Part 11 (1/2)
”From the bow two-thirds of the way to the stern there is a flooring, beneath which are the storage batteries, the tank for the gasolene, and the tanks which are filled with water for submerging; in the last one-third of the boat the flooring drops away, and the s.p.a.ce is occupied by the propelling machinery.
”There are about a dozen openings in the boat, the chief being three Kingston valves, by means of which the submerging tanks are filled or emptied. Others admit water to pressure gauges, which regulate or show the depth of the vessel under water. There are twelve deadlights in the top and sides of the craft. To remain under water the boat must be kept in motion, unless an anchor is used.
”It can be steered to the surface by the diving rudders, or sent flying to the top through emptying the storage tanks. If it strikes bottom, or gets stuck in the mud, it can blow itself loose by means of its compressed air. It cannot be sunk unless pierced above the flooring. It has a speed capacity of from eight to ten knots either on the surface or under water.
”It can go 1500 miles on the surface without renewing its supply of gasolene. It can go fully forty knots under water without coming to the surface, and there is enough compressed air in the tanks to supply a crew with fresh air for thirty hours, if the air is not used for any other purpose, such as emptying the submerging tanks. It can dive to a depth of twenty feet in eight seconds.
”The interior is simply packed with machinery. As you climb down the turret you are confronted with it at once. There is a diminutive compa.s.s which must be avoided carefully by the feet. A pressure gauge is directly in front of the operator's eye as he stands in position.
There are speaking-tubes to various parts of the boat, and a signal-bell to the engine-room.
”As the operator's hands hang by his sides, he touches a wheel on the port side, by turning which he steers the little vessel, and one on the starboard side, by turning which he controls the diving machinery.
After the top is clamped down the operator can look out through plate-gla.s.s windows, about one inch wide and three inches long, which encircle the turret.
”So long as the boat is running on the surface these are valuable, giving a complete view of the surroundings if the water is smooth.
After the boat goes beneath the surface, these windows are useless; it is impossible to see through the water. Steering must be done by compa.s.s; until recently considered an impossible task in a submarine boat. A tiny electric light in the turret shows the operator the direction in which he is going, and reveals the markings on the depth gauges. If the boat should pa.s.s under an object, such as a s.h.i.+p, a perceptible shadow would be noticed through the deadlights, but that is all. The ability to see fishes swimming about in the water is a pleasant fiction.
”The only clear s.p.a.ce in the body of the boat is directly in front of the bench on which the man in the turret is standing. It is where the eighteen-inch torpedo-tube, and the eight and five-eighths inch aerial gun are loaded.
”Along the sides of this open s.p.a.ce are six compressed-air tanks, containing thirty cubic feet of air at a pressure of 2000 lbs. to a square inch. Near by is a smaller tank, containing three cubic feet of air at a fifty pounds pressure. A still smaller tank contains two cubic feet of air at a ten pounds pressure. These smaller tanks supply the compressed air which, with the smokeless powder, is used in discharging the projectiles from the boat.
”Directly behind the turret, up against the roof on the port side, is the little engine by which the vessel is steered; it is worked by compressed air. Fastened to the roof on the starboard side is the diving-engine, with discs that look as large as dinner-plates stood on end. These discs are diaphragms on which the water-pressure exerts an influence, counteracting certain springs which are set to keep the diving rudders at a given pitch, and thus insuring an immersion of an exact depth during a run.
”At one side is a cubic steel box--the air compressor; and directly in the centre of this part of the boat is a long pendulum, just as there is in the ordinary torpedo, which, by swinging backwards and forwards as the boat dives and rises, checks a tendency to go too far down, or to come up at too sharp an angle. On the floor are the levers which, when raised and moved in certain directions, fill or empty the submerging tanks. On every hand are valves and wheels and pipes in such apparent confusion as to turn a layman's head.
”There are also pumps in the boat, a ventilating apparatus, and a sounding contrivance, by means of which the channel is picked out when running under water. This sounding contrivance consists of a heavy weight attached to a piano wire pa.s.sing from a reel out through a stuffing-box in the bottom. There are also valves which release fresh air to the crew, although in ordinary runs of from one-half to one hour this is not necessary, the fresh air received from the various exhausts in the boat being sufficient to supply all necessities in that length of time.”
Another submersible of somewhat different design is the production of the Swedish inventor, Mr. Nordenfelt. This boat is 9-1/2 metres in length, and has a displacement of sixty tons. Like the _Goubet_ it sinks only in a horizontal position, while the _Holland_ plunges downward at a slight angle. On the surface a steam-engine of 100 horse-power propels it, and when the funnel is closed down and the vessel submerges itself, the screws are still driven by superheated steam from the large reservoir of water boiling at high pressure which maintains a constant supply, three circulation pumps keeping this in touch with the boiler. The plunge is accomplished by means of two protected screws, and when they cease to move the reserve buoyancy of the boat brings it back to the surface. It is steered by a rudder which a pendulum regulates. The most modern of these boats is of English manufacture, built at Barrow, and tried in Southampton Water.
The vessels. .h.i.therto described should be termed submersible rather than submarine, as they are designed to usually proceed on the surface, and submerge themselves only for action when in sight of the enemy.
American ingenuity has produced an absolutely unique craft to which the name submarine may with real appropriateness be applied, for, sinking in water 100 feet deep, it can remain below and run upon three wheels along the bottom of the sea. This is the _Argonaut_, invented by Mr. Simon Lake of Baltimore, and its main portion consists of a steel framework of cylindrical form which is surmounted by a flat, hollow steel deck. During submersion the deck is filled with water and thus saved from being crushed by outside pressure as well as helping to sink the craft.
When moving on the surface it has the appearance of an ordinary s.h.i.+p, with its two light masts, a small conning-tower on which is the steering-wheel, bowsprit, ventilators, a derrick, suction-pump, and two anchors. A gasolene engine of special design is used for both surface and submerged cruising under ordinary circ.u.mstances, but in time of war storage batteries are available. An electric dynamo supplies light to the whole interior, including a 4000 candle-power searchlight in the extreme bow which illuminates the pathway while under water.
On the boat being stopped and the order given to submerge, the crew first throw out sounding lines to make sure of the depth. They then close down external openings, and retreat into the boat through the conning-tower, within which the helmsman takes his stand, continuing to steer as easily as when outside. The valves which fill the deck and submersion tanks are opened, and the _Argonaut_ drops gently to the floor of the ocean. The two apparent masts are in reality 3-inch iron pipes which rise thirty feet or more above the deck, and so long as no greater depth is attained, they supply the occupants with fresh air and let exhausted gases escape, but close automatically when the water reaches their top.
Once upon the bottom of the sea this versatile submarine begins its journey as a tricycle. It is furnished with a driving-wheel on either side, each of which is 6-1/2 feet in diameter and weighs 5000 lbs.; and is guided by a third wheel weighing 2000 lbs. journalled in the rudder. On a hard bottom or against a strong tide the wheels are most effective owing to their weight, but in pa.s.sing through soft sand or mud the screw propeller pushes the boat along, the driving-wheels running ”loose.” In this way she can travel through even waist-deep mud, the screw working more strongly than on the surface, because it has such a weight of water to help it, and she moves more easily uphill.
In construction the _Argonaut_ is shaped something like a huge cigar, her strong steel frames, s.p.a.ced twenty inches apart, being clad with steel plates 3/8-inch thick double riveted over them. Great strength is necessary to resist the pressure of superinc.u.mbent water, which at a depth of 100 feet amounts to 44 lbs. per square inch.
Originally she was built 36 feet long, but was subsequently lengthened by some 20 odd feet, and has 9 feet beam. She weighs fifty-seven tons when submerged. A false section of keel, 4000 lbs. in weight, can on emergency be instantly released from inside; and two downhaul weights, each of 1000 lbs., are used as an extra precaution for safety when sinking in deep water.
The interior is divided into various compartments, the living quarters consisting of the cabin, galley, operating chamber and engine-room.
There are also a division containing stores and telephone, the intermediate, and the divers' room. The ”operating” room contains the levers, handwheels, and other mechanism by which the boat's movements are governed. A water gauge shows her exact depth below the surface; a dial on either side indicates any inclination from the horizontal.
Certain levers open the valves which admit water to the ballast-tanks in the hold; another releases the false keel; there is a cyclometer to register the wheel travelling, and other gauges mark the pressure of steam, speed of engines, &c.
A compa.s.s in the conning-tower enables the navigator to steer a true course whether above or below the surface. This conning-tower, only six feet high, rises above the centre of the living quarters, and is of steel with small windows in the upper part. Encircling it to about three-quarters of its height is a reservoir for gasolene, which feeds into a smaller tank within the boat for consumption. The compressed air is stored in two Mannesmann steel reservoirs which have been tested to a pressure of 4000 lbs. per square inch. This renews the air-supply for the crew when the _Argonaut_ is long below, and also enables the diving operations to be carried on.