The Maryville times. (Maryville, Tenn.) 1884-1944, 1898-10-29
UNCLE SANS BIG GUNS
How the Huge ForEings Are Assem-
bled In the Government Gun
Foundry ut Washington.

III Dl. ANltHOldo lllElC 10 al AAAhSNA 1870
article on THE Gun Foundry at Wash
ington." The author sayst The guns
are made of what is called forged
steel. This steel is made by private
firms, principally at the famous Beth.
,ehem works in Pennsylvania, and is
sent to the gun foundry in the shape OF
large tubes, and in other shapes called
jackets and hoops. These steel pieces,
after being finished, are put together
and mad into guns. The jacket OF a
gun is about hals he length of the
tube, and rtseif is really large tube.
The inner tube, when ii arrives, is put
into lathe, and has the hole bored out
to nearly the size il will be when fin
ished; then it is turned down inside for
about half its length from the rear or
breech end to its proper size. Turned
down" means that the metal is cut off
with steel cutter. The jacket also is
bored out smoothly and the hole care
fully measured. The diameter of this
hole, or bore. III the jacket is little
smaller (some hundredths of an inch)
than the outside Of the tube after be-
ing turned down.
Overhead in the shop are big cranes,
which travel back and forth on tracks,
and which can easily lift and carry
heavy weights. The largest crane is
called the 110-ton crane, but it will lift
a weight even greater. Near the center
of the gun shop is large pit in which
there are furnaces. After the tube
has been bored out and turned down
outside, it is carried by crane and
lowered into the pit near the fur
naces, so that it stands on its muzzle
end. the breech end being up in the air
The Jacket is also lifted and lowered
into furnace and heated. This fur
mace has a top, or co7er. which lifts
off, and which is put on after the jacket
has been lowered into it. Hot air i;
forced into this furnace, which heats
the jacket till il expands so that the
size of its bore becomes greater in
diameter than the size OF the tube it i:
to inclose. When all is ready, the
cover is lifted from the furnace, thu
| crane hooks on to the jacket, lifts il
out of the furnace, and swings it ovei
the tube. The jacket is then quickly
measured, and carefully lowered ovel
the tube, which is standing on its end
| A stream Of cod water is then ad
mitted into the lower end of the tube
This water rises nearly to the top O.
the tube, and helps to cool both tub'
and jacket, now fitted together. Al
the jacket cools 1t shrinks to its proper
size, and so squeezes and holds the tubs
tight within.
When both are cold, the partly mad'
gun is lifted out of the pit, put into an
other lathe, and turned down outside
so as to be ready to have the hoop
put on. These hoops, which have beef
bored out to the proper size, are heate'
and shrunk on over the gun just as TIL
jacket was shrunk on over the tube
The whole gun is made, or built up, II
this manner. After all the hoops ar
on, the gun is bored out again to fina
size, put into rifling machine, ant
rifed; that is, it has grooves cut in
side of the bore throughout its length
These grooves commence at the muz
zle, and gradually curve till they reac'
the end of the bore. They are cut b.
what is called rifling bar, which is