A concrete lathe

[Billzilla]

Yes, a lathe made from concrete.

Lucian I. Yeomans designed concrete machine tools that were used to produce most of the American cannon shells in the First World War. His techniques have been almost forgotten since then.

“An unusual type of single-purpose lathe was designed by Lucien I. Yeomans, of
the Amalgamated Machinery Co., Chicago, for which he was awarded a medal
by the Franklin Institute of Philadelphia. This type of lathe was intended for
making large shell of from 6 to 16 in. in diameter. The head-stock and body of
the lathe were cast in one solid piece, with holes cored out for the spindle and
ways. The ways were merely accurately ground lengths of round steel shafting
so placed that the ends projected through the cored holes in the bed. They were
properly located by means of huge master jigs, and then type-metal was poured
into the cored holes and around the ends of the shafting. This held them securely
in place. The carriage and cross-slide guides were made and located in the
same general way. The lathe spindle turned in a machined bushing which was
set into the cored hole in the head and secured with type-metal. This method of
construction saved an immense amount of machining, as there was no work put
into its construction except such as could be turned or bored. The makers were
enabled to turn out a large number of machines in an astonishingly short time."

http://finance.groups.yahoo.com/grou...-Machine-Tools

And ...

http://flowxrgdotcom.files.wordpress...ing-lathes.pdf

Just thought it was interesting that something like that could be done.

[bigmuz]

That's cool.

Brass is a bit easier to turn than steel but it is pretty cleaver for war time.

[Gammaboy]

Muz, when talking of cannon, shell is the projectile, shell casing is the brass bit. Besides, alot of artillery didn't/doesn't use a shell case, the used bag charges instead. Very clever way of doing it, gets away from using war critical materiel too.

[Fondles]

Lovin the concrete lathe, awesome find Bill.

[motoxray]

Muz, when talking of cannon, shell is the projectile, shell casing is the brass bit. Besides, alot of artillery didn't/doesn't use a shell case, the used bag charges instead. Very clever way of doing it, gets away from using war critical materiel too.

Very true, as long as gunner remembers to swab the breach between rounds, in case smouldering remnants of the charge bag are left behind! The results are not pleasant.
My experience of these things is fairly old, though, so I wonder if anyone has come up with another option, as the swabbing slows down the fire rate as compared with cannister artillery.
Apologies for the hijack, Bill. Very interesting re the lathe, I would never have imagined it could be done.

[Momus]

Modern USA Hardinge CNC lathes use a form of concrete for their basic structure.

[thechuckster]

Very true, as long as gunner remembers to swab the breach between rounds, in case smouldering remnants of the charge bag are left behind! The results are not pleasant.
My experience of these things is fairly old, though, so I wonder if anyone has come up with another option, as the swabbing slows down the fire rate as compared with cannister artillery.

isn't that what the gas injection system (found in WW2 navy guns) is/was supposed to do? blow the breach clean before you rammed in the next round and charge behind it?

[Gammaboy]

isn't that what the gas injection system (found in WW2 navy guns) is/was supposed to do? blow the breach clean before you rammed in the next round and charge behind it?

That, and a little cooling.
I was actually referring to the concrete lathes when I said clever way to do it.
Modern stuff largely uses combustable cartridge case (some use cellulose acetate, some are a nitrocellulose mixed with binders) instead of charge bags.

[PHULL]

It's also a very common upgrade to majority of the chinese lathes too. Epoxy and granite chips

[bigmuz]

So they were turning steel in them? Bloody hell.