The Providence news. (Providence [R.I.]) 1891-1906, 1898-03-05
PAGES
9 to IL.

while naming gas bursts from the sSoeo
OF the mold. In England the pressure
at this stage OF the process Ia applied
from above.
This compression makes the lump Of
metal homogeneous. Before the hy-
draulic press was used 40 per cent of
every ingot had to be cut off from tho
top, because that part was porous. Now
only a small stub. or sinking head, is
left at the top. and that, with the piece
cut from the bottom OF the ingot to
remove impurities which may have set
tied in the mold is no more than 13 per
cent of the whole casting.
The ingot is left In the press for some
time after the gases have ceased to
escape. Then il is taken outside the
furnace room and two days later the
mold is broken away. the inner jacket
| adhering 10 the metal. This jacket II
removed in great lathe, and the de-
| fective part OF the ingot is cut away.
| Now IL is ready to be made into a tube
| for great gun.
The first step in the forging is to
make n hole in the big steel block
Sometimes this hole is bored on a lathe.
! These gun lathes are enormous ma
chimes. There is one at Watervliet ar
senal which weighs 100000 pounds. The
process of cutting q hole through the
ingot cold is much slower. however, than
| punching q hole through the hot metal.
and. though cutting is preferred when
the works are running under pressure.
as they now are, the ingots are usually
| punched out.
| great crane comes down the shop
and picks up the S5 ton casting with
what looks like a pair OF exaggerated
ice tongs. This crane runs on an ele-
waited track. 1t runs up and down and
I -. Al. at.
an engineer. who sits in little box a.
the top of the building and travels with
II. At the movement of a lever IL runs
this way or that. or ii raises or lowers
| the clamps which hang suspended from
| II by a chain whose links are an inch
thick. 1t works as easily and smoothly
and surely as the sand dredge that you
may have seen working in harbor or
the crane that picks up boxes and bar
rels at a wharf and drags them into the
hold OF vessel. The $4,000 pounds
which hang between the jaws Of its
clamp are as little to it apparently as
q block of wood. 1t picks up the great
casting and puts it. down on q car,
which carries il to the furnace ROOM
There a mandrel is put through 1t, and
it is hoisted by another crane and
swung into the mouth of the furnace.
AS II settles down the mandreI-a long,
straight shaft of metals tilted until
the casting slides off the end and set
ties on the bottom of the furnace.
There you may see IL and other great
hoops standing side by side, some
black. some red. some glowing white
with the furnace heat.
When the casting has reached the
temperature for forging. the crane low
ers the mandrel into the furnace, drops
| itatn ha hA1a In, fl,A Inc. .,..1 a.
It until the casting rests on it horizon
tally. Then il is lifted from the fur
mace. swung outward and run down the
room TO one of the great hydraulic
presses. This press is sometimes called
a "hugger," / believe. though ii pats
and squeezes the metal rather than hugs
it,
The presses used In the forging OF gun
tubes have a pressure of 1000 to 5000
tons There is an immense frame OF
steel. within IL plate and above that
plunger which works by hydraulic pres
sure. crossbar at the end of this
plunger covers the breadth of the open
space between the supporting pillars OF
the press. A little army of men guides
the mandrel on which the casting hangs.
Hydraulic lifts hold IL in position, turn
It over and move il backward and for
ward on the bedplate. AS il moves and
turns the plunger goes down and up.
and the crossbar kneads il and pats II
and squeezes IL just as you might pat
and squeeze and mold with your fingers
piece OF dough. The great white mass
radiates heat which is not altogether
ungrateful on midwinter day. though
am not prepared to say that / should
like II so close to me even with the ther-
mometer at zero. In the summer the
men who guide the end OF the mandrel
and the man who scrapes the scale from
the mass with fiat ended poker as II
goes through the press must lead lives
of great suffering. Near the furnaces
i'm the summer months the heat is some
thing awful, and men work stripped to
their waists bathed constantly in their
own sweat.s
AS you watch the kneading process
going on under the press you see that
the tube Is growing thinner and larger
and longer. The pressure from above
expands il at the sides and as II turns
, around and around IL Is expanded at
every point until the trained eye OF the
workman sees that IL In Of the right
shape for the shop Then ii Is lifted
from the press, still on the msndrel and
carried by one OF the overhead cranes
To a furnace where 1t is heated until 1t
is OF salmon pink. The right tempera-
ture is recognized by the color When
that is reached. the tube is hoisted out
of the furnace and plunged into a bub-
bling tank of oil. After that II is put
into an annealing furnace. where fire
of wood completes the process of tenn
pering IL. The Importance of this process
Is very great for IL the government in-
spectors who test bars from casting.
find that IL is below the high govern
ment standard IL is rejected and that
means a loss OF several thousand dol.
!. lars to the makers.
!, The forgings for the 10 and II
!, inch guns are delivered at the Water
|, vliet arsenal in the rough. There are
= il forgngs for IL inch gun. They
= range in weight from the trunnion hoop.
= which weighs 5000 pounds. 10 the tube
. and jacket, which weigh more than 32.
a 600 pounds each. The aggregate weight
= OF the IL pieces Is $4,000 pounds. and
81 ts.l..