Building an Arcology

[Scott Martin]

Hi Fritz

Light density will be higher in orbit than inside the atmosphere (you will need some serious filters in earth orbit to cut light down to "usable" levels for high-latitude crops and filter the UV) If you're parking one of these around Jupiter, you'll need to be using either an alternate to solar cells, or a *huge* solar farm powering grow-lights inside the arcology. On the "plus" side, you can use the *entire* inside surface for habitation. At higher tech levels you are probably better off just building towers on a Jovian Moon, since even with 20 m ceilings you will get more "room" out of an arcology constructed this way than a "spun" one, and if you're growing stuff with nuclear reactors anyway...

The "Pocket Empire" setting I've been working on (gads, for most of the last decade...) has *lots* of building materials in the habitable zones orbiting both stars. The current theory on the system is that the 5(!) planets in these habitable zones were destroyed by some kind of calamity a few hundred thousand years prior to the system being explored. Feel free to draw your own conclusions, but a binary system with 9 asteroid belts and 7 gas giants (and a couple of merrcury-sized infernos with mean temperatures high enough to melt lead) has a lot of building materials. Since it was settled by STL ship, there just wasn't any option other than building orbital arcologies. And one of the down sides to TL-8 arcologies is that it's really hard to design them to take combat damage. (more in another thread, or wait until I get the stuff on my website)

The "shrinking ceiling" effect of the embedded spheroids was one factor, but I still thank that they will be using pre-fab slabs of building materials far into the future. You could build spheres of any size you want (in vaccum) by melting your material (I'm assuming metal) and "spraying" it into a refractory mold to cool. But it will still be cheaper to build stuff with "off the shelf" components than "custom" ones. Besides, can you imagine the cost of the forms for a 15 km long x 2 km diameter cylinder

Scott Martin

<Edit "Pocket Empire" not "Pocker Empire" >

 

[Ptah]

Originally posted by Scott Martin:

It's all well and good to design or "efficiency" but when all is said and done, these things are designed for people, and people like open spaces, parks, forests, streams and so forth. Even in cities where land value is insane, you still generally find parks. Japan has piles of golf courses: wouldn't that land be "better" used for something else?

Have you seen the greens fees for golf in Japan?! There is no higher or better use. Yes what is available for the wealthy is different than what is available for the not so wealthy.

People need green space and open sky. That green space might also be used for agriculture, and "open" may have a roof on it, but I don't see that need going away. You can postulate that in the 43rd century that people have been trained to live in constrained boxes and eat yummyglop(TM) extrudates, but I probably won't be visiting YTU unless the campaign is to offer those folks a way out.

True. But I can see a Belter mom saying you will eat your yummyglop extrudate Johnny and like it. Think of those poor souls in Habitiat 17 that have to eat day old soylent green.

But IMTU we call animal protein yummyglop extrudate sausage, vegetarian protein yummyglop extrudate tofu, and carbohydrate yummyglop extrudate oatmeal.

Of course living in the US my view of the degree of food processing people will accept might be skewed. Basically every snack food and fast food appears to be a food extrudate, flavored and then shaped. Then again, the Romans were into to fermented fish sauce so who am I to judge.

 

[Pickles]

Originally posted by Scott Martin:
The amount that you "save" on materials will probably be more than offset on more expensive construction methods. How many geodesic spheres do you see in a modern city? How about blocks? you will probably see a few "cylindrical" towers, because these only require a curve in one dimension, and can be "approximated" using rectangular building panels anyway.

I have to go with Fritz on this one, tech level makes a lot of difference to how cheap and easy curvy shapes become. Take a look at the big skyscrapers going up even now in Dubai or Shanghai. Even London has a few - gherkin, anyone? With modern computer-aided design and manufacture, there's nothing overly difficult about creating compound curves in modern construction.

There are substantial structural and cost advantages to building this way, which I imagine would be even greater on an orbital arcology. Curvy shapes are inherently more structurally-sound than cubes, so you can enclose the same volumes with much more 'flimsy' structures. If you're using light, expensive materials, on the kind of scale we're talking about, any materials you save quickly add up.

Of course, you could also just turn a big enough asteroid into a thick-walled pipe, and use that as your hull. Nice bit of protection from those pesky solar flares, provided you can find one with enough structural integrity (the more we study them, the more they all seem to be loose aggregations of rubble).

 

[Pickles]

Originally posted by Ptah:
Then again, the Romans were into to fermented fish sauce so who am I to judge.

Hey, don't knock it 'til you've tried it!

I expect the amount of recreational open space per person in an arcology would, of course, vary with the type of society therein. Most European cities, on the other hand, have pretty strict rules about planning, set-back and protection of open space.

My arcologies are going to have big parks, little plazas and lots of private open space (who needs walls and a roof when you're living in an enclosed environment?).

 

[Scott Martin]

Hi Bromgrev

I'll stick to my "simple shapes" guns on this one: I just don't see making anything this big out of "exotic" materials and using less of them. This makes sense in a skyscraper where you are trying to reduce the loading of the upper floors (and thus "lose" less space on lower floors holding them up) but an orbital arcology, by design is *required* to be massive. If you build just the "base" structure to keep air in and a deck to walk on, then i can see using "exotic" materials. For the (yeah fritz) TL 6-9 structure I am referring to, then you need to add return piping for water, a meter or so of "drain" gravel (more if you are planning on having "lakes" (note 1) and finally pile a meter or two of "dirt" (probably a nice dustball or 10, a few dirty comets, add organics to taste) on top. On the "outside" you will probably have several meters of debris that you couldn't find a good use for netted to the outside of the hull (or inside a second hull) to provide radiation shielding. Since you are pointing this directly at the star, that may only be needed on the "front" face.

Fritz may just cheat and use a nuclear damper for his radiation shielding!

And I think that Bromgrev just volunteered to answer questions about arcology layout

I've been involved in some urban planning in North America, and mcuh of it seems to follow this pattern:

-Figure out what you already have
-Figure out what would be good in the future
-Set up policies and zoning so that you can get to "good in the future"
-Put the plan on a shelf, and let developers change the zoning to fit what they want to build.

lather, rinse, repeat
(this idiom will not translate well, but implies that you keep doing it and expect it to work better the next time)

I just *can't* see this working in an arcology.

Since an arcology needs to be a self-contained "world" mixed use is going to have to be part of the plan from the inception, and even with my "massive" structure, 45 square kilometers means that a lot of the agriculture will need to revert back to that mainstay on North American farming (at least in the 19th century) "Mixed" farming.

I also think that the european ideal of broad plazas and cafe's with patios will be the norm for this type of arcology. What's the point of having "open" spaces if you build your towns / cities so you can't take advantage of them?

I do think that you will need walls and roofs though: A company (IIRC Boeing) moved a group into a hangar that they had available to save costs, and they discovered that they needed to put cielings on the cubicles, because their employees could not work effectively without a "roof" over their heads. The hangar provided protection from the elements, but it was too far away for people to feel like they were in an enclosed space.

You can take the ape off the planet, but you still have to provide habitats that the ape wants to live in.

Note 1: You can make deeper "lakes" by bulging the cylinder out, but only if you are willing to expose your aquatic beasties to more radiation. I need to think about whether this is a "better" design, since it deals with a lot of the water return issues better than having to bury piping all over the place. I'm also having problems adjusting to thinking about the "gravity" field curving the wrong way...

Scott Martin

 

[Fritz_Brown]

Originally posted by Scott Martin:
<Edit "Pocket Empire" not "Pocker Empire" >

You haven't read John Ringo's March trilogy have you? (March Upcountry, March to the Sea, and March to the Stars)

Originally posted by Ptah:
Then again, the Romans were into to fermented fish sauce so who am I to judge.

I don't know about the Romans, but I LOVE prik nam pla!

Originally posted by Bromgrev:
(who needs walls and a roof when you're living in an enclosed environment?).

You obviously haven't seen any of my neighbors - and I don't want to see them in any lesser outerwear than I normally do.

I want walls! (Soundproof, too! Some of my neighbors like to party later than this old geezer.)

Scott, I appreciate your scenario - it makes the techniques used very different. For the lakes, though, why not simply run them at the same depth as all of your piping/mx access tunnels/structural bracing/fuel containment? If you figure a few meters for that, you get a decent depth for your lake just by running it from "ground level" down to the outer hull. Line the bottom with lead, or accept that you will get a bunch of three-eyed koi named Blinky.

For the "growing" of a sphere, I would design a lattice structure that could literally be grown (like a crystal) from the center out, with the center structures being removed and recycled by the same process (nannites!). Or, you could build it like one of those Hoberman Spheres - take it where you want it, expand it, build the shell over it, then collapse it and take it out an airlock.

 

[Pickles]

Originally posted by Scott Martin:
I'll stick to my "simple shapes" guns on this one: I just don't see making anything this big out of "exotic" materials and using less of them.

Actually, I agree that arcologies should be simple in shape. I was just pointing out that complex shapes at high TLs are not necessarily more costly or difficult to manufacture. Having said that, I think Fritz's sphere would qualify as 'simple' (especially if it were a hollowed-out asteroid), although I'm not sure whether it would be preferable to a cylinder. It would need artificial gravity, as axial spin would create a gradually reducing G over its inner surface as you got closer to the 'poles'.

If we're talking 1.6km diameters, I don't think you'd need to worry about restricting the crown spread of trees.

Fritz, Scott, I take your point about walls and ceilings. I used to determine fence heights around my garden depending on my neighbours: the ones I talked to got a 4' fence, the ones I didn't want to see got a 7' one. Still, with permanently clement weather, I could see an increase in the number of jobs and hobbies which qualify as 'outdoor activities'.

BTW, does anyone have any hard-and-fast data on radiation shielding? I've been looking around, but it's all a bit vague. Assuming a rocky cylinder, how thick would its skin have to be to provide a long-term safe environment? I can't see the inhabitants, livestock and houseplants and all, heading for the shielded room every time there's a big flare.

I don't see land drains as a requirement in a 100% controlled environment (ok, you'd want them just in case your irrigation system went crazy). You would only water your plants as much as you needed to, preferably by underground pipes, so there shouldn't be any problems with excess groundwater.

And I think that Bromgrev just volunteered to answer questions about arcology layout

Uh-oh.

 

[Scott Martin]

Radiation shielding requirement (as per "Colonies in Space, T.A. Heppinheimer, 1977) is "6 feet of rock"
This would be sufficient to reduce solar flare events as in 1956 down to 0.5 rem/year

As for the lakes, you need to keep your water reservoir somewhere, and lakes have a few advantages:
1) They moderate temperatures and humidity
2) People like to live nearby
3) It allows you to put down a "base" layer of gravel / rock / whatever and not worry about "underground" drainage.
4) You can use the lake to provide aquatic habitat: it becomes possible to hang a sign on your office door reading "Gone Fishing"

Point 3 is worth exploring a bit more. Cover the entire inside of your cylinder with 2-3 meters of gravel and drain rock, then put dirt and other organics on top of it. You can then treat this just as if you are on the surface of a planet, burying power lines, water mains etc. where you need them and when you need them. You probably won't have any houses with basements, but that's OK. This will limit the depth of any lakes to ~3 meters plus the "bulge" factor.

If you want an "urban" environment, put a couple of "decks" of forced-lighting agriculture in the "basement" (effectively building your "urban" arcology starting on the 3rd floor, with the two "basement" floors being gardens) This would allow these "Urban" orbitals to carry triple the population densities (more if you limit livestock) and also have deeper "lakes", all using the same basic orbital template.

In the future, as now, I suspect that building a lot of things to the same pattern will result in a better design that will cost less, so the ability to make this king of "tweak" to the "base" structure makes this significantly more feasible.

Besides, I'm sure that corporate bigwigs will want to compete for salmon or lake trout bragging rights, even if it is "Blinky the Lake Trout"

Actually the rad dosage shouldn't be a real issue, since the cylinder arcology structure only needs to heavily shield the "sunward" circular wall: no problem making that 2 M thick on a structure that large.

Scott Martin

 

[Ptah]

Originally posted by Scott Martin:
Radiation shielding requirement (as per "Colonies in Space, T.A. Heppinheimer, 1977) is "6 feet of rock"
This would be sufficient to reduce solar flare events as in 1956 down to 0.5 rem/year

Scott, anything in that book about providing some shielding using magenetic fields? Something they might have considered but dismissed in 1977 as impracticle. Current high T supeconducters might make some such practicle as a TL8 addition.

 

[Scott Martin]

Sorry, it's taking me a while to wade through this one again, and I'm still trying to get my old stuff online at the same time

Yes, they do discuss a combination of electric and magnetic shielding. This would be more applicable if you had a fusion reactor giving you power (and supercons) to burn. Bibliography entry is at the end of this post.

I'll stick with Low Tech: Rock has the advantage that you don't suffer radiation damage if the power goes out, reflectors won't "go out" with the lights.

Also a useful section of predicted meteor impacts on a toroidal station: diameter is approximately 1 mile, and the torus is a 400 foot diameter "tire". Collisions on larger bodies should scale according to exposed surface area, but with a requisite reduction (or elimination) of damage.

1/4" Pebble - every 3 years (loss of 1% atmosphere/hr
2" Rock - every 7,000 years, loss of 60% atmosphere in 10 hrs
Boulder (1 t) - every 250 Million years
Cometary Chunk (30 M diameter) - Sun is a red giant, don't worry about it

Bibliography has:
Hannah, E.C "Radiation Protection for Space Colonies" Journal of the British Interplanetary Society (date given is "in press", so post-1976)

Scott Martin

 

[Pickles]

Originally posted by Scott Martin:
Radiation shielding requirement (as per "Colonies in Space, T.A. Heppinheimer, 1977) is "6 feet of rock". This would be sufficient to reduce solar flare events as in 1956 down to 0.5 rem/year.

Thanks, Scott. In that case, it won't be an issue, as (IMTU) it will be a rock pipe carved from an asteroid. The walls will probably have to be thicker than that just for structural reasons. Probably need some reinforced concrete 'netting' around it, too. Plus some clever insulation to stop the whole thing cracking up from differential expansion between the inside and the outside of the skin, maybe a cavity wall - a big thermos-flask in space!

Actually the rad dosage shouldn't be a real issue, since the cylinder arcology structure only needs to heavily shield the "sunward" circular wall: no problem making that 2 M thick on a structure that large.

What about orienting the cylinder so that one end faces the star? A big, massive shield there would take a lot less material. Top that off with a great photo-voltaic umbrella. That's assuming it's orbiting the star, not a planet (then it would be shielding pretty much all-round, I suppose).

Hmm ... I'm going to have to fire up the old CAD and start making some plans ...

 

[Scott Martin]

Originally posted by Bromgrev:
What about orienting the cylinder so that one end faces the star?

that would be what I said (obviously with less clarity) here:

<SNIP> ...since the cylinder arcology structure only needs to heavily shield the "sunward" circular wall: no problem making that 2 M thick on a structure that large.

If you're breaking out the CAD, drop me a PM and I'll see about finding some pics that are public domain of the proposed "real thing".

Looking at the proposed size of these beasties, "four miles across and 20 miles long" (P 275) and points out that it takes 2 miles of atmosphere to make a "blue sky" (minimum required scattering depty) although with no pressure gradient by altitude I suspect that this would be smaller. This gives enough atmosphere "depth" so that the *atmosphere* will provide sufficient shielding from cosmic rays etc!

(I'm remembering a "think BIG" comment towards the beginning of this thread)

It would be interesting to see if atmospheric events could happen (cloud formation etc) at this scale: Centripiral accelleration isn't the same as gravity...

Anyway, available surface area (assuming 50% windows) on something this size would be around 325 square kilometers, or 5 and a half *million* acres. Twice the size of the principality of Liechtenstein, more than 10% of the size of Luxembourg, or just under 1% of the size of the Netherlands. We're building worlds, but small ones

Scott Martin

 

[parmasson]

If the arcology is big enough clouds may form and weather systems may develop. Moisture + heat + a really big space = weather!

 

[Pickles]

Originally posted by Scott Martin:
SNIP> ...since the cylinder arcology structure only needs to heavily shield the "sunward" circular wall: no problem making that 2 M thick on a structure that large.

Heh, I must have read "curved" instead of "circular" ...

... some pics that are public domain of the proposed "real thing".

You mean these babies?

http://www.nas.nasa.gov/Services/Education/SpaceSettlement/70sArt/art.html
http://ssi.org/?page_id=14
http://members.aol.com/oscarcombs/gallery.htm

Originally posted by Kurega Gikur:
If the arcology is big enough clouds may form and weather systems may develop. Moisture + heat + a really big space = weather!

Would that happen in an enclosed, controlled environment, though? Even with a lake, would there be enough evaporation for clouds to form? I know of clouds forming in airship hangars, but they were not a sealed environment. Personally, I'd want to keep weather in my arcology under control if at all possible.

 

[Scott Martin]

I think that the real issue is that this is still a "zero-G" environment: if the cloud layers don't spin fast enough, then there is no "up" or "down". Hot air "rises" but air moving "antispinward" also rises. Moisture + Heat + Space will probably create "weather" the question being whether or not we would recognize it as weather.

Of course if you buy Ringworld having weather, then this isn't an issue: your arcology has weather.

Arcology meterologists have a weather-control advantage that planet-bound meterologists dont: direct control of incoming radiation. Want to kill a gulf storm? Stop the sun from shining on that piece of ocean for a few days (yes, I know that tropical storms can't form in an arcology: coriolis forces are set at 90 degrees to earth normal...)

Hey Bromgrev

Yup, those are the very ones, and given the names of the folks involved, I suspect that significant chunks of those websites were either done by the original team, or folks inspired by the original works. I have much less time these days to troll the web for stuff these days, but I'll take the time to look over the stuff ou have so kindly found for me!

Certainly cheaper than trying to find a used copy of "Colonies in Space" but you won't be able to read it in the bath...

Scott Martin

 

[Pickles]

Originally posted by Scott Martin:
Certainly cheaper than trying to find a used copy of "Colonies in Space" but you won't be able to read it in the bath...

Not cheap, but not used:

http://www.amazon.co.uk/exec/obidos/ASIN/189652267X/ref=pd_ys_pym_a_2/203-9687832-9002345?%5Fencoding=UTF8

http://www.amazon.com/gp/product/189652267X/qid=1137345541/sr=8-1/ref=pd_bbs_1/002-4509880-3067214?n=507846&s=books&v=glance

 

[Scott Martin]

Actually it's this one:
http://www.amazon.com/gp/product/0811703975/qid=1137357623/sr=1-3/ref=sr_1_3/102-5293113-6823356?s=books&v=glance&n=283155

starting at $0.01 (plus shipping...) but the O'Niell and Dyson ones are probably a bit more current...

Scott Martin

 

[Golan2072]

Now for my all-in-one, self-contained micro-arcology ("micro" being a very relative term, ofcourse

) catering for the needs of 500 persons.
HG rules and the HGS software were used. Non-standard components are described here.

The arcology would be built near a good source of hydrogen (i.e. water or ice) to pipe-in fuel for the Refinery and the Power Plant. Otherwise, a small craft could be used to scoop fuel on a nearby gas giant.

Ofcourse, a very similar design could easily be made into a space habitat; the Air/Rafts will be replaced, then, with a fuel-skimming-capable small craft.


Ship: Standard Micro-Arcology
Class: Standard Micro-Arcology
Type: Arcology
Architect: T-Y-C Inc
Tech Level: 9

USP
ZU-D4001C2-000000-00000-0 MCr1,736.1 4.5 KTons
Bat Bear Crew: 82
Bat TL: 9

Cargo: 424 Residents (Not Locally-Employed): 416 Fuel: 270 EP: 45 Agility: 0 Shipboard Security Detail: 4
Craft: 10 x 1T Iskra-class Air/Raft
Fuel Treatment: On Board Fuel Purification

Architects Fee: MCr17.3 Cost in Quantity: MCr1,389.3


Detailed Description

HULL
4,500 tons standard, 63,000 cubic meters, Close Structure Configuration

CREW
10 Officers, 72 Ratings

ENGINEERING
Jump-0, 0G Manuever, Power plant-1, 45 EP, Agility 0

AVIONICS
Bridge, Model/3fib Computer

HARDPOINTS
None

ARMAMENT
None

DEFENCES
None

CRAFT
10 1-ton Enclosed Iskra-class Air/Rafts (Cost of MCr0.25)

FUEL
270 Tons Fuel (168 days endurance)
No Fuel Scoops, On Board Fuel Purification Plant

MISCELLANEOUS
500 Staterooms, 416 Residents, 424 Tons Cargo

USER DEFINED COMPONENTS
- 2 Basic Labs (10 tons, Crew 1, Cost MCr5)
- 500 Full Hydroponics Units (2 tons, Crew 0, Cost MCr1)
- 2 Extended Medlabs (8 tons, Crew 1, Cost MCr8)
- 5 Machine Shops (10 tons, Crew 1, Cost MCr5)
- 1 Bar (6 tons, Crew 1, Cost MCr2)
- 1 Library (10 tons, Crew 1, Cost MCr5)
- 4 Factories (100 tons, Crew 10, 1.000 Energy Point, Cost MCr50)
- 1 Lecture Hall (50 tons, Crew 0, Cost MCr1)

COST
MCr1,750.9 Singly (incl. Architects fees of MCr17.3), MCr1,386.8 in Quantity, plus MCr2.5 of Carried Craft

CONSTRUCTION TIME
146 Weeks Singly, 117 Weeks in Quantity

 

[parmasson]

Not my work but cool. It is a Renderosity site

http://www.renderosity.com/viewed.ez?galleryid=1145472&Start=73&Sectionid=0&filter_genre_id=3&WhatsNew=Yes