(Henry Spencer) wrote:

In article ,
Tux Wonder-Dog wrote:

The plate surface would be sprayed with, roughly speaking, grease before
each explosion; the plate itself would not ablate. This was tested, and
it was effective enough to eliminate any need to make the plate itself out
of anything exotic.

Tested at small scale - it's one of the Big Unknowns for a full scale
Orion. (There are a couple of unanswered questions about design
principles and details IIRC. No showstoppers, but contrary to the
handwaving of bombardmentfarce, we can't build one from a standing
start - a non trivial amount of development must be done first.)

And that's the crux of the matter. If that vast instantaneous pulse of
energy is to be absorbed to pass it on to the spacecraft, then it will be
like being inside a battleship while firing a broadside. Except that
battleship will have it helluva lot easier.

No, the battleship has it a lot worse -- it has nowhere near the
shock-absorber stroke that an Orion would.

Yet big-gun recoil absorbers are fairly simple and compact devices.

The recoil stroke for a battleship gun is severely limited by the
requirement that the whole motion fit within a cramped turret even when
the guns are elevated at a high angle. (You can't just make the turrets
bigger because their walls and roof are thick armor, and they're already
enormously heavy --

Which is why 'modern' (I.E. early 1930's) big guns push the trunnions
as far forward as possible - right against the mantlet plate. When
you look at the back of one of the Iowa's guns, most of what you see
is a honkin' big counterweight. This combo allows you to increase the
length of the recoil stroke without materially increasing the size of
the turret.

one of the problems cited with schemes to do major revisions to the Iowa-class
battleships was that the USN apparently no longer has a shipyard crane that can
lift one of those turrets.)

That's a bit of a red herring - as the turrets were not lifted on in
one piece in the first place. They are designed to come apart for
regunning or to repair battle damage. It's a non trivial job, but
it's doable. (In the second place, at least one of the cranes used
for such jobs is still operational about 10 blocks from where I sit.)

D.
--
Touch-twice life. Eat. Drink. Laugh.

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL