Evening star. [volume] (Washington, D.C.) 1854-1972, 1899-07-29
Powerful Guns.

| These new type 12-inch guns are heavier
and more powerful than those of the old
! type, and indeed more powerful even than
| the 13-inch guns, such as form the heavy
battery Of the Oregon. The old Pinch gun
weighs 40 tors, while the new weighs Sc.
| Each of these types well as the 13-inch
| gun is forty feet long But while the H.
| inch gun, that weighs COZ tons, has Il muz-
| zle velocity Of 2,4W feet per second, tie
new Pinch has a muzzle velocity of 1900
! feet But another great practical adj
vantage Of the new Pinch over the 13-inch
lies in the economy of weight in both gun
and ammunition highly important con-
slderation aboard a big battle ship. 4
| charge for the 13-inch gun weighs 1850
| pounds, LOO for the projectile and $50 for
| the powder. A charge for the new Pinch
gun, however will weigh only 600 pounds,
! 800 for the protectile and 200 for the smoke
! less powder, and inasmEch as 100 rounds
| are provided for each gun on fitting out a
| battle ship, the ret saving Of weight by the
change from the 13-inch to the Pinch gun
will be $50 tons on the ammunition and is
| ions on the guns Themselves or us tons
weight saved per ship By this means a
greater destructive effect will be secured
| IL proportion to tonnage. New designs are
| being used, fact, in making the latest
| guns of all calibars. calculated 10 insure a
much greater muzzle energy than is now
| obtained from the guns Of The same calibers
| heretofore made.
| Besides these guns there remain yet to be
made the entire batteries for the three adj
dluonal battle ships and nine cruisers au-
| thorized at the last session of Congress,
and these. with the batteries for the ships
already building, insure a long course of
uninterrupted activity in naval gun man
ufacture.
Require Great Skill.
The processes of gunmaking pursued at
| the naval gun factory are comparatively
simple, and yet they are the result of un-
told study, research and experiment and
require at each step the highest order of
mechanical and mathematical skill. The
production of the forgings, which in itself
Is long and difficult art, is not attempted
at the gun factory Instead, the govern
ment buys the forgings of private manu-
facturers-chiefiy the Bethlehem Iron Com
pany at South Bethlehem, Pa. the Mid
vale Steel Company, at Nicetown, Phila-
delphia, Pa, and the Benjamin Atha and
llllngworth Company, at Harrison. n. j.
and the gun factory concerns itself with
the transformation of these forgings into
completed guns. In producing the forgings
Tor gun of any particular caliber cast
ing Is first made in cylindrical form, of the
nneSt obtalnable open-hearth gun steel, of
a weight about double that of the forging
required. In the steel there must be no
bubbles, flaws riffs or imperfections what
ever, and the whole mass must be abso-
lutely uniform and perfect in texture
After casting about 30 per cent of the
weight of the ingot is cut off the upper
part and five per cent from the lower end,
and the remainder is then forged under
heavy hammer or by a hydraulic press to
shape approximating that of the finished
piece TO be made. and the product is then
put into lathe and rough machined.
After that it is treated subjected to sew
eral interesting chemical processes well
known to metallurgists, and improved as
to quality and temper, and pieces are cut
from the ends samples for testing If
the government inspector finds that the
samples meet the requirements the forging
is accepted and shipped to the gun factory
a WlG inU ri,,nr-
include, in addition to that for the tube
one for the jacket or strengthening cyln-
der placed over the tube, one for the chase
hoop and one for the jacket hoop, and
besides, there must be forgings for the gun
mount, carriage, ETC.
Process of Manufacture.
After the delivery of a set of forgings at
the gun factory, the tube forging is first
bored roughed out nearly to the desired
interior diameter, and the outside is like
wise turned on the lathe and smooth-ma-
chined to the finished diameter. Next, the
jacket forging is bored out inside to a
| diameter slightly less than the exterior
diameter of the tube which it is to encir-
Gle. Then 1t is expanded by heat In a hot
air furnace, and, lifted carefully by means
OF crane, is placed directly above the
tube, which is stood upright in shrinking
pit and securely held with the breech up
ward. The jacket is then allowed to de-
scend accurately and slip down over the
breech end of the tube. Later, as the
jacket cools; it grips tightly over the tube
and congresses it. practically forming one
piece. When cooled. the tube and jacket
now Joined in one are putsinto lathe and
the outside of the jacket is turned smooth
to it's finished dimensions
After this the forgings for the hoops are
also bored out to dlameters slightly less
than the respective portions of the gun
which they are intended to encircie and
one after the other they are put in place
aS hat cod ;a =,
jacketing. When all the hoops are on and
all the parts put together, the gun is
again placed on the lathe and finish bored