Colonists were portrayed as a sort of pampered leisure class hanging around low-G swimming pools, shopping, picnicing, loafing in parks, and hang gliding.