RE: Steam Powered Starships?

	Well, I'd want electricity for life support, jump engines,
navigation 
systems, running lights, interior cooling (more of a problem than
heating - 
ask the MIR crew), water reclamation & reprocessing, those
multi-megajoule 
particle beams we all know and love, etc.  When you take damage on a
ship 
with lots of electrics, you'll have shorts and hot wires occasionally. 
 With steam, you've got 300+ degree-Centigrade atmospheres of pressure -

even if a compartment is not open to space, this guarantees casualties. 
 Yuck.	And if you're running a 100 million degree-Kelvin fusion plant, 
most other safety problems will pale by comparison.  Not to say that
they 
wouldn't be concerned, but other stuff (liquid hydrogen, and I think a 
carbon-diamond-type ultrafine dust) is apparently much better reaction 
mass.
	The manuver drive in 'Footfall' was an Orion-type nuclear pulse
drive - 
build your ship with a big heavy plate on the back, and throw nukes out 
behind (a little more complex, really, involving laser-ignited fusion,
but 
nukes will work in a pinch).  The blast sends you forward - thank you,
Mr. 
Newton.  They used this to take off from the surface of Terra
(!!!!!!!!). 
 The attidtude drives were steam vents - there were large ice/water
tanks 
in the ship, and heat from the thrust plate was collected and used to
heat 
the water to provide thrust to change attitude.  This sort of thing
shows 
up in my Low-Tech Full Thrust rules (still under development...).  I'm 
still waiting for 'Footfall' to be made into a movie - sort of
'Armageddon' 
plus wierd alien invaders.

Noah

-----Original Message-----
From:	tom.anderson@altavista.net [SMTP:tom.anderson@altavista.net]
Sent:	Sunday, July 19, 1998 03:10 PM
To:	FTGZG-L@bolton.ac.uk
Subject:	Re: Steam Powered Starships?

 ---- Mick Blair wrote:
> Steam Powered Starships?
> It seems a safe bet that the ships in Full Thrust are Fusion powered.
> The question is how do that convert heat from the reactor into
> electricity?

eh? why do we want electricity? we do need a spot of electricity to
power 
such luxuries as computers and lights, but the main point of the engines
is 
to generate thrust. this could be done extremely effectively by using
the 
fusion core to heat water, prod
ucing superheated steam which would then be jetted out the back, or
through 
maneuvering thruster nozzles, to propel the ship - action and reaction,
all 
your basic rocket theory. i doubt that there would be any other
materials 
with the same combination of
good (high) density, fluidity, cheapness and ease of handling (only
safety 
equipment required: wellies, waterproof overcoat and overtrousers and a 
lifejacket for tank-cleaners!).

this is, i think, how the maneuver drive worked on the orion in
'footfall', 
in at least one mars-colony story (Earth authorities getting moody about

mars ships landing on earth, filing tanks with seawater and blasting
off, 
using up all that precious water
, so martians capture a achunk of ice from Saturn for fuel), and
probably 
in n million other hard-sf stories.

lots of auxiliary machinery could be run off taps into the steam pipes:
air 
pumps, generators, gyroscopes, cookers, airlock doors, trouser presses
...

a network of pipes would run all over the ship to deliver steam at
various 
pressures (high for generators, low for clothes irons); this would
require 
steam sockets in most spaces, just like we have electric sockets.

cometary nuclei and gas-giant rings (think Saturn) would be valuable as 
sources of reaction mass - two depleted fleets fighting over the only 
sizeable chunk of rock in the system might make for a good scenario.

> Emergency power might be generated by a solar boiler. A mirror array
> focuses sunlight onto water tubes, producing steam for the turbines.

or the crew would have emergency primus stoves ("pump, dammit, pump!").

> This brings about the image of a fleet in orbit having to wait until
> they have raised steam before moving or fighting.

rasing steam with a fusion reactor is, i would guess, quite quick.
however, 
they would be dependent on 'waterers' - equivalent to todays oilers or 
yesterday's coalers. hauling water through space might become a major 
occupation of shipping lines (shades o
f Arrakis!).

Tom