The Penn's Grove record., 1883-12-22
Making steel Cannon.

The two new SIX inch steel guns now
being constructed in the ordinance
shops in the navy yard at Washington
will probably not be finished for several
months. The work of building them is
necessarily a slow one. All the labor is
performed in the shops here, except the
manufacturing OF the steel. That is
done at the Midvale Works, in Easton,
Pa. The steel then is shipped to Wash
ington, and the work of converting 1t
into cannon is performed. This is q
complex operation, and to the locker on
is decidedly interesting. The steel is
first turned by a lathe working slowly,
but with tremendous power until the
heavy mass of 'tsteel in the rouRh," 30
to speak, becomes a long cylindrico-
conoidal column. In this condition it
is placed in proper position and a hole
drilled clear Through 1t by means OF
what Is called q ''hog Bit" The hog
bit is Il small rectangle OF very hard
steel, turned up at II end In such a
manner as to form a rude vertical Sec
ton of a spherical triangle. The whole
rectangular piece is then clamped
down upon q fiat shaft OF chilled iron
in such a manner q to fit in and form
one piece with the shaft. The latter
has at the opposite end a cylinder
shape, which end is held in a frame
and worked by appropriate machinery
moved by steam upon o'skiApd OF the
steel column 10 be peroirn sil The end
of the column Is first into a
little, and then the "ho'k. does its
work. 1t rev olives on ite on and the
bit describes a circle, tef ag out the
hard steel slowly but surely. As the
guns have a bore of SIX inch diameter,
and the bit describes q circle of only
two and three-quarter inches radius.
the enlargement of the p~erioration is
accomplished by other bits.
Once perforated the o hollow tube
of steel requires TO be 'jacketed."
''collared" and s'breeched" before it is
allowed to graduate into the society of
cannon. The jacket is an outside wrap
of steel, followed in the same way,
heated until it expands sufficient to be
slipped over the tube it is intended to
Jacket. Upon cooling this outside wrap
contracts and presses upon the now in
SLUG tuDc Will dlLntbb tnC oanko uCRIC
of cohesion as tue molecules of the steel
themselves. The objecto of the ''Jacket'
is to strengthen the gun and prevent
accident. The explosive force of gases
evolved from gunpowder being ire
mendous and occurring mostly at the
breech the primary obiectl s to strength
en- this latter part. Collars of steel,
great blocks of carbonized iron hayiug
been turned into shape and perforated,
are next expanded by the heat and slip |
ped over the breech part OF the gun.
When contracted they grow into and
become a part of it. The breech head
OF the gun is next lathed and fashioned. |
different workmen being employed on
different parts OF this. The rihing of
the gun Is another step. A different
kind of ''bit' from the s'hog," a spur
OF steel tempered to a great hardness, |
is clamped to the centre OF a semi
CIRCULAR piece OF copper and iron, and
this last device is slowly worked through
the gun ON a spiral turn, giving the
''rihe twist" The breech head is then
grooved n adjusted and the hreech
cap formally adjusted. This, as is
known to all who have examined breech-
leaders, swings back on q hinge or
spring, and when closed Is securely
locked by a lever clamp.