Re: Fw: [FT] Islamic Federation ships and Pournelle sensors

On Wed, 18 Aug 1999, Laserlight wrote:

> From: John Atkinson <johnmatkinson@yahoo.com>
> 
> >This Light Tug has some problems from an economical standpoint.  The
> >obvious "Standard" lighter is:
> >
> >Mass 50
> >Hull 5
> >Main Drive 5 (Thrust 2)
> >Cargo 40
> >Points 70
> >
> >and the light tug carries three of 'em.  For the price of two tugs
and
> >six lighters, we can purchase 10 light freighters (actually we are 10
> >points short) with 270 cargo capacity vice the 240 offered by the
> >lighters, and have the additional flexibility of multiple hulls with
> >FTL.

otoh, since the cargo bays aren't tied to the drive assembly, you don't
have your expensive components (the ones in the tug) sitting in port for
a
day or two while the ship is loaded - if trips between ports are on the
order of weeks and layovers are on the order of days, you have 10-15 %
of
a freighter's working life being spent in dock. contrast this to the
tug-and-lighter setup, where your tugs can spend 100% of their uptime in
action. that difference is almost certainly enough to make tugs
competitive.

it's interesting that this breaks down for longer trip times - if you
lay
over for a few days at either end of a journey of a few months, the gain
from a tug is far less. thus, short-haul cargo transport may be handled
by
(small) tugs, whereas long-haul backbone traffic is handled by (larg)
conventional freighters.

tom