subways and sewers

--- In spacesettlers@y..., "mgellis2" wrote:
>
> Some folks have mentioned using subways in space habitats. How
would
> this work? Are people assuming a robust habitat design with a
thick
> hull, several meters of soil (you'd probably need that if you
wanted
> to grow big trees) or water (for deep lakes), and room to build an
> underground level with subways, warehouses, etc.? I'm sure it
would
> be possible to do that, especially with advanced carbon materials
and
> so on, but I was curious if that was what people meant.

I'm quite sure you wouldn't need any advanced materials in the
habitat shell to take the loading of the water and soil it contains.

And for the
> early generation habitats made of steel and titantium, how would
one
> build a subway system?

I know a lot of literature makes reference to steel and titanium
shell structures, but there has been some discussion of using
concrete, cast basalt, or mooncrete. The analysis referred to a
comparison of how airplanes and spacecraft were made (steel,
aluminum, titanium) and who designed them (areonautical engineers)
compared to how large civil structures are constructed (earth,
concrete, steel girders, etc) and who designed them (civil
engineers.) Now who, thus far, has been instrumental in talking
about habitat designs: mainly the aeronautical engineers, and
they've brought their bias on how to construct things in space with
them.

If you're talking about building a world, I wouldn't necessarily
think that I'd want to build it like I would a Boeing 747. I'm
starting to favor the use of concrete.

I wonder if light surface rail systems like
> cable cars wouldn't be a better idea; it seems they would require
a
> lot less infrastructure (although I could be wrong).

IMHO, I'd rather put as much infrastructure "underground" in order
to preserve the open space-green space-sight lines-vistas to improve
quality of life.

>
> Related to this...how do you handle infrastructure like sewers and
> water lines? In an early generation habitat, where you only have
> something like half-a-meter of soil and then the hard shell of the
> habitat, would you have room for all the pipes and wires and so
on?
> Where would they go?

My own thoughts are leading me to a vision of a habitat that has an
extensive infrastructure "underground" because there will have to be
a lot of mass there for shielding, i.e. 3 meters. Within that
thickness of material, the designers could layout the entire sewer,
electrical, water, communications network. I'd even venture the
opinion that a substantial transportation network could even be
incorporated. Now whether that transportation system would be
comprehensive, I'm not so sure, but I think it could be incorporated
and service the majority of residents. Now that doesn't mean it
would have to be public transportation. It could be a network for
electric personal vehicles, Skytran systems, etc.

I'd even go so far to as put storage, factory, and support
facilities underground. I'd preserve the above ground buildings for
housing, schooling, recreation and office space.