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. 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.

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.

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.

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

Dan, U.S. Air Force, retired