Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1891-05-11
More Armos xssts.

has ias, bsen completed as the Annapo
proving ground test Of armor plates O.
even more impo. lance that the celebsstsd
trials Of September last. which 20 signaily
demonstrated the superiority OF homoser>
Qua afmof plates over compound.
In this laies. trial the best results attained
in September have been far surpassed BY
AZ American made plate Of nickel steel,
treated BY process of superficial carboniz'
on invented by q. A. Harvey Of Newark,
N. J.
Five experimental plates, all made by
Messrs. Carnegie, Phipps & Co.. Of Pitts
burg, were led. Each plate was eight feet
high. six feet wide and three inches thick.
This Was the FIRST exclusive t.ial OF An.
erican plates, and it was deemed best to
first study se qualities Of different tjpea
Of plates Of the least thickness, and sradu.
ally work up to gses'er thicknesses. Inc
Plates had the prescribed number OF bolt
holes, SO that they would not be any
stronger than If frey were actually bolted
to the sides Of ship.
In order to graduate the tfisl to the thick.
ness Of the plates, = six-pounder Hotchkiss
rapid re gun was used, firing Carpenter
forged steel armcr. piercing projectiles,
with e. king velocity of 1900 feet pei
| second. This was $50 feet velocity more
than sufficient to perfcrste an ordir >
steel piste oi the same thickness as those
fred st.
The FIVE plstes included one Of simple
steel, not Gated by the Harvey process
one Of simple steel, treated by that pro-
cess; two Of nicke. steel, uu Gated, one of
higher percen' age OF carbon than the
other; and ore of nickel steel treated BY
the Harvey process.
Twenty -one shots were fred st each
plate. The un.. Gated simple steel plate
wss wrecked. Nearly every projectile
passed clear through it and cracks ex.end-
cd in every direction, showing that the
conditions Of the trial were entirely be-
yond its capacity OF resistance. Inc IN
trea.ed nickle steej Of lower carbon did
better on account of the gses.er tenaci.
impsi ed to the metal by The nickel alloy.
The plate was not cracked but large NUN.
bar If prcjectiles succeeded in getting
| through it while others reb0unded bsdly
shaken up The rltreated nickel of high.
CT carbon did 3 i'll beer. Il was moi
cracked sna the eAtest penetration was
about three inches, bullying the bsc,
of the plate Only one Irojec lie
did that well. Iae others rsbounded
The all steel, tres ID By t'ie Harvey pro.
cess, was equally so d. il not better 1t val
somewhat oracke', bas the pene. alton was
iDsigrifc mt, only are projsc lies getting in
that far. Many cf Il, m were sha..ereo or
the surface. AT tbs nclusion Of the fir-
ing the plate brake INTO four places.
Ibe nickel steel tres;ed by the Heavey
g. 81, nRa - Lot 4
was 20 far superior 70 the conditions of the
trial thai ii was practically unir jured after
the q shots had been fred against it. The
surface WAS disfvured somewhat by the
smashing Of the hi hly tempered projectiles
and one Insignificant crack, due to internal
strains, was developed, bnt the firing could
apparently have been continued indefinitely
withou. des. ing the plate. Twenty Of
the pfojecsiles went to pieces on the surface
in no case penetrating more than q quartel
| Of sn inch, while one alone got in about al
inch
TIE success Of tbs latter plate far ex eei
ed lhe hopes VI the most sanguine believ'
ers in rickei-sseel and he III ,rvey process.
1t possessed great poser to resist cracking
due to the nickel, combined with greal
hsrdnt Sc due to lae Harvey treatment.
II the ressl.s OBJ ned in is trial can be
uniformly q .iaed. it is calculated that q
given thickness Of Is amor VIII be equal
| to an untreated steel srmor plste 25 pei
cent. tn cxer. Thus, for instance, al Sigh.
inch plate OF t,s new stmof would b.
quail 10 10 inches of seel. This will
reeui5 iu the saving Of hundreds Of tons
Of weigh. il the protec en- Of q large
ship, which can be applied in other diree
.iois, such as increasing the number and
weight of her guns t1d giving her more
ana uois on, or Increasing her coal supply,
AMI thus enabling her 0 steam further with
ous recosiing.
This light plate having shown what could
be the proper ioa Of nickel used ia / he
alloy, and having borne out the results oil
previous experiments VIII the Harvey
'process. the navy department will at once
order from both the Be ,lehem iron works
ani Carnegie, Ph'pps & Co., 1oA inch
plates for further experiments.