The mirror. (Stillwater, Minn.) 1894-1925, 1917-08-02
Making the Giant Guns

Making the Giant Guns
This is war of neutrality-suspicious.
from bombs hurled by hand at the enemy
to explosions of shells weighing 1000 pounds
thrown 20 miles by giant guns over 17-inch
calibre and weighing over 100 tons. 1t is
war of machinery, with the limits of danger
zones limited only by the range of the
greatest guns. In fact, the art of war today
is "a-r-t-illery," a statement which appears
literally to be true.
The United States army and navy are
now being rapidly equipped with guns of
various types, most of them American in
ventions, among which are machine guns,
horse artillery guns, field artillery guns and
howitzers, heavy siege guns, anti-aircraft
guns that can shoot 1000 feet straight up
in the air. and naval and coast defense guns
of 16 and 17-inch calibre, capable of hurl-
ing a ton of steel more than a score of miles.
AT the navy yard in Washington is as
sembed what is said to be the finest assort-
ment of machine tools in this country, if
not in the world, for in the nations capitol
is the big job of making the giant guns of
marvellous accuracy and power with which
American dreadnaughts are armed and the
coasts defended.
The governments gun factory at Wash
iugton, running "a hours day for year,
could, it is estimated, build only 20 12-inch
or 14-inch guns, so vast is the amount of
work required to construct one of these
monster weapons, of which one of Uncle
Sans dreadnaughts carry as many as a
dozen.
Not all of the governments great guns
however, are built at the Washington Navy
Yard. Some are constructed at the army
gun factory at Watervliet and still others
at privately owned steel plants. While the
naval gun plant at Washington machines
and finishes the rifles turned out there, it is
dependent upon private steel plants for the
monster rough forging required.
The time required to complete gun of
12-inch or 14-inch calibre ranges from eight
to nine months.
These rifles are the output of mechanics
of the highest skill, and weigh anywhere
from Sc to 80 tons, independent of thei1
mounts. They are fashioned with such
precision that they must agree in some Of
their dimensions within 1-1000 of an inch
with the size specified. This, of necessity
is an unavoidable brake upon speed in pro
duction.
These big guns are constructed on wha
is technically termed the built up principle
that is, they consist of series of steel tube
shrunk on successfully. When the ina
hoop or partial jacket has been shrunk upol
the gun this cumbersome mass is then ex
actly centered in the lathe, preparatory It
finish boring the inner tube.
The workmen in charge of this operation
watch every tiny curl of the cut metal t
: prevent any particle of it from jamming be
tween the boring bits and scratching o
marring the wonderfully smooth steel SUI
1 face. Many weeks are often required t
bore one of these big guns.
The power chamber is next formed at tn
} rear, and after that follows the delicate tas
of cutting and riAing the grooves. Almo:
). superhuman accuracy is required in th
operation, for the gun is machined to ZOO
of an inch by a tool that is mechanic;
= marvel.
1 The efficiency of the modern rifle d.
9 ponds upon the speed with which it can
loaded, fired and reloaded, and the breec
mechanism is the chief feature that maxi
this possible. The breech plug must al
70 solutely seal the rear of the rifle at the il
"A slant of discharge against the backward e
. cape of the intensely hot powder case
N which have estimated pressure of II tot
s to the square inch at the moment of ii
IS explosion. Because of the great precisie
" and highest type of engineering skill d
manded by this operation it takes fully
long to make the breech plug as it does
make the gun, and in the biggest of Unc
Sans rifles this often means a period
| eight months and even longer.-Ec.