message 0536

• How can the clan-based, spacefaring society of the Hani work?
• How do the spaceship drives work? And what about the underlying 'Jump mechanics'?

>From: Onno Meyer <Onno.Meyer@arbi.informatik.uni-oldenburg.de>
>Subject: cherryhlist
>Date: Thu, 16 Sep 1993 09:24:42 +0200 (MET DST)

[...]
> are, so its Immunes need to travel). But the point is, it isn't the
> job that becomes vital, it's always a place/thing. There's no need for
> a clan that makes basic tools to be Immune, but if the factory where they
> make those tools supplies an entire continent, then there is a reason.
>
I disagree. The Llun(?) became immune not to protect the dams itself
(who cares wether they're owned by Llun or somebody else) but to make
sure that the knowledge how to maintain the dams wouldn't be lost due
to some powerstruggle. It's clearly the hani who had to be protected.
 
> 	Jo and I have talked about this a lot. Nothing much has
> happened, as Jo is determined to work out how Cherryh's ships work
> before doing anything else. I've never seen a source book, unfortunately,
> but there is a bit of technical stuff in the boardgame "The Company War".
> At the moment in our Traveller campaign there's just a few cherryhish
> things -- jump effects humans as per the books, but is crossed with
> standard Trav. jump to still take only 1 week real-time. We once came
> across an NPC who seemed rather like an unsocialised Alpha azi. Merchants
> come from family ships, stations are much like in Union/Alliance, and so
> on. 
>
It should be easy to summarize everything known on the jumpdrive, and
every gap that remains has to be filled by guesswork.

The jumpdrive works in two different modes. It can change the velocity
of a ship flying STL in major leaps. Three of these leaps are sufficient
to brake a ship from more than half lightspeed down to insystem speeds.
I'd estimate that a braking pulse are about 0,2c worth. The ships can
accelerate with pulses, too. That has to be less effective or there would
be no difference between "stringed jumps" without dumping and regular
jumps. I'd estimate 0,05c for every pulse. These pulses can only change
speed, not direction (see the turnaround at Urtur). These pulses
probably can't be made instantly and/or are "noisy", or they would be
more frequent in combat.

There is little known on the hardware of the jumpdrive. It uses "vanes"
to project a jump-pulse, and the size of the vanes increases with   
increasing drive power (see the refit of the Pride and the description
of the dartship in ML).
The drive assembly is expensive enough to make the jumpdrive and the
realspace drive worth 90% of the total ships value (see the refit of
the Pride). The jumpdrive is heavy enough to be a substantial part of
a ships empty mass (see the chase in CH).
When the Pride was prepared to blow themselves and the hakkit to hell
(was that TKSB or CH?), there is some technobabble that shows that
a certain realspace speed toward the gravity well of the destination
is necessary, otherwise the ships just goes to the nearest large 
gravity well.
A jumpdrive takes not only the ship but also much of its environment
into jump (see the transits at Urtur). If this environment is to
heavy, there will be disaster (see the battle in DS, and the voyage
in the faded sun).
A empty merchanter or a warship can make several (4+) jumps on a 
single fuel load (see the chase in CH), but a loaded ship requires
new fuel every jump or every two jumps (see the Legacys operations).