Re: Modular Freighters (was Re: FB - Thrust Ratings for Freighters)

On Tue, 26 Jan 1999, Laserlight wrote:

> >i was wondering about containerisation in the context of interstellar
> >trade. specifically, since there will be a larger volume of stuff to
be
> >shipped around than now, and since it is probably going to fewer
places
> >(there must be hundreds of major ports in the world), it would make
sense
> >to use bigger containers.
> 
> This does not necessarily follow.  A container should be the right
size for
> convenient transport to the end destination.

i certainly can't argue with that.

>  In the case of modern cargo,
> this may mean you have a ship carrying truck trailers.  The ship could
carry
> more stuff if it weren't containerized, but it's faster just to pull
up to
> the dock and transfer trailers from the ship to a railcar and go.  You
> wouldn't believe what a cargo ship pays in port charges--they have a
real
> incentive to speed things up.

quite; the savings in cargo handling - both in terms of time and
manpower,
as containers are easily handled by mechanical lifting gear - outweight
the cost of containerisation in this case.

> In the case of starships, you have to have it fit the ship, the
interface
> lander,

unless you use space elevators. i don't know if we know if the
inhabitants
of the Tuffleyverse do. of course, you do have to fitthe kilcontainer on
the elevator, but if you're going to build something big, build it
properly big.

> and the surface transportation to get to the end user.

i was positing macrotrains to complement the kilocontainers and
elevator;
i'm inspired by the cargo transport system mentioned in one or two lines
in "The City and The Stars" or "Against the Fall of Night" by arthur
clarke (one of those two), where huge robotic trains carried freight
through underground vacuum-filled tunnels at extremely high speed. this
is
all very much a Big Engineering approach to industrial infrastructure,
and
possibly more suited to the apo-Tuffleyverse that will come to pass in
2300 or so. i can wait :-).

> You also need
> a container which you have a reasonable likelihood of filling, as
there's no
> point in building a 2000 ton box if nobody needs to ship more than 200
tons
> at a time.

i'd have thought a lot of people want to ship 2000 tonnes at a time.
what's that: 3000 cars or something? all in a day's output for the
AutoFacs of Nissan Prime.

> I think you were thinking of smaller containers being put into a large
> lattice, but why bother with what amounts to repackaging them?

if it saves handling costs. a thousand containers need lots of tug trips
to move them; a single kilcontainer only needs one. if you have five
thousand million tonnes of cargo a day going through (not that anywhere
will; that's just an extreme example), i should imagine you'd want to
make
the containers as big as possible to minimise the number. the optimal
size
would depend on the exact throughput and the costs associated with each
step.

the alternative to packing containers into kiloboxes is to just put them
in holds in the ship's hull; this is basically the same material cost,
and
means you have volume restrictions too, whereas a modular feighter could
fit passenger modules, bulk cargo bays, container lattices, liquid 
hydrogen tanks, etc, as needed.

of course, the sv approach, based on biotech, is to pack them into a
large
lettuce. or so i'm told.

anyway, just pushing the envelope. this may all be daft.

Tom