The torpedo experiments against the Resistance, which have been
suspended since November last, were resumed on June 9 at Portsmouth by
the officers of the Vernon. The injuries received by the ironclad in the
previous experiments having been repaired, so as to make the vessel
watertight, the old ship was towed up the harbor, and moored in Fareham
Creek. Our readers are aware that the Resistance is an obsolete ironclad
which has finished her career as a battle ship, and that nothing could
have converted her into a modern armorclad.
Although it was intended to render the experiments final and conclusive
as a practical demonstration under service conditions of the destructive
effects of the Whitehead torpedo when directed against a modern vessel
of war, the results still leave behind them much uncertainty. The
Resistance was built of iron, whereas battle ships are now exclusively
constructed of steel, and it would be perhaps hazardous to state that
the behavior of the two metals under a sudden and violent shock would be
exactly the same. The construction of the double bottom of the old ship
is also different. Since the last experiments were carried out against
her, however, measures have been taken to make her as far as possible
the counterpart, so far as under water arrangements and coal protection
are concerned, of a modern ship of war.
At the last attack, the Whitehead was directed against the after part of
the hull on the port side in wake of the boilers. During the present
series of experiments the old ship was assailed on the same side, but
directly amidships, in the neighborhood of the engine room. As no steam
was got up in the boilers, the effect of the jar upon the steam pipes,
glands, and feed connections remains a matter of speculation. So far as
the consequences of the burst upon the structure of the hull itself is
concerned, every care was taken to make the ordeal as complete and
instructive as possible. The wing passage, which has a maximum diameter
of 3 ft. diminishing to a point, was left empty, although at the former
experiments the lower portions were filled with coal. But behind this,
and at a distance of 8 ft. from the bulkhead, a longitudinal or fore and
aft steel bulkhead 3/8 in. thick had been worked to a length of 61 ft.,
and, with the coal with which the intervening compartment was packed,
formed (as in recent armorclads) a solid rampart, 20 ft. high, for the
defense of the engine room.
The height of the double bottom between the outer and inner skin plating
is 2½ ft. The watertight compartments were divided into stations by
means of vertical lightening plates pierced by three holes, and in order
to make them, as far as was practicable, resemble the bracket frames of
a modern armorclad, the center of the plates was cut away so as to leave
a single oval hole instead of the three circular holes. In view of the
differences of opinion which exist on the part of experts on the subject
of under water protection, the officers of the Vernon had determined to
submit the problem to the test of experiment. For this purpose steel
armor 1½ in. thick had been worked along the outside of the upper skin
of the double bottom throughout one of the compartments, in addition to
the other protection mentioned. The Resistance had been brought down by
iron ballast to a trim of 25 feet 9 in. aft and 19 ft. 7 in. forward,
giving a mean draught of 22 feet 8 inches. She was consequently rather
further down by the stern than before, but was in other respects the
same.
When in commission, the Resistance had a mean draught of 26 feet 10
inches. The present series of experiments was of even greater importance
than the first series. The attack was gradually developed by means of
fixed and outrigger charges of increasing power, and the _coup de grace_
was not given by means of a service Whitehead in actual contact until
various lessons had been derived.
The opening experiment on June 9 consisted of an attack directed against
a new system of torpedo defenses which are to be carried by ships in
action, or when in expectation of an attack, rather than an assault upon
the ship herself. The previous experiments had clearly demonstrated that
a Whitehead, when projected against a vessel at close range, and
consequently with a maximum of motive force, could not get through the
ordinary wire netting before expending its explosive energy in the air,
and that the spars by which the nets are boomed out from the ship's side
could be reduced to 25 ft. in length without danger to the hull. The
ordinary wooden booms employed on board ship, however, are heavy and
unwieldy, weighing, as they do, more than half a ton each. In ordinary
circumstances, the spars cannot be lowered into place and the nets made
taut in less than a couple of hours, and the work of stowing them is
equally slow and laborious.
Mr. Bullivant, who manufactures the torpedo netting and hawsers for the
navy, has devised a method of getting rid of the difficulties complained
of by substituting steel booms for the wooden booms and an arrangement
of pulleys and runners, whereby the protection can be run out and in,
topped and brailed up out of the way, with great facility. The system
was tried at Portsmouth last year with considerable success upon the
Dido, but as it was thought that some of the fittings were somewhat
frail and might collapse beneath the shock of a live torpedo, it was
resolved to submit them to a practical test under service conditions
upon the Resistance. The ship was consequently fitted with three of the
steel booms on the port side. They were 32 ft. long and spaced 45 ft.
apart, and connected by a jackstay to which the nets were attached. Each
steel boom weighed 5 cwt., or less than half the weight of the ordinary
boom, and whereas the latter is fixed to the ship's side by a hook which
is liable to be disconnected or broken by the jerk of an exploding
torpedo, Mr. Bullivant's boom works in a universal or socket joint,
which cannot get out of gear except by fracture, and which permits the
boom to be moved in any direction, whether vertically or fore and aft,
close in against the sides. Below each boom is a flange, which serves as
a line along which a traveler moves, the latter being actuated by means
of a topping line running over a pulley at the head and another near the
heel.
Upon the booms being topped to a perpendicular position, the nets are
attached to the runners at the bottom of the booms close inboard
(instead of, under the existing system, to the tops of the booms from
boats alongside or otherwise), and when this is done, the mere
depression of the booms into position will cause the nets to run out of
their own accord. In like manner, when the occasion for their use has
passed, the raising of the boom will cause the nets to come alongside,
when they can either be brailed up through the grummets or disconnected
for future use.
The action of the gear is so simple and rapid that the torpedo
protection can be always ready without arresting the way of the ship. As
a length of net 30 ft. by 20 ft. deep weighs about 3 cwt., it will also
be seen that the reduction of strains by working the crinolines from the
heel instead of the head of the booms is considerable. The attack by the
Whitehead upon the booms and nettings was made shortly before 2 p.m., at
the time of high tide.
The whole affair occupied a very few minutes. As soon as the red pennant
was struck on board to show that Mr. Bullivant was satisfied with the
arrangements, and that the target was ready, the torpedo vessel Vesuvius
got under way, and after circling round the doomed hulk discharged a
Whitehead against the netting from her under-water bow torpedo tube at
an approximate range of 50 yards. As on former occasions, the missile
was one of the old 16 inch pattern, but it was understood that the
charge of gun cotton had been reduced to 87 lb., so that the net
protection should not bear a greater strain than would be the case in
actual hostilities. The torpedo, which was set to a depth of about 10
feet, struck the net in the middle and threw up an immense spout of
water, but without getting to the ship, which was apparently uninjured.
Although it hit the net immediately below the center boom, no fracture
occurred, and the points remained intact. Although at the short range
the torpedo would spin through the water at from 30 to 40 horse power,
and would deliver a formidable blow upon the net, the thrust was
effectually resisted, though as a matter of course the net was much torn
by the explosion of the baffled projectile.
Although at the second torpedo attack made on the Resistance, the
following day, the offensive power that was brought to bear was quite
exceptional, the victory remained with the ship. The charge exploded was
an exceptionally heavy one. It consisted of 220 lb. of gun cotton. It
was consequently more destructive than any which is ever likely to be
launched against an armorclad much better prepared to resist it than the
obsolete and time-worn Resistance. An idea, however, had got abroad that
the Russians either have or intend to have a locomotive torpedo capable
of carrying the same weight of explosive in its head, and the object of
the experiment was to ascertain what would be the effect of the
detonation of such an enormous charge upon the submerged portions of a
ship of war.
But, while this was no doubt the primary purpose in view, the experiment
also served the secondary purpose of determining the result of the
explosion upon the net defenses of a ship. Mr. Bullivant's booms and
runners, which were found to be scarcely anything the worse from the
ordeal of the previous day, were again used. The damaged net was taken
away and one of the old service grummet nets slung in its place, the
cylinders containing the gun cotton being attached to the jackstay
immediately in front of the battered sides, and 30 feet from the hulk,
and sunk to a distance of 20 feet below the water line, which would
bring it about opposite the bend of the bilge. By 3 p.m. everything was
ready for the explosion of the charge--everybody had cleared out of the
ship while the surrounding small craft drew off to a distance of 300
feet. The charge was electrically fired from a pinnace. The burst was
terrific and the reverberation was heard and the shock distinctly felt
in the dockyard. But the remarkable thing was that the hulk did not
appear to jump in the least, though there was not more than six feet of
water under her keel. That she would not be seriously crippled by the
discharge seems to have been accepted as a foregone conclusion by
Captain Long and the other torpedoists, as the day for the third
experiment had been fixed in advance; but that the steel booms with
their double flange running ways, stays, travelers, and hinges should
have resisted the tremendous jar and upheaval was a genuine surprise for
all concerned, and goes far to prove that except a vessel be taken
unawares, it will be impossible for a torpedo to come into actual
contact with it. At the experiments last year the wooden booms were
unhinged and splintered under a much less violent shock. But the steel
booms employed, though somewhat bent, remained unbroken and in position,
and the joints were quite uninjured. All that is necessary for perfect
defense is that the booms should be made a little heavier.
The torpedo experiments against the Resistance were resumed on June 13,
when the old ironclad suffered some rough treatment. As the experiment
was understood to be the last of the second series, and was fully
expected to have a sensational termination, a considerable number of
interested spectators were attracted to the scene in Fareham Creek. The
torpedoists resorted to severe measures, but with a distinctly useful
purpose in view, having bound the ship hand and foot, so to speak, in
such a way that her name became a solecism. They exploded 95 lb. of gun
cotton 20 ft. below the water, and in contact with her double bottom.
This amount of explosive represents the full charge of the old pattern
16 in. Whiteheads; but as the hulk was, for prudential reasons, moored
close to a mud bank, and as the water was consequently much too shallow
to allow of a locomotive torpedo being set to run at the required depth,
a fixed charge was lashed fore and aft against the bottom plating of the
ship and electrically exploded from No. 95 torpedo boat.
In previous experiments this year the ironclad was attacked on the port
side, which had been specially strengthened for the occasion, and the
result was a victory for the defense. On June 13 the starboard side was
selected for attack, in order that a comparison might be instituted with
the effects produced under different conditions by a similar experiment.
Last year in the latter case the double bottom was filled with coal; and
after the charge, which was lashed against the ship in the same way, had
been exploded, it was found that the bilge keel had been shivered for a
length of 20 ft., while the lower plating had been much bulged above the
bilge keel. Four strakes of the skin plating extending up to the armor
shelf had also been forced inward and fractured where they crossed the
longitudinal frames. They had parted in the middle for a distance of 8
ft., while some of the butts had been opened so that gashes 2 in. or 3
in. wide appeared between them. The coal had been pulverized and
scattered in all directions, and other internal damage inflicted.
Nevertheless, the watertight bulkheads remained intact, and by confining
the influx of water to a single compartment so much buoyancy was
preserved that, though the ship heeled over to starboard and was maimed,
she remained afloat, and might have continued to fight her guns,
provided always that no injury had been sustained by her machinery, a
point which these experiments do not touch. Crippled, however, as she
was, it was thought at the time (and the probability was strengthened by
subsequent examination of the ship in dock) that the coal, instead of
being a protection to the double bottom, had in reality proved a source
of weakness by receiving the energy of the explosion from the outer
plating and communicating it to the inner plating, and so distributing
it throughout the submerged portions of the hulk.
The question was sufficiently important to demand an experimental
solution; hence the _raison d'etre_ of the present demonstration. The
double bottom, which is about 2½ ft. deep, was consequently kept empty,
and the torpedo placed in immediate contact with it in such a manner
that, being overhung by the contour of the hull, the ship would feel the
full force of the upward as well as the lateral energy of the charge. On
other accounts the importance of the experiment was obvious, for,
although it had been ascertained that torpedo nets were capable of
protecting a battle ship from the bursts of the heaviest locomotive and
outrigger charges, it might happen, of course, that the nets would be
rent or displaced by shell fire or swept away by a grazing ram or even
attacked by a double torpedo, the second passing through the gashes made
by the explosion of the first in any case. It was, therefore, of urgent
necessity that the effect of a torpedo bursting in immediate contact
with a ship's bottom should be practically and clearly determined. The
charge on June 13 was fired just before 5 p.m. in the wake of the
boilers, and it was soon perceived that something of a fatal character
had taken place from the appearance of coal dust sweeping up through the
hold. The report had not the dull boom to which the spectators had
become accustomed. Instead of this, the gun cotton exploded with a
sharp, angry, whistling noise, while the manner in which the mud was
churned up showed that the force of the rebound was terrific. The ship
lifted bodily near the stern, after which it was seen to leisurely heel
over to starboard some eight or ten degrees, and finally repose, though
not until the tide fell, upon the mud. The old hulk had been mortally
wounded at last.
A complete knowledge of the disaster which has overtaken her (says the
correspondent of the London _Times_, to which we are indebted for the
above particulars) will not be obtained until a careful investigation
has been made of the hull in dock. But, from a hasty exploration which
was conducted on board, it was evident that the shot had not only
dislocated the inner plating of the double bottom, but had penetrated
the bunker compartment, stored as it was with coal, that the watertight
doors and compartments had ceased to operate, and that water was flowing
into the hull through a hundred crevices. To such an extent was this the
case that, though a strong working party was at hand ready for any
emergency, it was deemed useless to attempt to free the ship of water
until her gashes had been temporarily closed from outside. When this has
been done, she will be pumped out and brought into dock for careful
examination. From what has been said, it will be seen that while the
explosion of 95 lb. of gun cotton in actual contact last November simply
crippled the Resistance, the explosion of a like charge at the same
spot, and under approximately the same conditions, has in this instance
not simply disabled, but really sunk the ship.
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