prepared, where we see some of the heaviest work carried out by
electric dynamos, the workman sitting on a raised platform to keep
careful watch over his business.
Passing through this with interested but cursory inspection of the
cone mountings for quick-firing naval guns, some ingenious elevating
and training gear and a field carriage whose hydraulic buffers merit
closer examination, we come to the shell department where all kinds of
projectiles are manufactured. Shrapnel in its various forms,
armour-piercing shells, forged steel or cast-iron, and small brass
cartridges for the machine-guns may be found here; and the beautifully
delicate workmanship of the fuse arrangements attracts our admiration.
But we may not linger; the plant for the machine-guns themselves claim
our attention.
Owing to the complexity and minute mechanism of these weapons almost a
hundred different machines are needed, some of the milling machines
taking a large selection of cutters upon one spindle. Indeed, in many
parts of the works one notices the men changing their tools for others
of different size or application. Some of the boring machines work two
barrels at the same time, others can drill three barrels or polish a
couple simultaneously. But there are hundreds of minute operations
which need to be done separately, down to the boring of screw holes
and cutting the groove on a screw-head. Many labourers are employed
upon the lock alone. And every portion is gauged correctly to the most
infinitesimal fraction, being turned out by the thousand, that every
separate item may be interchangeable among weapons of the same make.
Look at the barrel which came grey and dull from its first turning now
as it is dealt with changing into bright silver. Here it is adjusted
upon the hydraulic rifling machine which will prepare it to carry the
small-arm bullet (.303 inch). That one of larger calibre is rifled to
fire a small shell. Further on, the barrels and their jackets are
being fitted together and the different parts assembled and screwed
up. We have not time to follow the perfect implement to its mounting,
nor to do more than glance at those howitzers and the breech mechanism
of the 6-inch quick-firers near which our guide indicates piles of
flat cases to keep the de Bange obturators from warping while out of
use. For the afternoon is waning and the foundry still unvisited.
To reach it we pass through the smith’s shop and pause awhile to watch
a supply of spanners being roughly stamped by an immense machine out
of metal plates and having their edges tidied off before they can be
further perfected. A steam-hammer is busily engaged in driving
mandrils of increasing size through the centre of a red-hot forging.
The heat from the forges is tremendous, and though it is tempered by a
spray of falling water we are glad to escape into the next shed.
Here we find skilled workmen carefully preparing moulds by taking in
sand the exact impression of a wooden dummy. Fortunately we arrive
just as a series of casts deeply sunk in the ground are about to be
made. Two brawny labourers bear forward an enormous iron crucible,
red-hot from the furnace, filled with seething liquid--manganese
bronze, we are told--which, when an iron bar is dipped into it, throws
up tongues of beautiful greenish-golden flame. The smith stirs and
clears off the scum as coolly as a cook skims her broth! Now it is
ready, the crucible is again lifted and its contents poured into a
large funnel from which it flows into the moulds beneath and fills
them to the level of the floor. At each one a helper armed with an
iron bar takes his stand and stirs again to work up all dross and
air-bubbles to the surface before the metal sets--a scene worthy of a
painter’s brush.
And so we leave them.
DIRIGIBLE TORPEDOES.
The history of warlike inventions is the history of a continual
see-saw between the discovery of a new means of defence and the
discovery of a fresh means of attack. At one time a shield is devised
to repel a javelin; at another a machine to hurl the javelin with
increased violence against the shield; then the shield is reinforced
by complete coats of mail, and so on. The ball of invention has rolled
steadily on into our own times, gathering size as it rolls, and
bringing more and more startling revolutions in the art of war. To-day
it is a battle between the forces of nature, controllable by man in
the shape of “high explosives,” and the resisting power of metals
tempered to extreme toughness.
At present it looks as if, on the sea at least, the attack were
stronger than the defence. Our warships may be cased in the hardest
metal several inches thick until they become floating forts, almost
impregnable to the heaviest shells. They may be provided with terrible
engines able to give blow for blow, and be manned with the stoutest
hearts in the world. And yet, were a sea-fight in progress, a blow,
crushing and resistless, might at any time come upon the vessel from a
quarter whence, even though suspected, its coming might escape
notice--below the waterline. Were it possible to case an ironclad from
deck to keel in foot-thick plating, the metal would crumple like a
biscuit-box under the terrible impact of the torpedo.
This destructive weapon is an object of awe not so much from what it
has done as from what it can do. The instances of a torpedo shivering
a vessel in actual warfare are but few. Yet its moral effect must be
immense. Even though it may miss its mark, the very fact of its
possible presence will, especially at night-time, tend to keep the
commanding minds of a fleet very much on the stretch, and to destroy
their efficiency. A torpedo knows no half measures. It is either
entirely successful or utterly useless. Its construction entails great
expense, but inasmuch as it can, if directed aright, send a million of
the enemy’s money and a regiment of men to the bottom, the discharge
of a torpedo is, after all, but the setting of a sprat to catch a
whale.
The aim of inventors has been to endow the dirigible torpedo, fit for
use in the open sea, with such qualities that when once launched on
its murderous course it can pursue its course in the required
direction without external help. The difficulties to be overcome in
arriving at a serviceable weapon have been very great owing to the
complexity of the problem. A torpedo cannot be fired through water
like a cannon shell through air. Water, though yielding, is
incompressible, and offers to a moving body a resistance increasing
with the speed of that body. Therefore the torpedo must contain its
own motive power and its own steering apparatus, and be in effect a
miniature submarine vessel complete in itself. To be out of sight and
danger it must travel beneath the surface and yet not sink to the
bottom; to be effective it must possess great speed, a considerable
sphere of action, and be able to counteract any chance currents it may
meet on its way.
Among purely automobile torpedoes the Whitehead is easily first. After
thirty years it still holds the lead for open sea work. It is a very
marvel of ingenious adaptation of means to an end, and as it has
fulfilled most successfully the conditions set forth above for an
effective projectile it will be interesting to examine in some detail
this most valuable weapon.
In 1873 one Captain Lupuis of the Austrian navy experimented with a
small fireship which he directed along the surface of the sea by means
of ropes and guiding lines. This fireship was to be loaded with
explosives which should ignite immediately on coming into collision
with the vessel aimed at. The Austrian Government declared his scheme
unworkable in its crude form, and the Captain looked about for some
one to help him throw what he felt to be a sound idea into a practical
shape. He found the man he wanted in Mr. Whitehead, who was at that
time manager of an engineering establishment at Fiume. Mr. Whitehead
fell in enthusiastically with his proposition, at once discarded the
complicated system of guiding ropes, and set to work to solve the
problem on his own lines. At the end of two years, during which he
worked in secret, aided only by a trusted mechanic and a boy, his son,
he constructed the first torpedo of the type that bears his name. It
was made of steel, was fourteen inches in diameter, weighed 300 lbs.,
and carried eighteen pounds of dynamite as explosive charge. But its
powers were limited. It could attain a rate of but six knots an hour
under favourable conditions, and then for a short distance only. Its
conduct was uncertain. Sometimes it would run along the surface, at
others make plunges for the bottom. However, the British Government,
recognising the importance of Mr. Whitehead’s work, encouraged him to
perfect his instrument, and paid him a large sum for the patent
rights. Pattern succeeded pattern, until comparative perfection was
reached.
Described briefly, the Whitehead torpedo is cigar-shaped, blunt-nosed
and tapering gradually towards the tail, so following the lines of a
fish. Its length is twelve times its diameter, which varies in
different patterns from fourteen to nineteen inches. At the fore end
is the striker, and at the tail are a couple of three-bladed screws
working on one shaft in opposite directions, to economise power and
obviate any tendency of the torpedo to travel in a curve; and two sets
of rudders, the one horizontal, the other vertical. The latest form of
the torpedo has a speed of twenty-nine knots and a range of over a
thousand yards.
The torpedo is divided into five compartments by watertight steel
bulkheads. At the front is the _explosive head_, containing wet
gun-cotton, or some other explosive. The “war head,” as it is called,
is detachable, and for practice purposes its place is taken by a
dummy-head filled with wood to make the balance correct.
Next comes the _air chamber_, filled with highly-compressed air to
drive the engines; after it the _balance chamber_, containing the
apparatus for keeping the torpedo at its proper depth; then the
_engine-room_; and, last of all, the _buoyancy chamber_, which is
air-tight and prevents the torpedo from sinking at the end of its run.
To examine the compartments in order:--
In the very front of the torpedo is the pistol and primer-charge for
igniting the gun-cotton. Especial care has been taken over this part
of the mechanism, to prevent the torpedo being as dangerous to friends
as to foes. The pistol consists of a steel plug sliding in a metal
tube, at the back end of which is the fulminating charge. Until the
plug is driven right in against this charge there can be no explosion.
Three precautions are taken against this happening prematurely. In the
first place, there is on the forward end of the plug a thread cut, up
which a screw-fan travels as soon as it strikes the water. Until the
torpedo has run forty-five feet the fan has not reached the end of its
travel, and the plug consequently cannot be driven home. Even when the
plug is quite free only a heavy blow will drive it in, as a little
copper pin has to be sheared through by the impact. And before the
screw can unwind at all, a safety-pin must be withdrawn at the moment
of firing. So that a torpedo is harmless until it has passed outside
the zone of danger to the discharging vessel.
The detonating charge is thirty-eight grains of fulminate of mercury,
and the primer-charge consists of six one-ounce discs of dry
gun-cotton contained in a copper cylinder, the front end of which is
connected with the striker-tube of the pistol. The fulminate, on
receiving a blow, expands 2500 times, giving a violent shock to the
gun-cotton discs, which in turn explode and impart a shock to the main
charge, 200 lbs. of gun-cotton.
The _air chamber_ is made of the finest compressed steel, or of
phosphor-bronze, a third of an inch thick. When ready for action this
chamber has to bear a pressure of 1350 lbs. to the square inch. So
severe is the compression that in the largest-sized torpedoes the air
in this chamber weighs no less than 63 lbs. The air is forced in by
very powerful pumps of a special design. Aft of this chamber is that
containing the stop-valve and steering-gear. The stop-valve is a
species of air-tap sealing the air chamber until the torpedo is to be
discharged. The valve is so arranged that it is impossible to insert
the torpedo into the firing-tube before the valve has been opened,
and so brought the air chamber into communication with the
starting-valve, which does not admit air to the engines till after the
projectile has left the tube.
The _steering apparatus_ is undoubtedly the most ingenious of the many
clever contrivances packed into a Whitehead torpedo. Its function is
to keep the torpedo on an even keel at a depth determined before the
discharge. This is effected by means of two agencies, a swinging
weight, and a valve which is driven in by water pressure as the
torpedo sinks. When the torpedo points head downwards the weight
swings forward, and by means of connecting levers brings the
horizontal rudders up. As the torpedo rises the weight becomes
vertical and the rudder horizontal. This device only insures that the
torpedo shall travel horizontally. The valve makes it keep its proper
depth by working in conjunction with the pendulum. The principle,
which is too complicated for full description, is, put briefly, a
tendency of the valve to correct the pendulum whenever the latter
swings too far. Lest the pendulum should be violently shaken by the
discharge there is a special controlling gear which keeps the rudders
fixed until the torpedo has proceeded a certain distance, when the
steering mechanism is released. The steering-gear does not work
directly on the rudder. Mr. Whitehead found in his earlier experiments
that the pull exerted by the weight and valve was not sufficient to
move the rudders against the pressure of the screws. He therefore
introduced a beautiful little auxiliary engine, called the
servo-motor, which is to the torpedo what the steam steering-gear is
to a ship. The servo-motor, situated in the _engine-room_, is only
four inches long, but the power it exerts by means of compressed air
is so great that a pressure of half an ounce exerted by the
steering-gear produces a pull of 160 lbs. on the rudders.
The engines consist of three single-action cylinders, their cranks
working at an angle of 120° to one another, so that there is no “dead”
or stopping point in their action. They are very small, but, thanks to
the huge pressure in the air chamber, develop nearly thirty-one
horse-power. Lest they should “race,” or revolve too quickly, while
passing from the tube to the water and do themselves serious damage,
they are provided with a “delay action valve,” which is opened by the
impact of the torpedo against the water. Further, lest the air should
be admitted to the cylinders at a very high pressure gradually
decreasing to zero, a “reducing valve” or governor is added to keep
the engines running at a constant speed.
Whitehead torpedoes are fired from tubes above or below the waterline.
Deck tubes have the advantage of being more easily aimed, but when
loaded they are a source of danger, as any stray bullet or shell from
an enemy’s ship might explode the torpedo with dire results. There is
therefore an increasing preference for submerged tubes. An ingenious
device is used for aiming the torpedo, which makes allowances for the
speed of the ship from which it is fired, the speed of the ship aimed
at, and the speed of the torpedo itself. When the moment for firing
arrives, the officer in charge presses an electric button, which sets
in motion an electric magnet fixed to the side of the tube. The magnet
releases a heavy ball which falls and turns the “firing rod.”
Compressed air or a powder discharge is brought to bear on the rear
end of the torpedo, which, if submerged, darts out from the vessel’s
side along a guiding bar, from which it is released at both ends
simultaneously, thus avoiding the great deflection towards the stern
which would occur were a broadside torpedo not held at the nose till
the tail is clear. This guiding apparatus enables a torpedo to leave
the side of a vessel travelling at high speed almost at right angles
to the vessel’s path.
It will be easily understood that a Whitehead torpedo is a costly
projectile, and that its value--£500 or more--makes the authorities
very careful of its welfare. During practice with “blank” torpedoes a
“Holmes light” is attached. This light is a canister full of calcium
phosphide to which water penetrates through numerous holes, causing
gas to be thrown off and rise to the surface, where, on meeting with
the oxygen of the air, it bursts into flame and gives off dense
volumes of heavy smoke, disclosing the position of the torpedo by
night or day.
At Portsmouth are storehouses containing upwards of a thousand
torpedoes. Every torpedo is at intervals taken to pieces, examined,
tested, and put together again after full particulars have been taken
down on paper. Each steel “baby” is kept bright and clean, coated
with a thin layer of oil, lest a single spot of rust should mar its
beauty. An interesting passage from Lieutenant G. E. Armstrong’s book
on “Torpedoes and Torpedo Vessels” will illustrate the scrupulous
exactness observed in all things relating to the torpedo depôts: “As
an example of the care with which the stores are kept it may be
mentioned that a particular tiny pattern of brass screw which forms
part of the torpedo’s mechanism and which is valued at about
twopence-halfpenny per gross, is never allowed to be a single number
wrong. On one occasion, when the stocktaking took place, it was found
that instead of 5000 little screws being accounted for by the man who
was told off to count them, there were only 4997. Several foolscap
letters were written and exchanged over these three small screws,
though their value was not more than a small fraction of a farthing.”
The classic instance of the effectiveness of this type of torpedo is
the battle of the Yalu, fought between the Japanese and Chinese fleets
in 1894. The Japanese had been pounding their adversaries for hours
with their big guns without producing decisive results. So they
determined upon a torpedo attack, which was delivered early in the
morning under cover of darkness, and resulted in the destruction of a
cruiser, the _Ting Yuen_. The next night a second incursion of the
Japanese destroyers wrecked another cruiser, the _Lai Yuen_, which
sunk within five minutes of being struck; sank the _Wei Yuen_, an old
wooden vessel used as a training-school; and blew a large steam
launch out of the water on to an adjacent wharf. These hits “below the
belt” were too much for the Chinese, who soon afterwards surrendered
to their more scientific and better equipped foes.
If a general naval war broke out to-day most nations would undoubtedly
pin their faith to the Whitehead torpedo for use in the open sea, now
that its accuracy has been largely increased by the gyroscope, a heavy
flywheel attachment revolving rapidly at right angles to the path of
the torpedo, and rendering a change of direction almost impossible.
For harbour defence the Brennan or its American rival, the
Sims-Edison, might be employed. They are both torpedoes dirigible from
a fixed base by means of connecting wires. The presence of these wires
constitutes an obstacle to their being of service in a fleet action.
The Brennan is used by our naval authorities. It is the invention of a
Melbourne watchmaker. Being a comparatively poor man, Mr. Brennan
applied to the Colonial Government for grants to aid him in the
manufacture and development of his torpedo, and he was supplied with
sufficient money to perfect it. In 1881 he was requested by our
Admiralty to bring his invention to England, where it was experimented
upon, and pronounced so efficient for harbour and creek defence that
at the advice of the Royal Engineers Mr. Brennan was paid large sums
for his patents and services.
The Brennan torpedo derives its motive power from a very powerful
engine on shore, capable of developing 100 horse-power, with which it
is connected by stout piano wires. One end of these wires is wound on
two reels inside the torpedo, each working a screw; the other end is
attached to two winding drums driven at high velocity by the engine on
shore. As the drums wind in the wire the reels in the torpedo revolve;
consequently, the harder the torpedo is pulled back the faster it
moves forward, liked a trained trotting mare. The steering of the
torpedo is effected by alterations in the relative speeds of the
drums, and consequently of the screws. The drums run loose on the
engine axle, and are thrown in or out of gear by means of a
friction-brake, so that their speed can be regulated without altering
the pace of the engines. Any increase in the speed of one drum causes
a corresponding decrease in the speed of the other. The torpedo can be
steered easily to right or left within an arc of forty degrees on each
side of straight ahead; but when once launched it cannot be retrieved
except by means of a boat. Its path is marked by a Holmes light,
described above. It has a 200-lb. gun-cotton charge, and is fitted
with an apparatus for maintaining a proper depth very similar to that
used in the Whitehead torpedo.
The Sims-Edison torpedo differs from the Brennan in its greater
obedience to orders and in its motive power being electrically
transmitted through a single connecting cable. It is over thirty feet
in length and two feet in diameter. Attached to the torpedo proper by
rods is a large copper float, furnished with balls to show the
operator the path of the torpedo. The torpedo itself is in four parts:
the explosive head; the magazine of electric cables, which is paid out
as the torpedo travels; the motor room; and the compartment containing
the steering-gear. The projectile has a high speed and long
range--over four thousand yards. It can twist and turn in any
direction, and, if need be, be called to heel. Like the Brennan, it
has the disadvantage of a long trailing wire, which could easily
become entangled; and it might be put out of action by any damage
inflicted on its float by the enemy’s guns. But it is likely to prove
a very effective harbour-guard if brought to the test.
In passing to the Orling-Armstrong torpedo we enter the latest phase
of torpedo construction. Seeing the disadvantages arising from wires,
electricians have sought a means of controlling torpedoes without any
tangible connection. Wireless telegraphy showed that such a means was
not beyond the bounds of possibility. Mr. Axel Orling, a Swede,
working in concert with Mr. J. T. Armstrong, has lately proved that a
torpedo can be steered by waves of energy transmitted along rays of
light, or perhaps it would be more correct to say along shafts of a
form of X-rays.
Mr. Orling claims for his torpedo that it is capable of a speed of
twenty-two knots or more an hour; that it can be called to heel, and
steered to right or left at will; that as long as it is in sight it is
controllable by rays invisible to the enemy; that not merely one, but
a number of torpedoes can be directed by the same beams of light;
that, as it is submerged, it would, even if detected, be a bad mark
for the enemy’s guns.
The torpedo carries a shaft which projects above the water, and bears
on its upper end a white disc to receive the rays and transmit them to
internal motors to be transmuted into driving power. The rod also
carries at night an electric light, shaded on the enemy’s side, but
rendering the whereabouts of the torpedo very visible to the steerer.