Building an Arcology

[Scott Martin]

Hi Gnusam

I wonder if we are in violent agreement. I also believe that 1 worker can feed 10: my issue is that I think that 1 worker can feed 100-200 at earth's current tech level using high intensity farming. Your first two points seem to agree with this thesis:

Originally posted by Gnusam Netor:
I don't think so. I believe it is reasonable that " 1 worker can feed 10", considering:
<snip>
+ it is in a (relativly) confined space, it is not the endless fields of Kansas.
-Yup, means that your workers spend less time "commuting" to where the work needs to be done
+ more intense work of one acre produces more, take the japaneese style of farming for instance.
-Yup, crop yields should be much higher than on earth

Your other points:
+ Food processing is included in this.
+ it is a nice round number.
+ Dude, it is in space!

would reduce the effectiveness (ratio) of acriculture (well, maybe not the last two) but even if processing doubles the amount of work required you are in the 1:20 range for the "growing" part of agriculture which (even going by USDA numbers) are *at least* 50:1 currently. 50:1 and 100:1 are also nice round numbers...

I didn't object to the amount of food produced (100 people eating off an acre seems a bit high to me actually) but to the ratio of workers used to produce said produce. And if I was going for high intensity Ag, I certainly wouldn't describe it as "An acre or so of open space..." and I sure as hell wouldn't bother to put buildings in an environmentally controlled area, especially at the expense of growing area. Doubly so if I was using such small modules.
Even high intensity "greenhouse" agriculture in crappy climates (I live in Canada BTW) at our current tech level is more productive than this.

You heard it here first: I just called 10,000 Dt "Small".

hmm: 140,000 cubic meters with an area of an acre gives a ceiling just under 3.5 meters. Where do the "buildings" go?

Scott Martin

 

[Scott Martin]

Hi Ptah

Shipping efficiencies would be moderately insane: in my proposed "Monster" arcology (actually on the small side of those proposed in the late '70s) the farthest you can possibly be from any point is about 20 km. No point in the arcology is more than 8 KM from an inter-arcology shipping point (docks at both ends) and shipping between arcologies has a near-zero cost. All you need to do is put the stuff in an insulated pressurized container ("a Truck", or if you're british, a "Truck truck") a short boost to kick it in the direction of another arcology, a short decell boost to stop it, dock and unload. 1 Kton of produce moved a few tens of thousands of KM, delivered at the cost of a few hundred liters of reaction mass in less than a day. More perishable cargos will "cost" more and be moved faster, stuff like grain may just be pushed into a holding orbit in an unpressurized cotainer.

This type of arcology would have a very "Euro-feel" to it, since there would be no need for powered private transport. A bicycle or short walk will get you anywhere you can go in the arcology, and you know *exactly* when the bad weather will be. Your maximum commute to work is unlikely to be more than 10 minutes, and you can fire a lot of psycologists who specialize in road rage (although you may need to hire them back to deal with claustrophobia and cabin fever...)

Scott Martin

 

[Ptah]

Originally posted by Scott Martin:


I didn't object to the amount of food produced (100 people eating off an acre seems a bit high to me actually) but to the ratio of workers used to produce said produce.

A quick number run, a yield of about 150 bushels/acre for corn is conservative, which comes to about 4500 kg which is about 12 people/years of food. This is after in-field losses. (Based on 1 kg grain=2000 calories).

You can also take a look at figure 4 here:
http://www.agry.purdue.edu/ext/corn/news/articles.03/CornYldTrend2003.html

I'd imagine that with current plant strains indoor corn growing (although insanely exspensive) could easily yield 200-300 bu/acre.

 

[Gnusam Netor]

Originally posted by Ptah:
Couldn't agree more. But those workers could still be feeding more than 10 per worker.

Fine, but you shouldn't really talk to me about it, talk to Steve Jackson.

Edit:
Ok, i think SJ has a point by making the space-station farming very work intensive, because space is more expensive then on earth. It is a bit much though. One farmer with equipment would be better in my mind.

 

[Ptah]

Some big numbers. If the arcology is a 1 km radius cylinder 10 km long, it will be about 2.24 billion dton. The inner surface area of the cylinder (excluding ends) would be about 24 square miles. 640 acres per square mile means that 184,320 people could be supported off of current corn strains. Each person would have 12,152 dtons of space.

The space for living, buildings etc. would be along the axis, and light could come in from the ends. Much more effciient uses of the volume could be found to grow more food.

I think I just designed an L5 colony.

Edit: If the central core was a "building" 100m in radius running the length of the cylinder, you would have about a 22 million dton living/work space. With 25% set aside for housing each person would have about 1,250 sq. feet of living space with a 3m ceiling. For a familiy of 4 that's a 5000 sq. foot house.

 

[Gnusam Netor]

Originally posted by Ptah:
Some big numbers. If the arcology is a 1 km radius cylinder 10 km long,

snip...

and light could come in from the ends. Much more effciient uses of the volume could be found to grow more food.

I think I just designed an L5 colony.

I think a better use of the sunlight would be to reverse those dimensions, thus a radius of 5km and 2km "long". Or have I missed something obvious here? more sunlight must be better, no?

 

[parmasson]

Look at Arizona, All irrigated I assume and at 190 bushels per acre, damn. I wonder what the maximum density would be if each stalk was just far apart enough not to touch.

[edit] Soybeans are 42.7 bushels per acre up from 35.4 in 1995.

I wonder what implications this efficiency has on the production of coffeejuice? We may want to consider an orbital construction facility.

 

[Ptah]

Originally posted by Gnusam Netor:
</font><blockquote>quote:</font><hr />Originally posted by Ptah:
Some big numbers. If the arcology is a 1 km radius cylinder 10 km long,

snip...

and light could come in from the ends. Much more effciient uses of the volume could be found to grow more food.

I think I just designed an L5 colony.

I think a better use of the sunlight would be to reverse those dimensions, thus a radius of 5km and 2km "long". Or have I missed something obvious here? more sunlight must be better, no? </font>[/QUOTE]I guess it depends on how close you are to the sun. Without an atmosphere at 1AU from a type G star it's probably too intense for current plant strains without filtering. But yeah, the plant strains for these environments are probably going to love light.
Your dimensions also look more efficient. The surface area with out the ends is still about 24 square miles. But the surface area of the ends combined is about 61 sq. miles.

 

[Scott Martin]

Actually you will lose between 25 and 50% of the "Cylinder" area to "cutouts" for light. Long axis of the cylinder points at the star, and large polished "Vanes" reflect light through the sides (cutouts) of the cylinder to illuminate it. The '70's literature has half of the area used as "window" but use of non-focusing optics would allow you a higher usable surface area ratio.

You could probably just use the ends if you were in close orbit, but you'd have issues with cooking one end of your cylinder that way...

For maximum usable area, you want long thin cylinders. The reason for 2 Km diameters is that is in the minimum reccomended size to not mess people (and plants and animals) with coriollis (sp?) effects.

Scott Martin

 

[Scott Martin]

It's also worth remembering that a significant chunk of your crops will be selected for "fixation" criteria: Ability to get metals out of waste products, balancing the gas exchange and providing trace nutrients will all be on your list of things needed somewhere.

And I'm sure that those infamous rose gardeners will be doing a *lot* of research to justify bringing their prize tea roses into orbit with them

Your agricultural land will be incredibly efficient, but you will lose significant chunks of area because you need the biosystem to do other things too. Nothing but corn-dogs is not a good idea for a sustained healthy diet.

Scott Martin

 

[Fritz_Brown]

Scott, that's what the park is for, man! Roses, air filter, shade (if you're going to open part of this thing to the sun), treehouses, rope swings, necking in the bushes, etc....

 

[Ptah]

Originally posted by Scott Martin:
Actually you will lose between 25 and 50% of the "Cylinder" area to "cutouts" for light. Long axis of the cylinder points at the star, and large polished "Vanes" reflect light through the sides (cutouts) of the cylinder to illuminate it. The '70's literature has half of the area used as "window" but use of non-focusing optics would allow you a higher usable surface area ratio.

You could probably just use the ends if you were in close orbit, but you'd have issues with cooking one end of your cylinder that way...

For maximum usable area, you want long thin cylinders. The reason for 2 Km diameters is that is in the minimum reccomended size to not mess people (and plants and animals) with coriollis (sp?) effects.

Scott Martin

Well the sides could be transparent and the crops "anchored" on a concentric cyliderilica and growing towards the transparent sides. I see alot of possibilities if we are using artificial gravity so we don't need to spin for gravity. Are we spinning for gravity?

Was the last one a comment or questions? I chose 1 km radius and 10 km length because I didn't have a calculator.

 

[Ptah]

Originally posted by Scott Martin:
It's also worth remembering that a significant chunk of your crops will be selected for "fixation" criteria: Ability to get metals out of waste products, balancing the gas exchange and providing trace nutrients will all be on your list of things needed somewhere.

And I'm sure that those infamous rose gardeners will be doing a *lot* of research to justify bringing their prize tea roses into orbit with them

Your agricultural land will be incredibly efficient, but you will lose significant chunks of area because you need the biosystem to do other things too. Nothing but corn-dogs is not a good idea for a sustained healthy diet.

Scott Martin

Agreed. There are many ways to configure the inside so more surface area is available for crops.

I believe tailor made bacterium and protozoa could provide many of the fucntions you mention above, in addition to making food.

Crops may be grown more for texture and comfort and luxury. The bulk of calories and nutrients may come from vat grown food formed into something recognizable with a decent texture, super pasta? The silage from crops and human waste would be used in addition to nutrients to feed the bugs. They probably won't even need light, heat would do fine.

The biggest part of the food processing chain is probably going to be generating the nutrients. Where are you getting the oxygen, carbon, nitrogen, phospohorous etc. and how are you converting them into available nutrients. This may be another reason bugs are preferred, the nutrients might be in a much rawer form than needed for plants. Further, where are we getting the oxygen, carbon, etc.? Grinding up asteroids? Lunar rocks? Bringing them up from the planet?

 

[Pickles]

An alternative configuration would be a long, narrow cylinder for the crops, with an outer 'wheel' for accomodation and parks.

The farm cylinder has a full-length lighting axle providing nice, even, continuous daylight for the crops. Nothing could be more suitable for automation than a perfectly even 'field', so I'm sure actual live farm workers could be kept to a minimum. Lots of inhabitants would pobably do it as a hobby.

The larger diameter wheel would have a higher apparent gravity than the farm cylinder and more windows (in the 'top' and sides!).

 

[Scott Martin]

Ptah:

The Arcologies I am describing have already had much of their design done: before 1977. They spin for gravity, and are made from "exotic" materials like steel. If you are designing a gravitic arcology, or one on a planet, then use a cube or slab, with "floors" like a skyscraper. Your call as to whether you use the "bottom" floors for agriculture (letting the gravity do most of the work moving "waste" to the "reprocessing" area) or on the "top" where you have "free" access to light.

I suspect that the spun design will remain in use because the maintenance costs will be very low: your power systems are either passive (mirrors) or solid-state (solar), and most of the things that will need maintenance will be things like pumps, filters etc. We have started to build automobiles that need no scheduled maintenance for the first year, in part due to new materials technology. If you can build truly "frictionless" surfaces then your pipes and pump maintenance will be significantly reduced, which really leaves you with air circulation. Since the cylinder (if used solely as an "agricultural" platform, air circulation could be done solely with fans, obviating filters completely. Of course you would nees lots of big critters (Cow, Moose, Kangaroo whatever) for Oxygen exchange to ensure that your CO&SUB2 levels don't drop too low. you need to worry about gas loss, but with high tech materials and centuries of experience dealing with vaccum environments this may be a minimal concern.

You might even raise cows as organic methane producers

That, like the rose gardener dig, was a joke... apologies for what passes for my sense of humor.

Ignoring the "cheap to maintain" argument, one of the main reasons that I would see this type of arcology reamin in use is that it's an "open air" structure. You can make vastly more efficient use of the volume, but the economics (discussed a page or two earlier) mean that you don't have to. Is there anyone on this board who would trade the ability to go for a walk outside (ever) for a 6,000 square foot house? To make that less abstract, would you be willing to move to the antarctic where going "outside" even in summer means that you need to dress up in hostile environment gear, and once outside you have the thrilling view of whites, greys and blacks)

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?

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.

Scott Martin

 

[Scott Martin]

For Robject's 100,000 passenger/week spaceport I would reccomend the same basic structure, but with two "basement" floors in each of the two cylinders ~5 meters per floor crammed with plants etc. Couple this to a large docking structure tethered to the center of the "dark" side of the arcology. Build the "port" staight up as a HG or FF&S docking platform (open structure, lots of fuel and cargo storage, space for offices, a bunch of "hangars" of set sizes (probably 100 Dt to handle all small craft and "overflow" scouts / X-Boats, 400 Dt for SDB's and small merchants 1K Dt, 5k dT and anything bigger gets docking clamps.)

You probably also want to have starship construction and repair silos available: these will be cylinders ranging in dimensions from a few tens of meters up to "silly" sizes depending on the type of starport, associated basesm supporting population and trade classification (A type"A" starport with an associated naval base, orbiting an "A" population world with an "Industrial" classification will probably have a few Silos in the multi-km range) for repair or construction put the ship into the silo (pressurizing it is optional, there are advantages to vaccum work: welding for example) do your construction / repair, then pull it out. last step is either:
1) Apply a small grav field and collect all of the dropped bits
2) push a "plunger" down the cylinder at low velocity (10 cm/sec) to collect all of the bits
The last thing you need "floating around" are bonded superdense "bolt" equivalents to collide with your expensive infrastructure. "Open Slips" a la the Weber books are all well and good, but "closed" slips won't cost that much more.


This gives you a bunch of advantages over the starports that I have seen:

1) allows you to couple the environmental systems of the "port" with the arcology
2) gives a nice place for the (up to 200,000) folks who work at the port / yards to live
3) due to the above workers no longer need to commute or have staterooms in the port
4) in case of emergency you can have "all hands" available in very short notice
5) Spacers have somewhere for R&R without needing to go "dirtside"
6) Commercial factors have somewhere to put those extensive offices
7) Corporate Bigwigs can have their corner office overlooking the golf course
7a) said bigwigs will *suck* at golf in a real G-field
8) you can put this *anywhere* not just orbiting the main world


The last point is worth going into in a bit more detail: since this facility is now self-contained, and a "nice" environment to boot, it makes sense to build a "Very High" port at the 100D limit (or close to wherever people jump in IYTU) This allows the port to act as an "anchor" for all intra-system commerce (belters no longer need to enter the "hole" to drop off their ore, fuel tankers no longer need anything more "hefty" than ion drives to function) and all of their trade needs can be met either by goods from the main planet, or direct from "external" markets. By building such a port in the 3I you are also reducing the number of people who can avoid "local" taxes by trading outside the 100D limit, since the local government will probably have claim to the station (and an appropriate "bounding" area around it)

Of course it would get interesting if a third party built the station... free trade zone anyone? And an interesting (3I) campaign, since the station may be considered a "world" by 3I standards (especially if the local scout commander was amenable to a suitcase of credits) Once it is registered as a "world" any attempt by the "main" world to exert sovereignty would be considered "War" with all the associated limitations of warfare between two members of the 3I imposed on it. You would be *amazed* at the punch of a 15 km long spinal PAW, and the excess power generation of a "world"...

I think that I'll steal Far Trader's sig for this one, since I've been working on this stuff for a few years now:

Original material in this post may be employed for personal non-profit use with the origin noted. Any other use is subject to permission from the author. Contact me through the private message feature of this board.

Permission freely granted to flagrantly steal the 3I "corporate war" campaign: if anyone wants to develop it I can give them the background for how the station got built in the first place.


Scott Martin

 

[Scott Martin]

(Severely off thread topic warning)

There are a couple of advantages in the "Quarentine" area as well, but the 3I (and Traveller in general) doesn't have "disease" as a major issue. I'd actually expect this to be a major issue, since most of the "species" in the Traveller universe are "transplants" so a single nasty bug would affect a LOT of species.

Scott Martin

 

[Fritz_Brown]

Scott, the only problem I have with a "cube" is that the walls are wasted surface area for the most part. A cylinder only "wastes" the ends, and (depending on the radius) can be utilized for things that would negate a living area (docking, etc.). A sphere, of course, can use the entire surface as "floor" without worrying about corners.

A cylinder is probably preferable to a torus, though, if you're going to spin for G - awful lot of wasted material to roof over the area between the ceiling and that vacuum in the middle.

 

[Scott Martin]

Hey Fritz

If you are building an appartment Tower, you "waste" the sides and the ends anyway. You also "waste" all of the internal walls, which account for a lot more space than the exterior walls anyway. Unfortunately these are needed to hold up the next floor...

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.

If you look at the breakdown for costs, you will notice that the cost of materials for the hull was far and away the smallest expense, so you're probably trying to save a MCr at the expense of a few GCr in cost overruns

"Well ya see sor, we haint nevr dun one a these here spheerz b'for, so'z we hadda make a few tings up on da fly, az 'twere. I t'ink dat the pear shap be quite fetchin' sor, if'n ya don't mind me sayin dat"
"C'n ya sign here fer the overtime me 'n the boyz put in? 'twere only three years late, and a couple a huntret million over"

Scott Martin

 

[Fritz_Brown]

Well, Scott, I'm not trying to design mine with TL6-7, like some folks around here... My initial thought was a planetoid, but you could grow a "sphere" shape w/ TL10+ I would guess.

I'm not really concerned about how much the materials cost - I'm more concerned about maximum utility from every surface and every cc of atmosphere. I will admit that a cylinder or "cube" has one big advantage over a sphere: you don't get decreasing area as you go "up". I got to thinking this morning about required space for trees, etc. and realized that a 3m tall tree would have less space at its crown than at its roots in a sphere. How much less is a function of how small your sphere is.

BTW, I did a little number crunching on light. The light hitting the Earth (in any one spot, sunny day) is about 12,000 lumens. A quick Google shows it takes a minimum of 3000 lumens to grow stuff indoors. Using the inverse square rule, you only have about 444 lumens available around Jupiter at its minimum approach to the sun (1/27 of Earth). I don't care how many windows you put in this thing - you will need some grow bulbs. (I'm betting this severely impacts your use of solar panels, too.)