The Hickman courier. [volume] (Hickman, Ky.) 1859-current, 1917-01-25
What Is Needed for Armor Plate Plant

i've to the establishment and lO-
cation of the government armor
plant, which we hope to locate at
hickman. AS this subject is now
one of vital issue, it should be
of more than passing interest to
our readers in this immediate vi
cinity. The following paragraphs
are extracts from document
prepared by the Armor Plate
Board:
The recommendation of the
General Board of the Navy with
especial reference to considera-
tions Of safety in time of war, -
requires that the plant should
not be located least of the Ap-
palachian Mountains, west of the
Cascade or Sierra Nevada Noun
tains, nor within 200 miles Of our
Canadian or Mexican borders. /"
For the information of those
interested in the location of this
Government plant the board
finds it desirable to make clear
what constitutes an armor plant
such as is contemplated by the
act of Congress, the requirements
for its efficient and economical
operation, and the conditions
which largely influence decisions
In the selection of site.
The manufacture of ar1mor
plate is highly specialized
branch of the steel industry, and
there is no commercial steel Of
which the same service is requir-
ed nor in which the same process
Of manufacture are used. Armor
plate is used in the gun turrets,
coming towers, and uptakes, but
principally In a narrow belt ex-
tending just above and below the
water line Of the ship. The larg-
est plates are about % feet long,
10 feet wide, and 1S inches thick,
and weigh approximately As
tons. The ingot from which such
plate is made would weigh a.
bout 800, 600 pounds.
The plant provided Tor in the
act of Congress coPtemplates the
manufacture Of armor from Bes-
semer pig iron purchased In the
open market. If the present pro-
cesses for manufacturing armor
are followed the pig iron will be
melted in open hearth furnaces
for reducing the amount of car
bon and eliminating impurities In
the pig iron much as in the com
mercial furnaces. At the proper
time the correct amounts of
nickel and chromium are added in
order to produce an alloy steel OF
the proper composition for armor
plate. The melts from one or
more furnaces are then poured
into an ingot preparatory for
making the plate.
The problem of making the m
gots is complicated by the neces-
sity for using q very large =
mount of scrap metal produced by
waste from the ingots and oy
cutting of the finished plate to
the shape required on the ship.
The ingot after brought to the
proper temperature Is earned TO
1 the heavy hydraulic presses which
are used in place Of rolls IN
forming . plate from the rregu-
lar mass Of steel IN the ingot:
The press exerts . pressure OF
10000 to 5000 tons upon an
area q few inches wide and sew
eral feet long. It thus reduces
| the thickness and increases the
area Of the ingot to the proper
dimensions of the plate.
The next step is to harden the
face of the plate. Two armor
plates of the same size are placed
face to face with a layer Of car
bonaceous material between them,
lconfined by border Of fire brick.
The two plates are then kept ut
Ia temperature in the furnace OF
about 1000 degree F. for . periot
Of fourteen to sixteen days. This
operation is known as cementa'
ton of the plate, and causes car
bon from the charcoal to pene'
trate about / inch into the metal
which upon being chilled forms =
q surface so hard that It would
scratch glass. The object Of tn
exceedingly hard surface y u
shatter q shell into small pieces
and thus make penetration Q!
the armor impossible. The tougi
backing affords the neceaBaE.
strength to prevent breaking o
the chilled exterior.