Re: GEV and Grav Vehicles

Thomas Barclay wrote:

> 1) Oerjan is right in a sense - Grav kills other manouvre tech not a
> weapons system. My point was it kills ground mobile arty. Arty that
> can fly probably uses something more like helicopter armaments
> (Mavericks, Hellfires, Rockets, etc) rather than something like a
> 200mm gun, I'd think. Though there may be a niche for flying arty
> platforms that still land to shoot.

Until you get Mavericks or Hellfires which you can fire indirectly at
ranges of 40 km and above, indirect-firing artillery will have a niche.

Whenever you have a supply dump (which isn't mounted on grav vehicles)
within 50-150 km of the enemy, indirect-firing artillery will have a
niche.

> 2) A tank is loud and noisy. So is a GEV. Either can be made lower in
> singature by the application of a) money and b) engineering. Grav
> might actually be the quietest and lowest signature possible.

Grav might be low-signature, but I doubt it. If something starts
messing with the local gravity field, I suspect it would be fairly easy
to detect :-/ It
probably wouldn't be anywhere near as noisy as a GEV, but it would have
other signature problems to cope with.
 
> 3) Can we build a hovercraft that ways 80 tons, carries the kind of
> armour a Leopard II or Challenger or late model Abrams does, mounts a
> 120-140mm CPR gun or another big main weapon? I have my doubts. If >
you could, it'd eat deisel at a far faster rate than even a tank! 

Considering that even the Challenger (the heaviest of the current
Western tanks) is "only" 62 tons fully loaded, and the various
ex-Soviet tanks average around 45 tons, I'm not entirely sure why you'd
want to make the GEV tank 80 tons :-/

I'm also not sure why you are talking about GEV tanks, when I wrote:

"... I wouldn't be surprised at all if you could build GEV SPs and APCs
with today's hovercraft technology. Not particularly economic, of
course, but probably possible."

Note the complete omission of tanks from the list; it was entirely
intentional. Modern 155mm SP guns average around 25-30 tons when fully
combat loaded, ie about half the mass of an MBT.

> It has
> to pay gas costs to hover - even when it is stationary (if it wants
to
> not have a lag in getting moving). I think if we had Fusion or
> A-Matter power, that'd be a non issue. But with gas engines or power
> cells, it is an issue.

Of course. That's why I considered it "not particularly economic", you
know.

Looking at today's military hovercraft and assuming that track
transmission is about as heavy overall as skirts (the skirts themselves
are probably lighter, but the extra turbines and fans aren't), we'd
need to increase their cushion pressure by about 75% from the 1989
level to make an M113 APC hover. I'd be quite surprised if this were
not *technically* possible today. Why you'd want to do this beats me,
though <shrug> It'd definitely have severe problems with dust/spray
clouds and noise, too.

An M109 or CV90120 (SP arty and severely overgunned light tank,
respectively) would need almost three times the cushion pressure;
that'd be more difficult but may still be possible to do.

An M1A2 would need about four times the ground pressure of today's
hovercraft. This starts sounding a bit too heavy for today's
technology. The most serious problem isn't the energy supply, though -
it is finding space for the lifting and maneuvering fans and air
intakes, preferrably somewhere where they won't be wrecked by the first
burst of small-arms fire directed at the vehicle <g>
 
> 4) GEVs can move through swamps and if packing non-recoil weapons
> could even fight there. I agree CPR arty would be problematic.

There are no non-recoil weapons. Only low-recoil ones... and I'd want
to be *very* certain of my platform's stability (and ability not to
drift into various nearby objects) before I fired any large weapons
from it while hovering over a swamp :-/ Particularly if I am to fire
them in any direction other than straight ahead of the vehicle.

> Oerjan, you can cuss me out for making you pick up DS2 - but you
> undoubtedly have a lot of first hand info of interest here so I don't
> apologize one bit ;)

I didn't have a lot of interest in it until you made me look closely at
it :-/

Oerjan Ohlson
oerjan.ohlson@telia.com

"Life is like a sewer.
  What you get out of it, depends on what you put into it."
- Hen3ry