(B2431) wrote in message ...
rom: (John Redman)


(alfred montestruc) wrote

Imagine if you will I take say a 75mm cannon, hone the bore free of
rifling, then cut it into 6" section to make cylinders for a radial
engine. I can make the engine block out of a ductile iron casting,
the pistons, rods, and shaft from forgings of the same alloy as the
gun tube is made from.

I can then machine fins on the outside of the cylinders and bolt them
to the block. See any showstoppers?

The gun tube is not a homogeneous metal casting though.

I never said it was any sort of casting. My impression was that
modern era cannon tubes were either forged from billets, or are made
of hot rolled bar stock that was quenched and tempered then machined
to final shape. Casting (especially steel) is something you generally
do only when having lots of flaws in the metal is ok, which is not the
case in a gun tube.

If you must, then you must use a much larger factor of safety and
thicker gun tube.




WW1-era guns
were of wire-wound construction, which is as it sounds; i.e. a series
of inner tube segments around which a thick wire was wound under
tension in a tight spiral with a further metal casing on top.
Effectively it was a like a barrel with one long continuous hoop
around it.

Cite this please, I goggle searched and found not a single refernce to
that.



You couldn't literally slice one of these into cylinder lengths and
have a usable tube, nor could you machine cooling fins into it, for
obvious reasons.


You could if they were hammer forge welded.


I saw some film on the History Channel where they showed the wire wrapping
being hammer forged into a single monolithic piece of metal. Granted the film
was from the 1930, but I would guess it was the same in WW2.

Hammer forging is the oldest form of welding. It is done by black
smiths. Japanese sword smiths use that technique to make the layers
of the samari sword that make it both strong and hard at the same
time.


Knifesmiths make "Satan's lace" blades using a similar method of hammer
forging rods into a billet.


Sounds plausible to me.