The morning news. [volume] (Savannah, Ga.) 1887-1900, 1898-09-01
HOW BIG GUNS ARE MADE.
Assembling the Huge FOrgings at
the Washington Gun-FOundry.

From ST. Nicholas.
The guns are made of what is called
forged steel This steel is made by pri-
lehem 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 be-
ing finished, are put together and made
into guns. The jacket of a gun is about
half the length of the tube, and itself is
really a large tube. The inner tube, when
it arrives, is put into lathe, and has the
hole bored out to nearly the size 1t will be
when finished; then 1t Is turned down In
side for about half its length from the
rear or breech end to it's proper size.
Turned down means that the metal is
cut off with a steel cutter. The jacket also
is bored out smoothly and the hole care
fully measured. The diameter of this hole,
or bore, in the jacket is little smaller
(some hundredths of an inch) than the out
side of the tube after being 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 1t will lift weight even
greater. Near the center of the gun-shop
is a 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
furnaces, so that IL 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 furnace has a
top, or cover, which lifts off, and which
is put on after the jacket has been lowered
into 1t. Hot air Is forced into this furnace,
which heats the jacket tll9 it expands so
that the size of its bore becomes greater In
diameter than the size of the tube it is 10
inclose. When all is ready, the cover is
lifted from the furnace, the crane hooks
on to the jacket, lifts 1t out of the fur
mace, and swings it over the tube. The
jacket Is then quickly measured. and care
fully lowered over the tube, which Is
standing on its end. A stream of cold wa
ter is then admitted into the lower end of
the tube. This water rises nearly to the top
of the tube, and helps to cool both tube
and jacket, now fitted together. AS the
jacket cools it shrinks to its proper size,
and so squeezes and holds the tube tight
within.
When both are cold, the partly made gun
Is lifted out of the pit, put into another
Eathe, and turned down outside so as to
be ready to have the hoops put on. These
hoops, which have been bored out to the
proper size, are heated and shrunk on over
the gun just as the packet was shrunk on
over the tube. The whole gun is made or
built up, in this manner. After all the
hoops are on, the gun is bored out again
to final size, put into a rifiing machine,
and rihed; that is, 1t has grooves cut in
side of the bore throughout Its length.
These grooves commence at the muzzle,
and gradually curve till they reach the end
of the bore. They are cut by what is called
a rihing-bar, which Is a long shaft with
cutters at one end. The gun remains
steady, while the bar enters into the gun
at the muzzle and turns at the same time,
thus cutting what are called spiral grooves
throughout the length of the bore of the
gun. This rihing is done so as to give the
shot or sheS1, when the gun is fired a twir-
ling or rotary motion, which prevents II
from tumbling end over end, and causes
it to keep pointed In the right direction The
shot or she'll (projectile) Is long, and has
copper band fitted on It's rear end When
the gun is fired, this copper band, being
softer than the steel of the gun, enters
into the grooves, rs turned by them, and
gives the projectile a spinning motion dur
ing Its flight.