The Scranton tribune. [volume] (Scranton, Pa.) 1891-1910, 1898-07-01
HOW A AIO.INCH SHELL Is MADE.
story OF the Process Until II Is Ready
for Its Work of Destruction.

The complete story of the manufac-
ture of one of the big battleship pro-
jectiles has always been hard to oh
tain. The Firth-Sterling projectile
works at Demmler. near Pittsburg,
are barred to an outsider, only repre-
sentatives of the government and Of
ficials of the company having access
to all the departments. Even the
workmen of one department are for
bidden to enter another Here is the
history of the making of a 1O-inch
shell:
In the casting shop molten steel is
cast in a solid piece about 12ts inches
in diameter. From the casting shop it
goes to the forge room, where, after
being reheated. it is hammered down
to 10A inches. being considerably
elongated in the process. 1t is then
conveyed to the machine shop and
placed in a specially constructed lathe.
The base of the projectile is inserted
in the lathe CHUCK" and the conical
end is swung from the lathe center. A
'roughing" cut is then run over the
shell, the shell itself is pointed, and
then receives a finishing cut.
The only parts of the shell that bear
the larger part of the conical end and
the surface of a copper ring that en-
circles the projectile near it's base. The
copper is quite soft, so does not in
jure the rifling. After the finishing cut
is given to the propectile. the diameter
of the largest part of the cone is 10
5-10O inches, and that of the cylinder,
which is the body of the projectile ex-
lNan al
100 inches.
The workmen now apply the band
score" which is a groove cut for the
reception of the soft copper band. For
10-inch projectile the groove is Ia
inches wide at the bottom and Y Inch
deep. The groove is wider at the bot
tom than at the top, so that the cop
per band retains it's position after it
has been placed in the groove and
pounded down until the copper swells
out and fills the groove, thus taking a
fiange hold on the under side.
Then the 'exacting score" is cut.
This presents sectionally view like
the letter V. with the letter lying on
one side and the convereing line point
ing to tie base of the shell. This grove
is made to permit a tool to be fastened
to the shell when it is desired to with
draw it from the gun. The shell, is put
in the cuttins-off machine, where the
surplus length is taken off. The next
move is the boring of five-inch hole
in the base to a depth of fourteen in
ches.
In the process of hardening the shell
is suspended point downward in a re-
ceptacle filled with molten lead. and
is allowed to settle until the hot metal
rises above the cone base. At first the
temperature of the lead is 500 degrees,
but is increased gradually to 1900 de-
gree3 The work of heating requires
four hours, when the she'll is with
drawn from the bath and sprayed with
water to give it a hard exterior. 1t
is then plunged into q, bath composed
of secret ingredients. and when with
drawn it is cooled with a jet of water.
The projectile goes again to the ma
chine shop, the hole in the base is
widened half an inch and the depth Is
increased two inches. The hole is
threaded" few inches and a screw
plug is inserted. The grinding room is
the next destination, and here the ex-
treme diameter OF the cone Is ground
down to 10 inches exactly. After a soft
steel cap has been fitted to the tin of
the projectile. on the theory that when
the shell strikes the armored side of a
battleship the soft steel preserves the
point of the projectile without inter-
fering with its penetrating power, the
shell is finished as far as the Firth
Sterling company is concerned. 1t is
exactly 27 l-3 inches long. After it has
been received at some United States
arsenal it is filed with an explosive
compound and is ready for it's work o,
destruction,
All large projectiles. from the 6-inch
size up, are made as described. The
machinery at the Demmler plant con-
sists Of twelve lathes. four boring mills,
two cutting off machines, two tool
lathes, two chasing machines, one
grinding and one centering machine.
This equipment is being reinforced, as
the company has enough work on hand
for the government and foreign coun-
tries to keep the plant busy for two
years,