Re: railguns

Ok, with all the other info I've gotten, and by perusing the digests,
here's
kind of what you're looking at:

Max engagement range is 36".  Equals 36 million meters.
Turn length is 7.5 minutes which gives you a turn of 450 seconds.
A kton of TNT is equal to 6.31*10^8 joules
A nuke (a small one), if my source is correct, produces around 1*10^10
joules
C=2.99*10^8 m/s

Now, with these numbers you can figure that the absolute minimum speed
of a
projectile has to be around 80,000 m/s.  Anything lower and it literally
will
not be able to make it from max firing range to the target in one turn. 
Since
7.5 minutes is way to long for a time-to-impact for a ballistic weapon
we need
to bump it up significantly.  So lets take it up to oh around 1 minute
(600,000
m/s).  That's still a long lag, but not too bad.  Ok, now assume a
projectile of
1 gram (itty bitty).  So we have

Energy=.5*.001*600,000^2=1.8*10^8 joules, or about 1/3 of a kton of TNT

A 10 gram projectile will be 1.8*10^9 or about 3 kton of TNT

Now just to get silly, let's take our velocity up a bit, say to around
3.6
million m/s.  That gives us a time-to-impact of 10 seconds. We'll use
our 1 gram
projectile again.

Energy =.5*.001*3.6 million ^2=6.48*10^9 joules

A 10 gram projectile would be 6.48*10^10, a 100 gram is 6.48*10^11, etc.

Just for reference 3.6 million m/s is equal to about .01 c, so you're
going to
see some minor relativistic mass shifts, which will both make it harder
to
achieve that velocity, and increase it's mass and consequently its
energy.

The more reasonable 600,000 m/s is a velocity of about .002c which is
still
considerable.

Now as far as the practicality of the weapon systems, and the affects of
a very
small projectile hitting a container full of atmosphere at VERY high
speed go,
I'm not going to speculate.

For personal weapons, the speeds, would be MUCH lower, and the
projectiles could
be correspondingly larger.

Bill

Los <los@cris.com> on 09/15/1999 03:36:04 PM

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  Subject      railguns 				      
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A question for you propellor heads. At what velocity do you think a
decent
railgun projector (ala KV design) would spit out its slugs and how large
would they be?

Los