Re: GEV capabilities

At 06:09 PM 11/16/98 -0500, you wrote:
>
>>On 16 Nov 98, at 10:14, Adrian Johnson wrote:
>>
>>> Q:	if a Ground Effect (hovercraft) tank fires it's main gun, won't
it be
>>> propelled in the opposite direction - in other words, there's
nothing to
>>> push back against the recoil...  This would not be a problem if you
had
>>> directional fans providing propulsion AND the gun was firing in a
direction
>>> opposite to the thrust of the fans AND you had "burst" thrust
capability on
>>> the engines to compensate for the momentary thrust of the cannon
recoil...
>>
>>Sounds like a good reason to use beam weapons ;)
>
>That would be too easy.  Besides, I'd rather have solutions for the
>technical problem I posed, which would let me off the hook for
proposing a
>technical problem with a blatently obvious answer...
>
>....ah....wha... what about the recoil effect from all those propelled
>coherent light photons... or... the.. um... shock effect from the
>matter-antimatter matrix tranciever...
>
>fiziks?  bah!
>

Let's see...

Let's say that an HKP/5 fires a non-rocket assisted 4kg projectile 
at 3000m/s (Mach 9.1, I believe that that is quite a bit faster than 
current tech...).

If the GEV vehicle firing is 60 tonnes, then the velocity of the 
tank after firing (assuming it was initially stationary) would 
only be 0.2m/s=0.7km/h. Now, most tanks will have recoil damping 
through the use of hydraulics, so this could be reduced even more.

As you can see, any powerplant capable of propelling the tank at 
combat speeds could easily keep the vehicle stationary while firing.
Not to mention that hovercraft can come to rest on their skirt, which 
makes them much more difficult to move than wheeled or tracked 
vehicles of comparable mass. They would likely do this with the 
engines on standby while in hull down position.

       Tony Christney
       acc@questercorp.com

  "If the end user has to worry about how the program was 
   written then there is something wrong with that program"
				  -Bjarne Stroustrup