Re: GEVs

On Fri, 3 Dec 1999 10:07:01 -0500 (EST), Roger Books
<books@mail.state.fl.us>
wrote:

>So why use little tiny blades.  Maybe auxilliary jets?  Compressed gas?
>Null-G packs.

In order to lift the GEV? Well, then by definition it isn't a Ground
Effect
Vehicle. You do make a point with the null-g packs (auxilliary jets and
compressed gas I think would be one use only due to "fuel" use and would
still
be unpractical). 

But null-g packs are fantasy. Sure you could build GEVs with them, but
we
haven't found anything to support anti-grav ability either. I'll change
what I
said and stipulate that GEVs, without resorting to some other sci-fi
macguffin, probably wouldn't be feasible. 

However, if you have a world with anti-grav ability, then GEVs might
make a
reasonable vehicle.

>> Still, I don't think these will make an appearance in the real world.
>
>Too late, already been used. :)  The Navy has used them and I believe
>they were used in Viet Nam.

The Navy had Hammer's Slammers style hovertanks in Vietnam? Wow! *L* 

I know hovercraft have been used in real life, but they weren't used as
a
replacement for tanks, and were restricted to some pretty specific
terrain
conditions. Which was a point I conceded earlier. GEV tanks might make
sense
on some planets.

>One other thing I still am not sure I believe is part of the vector
>of the GEV pushing it down hill.  If the skirts follow the terrain
>and the GEV stays level it appears to me as if the GEV would experience
>the same (or maybe even less) downhill force than the equivalent
>ground vehicle.  

The GEV is level. The force would be straight down. If the skirt follows
the
contour of a slope, part of the force would be down into the back of the
skirt, pushing the skirt down the slope. Thus part of the vector is
still down
the hill. You'd also have uneven pressure in the skirt from the front to
the
back, which I think would tend to push the front of the GEV upwards
parallel
to the slope. And then there's the turbulence effects within the skirt
itself.
I don't know enough about aerodynamics, but I'd guess this would NOT be
a nice
situation...

>However, I am encountering another problem that could be
insurmountable.
>GEV over water, when the pressure required to hover (say 10psi) exceeds
>the mass of the water underneath (not very well put, but I hope it gets
>the idea across) wouldn't the vehicle sink?  Anyone know at what
pressure
>this would occur.

Yep, the vehicle would sink. I'm not sure what pressure you'd need, but
the
GEV would sink if the pressure exceeds the mass of the water. Floating
on a
cushion of air over water is similar in effect to floating a boat. 

>Roger (I don't remember the Slammers going over water, did I miss a
story?)

I remember they mention water at one point. Can't remember the story
though...

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"