Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1890-10-10

marine is required annually to make good
losses and repairs entailed by collisions
alone. He said that the security of an iron
or steel ship against fatal injury depended
upon two things only-size and subdivision.
On the question of armor the speaker said:
Now, in 1890. you have perfectly regular
material, stronger and more ductile than any of
this iron, with no trouble as TO surface blister
ing and lamination. You can get Siemens
plates of 20 ewt., almost without extras for any
increased size, delivered at the ships side at
less than fS per ton: 1t has. unfortunately,
been as low as f6 IS. This change from iron to
steel was not made. without a vast amount of
anxiety on the part OF responsible engineers
who led the way.
The result may not be altogether pleasant to
the iron and steel makers To the shipbuilder
and engineer it calls for ungrudging acknowl-
edgment of Indebtedness to two eminent British
subjects, Bessemer and Siemens, and for the
grateful recogni ion of the enterprise and skill
of French, German and British makers. We
all owe Germany lasting debt of gratitude for
the birth and training of that true prince
William Siemens. In modern ships of war the
main use OF armor in the formation of shot
proof decks adjacent to the load water line,
and of more or less complete belts of side
aTmor combined with such decks is to protect
the machinery and magazines from shot and
shell.
There has been wide abandonment Of side
armor. founded upon the recognition of several
facts:
WHY SIDE ARMoR WAS ABANDONED.
First-The increasing penetrating power of
the gun. The Pinch gun is now more than
match, at close quarters, for the best lS-inch
steel plates. Itrequires the best 9-inch armor
to keep out steel projectiles from the 6-inch
gun at short range.
SecoEd-The great volume and accuracy of
broadside ports in armored side lnadmissible.
The crowding of men in the rear of an open or
unarmored port can no longer be accepted.
Thlrd-The propelling machinery and the
magazines are of more consequence than the
whole battery of guns. because the ship has be-
come. by virtue of her ram and torpedoes,
powerful lighting machine apart from her
guns.
Fourth-The large use of side armor by
reason of its weight and cost Limits the num-
ber of ships obtainable with given sum of
money.
But while side armor has been largely SUD-
pressed and superseded for these reasons, it
still possesses one great advantage. 1t prevents
the entrance of water into the zone between
wind and water through holes made by light
projectiles not capable of perforating armor,
but capable OF damaging seriously an unar-
mored side.
Those who have appreciated most keenly the
value OF side armor at the water line, for pr E.
serving the floating power of the ship against
light guns. have sometimes failed to see that
my apparent unreadiness to concur with them
has arisen from real sympathy.
My contention has been that all armed fight
ing shlps present equal claims to be kept a1oat
against the attack of the guns which they have
10 race. consider that in all such ships the
nrst duty of the designer is to enable the crew
to infiict damage on the enemy. Arms and mo-
blity, therefore. come first; endurance under
gun fire next. There must be degrees, varying
with the size of the ship, in the strength of the
arms and In the amount of the mobility. But all
the fighting men, except those in forlorn hopes,
are equally entitled to chance of existence
fire mi
ceive and endure. I have been unable to un-
derstand the exclusive claim for protection by
means of side armor In particular class of
ships in large navy. such ships not being dis
tinguished by exceptionally large crews, nor as
being centerS of operation for feet, nor as be-
ing required to attack fOrtresses And the
question as to the use of belt armor in classes
of ships not distinguished as above is per-
picked by the following considerations:
QUESTIONS OF ExPEDIENCY.
First and generally, whether in strengthen
ing the water-zone by side armor against feeble
projectiles, we do not expose it more to the
very serious attack of larger ones than it would
be if formed with an armored deck near the
water. Secondly, whether with ship of given
size and cost we are not sacrificing active Of
fensive qualities for the sake of a passive de-
fensive quality. Speed of ship. power of arm
ament, or stored-up capital Expended in the
ship may be made TO pay too dearly for pass.
i've defense against the invasion of water at the
water-zone. seeing that the invasion of water
beneath chat zone becomes q more imminent
and more serious peril to the State in propor-
tion to the reduced speed and the increased
cost
So we arrive at an alternative arrangement
a solid raft body at the water zone in place of
side belt armor.
1t appears that such raft body can be made
which, when undamaged, weighs with its cas-
ings not more than one-third the weight of
.AI1 No.. N11
ceed the weight of an equal bulk of dry fir.
Such a system of water line defense may
prove suitable for all fighting ships. large and
small, by reason of its lghtness and small cost
As understand the position, it is proposed to
give a trial to this system in the navy of the
United States
think the time is coming, if it is not already
come, when there will be demand, not only
for the recognition of the equal claims of all
the tighting-ships to be kept afioat against the
attack of the guns which they will have to
face, but also that their crews between decks
should be equally protected against the over
whelming effects of the bursting of high ex-
plOsives there.
For belt and battSry armor it is still mat
ter of debate whether the process of manufac-
ture first introduced. and since most success
fully developed, by NJ. Schneider, or that SUBJ
sequently devised and manufactured in Shef-
field, is the better
SHEFFIELD'S GREAT EXPERIENCE.
After this paper has left my hands, and be-
tore it will be read, there will probably be an
in interesting series of trials of armor on both
plans in the United States; what say may
therefore be very brief. Both systems have
been in open competition from the beginning
and gun trials have been made by all the mari
time powers. The experience of the Sheffield
compound armor-plate makers as to their own
and that of their rivals has been
very great. The amount of Steel-faced armor
which has been manufactured by them, or by
their licensee, during the last IL years, together
with that which Is in process of manufacture,
They urge several considerations in favor of
armor. They say that steel armor
cracks through under blows which are not suf-
fciently powerful to perforate the plate. They
consider that the manufacture of steel armor |
is less uniform and certain, because it is of
very great importance to oil-harden and anneal
such armor; and these processes are not re-
quired for steel-faced armor. They point out |
that this treatment can only be applied com
mercially to large ard awkward plates, with |
great risk, expense and difficulty, and that un-
der these circumstances good test plate offers |
no security as to the quality Of the plates it |
1t is conceded that hard-faced |
armor endures better under oblique blows. |
They say that cubic foot of steel armor |
weighs 492 pounds, whereas cubic foot of |
armor weighs only 4S0 pounds-a |
difference of 21 per cent IN favor of the latter.
An experiment has recently been made in |
England to ascertain whether it can be CONT |
IDENTIFY stated that oil-hardening and annealing, |
or some equivalent finishing process, is neces- |
sary for steel plates Messrs. Brown and |
Messrs Cammell, the two great Sheffield firms, |
makers of compound armor. are satisfied as 70 |
this necessity.
A nlne-inch plate OF steel was manufactured |
and cut into two plates each four feet square. |
One piece was left untreated, and the other was |
and annealed They were fired at |
by the six.nch gun with Firth steel projectiles |
weighing 100 pounds.
ctril. l.intro nj ha
ergy of the blow upon that which had been |
treated was 2,37S5 foot-tons. In the latter case |
the projectile made an indent of l05 inches, so 1