The Washington times., 1894-05-20
into GREAT FRAGMENTS
Armor Plate Shattered By the Big
Gun At Indian Head.
THE TRIAL OF GREAT INTEREST
Harveyized Nickel Steel Plate Fails to Stand
the Test-A Sad Blow to the Bethlehem
Company--Another Test to Be Made Soon.
Notable Gathering of Naval officers.

With roar and shock that made the
earth trenble the navy pet, the twelve-inch
rifle, hurled its s50-pound proiectile against
an eighteen-inch nickel-steel Harveyized
plate, the most powerful ever tried, at the
proving grounds yesterday, and tore the
thirty-three tons OF steel into great fragments.
The result was complete surprise for all OF
the experts, and a sad blow to the Bethlehem
Steel Company, for unless they can do better
with the next plate they will lose the $500. 900
represented by the group OF armor plate OF
which the sample tried to-day was the test
piece.
The trial was OF great interest to armor ex-
perts for several reasons. In the first place,
the plate was expected to show greater resist
ing power than any ever before submitted to
test Our naval people had tried seventeen
inch plates, and European governments had
fred at twenty-two-inch plates of compound
armor, but the latter is known to be more
easily penetrated than eighteen inches OF
homogeneous nickel steel, even when the lat
ter is not Harveyized. In the second place,
the trial was expected to settle some doubt
that had arisen as to the admissibility of
applying the Harvey process Of surface car
bonization to the heaviest plates and those OF
irregular shape.
Consequently there was notable gathering
of ordnance experts at the proving grounds
at Indian Head yesterday, and doubtless there
would have been more save for the weather,
which. realizing the threat OF the morning,
drenched everybody with rain before the day
expired. The plate submitted to test was
No. 5107 B, representing 613 tons of side
armor intended for the battleship Indiana
and made by the Bethlehem Steel Company.
1t weighed 33ll tons and cost about $4,000.
In shape it was an irregular oblong, 16 feet
long by u feet high, Is inches thick above.
with the lower edge (42 inches) beyeled off
to minimum thickness OF inches. 1t was
nickel steel, forged by hydraulic press and
Harveyized.
A thirteen-inch rifle, the largest In naval
use. was to be fired against this, but the plate
was found to be too narrow to warrant this
severe test, SO the twelve-inch gun, which
will hereafter be the maximum in our ord
nance construction. was leyeled at the plate,
distant about 400 feet. The projectile, a Car
penter armor piercer weighing $50 pounds
and driven by 269H pounds of Duponts
brown prismatic powder, hew across the
space with the velocity of 1,465 feet per sec
ond and struck the plate about a foot TO the
right OF the center. When the smoke cleared
away there was an exclamation of surprise
from the spectators. About thirty feet in
front of the target lay the shot, apparently
little changed while in the plate was gap
ing hole and more than that. three great
cracks, yawning open eight inches and run
ming clear across from bottom to top and
from the shot hole to the left edge.
An examination showed that the shot had
forced its point through the plate to the
backing and had then rebounded after crack
ing the plate. Had the plate been fastened
on the Indiana's side. instead OF ageinst thirty
six inches Of oak backed against the hillside,
the chances are that The battleship would have
had frightful wound.
Further experiments seemed to be needless.
but the contract conditions requiring it,
another shot was fired at fragments of plate
on the right about seven feet broad that re-
mained uninjured. This time the gunner put
419 $40 pounds of powder in the gun, and
the projectile. another twelve-inch Carpenter,
was given additional force and sent at the
maximum veloci.y-1.9 1926 feet per second.
Again the plate was rent in twain, splitting
widely across, but the shot did not escape,
for while it forced its point through the plate
and about eight inches through the oak back
ing it was twisted in several pieces, the
point remaining in the hole and the remain
der lying in fragments outside the plate.
This was the end of the test, and the plate
failed signally-just why the experts do not
agree.
1t was recognized after the first shot that
there had been an extensive but concealed
crack in the plate running from the center to
the left hand edge that had existed before the
trial. Certain ominous snnppings and crack
ings had been noticed while the plate was at
the mills. but a steam hammer had been
brought to bear upon it without disclosing
the hidden flaw, and it was supposed to be
all right.
Ordnance officers believe that this flaw was
the sole cause of the failure of the plate. The
manufacturers. however. believe that the
trial proves that these heavy plates
cannot be Harveyized with benefit. They
hold that in TACT the process really weakens
the plate by saiting up severe and destructive
internal strains when applied to heavy plates.
Nevertheless the ordnance officers, having
proved to their satisfaction the efficacy OF the
Harvey process on the scventeen-inch plates,
are not prepared to admit, until there have
been further trials, that it will not serve
equally well for the eighteen-inch plate, the
heaviest armor designed for our ships.
The Bethlehem company will have an op-
portunity to submit another 1S-inch plate to
test before the entire group of twenty plates
for the Indiana is finally judged, and as they
will doubtless take this chance to save the
$500, 900 which the plates cost, the next trial
may finally set at rest the doubt that now ex-
lists as to the cause of the failure yesterday.