Navies of the world

by Edward W. Very

SPAR-TORPEDOES.

The American Torpedo.

American Spar-Torpedo.

American spar-torpedoes are of two general forms. The first, for gunpowder charges, is in the shape of a long cylinder with hemispherical ends. The second, for dynamite charges, is in the shape of a large double convex lens. The powder torpedoes have a capacity for a charge of from 75 to 100 lbs. of small-grain powder; the dynamite ones have a capacity of from 15 to 30 lbs. In the gunpowder torpedo a large hollow spindle passes through the axis, closed and secured at one end by a large nut. This spindle is pierced with flame-holes at short distances, so as to permit the flame from the fuse to penetrate and ignite all parts of the powder-charge at once. Around this spindle is a guard of wire gauze to prevent the powder from the charge sifting into and choking the flame-passages. This spindle projects some little distance beyond the inner end of the torpedo-case, forming a handle or support by which the case is attached to a spar. At the inner end on each side of the spindle is a loading-hole secured by nuts and washers. There are also four handles, two on each side of the case, for convenience in transporting. The 100-pdr. torpedo loaded and fused weighs about 360 lbs. The torpedo-fuse, which is an electric one, finds a place by itself inside the spindle, the terminal wires passing through a simple water-tight gland.

Socket for American Spar-Torpedo.

Wood and Lay’s Spar-Torpedo.

Boat-Fittings for American Spar-Torpedo.

On the end of the torpedo-spar is lashed a cast-iron sleeve into which the end of the spindle is keyed. The torpedo-spar for use on the bows or broadsides of vessels varies in length from 20 to 50 feet, and is supported and pointed by guys and lifts in the same manner as is common with swinging spars generally. The wires from the fuse are brought in along the spar to the electrical machine and firing-keys arranged in suitable positions.

The spars used in boats are generally arranged on a different principle from those attached to the bows or beams of high-sided vessels. Arranged to work in a swivelled sleeve with a martingale at the rear end to regulate the depth to which they shall sink, the spar is either launched or dropped over and is permitted to swing without guys, the operator watching and exploding it as it is brought abeam and into the desired position by the driving ahead of the boat.

Fitting for Heel of
Spar Ship-Torpedo.

Chafing-Plate for Heel
of Spar-Torpedo.

The spar used with the dynamite torpedo is an iron or steel bar of diminished cross-section in order to offer a minimum resistance to the water, with a hinged piece at its rear end bolting to the keelson of the boat and acting as a martingale.

TORPEDO VESSELS.

In several of the navies of the world gun-boats have been designed for the purpose of using torpedoes, either locomotive or spar, to the total exclusion of battery—or, in some cases, with a limited artillery—fire.

Pietro Micca (Italian).

This vessel, having a displacement of about 530 tons, is built very low in the water, with a curved deck or cover, and is not armored except as regards a deck under the curved cover and over the engines, intended to resist the penetration of plunging projectiles, and which is of laminated steel 2¼ inches thick. Her estimated speed is 18 knots, and she is provided with tubes for discharging Whitehead torpedoes ahead, abeam, and astern.

Rau (Swedish).Ziethen (German).

Vesuvius (English).Uzreef (Russian).

Whitehead torpedo gun-boats of from 400 to 700 tons displacement and an estimated speed of from 13 to 16 knots. The peculiarity of the Vesuvius is in having an elbowed smoke-stack carried along the deck. The Rau carries a light rifled gun. All carry machine-guns.

The Alarm (American).

The Alarm is an iron ram gun-boat, built on the transverse bracket system, with a double bottom and water-tight bulkheads every 25 feet. Her dimensions are: length, 173 feet; beam, 28 feet; draft, 11 feet—which may be increased by sinking the vessel to the level of the upper-deck beams, arrangements having been made for the admission and ejection of water in the compartments formed by the double hull. The torpedo system of this vessel consists of three hollow steel tubes, one projected from the end of the ram a distance of 30 feet, and one from each broadside, 17 feet. These tubes slide in and out on frames, and are worked by small auxiliary engines and winches; the torpedo is fitted to the end of the spar and is fired by electricity. The port from which the spar is projected, being below the water-line, is provided with a water-box and double doors and heavy rubber washers, which grip the spar water-tight as it is run out.

In addition to the torpedo system, this vessel is arranged to carry a 10-inch rifle forward. Her ram is strengthened, and her bow is protected for some distance by a plating of 4½ inches. On her rail she carries machine-guns to resist the attack of torpedo-boats. Her propeller is of a novel pattern, serving as steering-gear and propelling power. This vessel was originally fitted with a propelling apparatus known as the Fowler steering-wheel, a novel propeller which both gave the vessel headway and steered her. The blades of the propeller were worked by means of a simple steam-valve arrangement manipulated by the helmsman. The steering qualities with this apparatus were little short of marvellous, as she could be driven and steered with as great facility astern as ahead, and could even be worked sideways. Her speed, however, was deficient, never reaching ten knots. At present the vessel has been fitted with the Mallory steering propeller, a form of screw with a jointed shaft so that it may be revolved about a vertical axis. This screw promises to give a speed more nearly warranted by the fine lines of the vessel.

The Intrepid (American).

This vessel is a gun-boat of about the dimensions of the Alarm, having a short, heavy ram bow and an armored belt at the water-line of five inches thickness all around. Her load draft brings her upper deck to within three feet of the water-line. This vessel carries no armament except a few Gatling guns on the rail, and her torpedo system consists of four ordinary swinging-spar torpedoes, two on each beam. Ordinarily these spars lie in crutches alongside, and they are manipulated by topping-lifts and guys in the ordinary way. The torpedoes are exploded by electricity.

The Destroyer (American).

Ericsson’s Torpedo Vessel (Destroyer).

This vessel is 130 feet long by 12 feet beam and 10 feet draft, built with a straight bow, bow and stern lines being the same and very sharp. She has no upper-deck rail, this deck being very low, with a long superstructure rising amidships. There are no openings in the sides of this superstructure, so that if desirable the vessel may be run with her upper deck completely under water. Thirty-two feet from the bow a heavy armored bulkhead crosses the vessel, inclined at a vertical angle of 45°, and intended as a thorough protection to the engines and boilers, enabling the vessel to approach bows on with impunity. Her armament consists of a bow-torpedo, which is projected from a tube in a manner not unlike the firing of a projectile from a gun. This torpedo consists of a solid block of light wood having inserted in its forward end a heavy bursting-charge in a steel case. The transverse section of this torpedo is square; longitudinally it is a rectangle with sharpened ends. Ignition of the charge is obtained by means of a percussion fuse. To project this torpedo, it is inserted in a tube provided with water-gates, fixed in the bow of the boat just above the keel. A steam piston-rod fits against the after-end and pushes the torpedo out with a velocity sufficient to send it at least 100 feet. The weight of the torpedo is about 1400 lbs. This vessel has been tried, but the system is not yet perfected.

The Uhlan (German).

This vessel is of a novel type, consisting of two separate hulls, one within and abaft the other, the intervening space being filled with cork. She carries affixed to a ram which projects ten feet forward from the stem a dynamite contact torpedo. Arranged to travel at a high speed, the idea is to carry her at full speed against the enemy, the crew finding refuge on a small raft which she carries and which is detached just before her striking. It is not expected that the main hull, in which are the engines and steering-gear, will be injured by the explosion. The raft, it is understood, is not completely detached from the vessel, but a long tow-line is paid out rapidly, and after the explosion of the torpedo the crew haul alongside and take the boat clear ready for another attack.

TORPEDO-BOATS.

The Thornycroft Torpedo-Launch.

This boat is built to combine great speed with a moderate seaworthiness and resisting power. The dimensions range as follows: length, 57 to 85 feet; beam, 7½ to 10 feet; draft, 3 to 4 feet. They are built of steel of an average thickness of ³/₁₆ an inch, being completely decked over. Generally they are divided into six separate water-tight compartments. The forward and after ones are store-rooms; the second one is arranged for the accommodation of the crew; the third is the pilot-house; fourth, engine and fire room; and fifth, for the accommodation of officers. The single-screw shaft projects some distance beyond the stern-post to allow the double rudder to work forward of it. The screw itself is of a peculiar construction, so built as to project the water straight aft instead of radially. These launches are fitted for either spar or Whitehead torpedoes. In the former case the swivelled sleeve in which the spar works pivots abreast the pilot-house. In the latter case two methods are in use. By one, a Whitehead is carried on deck on each side mounted on a carriage running on rails, by which they may be run up to a firing-case on the forward part of the deck. This firing-case is mounted on a pivot-carriage and has depressing-gear, so that the torpedo may be pointed in any desired direction. A pointing apparatus is provided in the pilot-house by means of which allowance of angle may be made for the movements of the boat or of the attacked vessel. The pivot-circle is graduated so that the torpedo may be correctly aimed with but little difficulty. By the other arrangement, a Whitehead is carried on each side on pivoted davits in a sling, so that it may be lowered into the water; the machinery is then started by hand, and the torpedo moves off without being projected. In this case the torpedo can only be fired right ahead.

H. M. Steam Torpedo Launch "Lightning".

Thornycroft Torpedo-Launch.

Length (extreme)	84	6
Beam	10	10
Draught	5	0
Speed	18 Knots

The Yarrow Torpedo-Boat

Yarrow Torpedo-Launch.

This is a launch of the same general construction as the Thornycroft, although a higher rate of speed is attained by this type, and there are several important modifications. The fire-room, or stoke-hole, is completely separated or bulkheaded off from the boiler, except the front part, so that in case the boiler collapses or is pierced by a shot there is no danger of scalding the crew. The pilot-house is placed aft in the compartment occupied by the officers. There is no visible smoke-stack. Two ports are cut in the sides of the launch, one on each side, and the products of combustion may be carried through either or both. The ports are provided with valves, which are held open by the force of the blast, but which close immediately if struck by a wave. The helmsman can direct the smoke through either port, so that in approaching a vessel the one on the side next to her is closed and the smoke through the other port is partially masked by the side of the boat. When running in a seaway both these ports may be closed, and a temporary smoke-pipe is shipped in the usual place.

These boats are provided with a rudder at each end, both rudders being operated by the wheel at the same time. The forward rudder may be drawn up into a well, if desired, or in case that it gets fouled it can easily be dropped overboard. These boats have attained in smooth water a speed of 22 knots an hour. The torpedo arrangements are similar to those of the Thornycroft. Above 18 knots there is no noticeable vibration of the frame.

The Herreshoff Torpedo-Boat.

Herreshoff Torpedo-Launch.

The general type of hull is the same as that of the Yarrow and Thornycroft, except that it is of composite construction, having a steel frame with wood planking below water and steel above. The propeller is a single two-bladed screw, placed under the keel just abaft the middle of the boat, the hollow steel screw-shaft being put in on a curve. The rudder is of the balanced type, and is suspended underneath the after-part of the keel. The pilot-house is abaft the smoke-pipe. The boiler of this boat is of a novel character. It consists of a cylindrical combustion chamber about 4 feet in diameter, within which is a spiral coil of about 300 feet of two-inch pipe. This coil is continued at the top so as to form a kind of dome under the cover of the combustion chamber. By the side of the boiler is a separator into which the steam passes before it goes to the engine. The water from the feed-pump is admitted at the top of the coil, and during its course to the bottom the greater part of it becomes converted into steam. Having passed through the entire length of the coil, the steam and water are discharged together into the separator, in such a manner that the water is entirely separated from the steam and can be blown off as required. The steam is taken from the top of the separator and returns through a short coil placed inside the combustion chamber, where it becomes superheated and is led thence to the engines. By means of this boiler a good working pressure can be obtained in about five minutes from the time of lighting the fires. This boat may be rigged to carry either the Whitehead or the spar torpedoes. Its speed is about 18 knots, equal to that of the Thornycroft.

Herreshoff Boiler.