The Sun.
London, England, 1861-08-07 00:00:00

IRON-CASED SHIPS.

The contest between the artillerists and the iron-
cased ship buiilders has at last taken a turn in
favour of the ships. Hitherto certainly all the
costly targets made to represent ship's sides when
armour-plated, have been so easily demolished by
the heavy Armstrong shot and the 68-pounders,
and pierced by the more penetrating projectile of
Mr. Whitworth's invention, that those eminent
artillerists had strong grounds for asserting, as they
did, that the victory would remain always within
the seope of their science. Whatever the strength
of the armour, they would only have to increase the
calibre of their artillery to break through it. The
prospect of this constant victory of the destroying
agent was not a very agreeable one for the country,
and we imagine that few persons, however they ad-
mired and wondered at the terrific power of these
modern engines of destruction, did not heartily
wish the noble ships might be made proof against
them, The recent experiments made at Shoe-
buryness, under the inspection of the Iron-plate
Committee, have brought out pretty clearly some
highly important features in the inquiry with
which they are entrusted. They have shown that
the method of bolting on the huge armour plates,
according to the plan adopted in the Warrior,
and the other iron-cased ships, weakens the plates ;
that the timber backing which was said to act like
the suit of buff to a man in armour, was not only
unnecessary, but rather a means of assisting the
breaking of the armour plates, and that angular
plates of little more than half the thickness and
weight, if properly laid on, were very nearly equal
as a protection for wooden ships even against
the tremendous 200 lb. bolt of the Armstrong
gun. Throughout the whole course of the experi-
ments upon iron plates, which have been carried
on really with surprisingly small ar d doubtful re-
sults for a great length of time, it has always been
observed that the fractures were made at the place
where the bolts fixed the plates. These were seen
to be the weak points, and yet no one proposed to
fasten on the plates by the very simple, and, as it
now appears, obvious contrivance of a short screw
from behind, holding without piercing through
the plate. This is a discovery, if we may call it so,
which is now first applied by Mr. Fairbairn in the
target constructed by him, and it is found capable
of resisting the heaviest missiles better than any-
thing yet tried. In fact, the plates of this target
were never more than battered and defaced ; they
showed no symptoms of breaking; they held on
under the attack, and were only partially knocked
off after the screws had been broken by the tremen-
dous concussion of the 200-pounder, fired at the
close range of 200 yards. Ordinary 68-pounder
round shot have commonly smashed up targets
made of similar plates bolted on to timber and gra-
nite backing, with less difficulty. There is every
reason to believe that by strengthening the screws
and the ribs the armour will be made proof against
the most powerful artillery that the art of modern
warfare can produce. It is doubtless to be regretted
that Mr. Fairbairn, whose high authority and ex-
perience in all iron matters has long been known to
all the world, was not consulted before the Warrior
had her armour put on ; but that was in the age of
wood, and we must congratulate ourselves on having
got so able an armourer for our Achilles.
But there was another bearing upon the question
of iron which was shown by this target. It was
built entirely of iron, and represented fairly eaough
a piece cut out of the side of such an iron frigate as
we hope the Achilles may be. There was none of
that costly double wall of the finest teak 18 inches
thick, as in the Warrior, but the plates came at
once upon the thin iron skin, to which were fixed
iron ribs half-an-inch thick and 11 inches broad,
precisely as in ordinary iron ships. The economy of
thus dispensing with such an immense amount of
labour and material will be obvious, but perhaps a
more important attainment is the gain of so much
lightness in the ship, especially when the armament
is a heavy one. In place of every hundred tons of this
timber the ship would carry coal, and thus one of
the great difficulties attending the iron-cased
ship service would be obviated. The Warrior
fully equipped will not be much under 8,800
tons, which is about 3,000 tons heavier
than the Marlborough ; yet if she were to
steam at full speed for a week her stock" of coal
wttsmhopoogai shipbuilding is so opposed to the use of wood
idtecletedthho:befraec.all but exhausted. The whole purport of
iron
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Mr.ll
Fairbairn, Mr. Scott Russell, Mr. Napier, and others
advocating the iron system for ships of war. Fur-
ther experiments may not confirm the results ob-
tained by this target of Mr. Fairbairn's ; though
for our own part we incline to think they will ; but
it is of the first importance that with the enlarge-
ment of Chatham Dockyard in view, and the esta-
blishment of iron-works upon a large scale before
us, it should be decided whether iron alone is not
the most advantageous build for the armour-plated
ships.
The other target tried at Shoeburyness was in-
tended to test the effect of angular-faced plates in
Messrs.
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Roberts and Burn ; it consisted of armour plates
three inches thick and two feet wide, rising at an
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backing, on to which the armour plates were boited.
The appearance of the target is described as resem-
bling the ridge and furrow of a glass roof. Though
this target was admitted to be too small, it never-
theless stood a vast deal of poundingfrom the Arm-
strong strong heavy guns, receiving very small damage
lfrom one of the huge 2001 b. bolts, It was soon shown