Re: tank gun acceleration versus orbital gun acceleration

Rob Hofrichter wrote:

>A tank gun shoots a round with muzzle velocity in the 1000 m/sec range 
>(see "Modern Land Combat" but Miller and Foss).  A gun barrel is say
appx 
>5 m long.  Assume (for the sake of serious simplicity) that
acceleration 
>in the gun barrel is constant.  The acceleration that the projectile is

>subjected to should be about 10,000 g (100,000 m/sec2).  Please notice 
>that I'm using conveniently rounded figures.

The biggest approximation is that you assume a constant acceleration.
With 
today's propellant-powered guns it isn't, so the accels for "dumb" tank 
main gun rounds peaks around 40-50,000 g.

>   Also note that we are talking about a "dumb" round--the guided
missile 
> rounds generally have fairly low velocities (gun-wise).

[ka-snip]

> From this, I think you can begin to see that barrel length is VERY 
> important to the solution.

Yep, and superguns tend to be very long indeed. But also the 
time-acceleration profile - if you can maintain a reasonably constant 
acceleration all along the barrel you get away with a far lower peak 
acceleration for any given muzzle velocity.

>I'm sure Oerjan can come up with better numbers--and probably has the
data 
>on how fast the guided tank rounds come out of the barrel...

Not at home, unfortunately :-(

Later,
Oerjan
oerjan.ohlson@telia.com

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