The Delaware ledger. (Newark, Del.) 1879-19??, 1883-12-22

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 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
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 ''steel in the rough" 80
to speak, becomes a long cylindrico-
conoidal column. In this condition it
is placed in proper position and hole
drilled clear through it by means of
what il called "hog bit." The hog
bit is small rectangle of very hard
steel, turned up at one end in such
manner as to form rude vertical sec
ton of spherical triangle. The whole
rectangular piece is then clamped
down upon fiat shaft of chilled non
IL ouOh q Ai1hhlCA 10 W III III anu ICIm
one piece with the shaft. The latter
has at the opposite end a cylinder
shape, which end is held in frame
and worked by appropriate machinery
moved by steam upon one end OF the
steel column 10 be perolrated. The end
of the column is first "dug into a
little, and then the "hog bit" does its
work. 1t reyolves on its axis and the
bit describes a circle, tearing out the
hard steel slowly but surely. As the
guns have a bore of Blk inch diameter,
and the bit describes a circle of only
two and three quarter inches radius,
the enlargement of the perforation is
accomplished by other bits.
Once perforated the now hollow tube
of steel requires to be "jacketed.
"collared" and "breeehed" 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
side tube with almost the same degree
of cohesion as the molecules of the steel
themselves. The object of the ''lacket"
is to strengthen the gun and prevent
accident. The explosive force of gases
evolved from gunpowder being tre-
mendous and occurring mostly at the |
breech the primary object ls to strength
en- this latter part, Collars OF steel, |
great blocks of carbonized iron baYiug |
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 part of it. The breech head
OF the gun is next lathed and fashioned,
different workmen being employed on
different parts of this. The rifling of
the gun Is another step. A different
kind of 'bit'' from the ''hog," spur
Of steel tempered to a great hardness,
is clamped to the centre of semi
circular piece of copper and iron, and
thus last device is slowly worked through
the gun on a spiral turn, giving the
''rife twist" The breech head is then
yrooved and adjusted and the hreech
sap formally adjusted. This, as is
known to all who have examined breech-
osders, SWINGS back on a hinge or
,pring, and when closed is securely |
ocked by lever clamp.