From: Patrick Salsbury (salsbury_at_sculptors.com)
Date: 09/26/98
Message-Id: <3.0.3.32.19980926145654.006a8fb4@mailhost.sculptors.com> Date: Sat, 26 Sep 1998 14:56:54 -0700 From: Patrick Salsbury <salsbury_at_sculptors.com> Subject: Re: Construction of first sphere
At 09:23 AM 9/23/98 -0700, you wrote:
> Considering how to construct the first three spheres, (three is the
>minimum number of "pontoons" needed to prevent overturning) I have
>arrived at the following:
>1) closest-packing of spheres, giving an arrangement with
>six-around-one, it might be advisable to begin with a frequency
>divisible by six, so the equators will link-up equally all around.
That may or may not be totally necessary. There's one idea I have
in mind for a sort of "universal" or "ball-in-socket" joint that we
could use on the hulls to join them together, while giving each hull its
own flexibility to move about as waves pass by, etc. On the whole, a city
that's a mile or so in diameter is going to have a size much larger than most wavelengths of any concern on the ocean. However, on the smaller
scale, hemispheres only 100m across will be affected by wave action.
If we connect the hulls with very large ball-in-socket joints,
(Think railroad cars, but with up/down flexibility as well as left/right)
we will have a large raft-like structure with individual "cells" that
can move about. All inner cells would be joined on 6 sides, and outer
ones would be joined by 1-3, on average, depending on the hull patterns
you lay out.
> By using steel rebar, and welding it at the hubs, one will get a
>cheap, high-tensile frame , onto which wire mesh can be laid, and
>accretion can take place. The accretion, I think, will prevent rusting.
>One thing about rebar: it only comes in twenty foot max lengths, so one
>may need to go to nine-freq alternate,with a 6-f triacon inside, and an
>eighteen outside.
The geodesic will get stronger as it gets larger, so keeping to
low frequencies might not be desirable. Also, pieces should be easy to
handle, and move around. 20' pieces of rebar are roughly as flexible as
uncooked pieces of spaghetti. By using shorter lengths, we should be
able to get more rigidity, albeit at the cost of more welding.
>2) I live about six blocks from the Puget Sound, and have been "seeing"
>this thing floating out there, between here and Indian Island.
You see it too, eh? I see it off the shore of Santa Cruz &
Moterrey, floating a few miles offshore, looking much larger than expected. :-)
>We would
>first float enough "barges" (for 9-f, it would be 45) to go around the
>equator. Then, a dome is built on this circle of floats, and attatched
>by heavy cable to two opposite , extra-floatation ones. Pulling the
>other barges out, one-by-one, until the whole dome is supported on three
>points, then removing the side barge, and the whole would invert itself
>into the desred position under-water. (displacement would make it
>lighter under water than above)
I've always considered underwater assembly to be easier/safer,
since you won't have to do any flipping over. Also, if done with the
correct materials, and manufactured above-water properly (i.e. - not
using rebar or other "conventional" building materials and trying to
make them fit to our purpose) we could get parts that easily snap
together underwater into a large spaceframe. This could either be
floated near the surface, (or suspended from the superstructure of
the city, once we have a few floating hulls in place), or it could
be built on the ocean floor in shallower zones.
I do like your idea of having pre-made hex/pent panels
above-water. We could make those and then just assemble the larger parts
underwater. (Anyone else here do SCUBA? It's worth learning, if not.)
>3) Tidal power can be harnessed by exploiting the differences in height
>from your anchors over time to power the accretion.
Or via "floating breakwalls, as Bucky designed, and are shown in
"Energy, Earth, and Everyone", by Medard Gabel and the World Game
Laboratory. Let's not forget all the wind & solar out there. I have a
feeling once we've got a basic structure out there, we're going to be
able to harness vast amounts of energy.
Pat
___________________Think For Yourself____________________
Patrick G. Salsbury - http://reality.sculptors.com/~salsbury/
Check out the Reality Sculptors Project: http://reality.sculptors.com/
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