On 4 May 2020 at 3:30, Alex Goodwin wrote:

> I'm in the middle of taking Asimov's description of Trantor and trying
> to Travellerise it.
>
> Long story short, the food imports account for ~12 million dton/day of
> cargo that needs to be shifted from orbit to groundside.
>
> GURPS Traveller: Starports, p 63, mentions both beanstalks and
> catapults as alternatives to shuttle service for transferring cargo,
> but doesn't go much further.  I get the impression that both are
> substantially more capital-intensive than shuttle service but
> substantially cheaper to run.
>
> As I'm the type of obsessive wombat who wants to figure out how much
> it _costs_ to import that food, does anyone have any ideas on how much
> such an array of beanstalks would end up costing at GTL 11/12?  (TTL
> D-F, if I've got it right).

There are a number of other ways to make the transfers than just
beanstalks.

Catapults (mass drivers) are generally only good for *launching*
cargoes.

Lofstrom Loops (aka Launch Loops) are practical for both luanching
and landing, but (like most of these things) need to be along the
equator. They are required a strip a few hundred miles long, with
"buffer zones" at each end in case of accidents.

There are ways to build "orbital towers" that support them on streams
streams of rings or spherescirculating between ground and orbit.

But these are dynamic structures and loss of pwer can cause a mess.

Beanstalks have problems too. Like what happens if they fail, and
limits on how much up/down traffic they can support.

Frankly, given Traveller tech, good old anti-gravity will do just
fine. Think along the lines of a huge tanker or container ship that
just shguttles between ground and orbit.

On the other hand, Asimov never considered what you do with all the
*waste* produced by that enormous population. Either you recycle it
on planet (and use it to grow food) or you have to ship it off planet
(and orbital farms or farms on another planet iun the system make
more sense than hauling that much food across parsecs).

--
Leonard Erickson (aka shadow)
shadow at shadowgard dot com