OFFENSIVE TORPEDO WARFARE.
THE term "Torpedo" is applicable more particularly to offensive
submarine mines than to those employed for the purposes of defence, and
therefore by _torpedoes_ will be understood every kind of submarine
explosive weapon designed to be used for active attack against vessels,
&c., no matter how they may be manipulated.
_Offensive Torpedo Warfare still in its Infancy._--Though during the
seventeen or eighteen years that torpedoes have been considered as a
legitimate mode of naval warfare there have occurred three big wars,
in each of which submarine weapons, offensive and defensive, have
played an important part, still the subject of _offensive_ torpedo
warfare must be even now considered as in its infancy, and therefore
any opinions expressed as to the merits and demerits of the various
apparatus in connection therewith can but be based on the theoretical
capabilities of each torpedo, and on the results of experiments carried
out with them during peace time, which latter as a rule are conducted
under far too favourable conditions to be relied upon.
_Their Use during the Civil War in America._--During the American
civil war, the only offensive submarine weapon that was used was
the outrigger or spar torpedo, which in those days was a crude and
imperfect machine, and manoeuvred from boats possessing all the
features which a torpedo boat should _not_ possess. Still under these
unfavourable conditions ships were sunk by such means by both Federals
and Confederates, proving that in future wars this mode of attack,
favoured by the vast and important improvements that have lately been
effected both in connection with the torpedoes and torpedo boats,
should play a prominent part, and prove a most destructive mode of
attack.
_Their Use in the Franco-German and Russo-Turkish Wars._--In the
Franco-German war of 1870-1, offensive torpedo warfare was not
resorted to by either side, the French fleet being deterred from
entering German waters by the submarine mines placed, or at least
supposed to be placed, in position.
From the Russo-Turkish war much light was expected by torpedoists
to be thrown on the subject of torpedo warfare, but alas, little or
nothing was done to settle any of the many vexed questions which exist
in regard to offensive submarine weapons. The torpedo experience of
that struggle tended rather to prove that the vast importance hitherto
attached to torpedo attack was much exaggerated.
One of the causes which led to the failure of offensive submarine
weapons, when employed on active service, seems to be due to the fact
that, owing to the extremely small radius of the destructive effect
of such weapons, it is absolutely necessary for complete success to
explode the mine in actual contact with the attacked vessel; to ensure
which, at night time, in an unknown harbour, with the position of the
vessel attacked somewhat uncertain, and even without the additional
obstacles of guard boats, booms, electric lights, &c., is a service of
infinite difficulty, and one which may easily terminate in a failure.
The foregoing would more especially apply to the spar torpedo attack,
but in an attack with the Whitehead fish, or towing torpedo, there
would be an additional cause of failure, viz., the complicated nature
of their manipulation.
Torpedoes may be divided into four classes, viz.:--
1.--Drifting or floating torpedoes.
2.--Towing torpedoes.
3.--Locomotive torpedoes.
4.--Outrigger or spar torpedoes.
_Drifting or Floating Torpedoes._--By "drifting" or "floating"
torpedoes are meant all those submarine machines which are dependent on
the tide or current of a stream for their action and motion.
During the American civil war this mode of attacking vessels was
constantly employed by the Confederates, and though not successful in
destroying any of the Federal ships, was the means of considerably
hampering the movements of their river flotillas.
Drifting torpedoes might be advantageously used for the destruction of
pontoon bridges, booms, &c., and in this way, had the Turks in their
late war used them, the Russians would have found the crossing of
the Danube a matter of infinite danger and difficulty; in fact, by
a systematic use of such weapons, combined with a little dash on the
part of the Ottoman flotilla on the Danube, that river should have been
to the Russians an impassable barrier. To use these torpedoes most
effectively, especially against a single vessel, a thorough knowledge
of the force and direction of currents should be gained before
proceeding to undertake an operation in which these submarine weapons
are used.
Another point to be remembered is, that if such a torpedo were started
with the flood, for example, towards an enemy, and did not explode,
there would be a chance of its being returned to the starting-place by
the ebb tide.
In this class the following torpedoes seem the most practicable:--
1.--Lewis's drifting torpedo.
2.--McEvoy's drifting torpedo.
3.--American extempore drifting torpedo.
_Description of Lewis's Drifting Torpedo._--"Lewis's" drifting torpedo,
designed for the express purpose of destroying booms or other floating
obstructions placed round a vessel at anchor for the purposes of
defence, is shown at Fig. 101. It consists of a box _a_, containing the
charge and fitted with several detonating fuzes. This box is attached
to one side of a beam _b_, and within 6 inches of one extremity, the
beam being about 20 feet long and 7 inches square; to the opposite
side, of the same end of the beam _b_ a heavy weight _c_, resting in
a shoe _d_, is attached by a long iron rod _e_, which reaches to the
other extremity of the beam, and is there connected to a bell-crank
lever and spring _f_, a pressure on which detaches the weight _c_; a
chain _g_, 18 feet long, connects the weight loosely with the upper
end of the beam, and another chain _h_, 9 feet 6 inches long, connects
it with a point more than 2 feet below the centre of the beam. The
apparatus is so constructed that it floats nearly vertical with the top
of the beam just above the surface of the water.
On the machine drifting against the boom or other obstruction, the
spring or lever _f_ at the upper extremity is pressed down, thus
releasing the weight _c_, which falling, becomes suspended by the two
chains _g_ and _h_, and brings the beam into an inclined position. The
weight of this mass of iron and the chain suspending it are suddenly
brought to bear on the top of the beam, dragging it under water and
clear of the boom, &c. At the same time the lower end, released from
the weight, rises, and the whole apparatus is carried forward by the
current against the side of the vessel, on striking which the torpedo
is exploded.
_Description of McEvoy's Drifting Torpedo._--"McEvoy's" drifting
torpedo is intended to be floated, singly or in groups, by the aid of
tides or currents against vessels at anchor, bridges, &c.
At Fig. 102 is shown a plan of this form of drifting torpedo.
It consists of the body of the torpedo _a_, which contains the charge,
at the side of which is placed the loading hole _b_; _c_ is the tube
containing the priming charge; _d_ is the framework surrounding and
protecting the wheel or screw _e_; _f_ is the fuze pillar, in the
centre of which is a steel rod _g_, and on the top a thin steel plate
_h_ is placed; _i_ is the nipple for the percussion cap; _k_ is a
horizontal bar, turning and resting on top of the fuze pillar _f_; _m_
is the lever for supporting the hammer _n_ when it is set; _l_ is the
screw barrel supporting the wheel or screw _e_; _o_ is a safety pin;
_q_ is the supporting chain, and _p_ the spring for working the hammer
_n_.
By means of a buoy or log of wood, from which the torpedo is suspended,
it can be adjusted so that the explosion shall occur at the requisite
depth.
To prepare the torpedo for use, unscrew the fuze pillar _f_, take off
the horizontal bar _k_, place a percussion cup on the nipple _i_, and
screw it tightly against the end of the steel rod _g_. The fuze pillar
is then ready for use, and should be screwed into the body _a_. Then
fill the torpedo with the explosive and close the loading hole _b_. The
hammer _n_ is then set by drawing it back and bringing the end of the
lever _m_ against it, at the same time running the screw barrel _l_
under the lever _m_, so that its end catches the screw of the barrel,
as shown in the figure. The safety pin _o_ is then put in its place and
secured by a few parts of thread, which by a sharp jerk on the safety
line will be easily broken.
[Illustration: DRIFTING TORPEDOES.
PLATE XXIX]
The horizontal lever _k_, which carries the lever _m_ and propeller
_e_, rotates on the top of the fuze pillar _f_, and is prevented from
rising by means of a screw. The torpedo being let go, the safety pin
_o_ is pulled out by means of a line which is attached to it. The
propeller will not revolve whilst the torpedo is drifting with the
current, but the instant it is stopped by the action of the current
the wheel will be caused to revolve, and after a few revolutions it
will unscrew the barrel from under the end of the lever _k_, and
the latter, dropping the hammer _n_, will be forced by the spring _p_
into contact with the thin steel plate _h_ on the top of the fuze
pillar, which blow is transmitted by means of the steel rod _g_ to the
percussion cap, and the torpedo exploded.
_American Extempore Drifting Torpedo._--This form of drifting torpedo,
which is readily made, was used in great numbers by the Confederates,
and though not successful in sinking any Federal ships, caused their
vessels considerable annoyance and delay.
At Fig. 103 is shown a sketch of this torpedo. It consists of a tin
case containing about 70 lbs. of powder. A stiff wire _a_, _b_ passes
through a hole punctured in a strip of tin _c_, and a stuffing box _d_;
the end _a_ of the wire is covered with fulminate, and so arranged
that the friction caused by its passage through the strip of tin _c_
will ignite it; a number of wires lead from _b_ to pieces of driftwood
on the surface _e_, _e_, _e_, and the case is supported at the proper
depth by a line attached to a section of log.
_Towing Torpedoes._--By towing torpedoes are meant those submarine
machines which are so shaped and arranged, that when towed from a ship
or boat in motion they will diverge to a considerable extent, thus
enabling the towing vessel to pass clear of the ship attacked, and yet
near enough to allow of the torpedo being brought in contact with some
part or other of her hull.
Towing torpedoes were for the first time employed on actual service
during the late Russo-Turkish war, when a modified form of the
well-known Harvey torpedo, designed by a German officer, was used by
the Russians, but in no case was it successful.
In this class of submarine offensive machines may be placed the
following:--
1.--Harvey's towing torpedo.
2.--Menzing's towing torpedo.
3.--The French towing torpedo.
_Harvey's Torpedo._--This form of towing torpedo was invented
conjointly by Captain John Harvey and Commander Frederick Harvey,
R.N., and is intended to be used at sea both as a means of offence and
defence.
At Fig. 104 is shown in elevation the small sized Harvey towing
torpedo, in which all the latest improvements that have been devised
are represented.
_a_ is the case of the torpedo, formed of Muntz's metal, but not
provided, as the original ones were, with an exterior case of wood; by
this alteration greater capacity combined with extreme lightness is
obtained, which undoubtedly much enhances the value of the small size
torpedo which is intended to be carried by and manoeuvred from boats;
_b_ is the principal or after lever, hinged on the top of torpedo at
_c_, and rests, when ready for action, in a crutch formed in the top of
the exploding bolt _d_; _e_ is the foremost lever, hinged at _f_, and
kept in position on the after lever _b_ by a groove formed in it and a
lashing which passes through a slot in the principal lever, as at _g_;
_h_ is the side lever, pivoted at _i_, and exerting a pressure on the
firing bolt _d_ by means of a lanyard which is passed through the bolt
_k_ and over the principal lever _b_; _l_ is the top lever, pivoted
at _m_, and exerting a pressure on the bolt _d_ by means of a lanyard
which is passed through the bolt _n_ and over the principal lever _b_;
this top lever _l_ has been added to ensure the action of the torpedo,
on its striking sideways against a vessel; _o_ and _t_ are handles, to
the former of which the lashings of the levers _h_ and _l_ are secured;
_p_ is the ring used for attaching the buoy rope; _r_, _r_ are two
loading holes, made in the side of the torpedo case, by which a charge
of gun-cotton may be quickly and efficiently stowed; this also is a new
feature in the small size torpedo; _s_ is the rudder formed for the
purpose of controlling the direction of the torpedo when the tow line
is suddenly slacked.
In regard to the large size torpedo, the construction of the case
remains as in the original ones, the improvements being, the
enlargement of the loading and fuze holes, and the addition of the top
lever _l_, as shown at Fig. 104.
The small size torpedo is capable of holding 47 lbs. of water, whilst
the large size one will contain 76 lbs. of water, or about 33 lbs. and
58 lbs. of gun-cotton respectively.
The slings are made of best Italian hemp, and consist of a span of
four legs, which are secured to lugs at the corners of the torpedo and
connected to an iron thimble, which is shown at Fig. 105; this thimble
is made suitable for either wire or hemp rope, and is so arranged that
should the seizing become slack, the parts of the slings cannot become
detached from the thimble.
[Illustration: HARVEY'S TOWING TORPEDO.
PLATE XXX]
The legs of the slings should be so fitted that when stretched
alongside the torpedo they extend 1 foot beyond the stem for the
large torpedo and 8 inches for the small one; the four legs should be
so fitted that when an equal strain is brought on them, the thimble
should be on a level with the upper lugs, and the upper fore span form
an angle of 80° to 85° with the side of the torpedo; this is shown at
Fig. 106. This arrangement gives the best divergence with the least
strain on the tow rope, and is suitable when the torpedo is kept at
short scope, as well as when a long length of tow line is out.
The mode of attaching the foremost and side levers is shown at Fig.
107. Before reeving the lanyards they should be well greased in the
wake of the fair leads, but not where they are made fast. The lanyards
should be made up like a reef point. Care should be taken that the
short arm of the side lever _h_ is brought close into the fair lead,
and its lanyard should be set up sufficiently taut to give a slight
spring in the principal lever _b_ by the strain thus brought on it.
This lever _b_ has a steel fish on the top, in order to prevent it
taking a permanent bend. If the side lever lanyard is properly set up,
the bolt will spring down about 1/8th of an inch when the safety key is
withdrawn, owing to the spring in the lever, and the shrinking of the
lanyard; this brings the muzzle 1/8th of an inch nearer the pin without
disturbing the side lever.
The bolt is so arranged that the torpedo can be fired by either of the
following methods:--
1.--Mechanically.
2.--Electrically at will.
3.--Electrically on contact or at will.
_Mechanically._--In this case the bottom of the inner cylinder, as at
_a_, Fig. 108, is fitted with the ordinary mechanical chemical fuze,
ignition being effected by the breaking of the glass vessel containing
the sulphuric acid on being forced into contact with the needle _n_, by
the action of the levers on the torpedo striking a vessel.
_Electrically at Will._--For this purpose a platinum wire fuze is used,
one terminal being connected to earth through the bolt, the other to a
wire leading up through the core of the bolt, and connected by means of
an ebonite joint with a single cored electrical cable leading from the
torpedo vessel.
_Electrically on Contact, or at Will._--In this case, a resistance
coil is inserted in addition to the fuze, and is so arranged that on
the bolt being forced down a short circuit is formed, cutting out the
resistance coil (about 20 ohms), and thus enabling the battery to fire
the fuze, which, owing to the 20 ohms resistance in the circuit, it was
previously unable to effect. Should the bolt so arranged be required to
be fired at will, it is only necessary to put a more powerful battery
in circuit, and so fire the fuze through the 20 ohms resistance.
_Exploding Bolt._--The exploding bolt is fitted to act with a pressure
of from 30 to 40 lbs. on its head for the large size torpedo, and from
15 to 20 lbs. for the small size one.
The bolts are all the same size, and differ only in the direction
of the slot for the safety key _k_, being port or starboard bolts
accordingly. The muzzle of the exploding bolt stands 1 inch off the pin
when in the safety position, that is, when the safety key rests on the
brass work of the priming case.
The safety key is secured in the slot of the exploding bolt, as shown
at Fig. 108, by eight or nine parts of strong whitey-brown thread
secured to the key, passed round the bolt, and securely knotted; the
parts of the thread should come away with the key, in order that none
of the parts may be worked down the tube by the exploding bolt.
In the event of the large torpedo being cut away in deep water after
the withdrawal of the safety key, it will explode by pressure on the
head of the bolt at about sixty fathoms depth; the small one at about
thirty fathoms.
_Buoys._--The buoys are of two sizes, and are made of solid cork
(such cork only being used as will ensure great floating power after
being immersed for a time); each buoy is built upon a galvanised iron
tube running longitudinally through; on the ends of the tube are
screwed wooden cones, which bind all together, and render the buoy
indestructible.
Two buoys are used for each torpedo, the larger buoys for the large
size torpedo, and the smaller buoys for the small size torpedo. The
buoy rope is of hemp, about five or six fathoms in length and two
inches in circumference, an eye being spliced in the end nearest the
torpedo; to this eye is bent the tow rope, with a single or double
sheet bend forming the knot by which the torpedo is towed; the other
end of the buoy rope is passed through one of the rings in the stern
end of the torpedo (according to whether working in deep or shallow
water), then through the tube of the first buoy, and an overhand knot
made in the rear; then through the next buoy, and a knot in the rear
of that. Recently, Captain Harvey has adopted a large and a small buoy
for each torpedo, the large one being practically sufficient, the
smaller one being added in the event of the other one becoming sodden.
_Brakes._--The brakes are used for the purpose of controlling the tow
ropes; they can be fixed by screws into the deck at the most convenient
place for command, and in a properly constructed torpedo vessel would
be placed below the water line, to prevent exposure of the men working
them. They are so arranged as to admit of the tow rope being quickly
veered, and at the same time are sufficiently powerful to bring the
torpedo to the surface when required. Success greatly depends on the
skilful handling of these brakes, for in conjunction with the cork
buoys they give the operator command of the depth at which the enemy
is to be struck. Unless a very high rate of speed is required, one
handspike will control the tow rope; the other strap can be thrown off
the drum, and the handspike allowed to lie on the deck ready to be
thrown into gear, if necessary. The surface of the drum in contact with
the strap should be powdered with rosin to increase the friction. The
tow rope should be so reeled up that in veering the reel may revolve
towards the men at the handspike. The spindle will contain several tow
ropes, that, in the event of one torpedo being cut away, another can be
immediately bent.
The brake for small torpedo requires only one drum and handspike. It
can be fitted to a steam launch by placing an extra thwart across near
one of the others.
Care should be taken that the riding turns lie fairly over each other,
to prevent a jamb when veering.
The brakes, both large and small, are so made as to ensure durability,
they being considered a part of the ship's furniture.
Brake for safety key line is a small reel on the same principle. When
going a slow speed, it may not be necessary, as the safety key line
can be attended by hand; but when going ten or eleven knots, it will
be found of considerable advantage, both in keeping the bight of the
safety key line from dragging astern, thereby lessening the divergence
of the torpedo, and also in drawing the safety key when a strong stop
is used.
_Arrangements for Launching and Towing the Torpedoes._--A yard across
either the main or mizen mast of a torpedo vessel, from 20 to 25 feet
above the water line, is a very convenient method for launching and
towing. The leading block on the yard, through which the tow rope is
rove, may be fitted to a traveller on the yard with an inhaul and
outhaul, that the distance out from the ship's side may be regulated as
convenient.
In a large vessel, the leading block for tow rope can be fixed to
the end of the quarter-boat's davits. The brakes for commanding the
tow rope should be screwed firmly to the deck. In a vessel properly
constructed for the service, they would be on the lower deck, the tow
rope having been led along the yard, and down each side of the mast.
A leading block for the tow rope is placed on the deck by span or bolt
a few feet in front of the brake. The safety key reel, if used, must
be fixed in a convenient position on deck, that the man attending it
can see how to control it; in a properly constructed vessel he would be
in the pilot house. The safety key line leads through a small leading
block on the ensign staff or some convenient point abaft the lead of
the tow rope, 15 to 20 feet above the water. The leading block on
the yard may be fitted with a lizard, if thought necessary. A sharp
instrument should be kept by the brakes ready to sever the tow rope.
In large men of war, arrangements are made for carrying a loaded
torpedo and two buoys in a convenient position on each side of the
vessel, in such a manner that the tow line can be bent, the exploding
bolt screwed in, the levers adjusted, and the torpedoes and buoys
dropped simultaneously when required.
_Preparing the Torpedoes for Use._--The torpedoes, port and starboard,
loaded and ballasted, having been hoisted out of the torpedo room, are
placed on the deck on their own sides, with their heads forward under
the leading block, and the buoys placed abaft them and strung together;
the exploding bolts are now entered into the torpedoes, and forced down
until their safety keys rest on the brass work, taking care that each
safety key points in the direction of the eye through which its lanyard
has to pass; the levers are now secured by their lanyards, as explained
at pages 120 and 121. The eye at the end of the buoy rope is now rove
through the large or small ring in the stern end of the torpedo. The
tow rope having been previously rove through the leading block on the
deck and on the yard, is rove through the thimble of the slings from
forward aft, and bent, with a single or double sheet bend, to the
eye of the buoy rope. The safety key line having been previously rove
through the leading block on the ensign staff, and the lanyard on the
safety key having been led through the eye of the handle, making a fair
lead with the slit in the bolt, are bent together with a double sheet
bend, and stopped to the eye of the handle by a split yarn of suitable
strength, the yarn having been first secured to the line by a round
turn outside the bend.
The line should also be stopped with another split yarn round all parts
of the slings close up to the thimble, having first made an overhand
knot in the line at a distance a few inches longer than that between
the eye bolt and the thimble.
The crew having been stationed at their respective posts, the handles
having been shipped on the tow reel, the tow line is then reeled up
until the torpedo will launch clear, and swing out under the leading
block on the yard. Hold the torpedo by the handspikes, and take off the
handles of the brake. In swinging out, care should be taken that in
starting from the deck the fore slings do not foul the fore top lever.
The stern of the torpedo can be steadied by keeping a slight strain on
the buoy rope. The safety key line must be kept clear, and not checked,
or it might break the stop and draw out the key before intended. The
buoys must be placed in a proper position and hands stationed by them
to launch them overboard the instant the torpedo takes the water. It
would be better to stop the screw, if circumstances would allow of it,
when lowering the torpedo and buoys into the water, to prevent the
chance of the buoys fouling the screw. The torpedo, on reaching the
water, will _immediately_ diverge clear of the ship; the buoys being
launched, as the strain comes on the buoy rope, they will be towed
clear away from the screw, and full speed may be put on at once. The
men at the handspikes must veer steadily, occasionally checking the
torpedo, that it may be kept near the surface, and not allowed to dive,
which it will do if the tow rope is slacked up altogether, and then a
sudden strain brought on it.
Eventually it will come to the surface, when the bow is pointed up
by the strain on the tow rope; greater the speed the more quickly
will it be brought to the surface. In shallow water this should be
particularly attended to, as in diving it might strike the bottom and
injure the levers, and, if the safety key has been withdrawn, explode;
moreover, it brings an undue strain on the tow rope. The torpedo can
now be gradually veered out to the distance required, the safety key
line so attended that a sufficient strain is kept on it as not to
allow of a long bight of line dragging astern of the torpedo; at the
same time having due regard to the strength of the yarn by which the
line is stopped to the handle of the torpedo. The distance veered must
depend upon the nature of attack. The tow line should be marked with
knots every 10 fathoms: under some circumstances the torpedo would be
close to the ship until passing the enemy; at other times veered to 40
fathoms it will be found most suitable.
The full divergence of 45° is obtained up to 50 fathoms; beyond that
the bight of the tow rope in the water drags the torpedo astern, unless
the tow rope is triced much higher up, which has its disadvantage;
40 to 50 fathoms of tow rope gives the best command of the torpedo,
veering 2 or 3 fathoms of tow line suddenly will always sink the
torpedo some feet below the surface. Should it become necessary to use
the torpedoes with a stern board, they can be so used, but in this case
the port torpedo is used on the starboard, bow and starboard on the
port; all other arrangements being exactly the same. In rough weather,
advantage should be taken of the roll, and the torpedo allowed to swing
out from the yard, and be let go by the run, checking the tow rope
immediately the torpedo is in the water. It is not absolutely necessary
to ease the vessel when launching; the torpedo can be launched at full
speed. In the event of its being found necessary to cut adrift the
torpedo, in consequence of coming suddenly across a friendly vessel,
the tow rope should be cut near the brake, and if the buoy rope has
been rove through the large stern ring, the torpedo will sink and be
lost, the buoy only remaining. If the buoy rope has been rove through
the small stern ring, the torpedo will be suspended by the buoy rope;
and should the safety key not have been withdrawn, can be recovered
with safety.
In the event of wishing to recover it when the buoy rope has been rove
through the large ring, a toggle must be lashed on the tow rope abaft
the leading block on the yard, when it can be recovered by the buoy
rope; as a general rule, however, it will be found best to expend the
torpedo, and not attempt its recovery.
[Illustration: HARVEY'S TOWING TORPEDO.
PLATE XXXI]
[Illustration: SYSTEMS OF ATTACK WITH HARVEY'S TOWING TORPEDO.
PLATE XXXII]
_Recovering the Torpedo._--Should the safety key have been withdrawn,
great caution is necessary. Tongs, shown at Fig. 109, for going round
the upper part of the bolt, to take the place of the safety key,
when once clasped and secured round the bolt, render the torpedo
safe to handle; this could only be done from a boat. With the safety
key in, there is no danger in hoisting it inboard again by its own tow
rope, and hoisting up the buoys at the same time with a grapnel.
_Different Methods of Using the Torpedo._--There are two methods of
employing the torpedo, either of which may be adopted, according to
circumstances.
1.--When it is towed with a length of line varying from
25 to 60 fathoms, and dipped when in position to strike
the attacked vessel.
2.--When it is kept suspended from the yard, &c., and
dropped at the spot, where according to the first
method it would have been dipped.
In the first method, it is not necessary to withdraw the safety key
till just before dipping; in the second method the safety key line is
belayed at about twenty fathoms, and the key withdrawn when the line is
tautened by the ship going ahead.
_Tactics._--Description of the various attacks that may be made with
the Harvey torpedo against a ship at anchor or under way. In the
following diagrams _T_ is the torpedo vessel, _S_ the ship attacked.
[Illustration]
...... The track.
------ The tow rope.
O-o-o The torpedo.
_Attacking a Vessel moored Head and Stern._--In this case the torpedo
vessel steers in for the bow or quarter of the vessel attacked,
according to the direction of the current, and on the side approached
launches the torpedo between the moorings, as at _A_; leaving the tow
rope slack, the torpedo vessel proceeds ahead or astern against the
current, and when at a sufficient distance off, the tow rope is held
fast, which will cause the torpedo to diverge into contact with the
vessel attacked, as shown by Fig. 110.
_Attacking a Vessel at Anchor by Crossing her Bow._--In this case
the torpedo is sufficiently diverged when near to the vessel with a
good scope of tow rope out. After having crossed her bow, proceeding
onwards, the tow rope will be brought obliquely across her cable, and
the torpedo will swing into her, as shown at Fig. 111. It may be here
remarked, that in all cases the depth of the explosion can be obtained
by the sudden slacking of the tow rope; and the tow rope once under
the keel, causes the torpedo to be hauled down near to it before
exploding.
_Attacking a Vessel at Anchor by coming up from Astern on either
Side._--In this case the torpedo is launched when on the quarter of the
vessel attacked, as at _A_, the tow rope left slack. After steaming
ahead some distance, hold fast the tow rope, when, by continuing to
steam on, the torpedo will diverge into contact with the bottom of the
vessel attacked, as shown at Fig. 112. _When skilfully performed_,
the total destruction of the enemy is certain, since the torpedo is
springing from a depth to the surface, and will, in consequence, strike
near her keel. The torpedo vessel can pass at her greatest speed, and,
if thought necessary, near enough to clear away any of the ordinary
obstructions, such as booms, nets, &c.
_Passing Down between Two Lines of Vessels at Anchor._--In this case it
would be impossible to fire at the torpedo vessel, for fear of injury
to their friends. Two or more torpedo vessels following each other with
preconcerted signals would cause great destruction. See Fig. 113.
_Attacking a Vessel in Motion from Right Ahead._--In this case two
torpedoes are launched, port and starboard, each diverging to its full
extent; when passing the vessel attacked, one or the other of the tow
ropes is brought across the cut-water, and by the simultaneous motion
of the two vessels in opposite directions, the torpedo is brought
alongside of or under the bottom of the vessel attacked, as shown at
Fig. 114. The torpedo vessel should keep the masts of her enemy in
one until close to, when either torpedo will be used, according to
the movement of the enemy. At the time of the tow rope taking the
cut-water, the brake is suddenly eased up; the tow rope will then pass
under the bottom, when by checking the tow rope the torpedo will be
hauled under the bottom.
To execute this attack, judgment, skill, and nerve of the highest order
will be required, as the risk of being run down will be imminent.
_The Attack from Astern._--In this case two torpedoes are launched, and
diverged as in the previous case; it is assumed in this instance that
the torpedo vessel can outspeed the vessel attacked, which will enable
her to bring a torpedo under the run of the attacked vessel, as shown
at Fig. 115.
[Illustration: SYSTEMS OF ATTACK WITH HARVEY'S TOWING TORPEDO.
PLATE XXXIII]
[Illustration: SYSTEMS OF ATTACK WITH HARVEY'S TOWING TORPEDO.
PLATE XXXIV]
_If Chased by a Hostile Vessel, and unable to Face her._--In this case
veer a torpedo astern, having first obtained a position a little on
the bow of the chasing vessel. When it is known by the length
of the tow rope out that the torpedo is about abreast of her bow,
hold fast the tow rope, which will cause the torpedo to diverge, and
be brought into contact, as shown at Fig. 116. As a last resort drop
spanned torpedoes.
Torpedoes can be used with a stern board, if necessary. The port
torpedo, in this case, will be launched on the starboard side, and the
starboard on the port side.
It should be here remarked that, although great speed is essential in
the torpedo vessel to come up with the enemy and choose an advantageous
position, it is not advisable to tow the torpedoes, if it can be
avoided, at a greater speed than 11 knots; because the strain brought
upon the towing gear is excessive, and the torpedo would require a
large addition of ballast to keep it sufficiently immersed to attain
the full divergence.
There is, however, one style of attack in which the highest speed can
be maintained, viz. by dropping the torpedo alongside in passing.
This mode of attack is one of the best, particularly under cover of
darkness, against a ship at anchor.
The position of the torpedo is known, and the tow line is never in
contact with the enemy during the operation; a skilled hand at the
brakes is all that is required, the vessel keeping a straight course at
the highest speed, passing as close as possible to the enemy, in order
to clear away all obstructions. The tow rope must not be checked by the
brake too suddenly.
_Defensive Purposes._--The Harvey torpedo may be used as a means of
defence by large ships against a torpedo vessel attacking with that
species of submarine weapon, as the latter would be forced to pass
outside the former vessel's torpedo, and thus decrease the chance of
a successful dip. Again, in the case of an attack by the ram, these
torpedoes afford some protection, as a deterrent.
_Night time._--Though a dark night and tempestuous are favourable to a
surprise, yet in the case of a Harvey torpedo attack it is essential
that the weapon should be seen to dip it at the proper time, therefore
daylight is necessary to this species of torpedo attack.
_Value of the Harvey Torpedo._--The Harvey torpedo is undoubtedly of
considerable value when _ably handled_, yet the skill and judgment
required is very great, and can only be acquired by _constant_
practice.
_Description of the Menzing Towing Torpedo._--This modified form of the
Harvey towing torpedo was designed by Captain Menzing, of the German
navy, to remedy what is considered by the Germans as the chief defect
of that weapon, viz. its liability to injure friendly vessels, and also
to do away with the necessity of using two torpedoes, one for each side
of a ship.
At Fig. 117 is shown a plan and elevation of this towing torpedo.
_a_ is the body of the torpedo, somewhat similar to the Harvey, but
narrower at the stern, and bevelled on both sides towards the bow; _b_
is an iron frame placed in the bow, capable of being turned either to
the right or left; _c_ is the hole for the introduction of the fuze,
and _d_ is the loading hole; _e_ is a rudder placed at the stern of the
torpedo; _f_, _f_ are levers, by pressure against which the torpedo
may be fired mechanically, or electrically at will; these levers are
connected to a block of wood fitted with stops to prevent them being
pushed too far over; _s_ and _p_ are two towing ropes, one on each side
of the torpedo, which pass from its stern through the point of the
frame _b_, and thence to the vessel, these are also connected to the
rudder _e_ in such a manner that on either of the ropes _s_ and _p_
being tautened the rudder _e_ is turned in the opposite direction; _w_
is an electric cable, strong enough to bear the whole pressure of the
torpedo when being towed right aft.
To diverge the torpedo on the starboard quarter of the ship, the line
_s_ must be slackened, and the whole towing strain brought on the rope
_p_, causing the frame _b_ to be pulled over to a knot _k_ in the
rope _p_, made at the proper position to ensure the torpedo towing at
the correct angle from the course of the vessel, and at the same time
causing the rudder _e_ to be turned to starboard; this is shown at Fig.
117 by the dotted lines.
To diverge the torpedo on the port quarter, the towing rope _p_ would
be slackened and the whole strain brought on the rope _s_, and an
action opposite to that already described would be the result.
Two cork buoys are used, similar to those employed with the Harvey
torpedo; one being attached at a distance of 10 feet from the stern of
the torpedo, and the other at such a distance astern that the torpedo
would be placed at a distance below the surface to allow of safety to a
friendly vessel.
[Illustration: GERMAN AND FRENCH TOWING TORPEDOES.
PLATE XXXV]
The torpedo is manipulated in a similar manner to the Harvey, the
circuit being closed at the moment of the first buoy disappearing, at
which time the torpedo would be about ten feet below the surface. The
two buoys are together capable of supporting the torpedo, and thus by
means of the second one it may be picked up, should it be necessary to
cut the towing ropes.
_Description of the French Towing Torpedo._--The towing torpedo used by
the French is represented in section and plan at Fig. 118.
_a_ is the body of the torpedo, formed of wood enclosed in a thin steel
case; _b_ is the head made of cork; _c_ is the case containing the
charge, which is generally 33 lbs. of dynamite, this case is supported
by the bolt _d_ resting on the plate _e_; _f_, _f_ are whiskers, which
are connected to the plate _e_; _g_ and _h_ are hollow tubes, one end
of _g_ being attached to the case _e_, and one end of _h_ to the rear
end of the body of the torpedo _a_, and they are so arranged that when
the case _c_ is released, its weight will draw out the tube _g_, which
slides along the tube _h_ to nearly the full extent of the latter; _k_,
_k_ are bolts, to which the towing sling is attached; _l_ is the fuze,
and _n_ is a small gun used for firing the torpedo at will. The hole
in the plate _e_ through which the bolt _d_ passes is larger than the
latter, so that when the plate is moved backwards by pressure being
applied to the whiskers the bolt is freed from support, and case _c_
attached to it falls.
The modes of firing are as follows:--
1.--The automatic plan of firing is effected by the
tube _h_, after it has fallen a certain distance,
corresponding to a depth of 9 feet for the case _c_,
drawing down by means of a line attached to it a plug
contained in the body _a_, which completes the circuit
of the firing battery.
2.--The plan of releasing the charge at will is
effected by means of the small gun _n_, which is fired
by electricity, and by its firing forces back the plate
_e_, thus releasing the charge, which is then exploded,
as previously explained.
_Locomotive Torpedoes._--By "Locomotive" torpedoes are meant those that
possess within themselves the power to move through the water, when
once started in a given direction.
Of this species of submarine weapons, the following are the most
efficient and are the ones most generally used:--
1.--The Whitehead fish torpedo.
2.--The Lay torpedo.
_Invention and Adoption of the Fish Torpedo._--The idea developed by
the fish torpedo is due to an Austrian marine artillery officer, who
is now dead. In 1864, Mr. Robert Whitehead, then superintendent of
iron works at Fiume, acting upon the suggestions of a Captain Lupuis
of the Austrian army, commenced a series of experiments to ascertain
the practical value of the above idea, the result being a fish torpedo,
commonly called "The Whitehead," which though far inferior to the fish
torpedo of the present day, was then considered to be a fearful and
wonderful weapon.
The Austrians were the first to purchase this weapon, and two years
later, in 1870, Mr. Whitehead came to England, and prosecuted numerous
experiments with his fish torpedo under the supervision of several
English officers, and on the 8th of October of the same year he
succeeded in completely destroying an old hulk moored at the mouth of
the Medway. The fairly successful results of these experiments induced
the English government to purchase the secret and several of Mr.
Whitehead's fish torpedoes, under the following conditions:--
1.--The right of manufacturing them in England.
2.--To be kept fully informed of all improvements, as
soon as made.
3.--The right of using all such improvements.
And the total amount paid to Mr. K. Whitehead at that time was the
sum of seventeen thousand five hundred pounds, which did not include
the sum of two thousand five hundred pounds claimed for the expenses
attendant on the Medway experiments. Since then a large number of
Whitehead's fish torpedoes have been purchased from time to time,
especially during the Turco-Russian war, when some two hundred were
ordered, also great numbers have been manufactured at Woolwich. The
English fish torpedo, as far as can be ascertained, is a vastly
superior weapon to the Whitehead fish torpedo, possessing as it does
increased speed, and therefore far greater accuracy.
Besides Austria and England, nearly all the European governments have
purchased the Whitehead secret and torpedoes, but in the case of some
of them, the last two clauses of the English conditions of purchase
were omitted.
[Illustration: WHITEHEAD'S FISH TORPEDO.
PLATE XXXVI]
The Turkish is the only government that has obtained the Whitehead
secret and torpedoes without paying for it. This was managed as
follows:--
"On the night of the 20th of December, 1877, the Russians made an
attack with Whitehead torpedoes on an Ottoman squadron lying in the
harbour of Batoum, but owing to a want of practical knowledge of the
manipulation of such weapons, no vessels were sunk or damaged, but two
fish torpedoes, one in perfect condition, were found the next morning
high and dry on the beach at that place."
The American government have up to the present time not sanctioned
the purchase of the costly Whitehead torpedo, preferring their own
locomotive torpedo, which will be fully described further on. On a
government purchasing the fish torpedo, a certain number of their
naval or military officers are sent to Fiume in Austria, where Mr. R.
Whitehead's manufactories are situated, and where the necessary very
exhaustive experiments with his torpedoes are carried out, and are
there thoroughly instructed in the manipulation of these machines, and
are also supplied with a double set of drawings of the various parts of
the torpedo. These officers, and all others whom it may be necessary to
initiate into the mysteries of the Whitehead secret, are bound on their
honour not to divulge it.
_Employment of Fish Torpedoes in War._--The fish torpedo has been
employed on actual service on three known occasions only, in two of
which it failed to fulfil its deadly mission.
On the 29th of May, 1877, a Whitehead fish torpedo was fired by H.M.S.
_Shah_ against the Peruvian ironclad _Huascar_, but failed to strike
her, owing to the latter vessel altering her course at the moment of
the torpedo being discharged. The next instance of the employment of
the Whitehead torpedo was that one mentioned at page 132. The last
and only successful attempt yet made occurred on the 26th of January,
1878, when the Russian steamer _Constantine_ fired a Whitehead
torpedo against a Turkish guard vessel off the harbour of Batoum, and
completely destroyed her.
_Description of Torpedo._--A general view of the Whitehead fish torpedo
is shown at Fig. 119. It is divided into three parts, connected
together by screws.
1.--The charge chamber.
2.--The adjustment chamber, in which is placed what is
known as the secret.
3.--The air and engine chamber.
Vertical and horizontal steel fins are fitted for the purpose of
maintaining the torpedo in an upright position whilst passing through
the discharge tube, or frame; the former fins run nearly the whole
length of the weapon, while the latter are considerably shorter. The
motive power of the torpedo is compressed air, forced by means of a
powerful steam air compressing pump into a portion of the steel chamber
(3) at a tension of upwards of 1000 pounds to the square inch, which
is equivalent to about sixty atmospheres, and which by means of a set
of small three cylinder Brotherhood engines, contained in the steel
chamber (3), drives two screw propellers. These engines are capable
of exerting a force of forty indicated horses, and yet only weigh
about thirty-five pounds, from which it will be understood that to
attain these results the workmanship and materials employed in their
manufacture are of the very highest order and fineness.
The torpedo is made of various sizes, ranging from 14' long and 14"
maximum diameter to 19' long and 16" maximum diameter.
_Capabilities of the Fish Torpedo._--The capabilities of the fish
torpedo are as follows:--
1.--If adjusted for a certain depth, from 5 to 15 feet,
and projected from above water, or if started from the
surface, or if discharged from a submerged tube, it
will rapidly attain that depth, and maintain it during
the run.
2.--If fired in still water, it will make a straight
run in the line of projection, provided that an
allowance has been made for the deflection due to
transverse currents.
3.--It can be adjusted to stop after having run any
distance up to its extreme range, and after stopping to
sink, float, or explode.
4.--Its range and speed vary considerably, according to
the pattern of the torpedo.
-------+----------------------------------------------+-----------------
| Whitehead Fish Torpedo. | Woolwich Fish
| | Torpedo.
+--------------+---------------+---------------+-----------------
|14' long, 16" | 14' long, 16" | 14' long, 14" | 14·5' long, 14"
| max. diam. | max. diam. | max. diam. | max. diam.
Yards. | one screw. | two screws. | two screws. | two screws.
-------+--------------+---------------+---------------+-----------------
200 | .. | .. | 20 knots. | 25-1/4 knots.
250 | 9-1/2 knots. | .. | .. | ..
300 | .. | 12-1/4 knots. | 19-1/4 knots. | 24-1/2 knots.
400 | 8 knots. | .. | 18 knots. | 23 knots.
600 | .. | 11 knots. | .. | 20 knots.
750 | .. | 10-1/2 knots. | .. | ..
800 | 7 knots. | .. | 16-1/2 knots. | 18 knots.
1000 | .. | 9 knots. | .. | 15-1/2 knots.
-------+--------------+---------------+---------------+-----------------
Pressure of air in engines varies for distance and
speed from 40 atmospheres to 140 atmospheres.
_Placing the Charge._--The explosive is generally placed in what is
termed the cartridge case, which case is similar in shape to the
interior of the charge chamber (1), and is fixed thereto by means of
wooden wedges.
_Ignition._--The method of ignition is mechanical, and is arranged as
follows:--Extending from the nose of the torpedo to the cartridge case
is a tube terminating in a copper case, in which is placed the priming
charge and detonating composition; within this tube is a steel rod
some 2 feet long, fitted with a needle point at its inner end, and its
outer end screwed into a frame; this frame is capable of moving in and
out, and is connected with a spiral spring which tends to force it, and
consequently the steel rod, or striker, inwards. By compressing this
spiral spring, the inner end of the frame is butted against a catch,
by which it is prevented from acting. On this catch being released,
no matter by what means, the spring is brought into action and forces
the frame and steel striker inwards, the needle point of the latter
coming into contact with the detonator fires the priming charge, and so
explodes the torpedo. The foremost extremity of the torpedo, which is
termed the nose piece, is so fitted that it is capable of being forced
inwards, but in a position of rest its inner edge is just clear of
the catch. On a pressure being brought on the nose piece in a direct
line with the length of the torpedo, it will be forced inwards, the
result being the releasing of the catch and explosion of the torpedo.
In addition to the nose piece, horizontal and vertical levers, or
whiskers, may also be used, a slight pressure on either of which
will similarly effect the explosion of the torpedo; also cutters for
penetrating nets, &c., are fitted to the nose piece when desired.
_Safety Wedge and Key._--For safety purposes a wedge is employed, which
when in the safety position prevents the catch from acting; this wedge
is so arranged that it may be withdrawn by the action of the machinery
after the torpedo has run a certain distance, and also may be replaced
by similar means in the safety position on the completion of the run.
As an additional precaution a safety key is used, which is inserted in
the head of the torpedo through the spring of the frame.
_Description of Adjustment Apparatus._--For adjusting the length
of range for withdrawing and replacing the safety wedge, &c., the
following apparatus is employed.
Two cog wheels, a large and a small one, are fixed on the upper part of
the after end of the torpedo, just in front of the screw propellers:
the small wheel is fitted with a certain number of teeth, thirty for
instance, which gears into an endless screw attached to the propeller
in such a manner that one revolution of the propeller moves the wheel
one tooth, therefore thirty revolutions would turn the wheel one
complete revolution. The big wheel is fitted with much larger teeth
than the small one, and by means of a pin on the latter wheel is moved
round one tooth for every complete revolution of the small wheel, and
clamped in this new position by a spring catch, which is also worked by
the pin on the small wheel. In front of these wheels is a stud which
works fore and aft in a slot, and attached to a spring which tends
to draw it to the after end of the slot. This stud is connected by
means of a wire rod to the valve that admits the compressed air to the
engines; when the stud is in the fore part of the slot the valve is
open, and when in the after part it is closed.
_Adjusting Length of Range._--By means of a lever the spring of the
stud is compressed, and the stud moved to the fore part of the slot;
then the big wheel is moved round until a stud on its face is the
required number of teeth above the lever. For every thirty revolutions
of the propeller, and consequently one tooth of the big wheel, a
certain known distance is traversed, which varies according to the
pattern of the torpedo.
_Adjusting Apparatus._--When the propeller has made the number of
revolutions corresponding to the length of range required, and
consequently has moved the big wheel the number of teeth it was set
above the lever, the stud on the big wheel presses against the lever
and so releases the spring in the slot, causing the slot stud to fly
from the fore part to the after part of the slot, by which action
the valve admitting the compressed air to the engines is closed, and
consequently the engines cease to work.
Attached to the axle of the big wheel is a small brass arm, which
is connected by means of a brass rod to the safety wedge, and is
so arranged that after the required number of revolutions of the
propeller, the safety wedge will be drawn out; or it may be drawn out
at the instant of the torpedo leaving the tube, carriage, &c. Also by
means of an additional lever at the fore part of the torpedo, which is
connected by means of a wire rod to the valve that admits the air to
the engines, and by arranging the attachment of the safety wedge to
the brass rod from the big wheel, so that on the wedge being withdrawn
it is released from that brass rod, on the torpedo having completed
its run, the action of closing the valve which admits the air to the
engines causes the additional lever to force the wedge into the safety
position.
_Torpedo to Float at End of Run._--This is due to the difference of
buoyancy at the end of a run from what it was at the commencement,
owing to the compressed air being used in working the engines.
_Torpedo to Sink at End of Run._--This is effected by means of the
adjustment chamber (2), in the after end of which there is a spiral
spring valve, which can be attached to the brass rod on the outside of
the torpedo that works the valve which admits air to the engines, in
such a way that on the valve being closed, and therefore the run of the
torpedo completed, the spiral spring valve is opened, admitting water
to the adjustment chamber (2) of sufficient amount to sink the torpedo.
_To Explode the Torpedo at End of Run._--This is effected by connecting
the vertical firing whisker to the rod which otherwise would be
connected to the safety wedge lever, by which means, on the valve
admitting air to the engines being closed, a force is transmitted
to the vertical whisker instead of to the safety wedge lever, and
consequently the torpedo is exploded.
_Adjusting the Depth._--A small wheel, the face of which is marked in
feet, is placed on the left side of the fore part of the adjustment
chamber (2). To adjust for depth, by means of a key turn the wheel
until the number corresponding to the depth of run required is opposite
the pointer.
The torpedo is maintained at the desired depth by means of certain
mechanical apparatus contained within the adjustment chamber (2), and
which constitutes what is termed the secret of the fish torpedo. This
chamber is connected by screws to the foremost and after chambers of
the torpedo, in such a manner that by means of a number of small holes
bored round the circumference, as shown at (2), Fig. 119, the faces
of the chamber are exposed to the pressure of the water, which varies
with the depth to which the torpedo descends. Within the adjustment
chamber is an endless strong spiral spring, attached to the after face
of the chamber, and so arranged that after being set to a certain
tension, capable of resisting an equivalent pressure on the outside
of the aforesaid face, any increase or decrease in this exterior
pressure will cause the spiral spring to work a rod by which the
horizontal rudders of the torpedo are regulated, and thus the desired
depth for which the spring is set is maintained. The course of the
torpedo is represented by a series of curves, above and below the line,
representing the depth it is set for, these curves gradually decreasing
until at 100 yards' distance from where the torpedo was started the
curves are so small that the path of the torpedo is almost identical to
that of a straight line.
Within this adjustment chamber is also placed an automatic balance,
which also assists to maintain the torpedo at the desired depth, by
reason of its swinging forward on the torpedo descending, and swinging
aft on its rising, which motion is used to regulate the horizontal
rudders. The above is merely a general idea of the arrangement used in
the Whitehead fish torpedo, to enable it to reach and maintain whatever
depth it may be necessary to use it at from 5 to 15 feet.
_Projecting the Torpedo._--The fish torpedo may be projected in various
ways, viz.:--
1.--Through a submerged tube in the stem, or on the
broadside.
2.--From a carriage above the surface.
3.--From the surface.
_Discharging Torpedo through a Submerged Tube in the Stem._--In this
case a tube is fitted to an orifice in the stem; this opening is as
far below the water line as possible, and is closed by a watertight
cap and a sluice valve; the inner end of the tube is fitted with a
watertight door; the torpedo being prepared for action is placed inside
the tube, the inner door closed, and the tube filled with water; then
the watertight cap and sluice valve are opened, and the torpedo started
by means of a piston which is worked by compressed air. This piston can
be worked from deck, and so the torpedo fired at the proper instant.
To prevent the torpedo from slipping out of the tube, a stop is placed
in the fore end of it, which can be withdrawn at the same time as the
compressed air is admitted behind the piston. The torpedo being clear
of the tube, the sluice valve and watertight cap are closed, and the
tube emptied of the water, the projecting piston being at the same time
forced back.
_On the Broadside._--In this case, the discharging tube works inside an
iron casing, through a stuffing box at the inner end, and in a shield
attached to the outer end of the tube. This shield, placed on the fore
side of the orifice, is of such a length as to protect the torpedo from
the pressure of the water passing the vessel. The mode of discharging
the torpedo in this case is similar to that used when projecting it
through the stem.
_Comparison of the Stem and Broadside Methods of Projecting the
Torpedo._--The former method of projecting the torpedo seems the most
suitable to specially built torpedo vessels, but not so to large
ironclads, on account of the difficulty of fitting a tube to the stem
of such a ship, and also that in so doing the efficiency of the vessel
as a ram would be impaired.
In regard to the accuracy of the firing of the above methods, both seem
equally good, though in the case of firing on the broadside it would
be necessary to prepare carefully calculated tables of deflection, any
mistake in the using of which would be fatal to a successful torpedo
shot.
_Projecting a Torpedo from above Water._--In this case an iron carriage
is used, which is fitted with a frame, in which the torpedo rests; the
outer end of this frame is provided with a lip, some few feet long,
by which means the rear end of the torpedo is slightly canted up on
leaving the frame, and any undue strain on the tail of the torpedo is
prevented. The frame is mounted in the iron carriage in such a way that
it can be elevated or depressed by means of a screw, as in the case of
a gun mounted in an ordinary carriage. The torpedo is ejected from the
frame by means of a piston as previously explained, a small reservoir
of air being attached to the carriage, so that it can be used at any
port.
_Firing a Torpedo from the Surface._--The torpedo possesses sufficient
buoyancy to float with a small portion of its upper surface above
water; such being the case, it is only necessary to set the various
adjustments, point it in the required direction, and by hand turn back
the lever on the upper part of the weapon (which opens a communication
between the air chamber and the engines), when it will instantly dart
off and very rapidly attain the depth it is set for.
_Method of Firing a Fish Torpedo from a Boat._--To manipulate a fish
torpedo from a boat, it may be carried in a light frame, which can
be lowered or raised by means of a pair of davits. When required to
discharge the torpedo, the frame containing it is lowered into the
water, so as to bring the torpedo about two feet below the surface, the
head being somewhat lower than the tail.
_Thornycroft's Method of Firing Fish Torpedoes from a Boat._--Another
method, which has been patented by Mr. J. I. Thornycroft, of the firm
of J. I. Thornycroft and Co., steam launch builders, and which is
fitted to the torpedo boats built by them for foreign governments, is
shown in elevation and plan at Figs. 120 and 121.
The apparatus consists of two or more bent levers _A_ securely and
rigidly fixed on a shaft _B_, which works in bearings fixed on the deck
of the vessel _C_ from which the torpedo is to be discharged. On the
ends of the levers _A_ furthest from the shaft _B_ are pivoted other
levers _D_, to which the cradle or case _E_ for sustaining the torpedo
is suspended. The other ends of each of these levers are connected to
the vessel by means of rods or tubes _F_, jointed at each end in such
a way that when the shaft _B_ is made to revolve in its bearings, the
case containing the torpedo is guided over the side of the vessel and
close to it, and is held in a position convenient for discharging the
torpedo, as shown at Fig. 120.
The shaft _B_ may be made to revolve by means of ropes _G_ and pulleys
_H_ attached to the levers _A_, or by hydraulic or steam pressure, as
may be found most convenient.
The torpedo case can be towed alongside the vessel if necessary without
deranging the apparatus. The torpedo case is carried in the angles
of the bent levers, and is stowed away so that neither it nor the
suspending levers project at all beyond the hull of the vessel; also
when lowered, the levers and suspending rods fold over one another so
as to occupy very little space, and the torpedo is suspended close to
the hull.
Also the torpedo during the operation of lowering as well as when in
a firing position remains close to the side of the vessel, thereby
obviating any risk or inconvenience from excessive leverage which would
have a tendency to capsize the boat.
For especially built torpedo launches, the above mode of carrying and
launching the fish torpedo is certainly the best yet devised.
_Woolwich Fish Torpedo._--In the Woolwich torpedo, the engines exert a
force of nearly 60 indicated horses, and work up to 1000 revolutions
per minute; the total weight of the torpedo fully charged (33 lbs. of
gun-cotton) is about 500 lbs.
[Illustration: THORNICROFT'S BOAT APPARATUS FOR FISH TORPEDOES.
PLATE XXXVII]
The Whitehead fish torpedo costs about 380_l._, while the Woolwich one
costs only 300_l._
_The Lay Torpedo Boat._--Priority of invention of this torpedo was on
the 13th of June, 1873, awarded by the Commissioners of Patents to Mr.
John Louis Lay, several other persons having claimed the invention,
among whom was Colonel Von Scheliha, an officer of the Russian army.
This locomotive torpedo, or more properly called torpedo boat, has been
for several years adopted by the American government, during which time
it has undergone a series of exhaustive experiments, which has proved
it to be a most valuable and efficient weapon of offence and defence.
Lately the Russian government have adopted it, and intend using it
extensively in the defence of their harbours, &c.
_General Description of the Torpedo._--At Fig. 122 is shown a
longitudinal section of a Lay torpedo boat constructed and provided
with guiding and controlling apparatus, and with means for propelling
it by ammoniacal gas. Fig. 123 is a horizontal section of the same;
_A_ is the hull or body of the boat, which has conical ends _A_^{1},
_A_^{2}, and is formed of thin plate iron, or steel, or other suitable
material. The section in the end _A_^{1} forms the magazine containing
the charge of dynamite or other explosive material; _A_^{3} is the
section containing the gas reservoir or holder; the compartment _A_^{4}
contains the apparatus for holding and paying out the electric cable;
the compartment _A_^{5} in the end _A_^{2} contains the motor engine,
the steering apparatus, and other parts to be hereinafter described.
All of these compartments or sections are separated from each other by
means of air-tight bulkheads _A_^{6}. The torpedo boat may be propelled
by means of a single screw, double screw, or two screws. In the latter
method, which is shown at Figs. 122 and 123, the propellers _B_ and
_C_ are made to revolve in opposite directions; the shaft _D_ of the
propeller _B_ is hollow or tubular, and the shaft _E_ of the screw
_C_ passes through the same; these screws are actuated by an engine
shown at _F._ _H_, _H_ are the horizontal rudders, or side wings, two
forward and two aft; these wings are mounted on shafts or spindles
passing transversely through the boat; these rudders may be set to
occupy a horizontal position, or a more or less inclined position in
the proper direction, to cause the submerging of the boat by the action
of the water on the said rudders as the boat moves forward, and they
are adjusted before starting. _N_, _N_ are two guide rods, one aft
and one forward, which project up from the boat to enable the operator
to determine its position at any part of its run, and in the case of a
night attack they are provided with lights; the said rods can be raised
or lowered at the will of the operator. _Q_ is the electric cable,
which affords a medium of communication between the operator on shore,
&c., and the torpedo boat, whereby it may be started, stopped, steered,
fired, and has her position ascertained; this cable is carried in the
boat in a coil arranged longitudinally in the air-tight chamber _A_^{4}
in the reel frame _R_, and is payed out as the torpedo progresses
through a tube _S_, projecting aft under the boat and beyond the
rudders and propellers, so that the said cable will not be fouled by
the same; or it may be payed out through a hollow shaft in the centre
of the boat. One end of this cable is connected to a keyboard at the
station on shore or on board of the ship or other structure from which
the torpedo boats are controlled. This keyboard is provided with a
suitable battery or other means for generating the electric current, as
hereinafter described.
The said cable is composed of several wires, each of which is insulated
from the others. One of these wires is connected with the mechanism
for starting and stopping the boat, one is connected with the steering
apparatus, one serves for indicating to the operator at all times the
exact position of the rudder, one is connected with mechanism for
elevating and depressing the said guide rods, and one serves for firing
the charge in the magazine.
The motive power for effecting the necessary movements of the mechanism
or apparatus in performing the above operations is obtained from the
aforesaid engines, which are provided with suitable valves arranged in
combination with electro magnets, shunts, and the devices connected
with the said wires of the cable, as hereinafter set forth.
This form of cable has since been replaced by one which consists of two
wires only, the one for performing all of the necessary operations,
exclusive of the firing or exploding of the magazine, and the other
exclusively for this latter purpose. This improvement is effected by
employing a series of relays or resistance coils, or a multiple, or
compound relay in the boat. The advantages gained by this improved form
of cable are:--
1.--Increased flexibility.
2.--A greater length of cable may be coiled in a given
space.
3.--A thicker coat of insulating material may be used,
thereby more perfectly insulating it.
4.--It is much cheaper.
Two rudders are generally used, one below and one above the boat, as
shown at _U_, Fig. 122. These rudders are operated and controlled by
means of a small auxiliary engine _T_, Fig. 122, which is started,
stopped, and reversed by the electric current conducted through the
cable _Q_ in connection with magnets attached directly to a valve
forming part of the said engine. This valve is so actuated by the
magnets that when the current passes in one direction the engine _T_
will move the rudder to starboard, and when the current acts in the
opposite direction it will turn the rudder to port.
The mechanism for firing the charge in the magazine _A_^{1} is clearly
shown in Fig. 124, and operates as follows:--Projecting from the front
extremity or stem of the boat is a rod or pin _V_, which extends
through a suitable packing box _W_ into the said magazine or charge
chamber; when the boat strikes an object, the said rod is forced
inward into contact with the springs or points _X_, thereby closing
an electrical circuit and igniting a cartridge, shown at _Y_, in the
magazine.
The charge in the magazine can also be fired at any moment by the
operator on shore closing a circuit on the keyboard and thereby
cutting out one of two resistance coils placed in the circuit to
prevent accidental or premature discharge--that is to say, there are
two resistance coils. The battery is not sufficiently powerful to
fire through both resistance coils at the same time. When the boat
strikes an object, the resistance coil in the magazine is cut out by
the driving inward of the rod _V_, as above described; the battery
then fires through the one on the keyboard. On the other hand, if
the operator desires to fire the torpedo boat before she touches the
object of attack, he manipulates the switch to cut out the coil in the
keyboard, the charge then being fired through the coil in the magazine.
This arrangement of the two resistance coils is very effectual in
preventing accidents.
In some instances the magazine is made detachable from the hull of the
boat, so that on striking an object it will descend or drop down in the
water before exploding. This modification is shown at Figs. 125 and 126.
The magazine _A_* is attached at its lower side to the boat by a chain
or other suitable connection. At its upper edge it is held by a rod
_a_*, as shown in Fig. 125. This rod is fitted to slide in dovetailed
bearings, as shown at _b_*, and when this magazine is in its place
on the boat the said rod is engaged with a catch or stop _c_*, but
when the said rod is driven against any object it is forced back and
released from the said catch or stop, and the magazine then drops, as
in Fig. 126, and is fired.
To effect the firing a ball _d_* is used and placed in a tube
containing two springs or plates _e_* and arranged in an upwardly
inclined position, as shown in Fig. 125, one of the said springs being
connected with the cable and the other with a wire that passes through
the cartridge to earth.
While the magazine is in the position shown in Fig. 125 the circuit
is incomplete, but when the magazine drops the said ball falls into
the position shown in Fig. 126; the circuit is then completed, and the
magazine is fired.
The electrical or electro-magnetic apparatus for generating, directing,
and controlling the currents, whereby the above-described operations
are effected, may be of any suitable kind, the following being the form
of apparatus usually employed.
A battery _r_, shown at Fig. 127, consists of any desired or requisite
number of cells constructed and arranged in any suitable manner, and
connected by proper conducting wires with the keyboard _s_. The latter
is provided with a series of pole changers _s_^{1}, _s_^{2}, _s_^{3},
_s_^{4}, and switches _s_^{5}, _s_^{6}, and is shown in Fig. 128.
Each of these pole changers is arranged to effect and control one of
the above-named operations, and is therefore connected with one of the
aforesaid insulated wires forming the cable. For instance, the pole
changer _s_^{1} effects the starting and stopping of the propelling
engine; _s_^{2} controls the steering apparatus; _s_^{3} is connected
with the steering index; _s_^{4} operates or adjusts the aforesaid
guiding rods; and the switches _s_^{5}, _s_^{6} control and effect the
firing of the charge in the magazine.
[Illustration: LAY'S LOCOMOTIVE TORPEDO.
PLATE XXXVIII]
[Illustration: LAY'S LOCOMOTIVE TORPEDO.
PLATE XXXIX]
The connections between these pole changers and switches, and
the apparatus they operate or control on board the boat, are as
follows--that is to say, the said propelling engines have a throttle
valve, which controls the admission of the gas from its generator or
reservoir to the cylinders of the said engine, and in combination
with this valve in the boat there is a shunt and set of electro
magnets. The armature of the latter is connected with a lever, which
is pivoted so that the action of the electric current in one direction
through these magnets will pull one end of the said lever down, and the
action of the current in the other direction will pull its other end
down--that is to say, by reversing the current through these magnets
the movement of the said lever is reversed; and this lever, connected
by suitable means with the slide of the said throttle valve, will open
or close the same, and thereby start or stop the engine as required.
For operating and controlling the above-described steering apparatus,
and indicating the position of the rudder to the operator on shore, the
following devices are employed, in combination with the pole changers
_s_^{2}, _s_^{3} on the keyboard:--The pole changers are geared
together by insulated toothed wheels, which are fixed on the spindles
or axes of the said pole changers, so that the latter work accurately
together and maintain the same relative positions to each other. The
pole changer _s_^{2} is connected by one of the said insulated cable
wires with a shunt on board the boat, which shunt is connected with a
set of magnets arranged in combination with the valve of the engine
that drives the steering apparatus, and which valve is reversed or
opened and closed by the reversal of the currents through the said
magnets, as above described, and the said engine moves the rudder
to port or starboard at the will of the operator. In order that the
operator may know the exact position of the rudder at any moment, a
series of pins or projections fixed on an arc or other portion of the
rudder stock, and arranged in combination with an insulated spring
projecting into the path of the said series of pins, are employed. This
spring is connected by one of the cable wires with the pole changer
_s_^{3} on the keyboard, which is geared with and moves in unison with
the pole changer _s_^{2}, so that the electric current that controls
the steering engine, and the current that returns the indication of the
rudder's position, will both be reversed simultaneously. A separate
battery is connected with the index on the said keyboard, whereby a
constant current is maintained between this index and the indicating
apparatus on the boat.
The current passing from the said spring to the shore is made to
indicate the position of the rudder by the index on the keyboard by
the contrivance shown in Fig. 129. This contrivance consists of a
set of magnets _w_, which have a vibrating armature _w_^{1} pivoted
to oscillate between them. One end of the armature lever is provided
with insulated spring pawls _w_^{2}, which take into ratchet wheels
_w_^{3}. On the same shafts on which these ratchet wheels are fixed are
wheels _w_* formed with insulated teeth and geared with each other. The
shaft of one of these wheels is geared by bevel pinions _w_^{4} with a
vertical shaft _w_^{5}, to which is attached the index needle or finger
_x_**, Fig. 128. Therefore it will be obvious that this index finger
is placed in connection with the aforesaid spring and series of pins
attached to the rudder yoke on board the boat.
Now it will be obvious that when the rudder is turned in either
direction these pins will come successively in contact with the said
spring, and at each contact and separation the circuit will be made and
broken, and an impulse will be transmitted through the cable, whereby a
corresponding movement will be transmitted to the said index finger or
pointer _x_** on the keyboard.
The pole changer _s_^{4} is connected with another of the insulated
wires of the cable, which on board the boat is connected with a shunt
and set of magnets arranged in combination with the aforesaid cylinders
that operate the said guiding rods, so that by sending the current in
one direction the said rods will be raised, and by sending the current
in the opposite direction the said rods will be lowered.
The switch _s_^{5} is connected with another of the said insulated
wires of the cable, which forms the circuit, including the aforesaid
two resistance coils.
By adjusting this switch the operator completes the circuit through the
two resistance coils, and then, but not till then, the charge can be
exploded, either by the operator, or by the action of the firing pin or
rod when the same is driven in and cuts out the other resistance coils
as above described. The resistance coil _X_^{1}, Fig. 124, is connected
to the binding screws 9, 10 by the wires 7 and 8. These binding screws
are in metallic connection with the two springs _X_, but otherwise they
are carefully insulated. One pole of the fuze _Y_ is connected to the
binding screw 10, the other put to earth through the body of the boat,
as at _E_; the main wire 11 is connected to the binding screw 9. Now
when the operator cuts out the resistance coil at the firing station,
which is done by moving the switch _s_^{6}, the electric current is
sufficiently powerful to ignite the fuze _Y_ through the resistance
coil _X_^{1}, so that at any moment the torpedo may be exploded by
the operator on shore, or by the contact between the torpedo and the
attacked vessel the rod _V_ will be driven in, and, coming in contact
with the springs _X_, will bridge over the space that originally
existed between them and so cut out the resistance coil _X_^{1}, and
the torpedo will be exploded automatically.
_Capabilities of the Lay Torpedo Boat._--The capabilities of the Lay
torpedo boat are as follows:--
1.--It may be launched from the shore, a vessel,
or a structure, and be kept under observation, and
accurately guided or directed to the ship or other
object to be attacked; and it may be exploded at any
desired moment, or it may be caused to return to the
original point of departure without being fired.
2.--It may be totally and instantaneously submerged to
prevent its destruction or capture by the enemy, and it
may be raised to the surface, as soon as the danger has
passed, in a condition fit for immediate action.
3.--It may be used as a tug or towing boat to take out
a number of torpedoes, which may be sunk and exploded
when desired.
4.--It may be used in connection with certain apparatus
to clear away obstructions found to prevent the
entrance of ships into harbours, and it may also be
used to clear harbours of mines, &c.
_Launching the Lay Torpedo Boat._--For facilitating the launching and
controlling of the Lay torpedo boats, a structure or submarine fort
is used. This structure may be square, or oblong, and may be made to
carry any number of the torpedo boats. The body is constructed of plate
or sheet iron of suitable strength and stiffened with angle iron, or
otherwise, and divided longitudinally or transversely into watertight
compartments, into which the water is admitted to sink the said
structure. At the top or upper side, cylinders or tubes are placed,
each of which is capable of containing and launching one of the torpedo
boats. At the forward end of each tube is a door, or cover secured to a
rod or shaft fitted to turn in suitable bearings; this rod or shaft is
provided with an arm which is connected to the piston rod of an engine
worked by gas contained in a reservoir, or by other suitable means.
The slide or other valve which controls the admission of the gas,
&c., to this engine is arranged in connection with electro magnets,
connected by a suitable cable with a keyboard on shore, or wherever
the operator's station may be. By sending an electric current through
this cable in one direction through the electro magnets, the door is
closed; and by sending such a current in the opposite direction it is
opened. The cables carried in the torpedo boats, and through which the
mechanism on board each torpedo boat is operated and controlled, are
also in this case connected with the keyboard, which must be provided
with a number of sets of pole changers and switches, or equivalent
devices, corresponding with the number of boats to be controlled by
means of the said keyboard.
This apparatus will form a very convenient adjunct to fortifications or
stations liable to be attacked by sea. The said fort may be prepared
for use by placing torpedo boats in the said tubes, and may be kept
floating until the enemy's ships have arrived closely enough to
permit the determination of the point where the said fort can be most
advantageously located for operating against the said ships. The fort
is then towed to this point, or taken as near as possible thereto on
rails, and towed the remainder of the distance. It is then submerged,
and will be ready for immediate operation. The said fort is provided
with suitable valves for the admission of water to sink the same, and
with means for forcing in air through the pipe _P_* to expel the water
when the fort is to be raised.
When it is desired to launch either of the said torpedo boats, the door
of its tube or cylinder is first opened by sending a current through
the cable that controls the door, as above described. Then the current
is sent through the boat's cable to start her propelling engines. The
said boat will then emerge from the cylinder or tube and will rise to
the surface, or as near the surface as may be desired, and may then be
directed and controlled by the operator at the keyboard, as previously
described. And one after another of the said torpedo boats may be thus
launched and exploded, without giving to the enemy any clue to the
point or position from which they are being sent.
[Illustration: LAY'S LOCOMOTIVE TORPEDO.
PLATE XL]
_Launching the Torpedo from a Ship._--The method of launching the Lay
torpedo boat from an ironclad or other large ship is shown at Fig.
130. The tubes or cylinders _S_ in which the torpedo boats _A_ are
held are, in the apparatus shown at Fig. 130, closed at their inner
ends by plates, or covers _S_^{1}, which are provided with suitable
water-tight and insulating packing boxes _S_^{2} for the passage of the
electric cables of the said torpedo boats, each cable being connected
with the keyboard, which is placed in any convenient part of the ship,
and at their outer ends the said tubes are furnished with strong and
well-fitted slide valves, or sluice gates _S_^{3}, which are opened
by screws, connected by gearing with a hand wheel, and shaft _S_^{4},
_S_^{5}, for the admission and exit of the said torpedo boats. Also
these cylinders are provided with packing pieces at their sides,
arranged to be pressed by screws or otherwise up to the sides of the
torpedo boats in these cylinders, and thereby hold them firmly and
immovably in rough weather.
_The Method of Sinking and Raising a Lay Torpedo Boat._--The apparatus
by which this is effected is shown at Fig. 131, which is a longitudinal
section of a portion of a torpedo boat. The hull _A_ of the torpedo
boat is provided with a water chamber _l_, which has holes or apertures
_l_^{1} in the bottom of the same, and is also provided with an air
cock at _l_^{2}. In connection with this chamber is arranged a small
cylinder _m_, provided with a piston _m_^{1}, whose rod _m_^{2} is
attached to the lever of the said cock. A spiral spring _m_^{3} is
provided to resist the inward movement of the said piston. The said
small cylinder _m_ is connected by a pipe _m_^{4} with a valve chest,
in which is arranged a slide valve _m_^{5}. The said slide valve is
connected by a rod or rods to the lever or levers _m_^{6}, whose
fulcrum is at _m_*, and the said levers are connected by the links
or rods _m_^{7} with the armatures of electro magnets _n_, which are
included in the circuit of the cable, whereby the boat is controlled
from the keyboard at the station; _o_ is a pipe extending from the said
valve chest to the aforesaid water chamber _l_; _p_ is a feed pipe by
which gas is conducted from the reservoir or generator to the valve
chamber.
When it is desired to sink the torpedo boat an electric current is sent
in one direction through the said magnets, and thereby operates the
slide valve to admit gas to the cylinder _m_ in front of the piston
_m_^{1}, which is thus forced inward and opens the air cock _l_^{2}.
The opening of this cock permits the escape of the air from the water
chamber _l_, and consequently the entrance of water through the
apertures _l_^{1}, and the boat then immediately sinks.
When it is desired to raise the boat a current is sent in the opposite
direction through the said electro magnets, thereby operating the said
valve and piston in such a manner as to close the cock _l_^{2} and
open the port _o_^{1} and the pipe _o_, thereby allowing the gas to
pass from the valve chamber into the compartment _l_; this gas by its
pressure expels the water from the said compartment, and the boat then
having its normal buoyancy restored immediately rises to the surface.
_The Lay Torpedo Boat used as a Tug to take out a Number of Small
Torpedoes._--This arrangement is shown at Figs. 132 and 133. The
small vessels or torpedoes are designed to be first sunk and then
exploded, chiefly for clearing harbour or the like of mines or other
obstructions. These results are accomplished by means of the following
devices and arrangements, that is to say, each of the small vessels
or torpedoes _F_ is provided with apparatus which is included in an
electrical circuit formed by a suitable insulated cable _G_, extending
throughout the train of small vessels or torpedoes _F_. One vessel of
this train, preferably the rear one, is connected with the station by
an electrical cable _H_, which is payed out from a coil or coils, or
a reel or reels, in the said vessel as the same travels through the
water. This cable _H_ connects with the cable _G_, which is connected
with the towing boat _A_, and passes through the series of boats
_F_ to the said cable _H_. One wire of the said cable is arranged
in combination with sealed or covered apertures in the bottom of a
compartment or compartments of these small vessels _F_, as shown at
_I_, the covers of these apertures being so formed as to be ruptured
or destroyed by the explosion of a cartridge or cartridges placed in
the said compartment or compartments. When a current of electricity is
sent through the aforesaid wire of the cable it will explode the said
cartridges and open the apertures, thereby admitting water into the
said compartments so that the vessel _F_ will sink.
The cable _G_ that passes through the train of torpedoes or vessels _F_
is so arranged that when a current passes through the other wire of the
said cable it will fire cartridges placed in the charge chambers or
magazines of the said small vessels, as shown at _J_. The part of the
cable or towing line _G_, which connects the towing boat _A_ with the
train of small boats or torpedoes _F_, is attached to a hook or other
device, which can be disengaged by sending a current through the cable
_K_, connecting the boat _A_ with the shore or other station. It will
be understood that when being used for this purpose the said boat _A_
is not or need not be charged with explosive material.
[Illustration: LAY'S LOCOMOTIVE TORPEDO.
PLATE XLI]
The aforesaid towing boat _A_ takes the train of torpedoes _F_ to any
required position. It is then disengaged from the train, leaving the
said small vessels or torpedoes _F_ floating in such position. Then by
sending a current first through one wire of the cable _H_ the boats _F_
are first sunk by the explosion of the cartridges and opening of the
apertures, as above described. They may then be discharged immediately
by sending a current through the other wire of said cable _H_ and
firing the cartridges in their magazines, or they may be left submerged
to form mines which may be exploded at any desired moment.
The said small vessels or torpedoes may be provided with vertical rods
to indicate their position to the operator at the station; these rods
are shown at _L_, and they should be made hollow to allow the air in
the water compartments or chambers to escape to permit the water to
enter the same when the vessels _F_ are to be sunk; or other suitable
provision may be made for the escape of the air from these compartments.
The said vessels _F_ are preferably made cylindrical with conical ends,
and are provided with suitable insulating and water-tight packing
boxes, as shown at _F_^{1} for the cable _G_ to pass through at the
stem and stern of each vessel.
_The Lay Torpedo in Clearing Obstructions._--For this purpose the
torpedo boat is provided with an apparatus, shown at Figs. 134 and
135, in combination with the electric cable, whereby the said boat
is controlled and guided, and there is arranged in the boat _A_ a
compartment _A_^{3}, from which extends down into the water a line
or rod _U_, provided at its outer end with a hook or claw _U_^{1},
properly formed to take hold of any chain or bar with which it may come
in contact. In the said compartment _A_^{3}, and upon the upper end of
the said line or rod _U_, is placed a small case or cylinder _U_^{2}
containing a charge of dynamite or other explosive material and a
cartridge or fulminating cap, or a bottle of sulphuric acid, surrounded
with a certain quantity of chlorate of potash and sugar. This case
or cylinder _U_^{2} is shown detached and drawn to an enlarged scale
at Fig. 135, and it will be seen that the said case is provided with
a tube 1 containing a cartridge, or a phial filled with explosive
substance at 2, and a ball or weight at 3. The said case is fitted
to slide upon the said line or rod _U_, and when placed at the upper
end thereof and not held or retained will slide to the lower end of
the same. In the said compartment _A_^{3} is arranged at _U_^{4} an
electro-magnetic apparatus, included in the circuit of the said cable,
and connected with a bolt or catch which in its normal position holds
the said explosive case and prevents its running down on the grappling
line or rod _U_. This explosive case is also provided at its lower end
with a grappling hook _U_^{5}.
When the grappling hook _U_^{1}, on the lower or outer end of the line
or rod _U_, engages with any obstruction the boat will be stopped, and
this stoppage will be indicated on the keyboard. The operator by this
indication is apprised of the stoppage of the boat by an obstruction,
and by sending a current through the cable by means of a switch
provided for this purpose on the keyboard he can immediately release
the explosive case _U_^{2}, which runs down the line or rod _U_, and
engages by its grappling hook _U_^{5} with the hook _U_^{1}. The line
or rod _U_ is then disengaged from the boat _A_, and the explosive
case _U_^{2} turns or falls over. As it turns over the ball or weight
3 contained in the tube 1 drops on the said phial 2, fractures it, and
thereby allows the acid to mix with the explosive or fulminating charge
and explode the case _U_^{2}. This explosion will rupture or destroy
the obstructing chain or bar, so that the ironclad ships or other
vessels can pass freely and safely into the harbour or beyond the point
where it was intended to stop them.
_Used to clear away Mines and Electric Cables._--For this purpose there
is an implement _V_ provided, Fig. 136, somewhat of an anchor form, but
with four or any desired number of arms _V_^{2} extending outward at
a suitable angle from its shank _V_^{1}. In the neck of each of these
arms are fitted two small plain or toothed discs _V_^{3}, which are so
arranged as to present their teeth to any object lying in the angle or
corner formed by and between the arms _V_^{2} and shank _V_^{1} of the
said implement, as shown at _W_.
In using this implement it may be attached to a line or cable coiled
in the torpedo boat, which, in this case, is used without being
charged with explosive material, and is sent in advance of any ship
that has to enter or pass through the suspected water. This line must
be arranged in combination with a detaching apparatus controlled by
electro-magnetic apparatus included in the circuit of the cable which
connects the torpedo boat with the keyboard at the operating station.
[Illustration: LAY'S LOCOMOTIVE TORPEDO.
PLATE XLII]
By sending a current from the station the operator releases the said
implement or its line from the detaching hook or holding device. The
said implement then sinks to the bottom; then the said boat returns
to the ship, paying out the said line as she so returns. The end of
this line is then taken by a steam tug or other vessel, and the said
grappling implement is thereby dragged along through the water over
which the ships are to advance, thus breaking any wires or cables that
may be in its course. This operation is shown at Fig. 137, in which _A_
is the towing boat, _K_ the controlling cable, _V_ the said implement,
_V_* the line attached to the implement _V_, _X_ _X_ submerged mines,
and _X_^{1} _X_^{1} are the mine cables.
In some instances it may not be practicable to reach the enemy's
ship or other object of attack directly from the station to which
the torpedo boat is connected, and from which it is controlled. In
this case a small boat, &c., is used in addition, which should be so
arranged as to present to the enemy's view as slight a surface as
possible. This mode of attack is shown at Fig. 138, where _A_ is the
torpedo boat, and _N_ is the small auxiliary boat. This boat _N_ is
provided with a keyboard and battery like that described at page 144,
and the electric cable _L_, carried on and payed out from the torpedo
boat _A_, is connected with the keyboard. The boat _N_ is also attached
to and towed by the torpedo boat _A_ by the tow line _O_; and the
torpedo boat is steered and guided by means of the said keyboard in the
boat _N_. The auxiliary boat is designed to contain two men, who lie
down, one at the bow, the other in any convenient position abaft him;
the latter has control of the keyboard, while the former by the aid of
a telescope keeps the torpedo boat in view, and transmits his orders to
the man at the keyboard. On arriving at such a distance from the enemy
as to render an attack practicable, the tow line _O_ is disengaged,
and the torpedo boat _A_, guided and controlled, and fired from the
boat _N_. The torpedo boat being exploded, the auxiliary boat can be
rowed back to the station or ship to which it belongs. By this means
the range of action of the torpedo boat is greatly extended, and with
comparatively slight danger to those employed in making the attack.
A more recent form of the Lay torpedo boat is shown at Figs. 139, 140,
and 141, where Fig. 139 is a plan or top view of such a boat, Fig. 140
is a side elevation of the same, and Fig. 141 is a midship section on
the line _x x_. _A_ is the hull of the boat, _a_ is the main or central
portion of the said hull, _b_, _b_ are side or auxiliary portions of
the same. These parts _a_ and _b_ may be oval or circular in transverse
section; they are constructed of thin steel or other suitable sheet
metal, and secured together by riveting or bolting. The side or
auxiliary portion _b_ form the reservoirs or chambers for the gas; they
also serve to contain the propelling engines. _c_ is the magazine, _d_
the chamber or compartment for containing the coiled cable, _e_ is the
compartment containing the electrical steering and other apparatus, _f_
is the firing rod or pin, _g_ is the water ballast chamber, _h_ is the
cable, _i_ the paying-out tube, _j_, _j_ are the screws or propellers
which rotate in opposite directions, and _k_, _k_ are the sight or
guiding rods.
The parts of the apparatus or mechanism whereby the various operations
of the torpedo boat are effected are connected to the cable and
controlled by electric currents transmitted from the station through
the cable, as previously described. The Lay torpedo boat weighs about 1
ton, its length is 23 feet, and speed 12 knots per hour.
_Spar or Outrigger Torpedo._--By a spar or outrigger torpedo is meant a
torpedo which is carried at the end of a pole or spar projecting from a
boat or vessel, and which may be fired either by contact or at will.
This system of submarine offence has up to the present time been the
only one that has successfully stood the crucial test of actual warfare.
During the civil war in America the spar torpedo attack was resorted to
by the Confederates and Federals, principally by the former, the result
being the loss of two large men of war and severe injury to several
other ships composing the Federal fleet, and the loss of one vessel of
war belonging to the Southerners.
The spar torpedo was also used on several occasions by the Russians in
their attacks on the Turkish ships in the war of 1877-8, but in only
one attempt was it the means of sinking a Turkish vessel.
_Description of McEvoy's Duplex Spar Torpedo._--At Fig. 142 is shown a
sketch of Captain McEvoy's improved patent duplex spar torpedo, which
is the form most generally used at the present time, and which seems to
fulfil all the requirements of such a submarine weapon, viz.:--
1.--Handiness, at the same time capable of containing a
charge of gun-cotton sufficient in contact to destroy
the most powerful vessel afloat.
2.--Certainty of action.
3.--Capable of being fired either on contact or at will.
4.--Mode of attaching the spar simple and very secure.
[Illustration: LAY'S LOCOMOTIVE TORPEDO.
PLATE XLIII]
In Fig. 142, _a_ is the case, capable of containing some 33 lbs. of
gun-cotton; _b_ is the tube through which the three wires _w_, _w_^{1},
and _w_^{2} are led; _c_ is the socket in which the wooden or steel
spar is introduced and secured, _d_ is the striker, which is attached
to a brass contact plate within the head of the case _a_ in such a
manner that any pressure either on the head or side of the striker _d_
will force the aforesaid plate in contact with the two studs to which
the battery wires are attached; _e_ is a cradle affixed to the striker
_d_ to ensure its action on contact being made by the torpedo with the
attacked vessel; the explosive is inserted at _f_, the socket _c_ being
made to screw on and off.
When a hollow steel spar is used, the battery wires are sometimes led
through the interior of the torpedo and the spar, by which means they
are well protected; the only objection to this method of leading the
wires being the probability of injury to them, should the spar be
broken on contact, or by a shot.
_McEvoy's Arrangement of Torpedo Wires._--At Fig. 143 is shown the
arrangement of wires as devised by Captain McEvoy, whereby the spar
torpedo may be exploded at will or on contact. _c_ and _z_ are the
poles of the firing battery, to which are attached respectively the
wires _d_ and _d_^{2}; _f_ is the fuze, which is placed in the centre
of the charge, and to the poles of which the wire _d_^{2} is attached,
the other end of this wire being connected with the stud _s_; to the
stud _s_^{1} is attached the other end of the wire _d_, and at the
point _c_ in the same wire is inserted a contact breaker; another wire
_d_^{1} is connected to the wires _d_ and _d_^{2} at the points _r_
and _r_^{2} respectively, and at the point _k_ in this same wire is
inserted a firing key, which latter is shown in section at Fig. 144,
from which the mode of connecting the two ends of the wires and of
using the key will be at once apparent. The contact breaker is somewhat
similar to the firing key, but there is no spring in it, contact being
made or broken by screwing the two parts together or apart. The object
of the contact breaker is to prevent the torpedo being exploded by
contact, and so to place the control of the weapon entirely in the
hands of the operator. As will be seen from Fig. 143, if contact is
broken at _c_, it is impossible to fire the torpedo unless the firing
key _k_ be pressed in; but should contact be made at _c_, then either
by means of the firing key _k_, or by the torpedo striking the hostile
vessel, its ignition will be effected.
The foregoing method of arranging the spar torpedo wires is certainly
very neat and effective, and is at the present time in extensive use.
As yet it has not been adopted by the English government, they still
preferring to fire the spar torpedo at will alone.
The different methods of manipulating the spar torpedo from boats will
be described in the following chapter.
_General Remarks on Offensive Torpedoes._--The torpedoes that have been
described in this chapter are the only ones that at the present time
can be considered as having been proved to be practically useful, and
which in future wars may be employed against ships with some chance of
success.
The spar, the Whitehead fish, and the Harvey towing torpedo have each
been subjected to the test of actual service, the former weapon being
the only one that has under those conditions been successfully used.
Taking this fact into consideration, also the high pitch of excellence
that has been attained in the construction of steam torpedo boats, and
also the results of the numerous exhaustive experiments that have been
from time to time carried out in England, America, and Europe, with
various modifications of the locomotive, towing, and spar torpedoes,
there can be no two opinions as to which of the numerous species of
offensive submarine weapons is the most practicable and effective, and
that is the spar or outrigger torpedo.
To manipulate successfully locomotive and towing torpedoes in an attack
against hostile vessels, the operators must be not only unusually
fearless and self-possessed, but also must possess a thorough practical
knowledge of the complicated method of working and manoeuvring those
weapons--in fact, they must be specialists; whilst in the case of the
spar torpedo, which may be fired by contact, it is only necessary to
employ men capable of handling a boat well, and possessed of dash and
pluck, to ensure an attack by such means being generally successful.
Of course under some circumstances, such as in a general action, when
the locomotive and towing torpedoes are manipulated from specially
constructed torpedo vessels, they will prove of great value, and the
fish torpedo fired from a boat, in close proximity to the attacked
vessel, in smooth water, and unmolested, would sink a vessel which
under the same circumstances, owing to her being protected by booms,
might prove impregnable to a spar torpedo attack; but such favourable
conditions will not often occur in war time.
[Illustration: M^{c.} EVOY'S DUPLEX SPAR TORPEDO.
PLATE XLIV]
As an offensive submarine weapon of defence, the Lay torpedo boat
should prove of real value; and also manoeuvred from specially
constructed vessels, it seems capable of being used in a variety of
ways. As yet little is known of this weapon, all the experiments
carried out with it having been confined to America; but now that
Russia has adopted it, and one or two have also been secured by the
Peruvians, its practical value will become more generally known.