Re: [GZG] Railguns

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Gzg-l mailing list
Gzg-l@mail.csua.berkeley.edu
http://mail.csua.berkeley.edu:8080/mailman/listinfo/gzg-lHugh, I am not
disagreeing with your general conclusions, but there is a little thing I
would like to correct on your reasoning:

>A 5" shell is about 30kg warhead, a 16" Iowa shell is 1225kg. The
only weight I've seen (so far) given for the 32MW railgun is a
20kg dart. So for ammunition storage and handling it's much closer
to the 5" than to a battleship gun.

They are talking about 33 MegaJoules, not megawats (I do not think they
mention how much power was necessary to achieve that energy, or how big
the batteries and capacitors were). 
 
That is the (I assume, muzzle) energy of the round that was shot.
Assuming sea level, and standard (or close to standard) atmosphere and
temperature, Mach 7 is 2380 metres per second. 
 
33 megajoules kinetic energy, at 2380 m/s, would imply the projectile
had a mass of almost 12 kg (about 25 lbs).
 
Anyway, it IS an amazing and potentially game-changer achievement. There
are not many man-made things than have reached that speed. 
 
And it is a step forward towards Gauss Rifles ;)
 
Just my 2 cents,
 
David