CHAPTER I.
SPAR-TORPEDO OUTFIT.
GENERAL DESCRIPTION.—CARE AND PRESERVATION.
_Class D._—Includes one set of Ship‘s Torpedoes, Service and Exercise, one set of Boat‘s Torpedoes, Service and Exercise, and one set of circuit-closers and appurtenances for the conversion of Service into Contact Torpedoes.
Service and Exercise Torpedoes are to be used from ships and boats; Contact Torpedoes from boats only.
Many articles in a Torpedo Outfit are common to the different sets comprised in Class D, in which case similar articles are classed together for convenience of stowage and transportation. If the whole of Class D is not issued, then only a proportionate part of those articles designated as “Spare” are issued. Articles that belong exclusively to any one set are issued with that set only.
SERVICE TORPEDO.
=Pattern D.—Plate I.=
(Twenty-four are issued.—Twelve for use from ships and twelve from boats.)
This torpedo, intended for use from either ships or boats, is 12⅜ inches long and 9 inches square, inside measurement, and is made of sheet iron tinned inside and out, coated inside with shellac and painted outside with asphaltum. Around a filling hole in the top is soldered a brass ring having on its inner circumference, a screw-thread for a brass screw-cover which bears a stuffing-box for the entrance of the spar leading-wires. A rubber washer between the cover and ring makes the case water-tight. Riveted to the top is a tinned malleable iron frame fitted with four lugs. A handle secured to two of the lugs forms a brace for the spindle that attaches the torpedo to the secondary spar; this spindle has two curved arms at one end that straddle the handle and secure to the other two lugs by screw-bolts, a projection on the crown of the handle fitting into a recess in the stem of the spindle. To the bottom of the case is riveted a tinned malleable iron plate for attaching a circuit-closer.
The primer-case, 8⅛ inches long and 3 inches square, inside measurement, is made of tin coated inside and out with shellac and is closed at one end.
The torpedo-case, empty but complete except the spindle, weighs about 15 lbs. The charge of the torpedo, including the primer of 2½ lbs. of dry gun-cotton, is equivalent to about 34 lbs. of dry gun-cotton.
When issued, the torpedo-cases are completely filled with wet gun-cotton, the screw-cover is screwed down tight and the hole in the stuffing-box is closed tight by screwing down the water-cap over the spherical rubber packing placed sideways in its seat.
EXERCISE TORPEDO.
=Pattern D.—Plate II.=
(Twelve are issued, two of which are empty, for use from ships or boats).
This torpedo, 12½ inches long and 3¹/₁₆ inches square, inside measurement, is made of tin and is closed at the lower end. It is coated inside and out with shellac. To the upper end is soldered a brass flange having a loop on one side and a throw-back hinge on the opposite side. The cover consists of a square brass plate with two loops one of which rests over the loop on the flange, the other receiving the lug of the throw-back hinge. A thumb-screw, fitted to the end of the lug, secures one side of the cover and a transportation thumb-screw, fitted to the loops, secures the other side. The cover bears a stuffing-box for the entrance of the spar leading-wires. A rubber washer between the cover and flange makes the case water-tight. A loop is fitted to one side of the case to receive the lower end of the spindle.
The weight of this torpedo, empty but complete, except the spindle, is 3¼ lbs. and its charge is equivalent to about 4 lbs. of dry gun-cotton.
When issued, all the exercise torpedo-cases, except two, are completely filled with wet gun-cotton, the cover is closed tight and the hole in the stuffing-box is closed tight by screwing down the water-cap over the spherical rubber packing placed sideways in its seat.
STUFFING-BOXES.
=Plates I. and II.=
Stuffing-boxes provide a water-tight entrance for the spar leading-wires through the covers of the torpedo-cases.
In the center of each cover, around the hole for the entrance of the leading-wires, is a brass rim fitted with a screw-thread outside, and bored out, inside, with a slightly conical taper, providing a seat for the packing.
The packing is of partly vulcanized rubber, 1 inch in diameter, spherical in shape, with two parallel holes, each ¼ inch in diameter, for reeving the leading-wires.
The water-cap screws on the brass rim and compresses the packing in its seat, a friction-ring in the top of the cap preventing twisting of the packing when screwing down.
A hole, ⅝ inch in diameter, through the top of the water-cap, permits reeving the spar leading-wires.
When rubber packing is to be left seated for a long time the seat for the packing should be coated with shellac and the packing brushed with black lead to prevent adhesion.
CIRCUIT-CLOSER.—CONTACT TORPEDO.
=Pattern B.—Plate III.=
(Four are issued, to convert Service Torpedoes into Contact Torpedoes, for use from boats.)
The circuit-closer consists of a cylindrical brass casting, having one end closed, and on this end are four feet by which it is secured to the lower head of the service torpedo by screws. The cylinder, 4¾ inches long and 5 inches in diameter, is closed at the open end by a screw-cover, having four lugs that serve as bearings for the contact-arms; these arms, four in number, work in slots cut in a plunger that passes through the center of the cap, and they are held in place by screws through the ends of two arms and their lugs. Inside the cylinder are two insulated contact-springs secured to binding-posts in an ebonite collar. This collar screws on the end of a short brass tube that carries a plunger tipped on the inner end with ebonite. A stout spiral spring in the tube through which passes this plunger, maintains, normally, the end of the plunger clear of the contact-springs. A rubber diaphragm separates the plunger in the cover from the plunger in the tube, and also acts as a washer to the cover, making the cylinder water-tight; a brass washer, laid on this diaphragm, acts as a friction-plate for the cover to turn on when screwed up. A safety-pin through the outer plunger prevents its being forced in accidentally. When this pin is withdrawn, any pressure on the contact-arms tends to force the inner plunger in against the action of the spiral spring and to close the break between the contact-springs.
The break is ³/₁₆ inch and the tension of the spiral spring is 75 lbs.
On the side of the cylinder is fitted a stuffing-box furnishing a water-tight entrance for the leading-wires to the binding-posts of the contact-springs.
The circuit-closer, complete, weighs 7 lbs.
SECONDARY SPARS.
=Pattern A.—Plate IV.=
(One is furnished for each Service Torpedo.)
These are iron pipes, 8 feet long. Those for ships‘ use have a slot cut in one end, for a key. Those for use in boats are fitted at one end with an iron disc, called a butt, and at 2 feet 2 inches from the butt an iron cap is riveted to the spar. All secondary spars have, at 5 inches from the outer end, a hole for the torpedo-pin. Secondary spars are packed six in a box; those for ships having a key stopped to each to be used in securing the secondary spar to the inner spar-band; those for boats having a toggle stopped to each to be used in securing the secondary spar to the boat spar.
TORPEDO PINS.
=Plate IV.=
Torpedo pins are short iron pins with an eye in one end, to which a spun-yarn tail is spliced, designed to secure torpedoes to secondary spars. One is provided for each service and exercise torpedo. They are packed, with the spindles, in Box 53.
REEL BOX.
This contains 300 feet of insulated double-conductor wire cable. The inner ends of the cable are connected to binding-screws on the sides of the reel, where short wires are to be attached, for making connections with batteries, etc., after the requisite amount of cable has been unreeled. A handle is becketed to the cover of the box, to be used in reeling up the cable. The binding-screws must be kept free from rust (no oil to be used in cleaning), and must be occasionally turned to keep them from setting.
The cable, as now issued, consists of two cores, each core composed of seven No. 22 A. W. G. copper wires of not less than 95% conductivity, coated with tin and laid up in a strand. Each core is separately insulated with okonite composition to an external diameter of ¼ inch and is wrapped with tape soaked in okonite composition. The two insulated cores, laid side by side, are covered with hemp braiding to protect them from chafe.
The resistance of the core is 2.2 ohms per 1000 feet.
The cable in the reel box is for general use and to replace disabled permanent wires. It must never be subjected to a strain of over 100 pounds, nor jerked or hauled in from any length, but under-run.
The cable must be stowed in a cool, dry place.
SHIP‘S WIRE-BOX.
This box is marked “Wire-Box—Ship‘s.” It contains four spar leading-wires of insulated double-conductor copper wire cable, 70 feet each in length, precisely similar to that found in the reel box, and two machine-connecting wires 12 feet each in length.
The spar leading-wires are to connect the torpedo with the terminals of the permanent wires. To guard against mistakes in making connections those for use on the starboard side are painted green and marked with one knot and those for use on the port side are painted red and marked with two knots.
The machine-connecting wires are insulated wires for connecting the D. E. machine, Pattern A., with the firing-key and for general purposes.
BOAT‘S WIRE-BOX.
This box is marked “Wire-Box—Boat‘s.” It contains the same articles as “Wire-Box—Ship‘s,” similarly marked.
CONTACT SPAR LEADING-WIRES.
=Pattern B.—Plate V.=
These consist, practically, of three insulated copper wire cables which lead, in use, as follows:—1st. wire, from the detonator to one terminal of the battery; 2nd. wire, from the circuit-closer to the second terminal of the battery _via_ the safety-break; 3rd. wire, branching in two legs at its outer end, from the detonator and the circuit-closer to the second terminal of the battery _via_ the hand-firing key and the safety-break.
The safety-break and the hand-firing key are connected to their proper leads by wires of convenient length to permit placing the battery out of the way when connected up.
The safety-break consists of two round, tapering pieces of brass each fitted with a score and two small holes in the smaller end to which the leading-wire is permanently secured. The larger ends, fitted to ship together bayonet fashion, can be readily connected or disconnected at pleasure.
Directions for using these wires are given in “Preparation of Contact Torpedo.”
SPAR-BANDS.
=Plate IV.=
These, of wrought iron, furnish a ready means of securing secondary spars to the ordinary wooden torpedo-spars supplied to ships. These bands, with loops on top, are secured to the end of the wood spar, 3 feet apart, with wood screws. The inner band has a key-way, to hold the secondary spar in place. Care must be taken that the loops of both bands are exactly in line.
SUPPLY-BOX.
This box, containing tools and small articles required in spar-torpedo work, is marked on top, “Torpedo Supply-Box.” For contents see Box 3 “List of Articles in Outfit supplied from Torpedo Station.”
BOAT-FITTINGS.
=Pattern B.—Plate VI.=
These, for the support and handling of the boat spars, consist of bow-fittings, 2 swivel-crutches and 2 heel-rests.
The heel-rest is an iron crutch bolted to the rail well aft. A hinge allows the rest to be laid inboard when not in use.
The swivel-crutch is a square iron collar fitted with a shank that turns freely in a bearing firmly bolted to the rail, 9 feet abaft the cross-beam. The collar is made in two parts, the upper one working on a hinge, and has two rollers.
Bow-fittings consist of a cross-beam with its attachments. The cross-beam, made of heavy wrought-iron tubing, is secured across the bow to castings let into the rail. On sleeves, at the ends of the cross-beam, are elevating-arms free to revolve in a vertical plane. At the outer end of each arm a swivelled guide-ring is placed, projecting at right angles to the arm in the direction of the beam of the boat. In the lower part of this ring is a roller. Connected with the sleeve of each arm is a gear moved by a worm on the forward end of a shaft extending aft into the boat, an elevating-wheel being keyed to the after end of the shaft.
The worm-shaft is in two lengths joined by a hook-coupling interposed near the forward end of the shaft to allow the worm sufficient play to engage the gear of the elevating-arm during the revolution of the shaft.
The worm-shaft is allowed a fore-and-aft motion such that, when the shaft is forward, the worm is disengaged from the gear of the elevating-arm, leaving it unsupported and free to drop and, when the shaft is aft, the worm is engaged with the gear so that the elevating-arm may be controlled by the elevating-wheel.
The shaft is held aft by a clutch placed just forward of the elevating-wheel. The clutch consists of a sleeve, supported on trunnions by a bearing bolted to a chock on the forward deck of the boat, carrying a yoke-link, loosely bolted to two lugs on its forward lower end and a detaching-lever, loosely bolted to two lugs on its forward upper end. The worm-shaft, passing through this sleeve, bears a rigid collar so placed that, when the shaft is aft, the collar is close up against the forward end of the sleeve. The yoke-link, when swung up, embraces the shaft and bears against the forward side of the collar, holding the shaft aft. The yoke-link is held up by the detaching-lever which is thrown forward between the upper ends of the yoke-link, a transverse roller in the detaching-lever, with ends projecting on either side, locking the yoke-link in place. A pin, passed through eyes worked in the upper ends of the yoke-link, prevents accidental tripping of the detaching-lever. When this pin is withdrawn and the detaching-lever is pulled aft the yoke-link falls and the shaft is free to move forward.
By the worm-shaft and its attachments the elevating-arm can be rotated around the cross-beam, held in any position in its plane of rotation, or released at any desired moment.
The gear and worm are protected by hoods.
BOAT SPARS.
=Pattern A.—Plate VII.=
The spar, made of steel, consists of two tubes, 18 and 15 feet long respectively, one 4 inches and the other 3½ inches in diameter, joined together with a telescopic joint. The tubes—with a lap of 2 feet—are held together by two screws. At the larger end of the spar is an eye-bolt for the heel-rope screwed in from the inside, and at 5 feet from the smaller end is a hole for reeving the spar leading-wires. This constitutes the main spar, which can readily be taken apart for stowage by removing the screws. To assemble the spar, a feather fits into a score on the end of the larger tube, bringing the screw-holes opposite each other. Iron spar-clamps are furnished, to facilitate the assembling of the spar.
The two tubes composing each spar are marked by similar letters or numbers.
=_Note._=—Spars must invariably be taken apart after use, joints lubricated, and protected by a canvas cover.
DETONATORS.
=Plate VIII.=
Detonators are cylindrical copper cases, closed at the bottom, containing 35 grains of fulminate of mercury, primed on top with dry, pulvurulent gun-cotton.
A plug, made of 1 part of ground glass and 2 parts of sulphur, melted together, is cast around the detonator-legs:—tinned copper wires, No. 20 A. W. G., 6 inches in length, insulated with a double layer of cotton thread soaked in paraffine, the outer layer colored red.
The inner ends of the detonator-legs are bridged by a platinum-iridium wire, 90% platinum, 10% iridium, ³/₁₆ inch long and 2 mils in diameter, having a resistance of .65±.03 ohm.
The plug is inserted in a copper band; dry pulvurulent gun-cotton is loosely packed about the bridge and on top of the fulminate of mercury and the band is screwed on the upper end of the detonator-case, thus closing it.
Detonators are painted red. They are supplied for use with gun-cotton torpedoes.
DETONATOR BLOCKS.
=Plate VIII.=
Wooden cylinders, with a cover that has a small circular motion. Each block holds 8 detonators placed in holes around the circumference, the cover locking them in. Each block is placed in a covered tin cylinder painted red and marked “Dangerous.” These blocks will be placed in different parts of the ship, never below the water-line. (See Ord. Inst.)
DUMMY DETONATORS.
These are empty detonator-cases, with a hole bored in the bottom, for use in making connections in practice. The detonator-legs are not bridged but are cast in the plug on the bight.
Dummy detonators are painted white and the legs are insulated with white cotton thread.
IGNITERS.
Igniters are cylindrical brass cases, closed at the lower end, containing a charge of rifle gunpowder.
The upper end is closed by inserting a plug precisely similar to that used in detonators, except that the igniter-legs are insulated with white cotton thread instead of red.
The bridge is primed by twining about it a wisp of long-staple, dry gun-cotton.
Igniters are coated with white shellac. They are supplied for use with improvised gunpowder torpedoes.
GUN-POWDER FUZES.
These are stout, cylindrical, paper cases, closed at the lower end and charged with rifle gunpowder. In the center of the charge is placed an igniter the legs of which project on either side of a wooden plug which is seized in the upper end of the case to close it.
Igniters are coated with orange shellac.
A rubber insulator, for preventing short-circuit between the splices when the fuze is attached to leading-wires, is seized around the upper end of the case.
Fuzes are supplied for use with improvised gunpowder torpedoes.
BOX CONTAINING GUN-POWDER FUZES AND IGNITERS.
This is marked with a list of contents. It is packed in Box 7, from which it is to be removed, when received aboard ship, and stowed in the magazine or ammunition room.
GLASS JARS FOR DRY PRIMERS.
=Pattern B.=
Glass cylindrical jars, fitted with cork covers, each having a capacity for 6 two-inch, or 24 one-half inch blocks of gun-cotton. These blocks of dry gun-cotton are tied together with boiled tape and have litmus-paper between them. They are never to be stowed below, but must be placed in different parts of the ship above the water-line. Being glass, the jar, without being opened, renders the litmus-paper readily discernible. Each jar is placed in a wooden case fitted with a sliding cover, painted white, and is stencilled with contents, and with precautions.
The dry primers, as used, are replaced by drying the wet blocks removed from the torpedoes in priming them.
GUN-COTTON DRYING APPARATUS.
=Plate XVIII.=
A steam-drier, for drying wet gun-cotton for use as primers, consists of a sheet-iron box containing two removable galvanized-iron wire baskets in which the blocks to be dried are supported, strung on rods. The blocks are separated from each other by small iron washers, ¼ inch thick, also strung on the rods, to permit free circulation of the air. A door in the front of the box permits entering and withdrawing the baskets.
In the bottom of the box is a flat of steam-pipe the two ends of which, projecting from the side, are screw-threaded for ready connection with steam-heating apparatus, or with any other convenient source of low-pressure steam.
A wire-gauze bottom, below the flat of steam-pipe, permits the entrance of air and serves to keep out dust and to prevent undue radiation of heat toward the outside.
In the top of the box is a ventilating opening, with a rotary damper, protected by a hood, and also a hole for the introduction of a thermometer.
CHEMICAL BOX.
This box is marked on top “Chemical Box.” For contents see Box 16, “List of Articles in Outfit supplied from Torpedo Station.” For use of contents see “Inspection of Gun-Cotton.”
The outfit includes a number of spare washers, spherical packings, diaphragms, etc., to supply necessary waste.
In addition to the articles already mentioned, every vessel having a “Ship‘s and Boat‘s” spar-torpedo outfit is supplied from the Torpedo Station with the following articles, to be placed on board at the navy yards, as permanent fittings; viz.:
Double-conductor insulated copper wire, incased in lead, in such quantity as may be required for permanent wires; 2 electric switches; 13 terminal binding-screws.
PERMANENT WIRES.
=Plate IX.=
In order to do away with the inconvenience of leading out lengths of wire from place to place, and to avoid injury to the wire, permanent wires are put in place when the ship is fitted out. These wires are led from terminals conveniently placed for battery connections via the electric switches or firing apparatus to the terminals, abreast the heels of the torpedo-spars.
Permanent wires should be protected from hostile fire, from chafe, wear, and the sun; should never be taut; should never be led around sharp angles; metal staples should never be used to hold the wires in position, even temporarily; no part of the copper wire should be exposed to the action of salt water; splices should be soldered and carefully insulated; and the wires should be boxed in throughout their lengths.
ELECTRIC SWITCHES.
=Plate X.=
In connection with permanent wires electric switches are used, and are permanently placed in a suitable position before a ship leaves the navy-yard.
Their object is to connect the firing-battery or the firing-key of the D. E. machine with any or all the torpedoes. The plate represents the switch in position, on the starboard side, with the battery off, or the wires from the firing-key disconnected from any permanent wire, electrically. The switch should be protected from salt water and the weather as much as possible. It is thought best to inclose it in a box, as nearly water-tight as possible, provided with a door which opens in front.
=_Note._=—Where permanent firing apparatus is furnished, the electric switches will not be issued.
TERMINALS.
=Plate X.=
Terminals are ordinary brass binding-screws secured to base-pieces of black walnut which are to be secured in position by screws. The figure illustrates the manner of making permanent and temporary connections with the terminals. The counter-sunk space in the back of the base-piece is to be filled with melted wax, after the permanent wire has been attached, before securing the terminal in place. The binding-screws must be kept clean and free from paint.
ARTICLES OF TORPEDO OUTFIT SUPPLIED AT NAVY YARDS.
=Ship‘s Spars.=—Such ship-rigged vessels as are now fitted for spar-torpedoes are supplied with four torpedo-spars, fitted two on each side, abreast the foremast and mizzenmast. Barque-rigged vessels are supplied with but two spars, fitted one abreast the foremast on each side. The present regulation spar is of hickory or oak, 45 feet long, 8 inches in diameter at the heel, and 6 inches at the outer end. It should be of the best material, straight-grained, and as nearly as possible a natural-growth pole. In working down a larger spar, care should be observed to follow the grain of the wood. Yellow oak is considered superior for torpedo-spars. Red oak is too brash.
=The Heel Fittings.= (_Plate XI._)—The thrust-plate is placed at about the height of the channels, in accordance with the regulations established by the Bureau of Ordnance. Discretion must be used in so placing this as to allow the spar to come alongside, so that the torpedo can be shipped from the rail or from a port. The elbow of the heel-bolt transmits the recoil of the spar to the thrust-plate, without injury to the bolt itself. Good results have been obtained by using a lashing of 6 turns of 3½-inch manilla, in place of the shackle, the elasticity of the rope serving to take up a portion of the thrust of the spar. An excellent plan is to secure the heel of the spar to a spare eye-bolt in the channels, as shown in Fig. 2.
=The Spar Fittings.= (_Plate XII._)—The most approved method of fitting a torpedo spar with guys and topping lift is shown in the plate. Spans are fitted to the spar on which the forward guy and topping lift travel freely, and these spans are rove through lizards to divide the strain along the spar and prevent vibrations. The forward guy should be single, with as much drift as possible, and long enough to let the spar trail aft, after the explosion. The forward guy, the pendant of the topping lift, or that part of it secured to the span, the spans and lizards should be of galvanized-iron wire rope, ⅝ inch in diameter. The after guy may be a single part of small manilla rope, say 3-inch. The forward guy should be led from as near the water-line as possible to keep the spar from rising.