National Republican. (Washington City (D.C.)) 1872-1888, 1874-10-29
THE NAVY YARD.
CASTING OF A COMPOUND ENGINE
CYLINDER

OACI4NG OE a OO44EOGNO @@-NN- 49,
Cylinder.
Visitors to the navy yard lately may have no
tieed in the machine shops Of the department OF
steam engineering two large castings undergoing
the finishing necessary TO complete them for q
pair Of compound engines, now being constructed
IN that department. The modern compound en-
CINE, with which the Navy Department is now
superseding the old type, has two cylinders, one
termed the high pressure and the other the low
pressure. These are so arranged as to admit Of
the steam, after It has acted the piston Of the
40 luther duty on its piston Il Is claimed that
by such an arrangement more Of the energy stored
up in the steam is transmitted from the boilers to
the propelling apparatus Of the ship. large
number Of persons were congregated In the troA
foundry yesterday to witness one OF the most In
teresting and exciting Of the several processes
tern-shop until they are ready for the ship. 1t
was the casting Of q loE-pressure cylinder, the
counterpart Of the high pressure now undergoing
The mold, which has been In course Of prepa-
ration for some time, is constructed Of son bricks
and loan, and required in its manipulation more
than the ordinary skin Of molders. It being
ready, pit was excaTated and the mold put
together in it, securely elamped, and then sand
rammed around the outside, to enable It to with
stand the enormous pressure to which It Is sub
iected by the molten metal.
Viewing the preparations from the foundry
floor one sees a large circular iron tank, lined
with hne brick and clay, placed in front Of the
cupolas. Leading from the tank and encircling
the OF the LQOulQ Is q EFelCl. cOueIIuCLou OA
brick and sand, for the purpose Of conducting the
metal from the tank to the top Of the mold. In
the bottom of the trench and Immediately above
the mold are q number Of small openings or
gates /" through which the metal flows into the
mold. Numerous small pipes, with tufts Of shay
ings in the end, project above the mold; they are
placed there for the purpose Of conveying away
the gases generated by the intense heat Of the
metals from the various parts Of the mold A
large laole WAS eonheetSa 70 One o. ny POnoeL9us
cranes and adjusted to be swung to the opposite
side Of the mold 70 assist in the pouring. The
casting, which will weigh when finished about
pouring about thirty. I'VE thousand pounds Of
metal. The eupolas were charged with successive
layers Of coal and iron, and the fires lighted
about % o'clock, and 1.-THE blast started about Il
O'Clock. In about one and half hours after
starting the blast the metal had commenced to
be liquid enough to be tapped from the eupolas
an hour was. occupied in filling the tank and
ladle, and during this period the molten metal
ran in constant stream, with an occasional ftful
EXPLOSION the scintillations Of which riValed .
display of fireworks. This, with the intense heat
emitted by the fluid, combined to impress the
behOlder with both admiration and awe. Every
thing being ready, the foreman took prominent
position, and at the word OF command the tank
was tapped and the metal flowed along the
trench into the mold. Simultaneously the lsdle
on the opposite side was tilted, and its contents
also flowed into the mold. In about two minutes
q shout from the foreman TO draw the overflow
plugs announced that the mold was hlled. The
surplus metal from the tank was allowed to run
of into pigs. The oyerhoWs were then closed
ana more metal dQQeQ the lhQle 70 cOupen-
safe for the shrinkARe the casting undergoes in
cooling. During the pouring men with heated
iron rods set fire TO the TUFTS Of shavlngs in the
vent pipes in this way igniting the gases passing
through them and assisting their escape.
There being no ebullitiOn Of the metal, and the
vent becoming free, It is evident, as far as at
present able to Judge, that the casting is q sue
cess. In managing the preparations for the cast
ing these cylinders, which are very intricate
castings, consider able experience, forethought
and good Judgment are required. The Workmen
must be disciplined and familiar with their du-
ties. Every detail must have been matured and
contingencies provided for. When the metal
once commences 10 hoW into the mould there is no
time to reflect about provisions that should have
been made. Should by any means q small guam
tity Of water have gained access to the mold, or
any of the gases become imprisoned therein,
violent explosion may ensue, scattering death
and destruction around, as was the case some
twenty years ago, when, on a similar occasion, an
explosion occurred which resulted in the partial
destruction of this same foundry.