Re: What is a "conventional engine"?

In <URL:news:local.spelljam> on Sat 05 Mar, Novamaster wrote:
> A large undead could pull it (Roc, Dragon, etc). Or prehapes a stripped
> down helm. The rules for Nonmagical Engines are in the Concordance of
> Arcane Space read
>
> "Nonmagical Engines
>
> Cost: varies, but approx. 10,00 gp
>
>     There are a number of ways of moving through space-gnomish engines,
> chemical propellants, even explosive mixtures ignited in a closed space.
> These are sometimes used in space to ravel through magic-dead areas
> (called "Sargasso") as well as for lifeboats and shuttles that are too
> insignificant to merit a full-blown helm. Non-magical movement is used
> as a back-up system for larger ships when all other options fail.
>     All nonmagical engines share one feature-they are slaw compared to
> helms. Their movement is never more than 17mph and their SR is 1. At
> such rates, it would take years to read even a nearby planet.
>     Further, they cannot be used to lift off from celestial bodies
> larger than class A due to their limited power. Little research has been
> done in expanding this "weak sister"to the spelljammer helms (because
> the helms provide such a good alternative_, but there are situations
> where they are useful."

I think after a lot of mulling around, we settled on 6" move
being roughly equivalent to 17mph, for SJ purposes.

Also, there was the rule that you needed at least 10" move to
lift off from an Earth-type planet, so a standard Fly spell with
12" (giving 34mph) was good enough.

We also had an even slower move of 3" (8mph) for some things,
but, this was useful for moving large cargos around, if you could
trade-off weight (or volume) lifted against speed.


If your normal Fly spell was using command of winds, or air
elementals, trying to use it to lift things into space...


One of the problems of SJ is that while speed in atmosphere is
obviously limited by air resistance, you need to not look too
closely at there being no air resistance in space (I am ignoring
'ether resistance' here).

If you try and get 'realistic', 10" might give you 1G
acceleration, and that will take you between planets in quite
reasonable times, though your travel time calculations may get a
bit more fun! [grin]

If you say 1AU is 100Mmls, and you are flying at 17mph, that's
about 670 _years_, where as a SJ helm in overdrive will do that
in a _day_.

If you say that you have 0.5G acceleration (say, from 5" move),
and you accelerate half way, then decelerate for the second half,
my (possibly highly dodgy) calculation suggests this takes about
4 days. Double the acceleration, quarter the time.

Even if my calculations are way off, that shows you the sort of
difference accelerating in space, as opposed to having a fixed
speed, can have. Mind you, avoiding those square roots can make
using a fixed speed a lot more attractive...

So, this might show that the people doing the original SJ design
knew what they were doing! [grin]


> Jason Hosler wrote:
>
> >Besides the chemical engines that have been mentioned
> >before, I remember one suppliment that mention a lich
> >travelling between planets in a carriage pulled by
> >undead pegasii.  There has also been mentioned things
> >like building a large brass sphere and filling it with
> >dew, training Rocs and other giant avians to keep
> >flying up, and the ever popular magic down a comet and
> >ride it out.

I liked the using loads of mirrors, to concentrate the moonlight,
which comes from the moon, which lifts the tides, on a vehicle,
so it flies! Only on moon-lit nights, though! [grin]

--
Dreamer
dreamer@??????.?????.??.uk
http://www.romsys.demon.co.uk/