Evening star., 1926-10-24

construction of these patterns to
compensate for the transformation of
the steel from molten to solidifed
form.
These patterns are made of the best
grade of white pine, Philippine ma
hogany, cherry and maple. All the
material is dried in a special kiln de
vised by the United States Forest
Service. The pattern shop produces
practically all of the patterns for cast
ings involved in the fleets armament.
They include patterns for all castings
made for airplane catapults. gun
mounts, sights, turrets and various
other naval ordnance.
X X X
ALL the steel mill, foundry and
forging work at the Washington
Navy Yard is scheduled to be deliv-
cred at various dry docks and naval
stations on specified dates when GER
tain battleships. cruisers. destroyeTs
or submarines needing repairs or new
apparatus will dock at those points.
The various naval shops and foun-
dries secure contracts for the manu-
facture of ordnance because they win
out in competition against CONNER
cial concerns. Our local navy yard
has to underbid professional COM
petitors on the production OF much
of the ordnance material which II
makes. All this material is inspected
as carefully as though it were made
by a private concern instead OF being
produced in a Government shop for
use on national ships of war.
Brass is melted in graphite cruel.
bles. which are placed in cylindrical
E., I,nH q tn CIJrynIIn6an
by hot Goals. The cartridge trim
mings and other brass scrap ar
dumped into these pots and heated TO
a temperature of from 1000 to 2,5np
degrees Fahrenheit. Sand forms bufr
around wooden patterns are used IN
making the brass castings, forglr gs
and other parts. All this sand is re-
inforced. 1t Is a common sight to see
every conceivable shape of sand mold
being carried on electric cranes about
the navy yard brass foundry.
a spectacular feature of the steel
casting output is the sand-cleaning
room. where streams of steel shot
under 100 pounds pressure are vol
leyed against the castings in order to
clean them for assembly and delivery
to dry docks or ports. The cleanup"
man is dressed for the occasion in
heavy canvas uniform, through which
the fine sand cannot penetrate. He
wears a heavy helmet made of copper
and glass-quite similar to the diving
helmets used in deep-sea diving. This
helmet is equipped with a special air
line which provides plenty of pure air
for the operator as he works. The
Crushed-steel shot are sprayed over
the castings by use of q large rubber
hose. More than $4,000 castings of all
sizes and shapes are cleaned of sand
each year in this novel manner.
The forge shop at the navy yard is
equipped with some of the largest
steam hydraulic presses ever made.
One is 2,000-ton forging press, which
weighs 100000 pounds. Thirty large
freight cars were required to deliver
this press to the navy yard when 1t
was purchased nine years ago. This
mammoth press and its foundat ton
cost more than $500 000--the largest
piece of machinery ever delivered and
mounted in the District.
Electric cranes which are so sensi
tive to their control devices that they
seem to be endowed with human in
telligence lift and carry corrugated
ingots of cast steel which weigh from
s to 90 tons apiece as though they
were no bulkier than ordinary paper
weights. Mighty slabs OF metal are
moved as II by magic to whatever po-
sitions are desired. BY opening or
closing an electric throttle the
driver of the herCulean crane gov
erns its movements. Massive ingots
are heated to forging temperature in
special vertical or horizontal furnaces.
Then they are transported by crane
power to the heavy forging machines.
In the largest hydraulic press the de-
scending die exerts a pressure of
1000 tons Every time it strikes the
red metal it delivers a blow of
1000 900 pounds. The strongest cast
steel is shaped by this mighty tool as
though it were as malleable as pie
crust.
nURING the fiscal year 1885 this
- Government forge shop produced
3.952,722 pounds of forging for naval
ordnance. A recent job consisted of
the production of 90, 900 4-inch illu-
minating shells or flares. These flares
are discharged during darkness so
that gunners may benefit by their
tlluminative properties in making their
shots. Eight thousand 5-inch projec-
tiles are now under construction.
Four thousand copper rotating bands
for 14-inch target projectiles are also
under manufacture at present by a
drop-forging process. Forgings for
guns up to and including inches di-
ameter and Sc caliber length can be
made.
A bronze aluminium alloy is now be.
ing forged into sleeves as coverings
for submarine guns. These forgings
weigh $4,000 pounds apiece and are
the largest ever made of this alloy.
They protect the guns against the cor
rosive action of salt water. Three
catapults-airplan launching devices
for use on ba attleships-were COM
pleted recently, weighing 10000 pounds
apiece in the form of rough forgings.
Raw material as delivered from the
foundry to the forge shop is in the
form Of large cast ineots. The re-
quired grade of materials for certain
forgings Is selected according to its
chemical composition. The material
is heated in one of the furnaces to a
temperature Of about 2200 degrees
Fahrenheit-the customary forging
tempera ture. A travelling crane then
transports II to the steam hammer or
hydraulic press. where II is hammered
and pressed to the required shape and
dimensions. After the forgings are
made according to specification they
are accorded special heat treatment.
When this process is finished. they are
subjected to expert visual inspection
and certain physical tests. If found
satisfactory, the forgings are then
sent to the machine shop for finishing.
The Navy Yard forge shop has per.
fected unique method Of making
large ordnance rings. To manufacture
these mammoth rings in solid pieces
Is a champion achievement. These
rings are not welded nor are they
fused together by acetylene or elec.
trical processes. They are manufac-
tured from solid cast steel, which is
shaped. slotted. curved, cut and mold.
ed to form the completed rings by an
inexpensive and efficient system OF