The Roanoke times. [volume] (Roanoke, Va.) 1890-1895, 1893-07-13
TESTING ARMOR PLATE
Interesting Experiments at the
Naval Proving Grounds.
AMERICAN MANUFACTURERS LEAD.
Commander Sampson. Chief of the Ord
nance Bureau. Says the United States
Makes the Beat Armor In the World,
and Makes 1t Cheaper.

and Makes 1t Cheaper.
WASHINGTON, July l2.-The third of a
series of armOr plate tests of worldwide
interest and Importance took place yester-
day ut the naval proving grounds, twenty
miles south of this city, on the Potomac
river The first of these tests was at An
napois several years ago, when plates
from England, France and the United
States were i'll competition, and the second
In the fall of 1891, when the merits of the
Harvey process were demonstrated Yes
terday the results of the labors of Ameri-
can manufacturers, encouraged by the lib
eral inducements of congress and the adj
ministrations of the navy department,
were subjected to the requirements en-
bodied in the contracts for side and turret
armor for the vessels of the new navy now
approaching completion. The results
generally speaking, were most satisfactory
Among those who witnessed the tests
were Secretary Herbert, Captain Ord
Brown, the famous English ordnance ex-
pert; NJ. Bouvard, superintendent of the
armor department. of the Cruzot works
France; Commodore Sampson, chief of the
ordnance bureau, and representatives of
the contracting firms.
There We're two plates tested which
We're attacked by three projectiles each.
The tests were for acceptance and for pre-
MUM, it having been stipulated that IL
the plates resisted penetration under a GER
tain prescribed velocity the makers should
receive premium of $50 n ton, in addition
. to the contract price of S575 ton.
The first test was of 9.inch plate. @
1eet and inches wide and feet and &
Inches long, sample Of the side armor Of
the monitor Monadnock. 1t was nickel
steel. weighed 10 tons and was made by
the Carnegie-Frick company, of Pitts
burg. Three Hotter proiectiles, weigh
ing 80 pounds each, were fired against il,
from an S-inch rifle, the muazle being SIS
feet from the face of the target The first
proJectile had a velocity of 400 feet a sec
ond at the moment of impact, and pene-
trated the plate and oak backing to n
depth of Ill inches. The second project
lie, with striking velocity of ,6S3 feet
went through the plate, 3 feet of oak back
ing and lost itself in the earth against
which the butt was built. The third pro-
Jectile had II velocity of l $50 feet, and pen
etrated plate and backing to depth of
14}l inches. The plate well withstood the
strain of the attack. no cracks being per
ceptible. and it fully met every require
ment for acceptance. But the result of
the second shot deprived the makers of
any chance for the premium. Depending
OIl tIllS teSU were ABOUT 2JU tons of Dlutp
involving nearly Sl50.0O0.
The test of the second plate was an en-
act duplicate of the first in its results. 1t
was sample of the curved plates for the
barbette on the Indiana, made by the
Bethlehem company, and, like the first, of
nickel steel. Its dimensions were feet 4
inches in height, 10 feet | inch in length
anu Ia inches thick, forming n mass weigh
ing 3lls tons. Ii was the heaviest plate vet
tested, and its thickness will probably not
be surpassed to any great extent until
there is II change in the method of naval
warfare and shipbuilding. 1t was sub
Jected to attack from l2-inch rifle,
which threw monster Carpenter she'll
weighing $50 pounds. Its muzzle was $40
feet from the face of the plate The strik-
ing velocity of the first shot was ,322 feet
second and il penetrated to depth of
1866 inches, lacking less than half an inch
of going through. The second shot was
Tired with velocity of ,495 feet second
and went inches into the oak backing
The third and last shot was to determine
whether or not the premium was TO be
paid, and the velocity was raised to ,S5S
feet second. When the smoke and dust
following the discharge had lifted it was
found that the shell had gone clear through
the plate and 81 inches of oak backing.
and then, finding the embankment rather
thin, was detected into the air and plunged
into the river some hundreds OF Yards
away. or was lost i'll the woods on the hill
side. Expert opinion on this point diff
fered. but that it had plowed its way
through all instructions and disappeared
from view WAS obvious. The plate secured
Tor Its makers the acceptance of the whole
contract, amounting to from 800 to 100
tons. but earned no premium. Like the
Monadnock plate it showed no cracks I'M
der the terrific strain to which il had been
subjected
Even more satisfactory than the show
ing made by the plates was that of the
pro1ectiles. The S-inch shells were of the
Hotter conical pattern, and the l2.nch of
the Carpenter conical pattern. All four of
the shells that were recovered appeared
wholly unchanged to the Impractical eve
of the layman, and the gauge showed that
they were disturbed TO such II small de.
gree that they might again he fired with
the attachment of new strip for riiing.
Some idea of the force with which the
shells struck the face of the plates may be
gained from the fact that the energy of
the last shot fired was equivalent to the
force necessary to move q mass of 81 600
tons through one foot of space.
The cost of the tests WAS no small item,
and, as they compelled the acceptance of
the plates represented it falls upon the
government. In round numbers the bar
bette plate cost $4,000 the armor plate
5000, and the firing OF the rifles Gf the
projectiles are not again used) 5000
After the tests had been concluded all
the officials and experts expressed I'M
bounded qualification AT the results. Cap
tain Ord Brown, of England, looking in
admiration at the barbette plate, said: 1T
is piece of magnificent metal l do not
understand why there are no cracks from