Chapter V: Offensive Torpedo Warfare (1)

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.

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.

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.

PLATE XXXI]

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.

...... 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.

PLATE XXXIII]

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.

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.

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.