Re: GEV and Grav Vehicles

On Tue, 30 Nov 1999 18:53:49 EST, RWHofrich@aol.com wrote:

>Mass drivers would still create plenty of recoil--I am assuming by
saying 
>that recoil won't be a problem you are assuming the anti-grav could
just dial 
>up a bit more "thrust" in order to counteract the recoil. 
Unfortunately, if 
>it had the capability to dial up that thrust, wouldn't it just be a 
>higher-rated grav unit (faster, higher flying, whatever)?  

Sorry, yes you get recoil. It just won't be much of a problem.

Remember, energy is mv**2, but momentum is mv. In other words, if you
have a
very small projectile and accelerate it relatively slowly, you will
build up a
lot of energy without much reverse momentum. The "v" component would be
more
important than the mass component. The launcher and vehicle would have a
lot
of mass compared to the projectile. I think it was in the end of
Gibson's Mona
Lisa Overdrive that a mass driver fired from a blimp. Recoil wasn't much
of a
problem.

That's also assuming you're using a mass driver with magnets. You can
also
build a mass driver with two rails, a magnetic field, and a plasma flow.
Part
of the projectile would be eaten up by producing the plasma bridge. The
result
is even less recoil. I'm not sure this is feasible in a tank based mass
driver, though...

This last one I'm remembering from physics class more than a dozen years
ago...

>I think that assumes that we're dealing with the "marginal" powerplant
type 
>GEV's currently in use.  If we were talking about something that
basically 
>had the "thrust" (with the help of limited ground effect) to
hover--like a 
>helicopter--then we aren't really talking about something that would
need a 
>vulnerable skirt.  Of course, such a vehicle would almost definitely
require 
>a fusion or a-matter plant and could basically fly like a VTOL, but
what the 
>heck!

If the vehicle can hover ala a helicopter, it would need to generate
more lift
than you get just from ground effect. I think then, by definition, you
don't
have a GEV but a rotary wing tank. Or, perhaps, a hybrid GEV/helicopter.
But
the lift required would be enormous for a helicopter. I'm not sure you
could
lift a tank with a bottom mounted propeller. I'd imagine you'd either
need
very long blades or an incredible amount of speed to generate the
necessary
lift. I'm not sure that's feasible. I'd love to see a calculation on the
speed
of the blades and the temperature they'd build up from spinning fast
enough.

Oh, and the skirt... You'd need SOMETHING around blades to protect it,
I'd
think. 

On the other hand, with a fusion plant maybe you could do it. I'm still
not
sure it's feasible. I have my doubts, but they are kind of fun. I always
did
like the Slammers stories (even if Drake does have a problem with 2-D
characters...).

>Ouch--not a pleasant thought, especially for those of us that like
grunts.

There's got to be a Slammers parody in here somewhere! 

>And you'd have to watch for throwing tracks--supposedly (and I'm not a 
>tanker, so this is hearsay) the speed governors placed on the Abrams
were 
>there to prevent some hot dog to scoot around at speeds that increased
the 
>chances of throwing tracks.

I guess if you have a fusion plant you can assume you have tracks strong
enough to handle the load. But, ground pressure is still a big problem
with
tracked vehicles. 

Personally, I'm a big follower of strong AI (I know... I've been down
this
road before on this list! *L*). I personally think the way to go is
turretless
tanks. Essentially self propelled anti tank weapons mounted on a rising,
rotating mount. Just a chassis with an autoloading gun that can rise
from a
hull down position. Then, do away with the human driving it, by
replacing the
driver with an AI. There's a limit to how small they could be, as they
would
have to hold ammunition. Couple it to a small calibre projectile fired
from a
mass driver, and you have something very hard to hit and very
powerful...

Allan Goodall		       agoodall@interlog.com
Goodall's Grotto: http://www.interlog.com/~agoodall/

"Surprisingly, when you throw two naked women with sex
toys into a living room full of drunken men, things 
always go bad." - Kyle Baker, "You Are Here"