Re: GEVs

On Sun, 05 Dec 1999 15:11:03 -0500, Roger Books <books@mail.state.fl.us>
wrote:

>> But null-g packs are fantasy.
>
>So do you run grav-tanks?

Yep. I'm perfectly happy to suspend my disbelief. 

You have to understand that any "objections" I may have are to the
thinking
that some of the stuff we use in games is likely to occur at some point
in our
real future. But I'm perfectly willing to accept them as part of a story
or
game environment. Jon's geo-political spectrum is far more flawed than
his
science (I still snicker at the NAC... *L*) but it's fun to think about.
I
enjoy the Slammer books (well, most of them... there were a couple where
Drake
was just going through the motions). That doesn't mean they are likely
to
occur, or that their lack of liklihood takes away from the story for me.

As a good friend, and science fiction anthology editor (as well as head
librarian for one of the largest public collections of sci-fi in the
world)
once told me, science fiction has nothing to do with predicting the
future...

>The part of the force pushing backwards on the skirt is exactly
balanced
>by
>the force on the frame of the vehicle.  There is NO net thrust from the
>air cushion EXCEPT for that of the escaping gas.

Okay, now that I'm actually more awake, I thought about that. You're
right.
That leaves the air going out the cushion, with the force vector
parallel to
the ground, not straight vertical. Thus the vector has a downward
component.

> 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.
>
>That's the wonderful thing about compressed air, it balances to the
same
>pressure
>at all points.

Then as soon as you hit the slope the air pressure will drop. You will
have to
run the fans up to a higher power as the volume in the skirt increases,
or you
risk grounding the vehicle.

I suppose it would work... except for the thrust vector on a slope. And
I'm
not sure you could generate enough force for a grav tank. Depends on the
size
and weight of the vehicle. But one thing that got lost in my original
post:
with all the weight and energy going into pushing the tank so that it
hovers,
you're taking away from weight for armour and armament (and crew space,
electronics, etc...). Except in special terrain situations you'd have a
more
efficient vehicle if you used something like tracks.

>I can see it now, you drive your tank across the swamp, going fine over
>the
>muck as the water is pushed away, when you hit the main channel where
>the
>water is 20 feet deep.  At least you make lots of bubbles as you go
>down. :)

*L* Yep. On the other hand, you can get around this by making a BIG
vehicle.
The Russians have a huge ground effect vehicle (that looks a lot like an
aircraft) for landing troops amphibiously. It uses aerodynamics and
speed to
create the ground effect. They would be good for amphibious operations. 

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"