RE: To Grav or not to Grav?

G'day,

OK just to play devil's advocate, be contrary etc.... ;)

> What exactally does it mean to use grav vehicles?  I
> presume from the term that it means your vehicles have
> a contra-gravitic suspension, and probably a
> reactionless thrust mechanism (as spacecraft do). 
> They are powered by a fusion engine.	This means you
> have effectively unlimited endurance (a few gallons of
> hydrogen being enough to fuel the vehicle for a month
> of combat operations).  

At exactly what rate does fusion burn up the hydrogen (sorry its been
way
too long since my astronomy classes to remember)? This may actually end
up
being a very stiff assumption. You could probably still extract the
hydrogen
from atmosphere etc, but just assuming a few gallons will keep you going
months seems a little too giving to me.

> From a design perspective, this creates some
> interesting implications.  First, the difference
> between land and water vehicles is irrelevant.  Why
> have a specifically-designed coastal patrol vessel
> when you can use your main battle tanks to go sink
> ships?  The only difference would be that a grav
> vehicle designed for this role would carry different
> electronics suites from one intended to hunt tanks on
> land.  The difference between aerospace fighters,
> VTOLs, and Grav tanks is a matter of streamlining and
> power of engines rather than fundamental design
> differences....

OK dumb question, but why have different designs at all? If they've
broken
with the effect of gravity to a large extent then does it really matter
if
they're streamlined or not? Why not just use exactly the same kit for
everything from shuttle to tank?

> First, there is complete freedom from the fuel
> logistical tail.  Instead of convoys of tanker trucks
> hauling distilled petroleum products (which require a
> source of petroleum, and a chemical industry in place
> to refine them), an attacking force need only bring
> one or two hydrogen crackers per batallion, which can
> refine the fuel from any given water source in a
> single afternoon, fuel up the task force in a few
> hours (probably through in-flight refuelling) and then
> go take a nap for a couple weeks until they are needed
> again.

Assuming you're on a world with free standing water ;)

May be a tad more difficult if you've got to mine for it, get it from
the
atmosphere, go to the poles and lug some back etc etc. Think Mars under
its
current climate for one, while there may be stores of ice etc
underground,
you're best bet is the poles... now if you don't happen to be in control
of
them...

> Second, there is freedom from terrain.  While grav
> tanks/trucks can be held up by bad terrain when
> operating "tactically", at extremely low level,
> hopping up 100' or so makes any terrain easy....

Assuming you've got a pilots licence too - which is pretty safe bet if
they've been "flown down" from a space ship in the first place. I was
just
imagining a whole group of tanks flying over the Himalayas....

>  They could not operate in an intense enemy air
> defense environment, and take heavy casualties if air
> assaulted directly into contact.  

Do you think the grav vehicles would also suffer from this, or would
they
armoured nature make them more immune?
 
> While they don't have the life support
> facilities to fly around the world with their crews
> and passengers inside?

Why, if they're sealed and have such a good energy plant? On top of that
advances in algal scrubbers etc could see even biologically based life
support units being tiny in the not too distant future.

> In fact, these factors, taken together suggest that in
> event of a conflict between conventionally-propelled
> units and an all-grav force, the conventional force
> would be at such a disadvantage as to render it
> meaningless.

Assuming the gee-whiz gizmo that keeps the thingimee going on the do-dat
of
the grav tank isn't impossibly hard to get in the boon docks and can't
be
easily replaced with a bullet casing or some such. The one thing growing
up
on a farm taught me was that the more "techo" stuff got the more it was
likely to be %^&@# useless if something went wrong in the bush. E.g. I
accidentally put our aged truck in a dam once, but it was very easy to
get
myself out (roll down window and exit), but when the guy up the road did
the
same with his flashy new one he ended up having to smash a window...
he's
exact comment went something along the lines "$^%@! electronic window
control wouldn't $%^! work would it?!!" ;)