From: jim@apsicc.aps.edu (frost...)
Subject: Re: 2-mile long gun
Date: Wed, 14 Oct 92 22:40:00 GMT
Organization: Albuquerque Public Schools - Career Enrichment Center
News-Software: VAX/VMS VNEWS 1.41    

In article <1992Oct14.064246.27192@syacus.acus.oz.au>, steven@syacus.acus.oz.au (Steven Malikoff) writes...
>wellison@kuhub.cc.ukans.edu writes:
><intro about railguns>
>: few nanoseconds later, the cap bank is discharged into the rails. The puck
>: begins to travel forward, but the rails collapse so fast, that the puck is sort
>: of squirted out of the barrle, to the tune of the fastest speed attained by
>: mass by man, 335,000 MPH ! ! ! Gueniss book of world records mentions the
> 
>Hmmm... I seem to remember it is the intense electric field that propels
>the puck along the rails, not the rails collapsing upon the puck. The heat
>generated does not completely ruin the rails (just mostly!) so while it's
>ok for small devices, a large one would be very expensive due to the fact
>you'd have to rebuild it all the time.
> 
>Steve Malikoff.
>steven@syacus.acus.oz.au
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Steve,
  You are both close. As an aside before my explanation the electromagnetic
railgun is already down to the size that would fit onto the bed of a medium
size truck. There are at least two companies here in the states that are work-
ing on reducing it down further so that it can be a viable tank-mounted weapon
with the premise that it would not have to fire heavy explosive or kinetic
energy projectiles to do damage. 
  The railgun is an ideal weapon for space because to work effectively it really
needs a vacuum within the 'barrel' section. In this manner when the capacitive
bank is discharged into the accelerating coils there is no air resistance to
slow the rapid acceleration of the projectile. For an example of how effective
these can be the Sandia National Laboratories on the south side of Albuquerque
have a railgun test facility located in the Manzano Mountains farther southeast
of the city. The railgun is stationary and aimed up a canyon on the Labs land
,which is off limits incidentally, to test fire various configurations of de-
vices. Typically, on a test all they fire is a plastic cube, one inch (25mm) on
a side. This cube has a mettelic foil backing, that's all. On discharge the
electromatic force generated is enough to propel the cube to a velocity of
several miles a second up the canyon. As the cube leaves the barrel of the
railgun it passes through a thin fragile cover which serves to keep the vacuum
in the acceleration chamber. At this velocity there is little fear of the cover
affecting the trajectory of the projectile. Tests have been done on different
materials and the little plastic cube has enough kinetic energy to put significant
holes into half inch armor plate.
  There is no distruction of the 'gun', barrel, guide rail warping, etc. Only the
cover needs to be replaced before the 'barrel' is again evacuated of air to be 
ready for another 'firing'. 
  A simple concept, great potential.
							Jim
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   We are rapidly ascending through prosperity to poverty...  Twain
                    Internet:    jim@apsicc.aps.edu
       Albuquerque Public Schools - Instructional System Manager 
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