Submarine Cable
a wire, or combination of wires, protected by flexible non-conducting waterproof material, designed to rest on the bottom of a body of water, and serve as a conductor for the currents transmitted by an electromagnetic telegraphic apparatus. SUBMARINE MINES AND NAVI- GATION. Submarine mines consist of spherical or cylindrical containers, usually made of steel, and sometimes lined with concrete, filled with a charge of ex- SUBMARINES plosives. They are generally anchored in such a manner that they are concealed beneath the surface of the sea, but they are also sometimes allowed to float and drift. They were first used during the American Civil War, 28 vessels being destroyed by them. Their use was developed to a very marked degree in the European War, during which they were employed in enormous numbers by all the belligerents. The North Sea was completely inclosed by two mine barrages, the first being laid early in the war by the British navy across the Straits of Dover, and the second by the combined actions of the American and British navies. This was an immense barrage, stretching from the Orkney Islands off the north coast of Scotland, to the coast of Norway, a distance of 240 miles. It contained more than 70,000 mines, and covered an area of 6,000 square miles. It is claimed that its completion sealed the fate of the German submarine. Previous to the war, the charge employed was usually wet guncotton, and the explosion was brought about by successive detonations of fulminate of mercury and a small secondary charge of dry guncotton. Frequently A B TORPEDO TUBE QUARTERS FOR CREW C2-900 H.P. MOTORS (DIESEL) D= 2-500 H.P. ELECTRIC MOTORS ABCDEFGHIJKL = = 3 = = SCREWS RUDDERS TORPEDO TUBES 3 inch GUN SPACE FOR EXTRA TORPEDOS 3 inch GUN DIVING RUDDER PERISCOPES G E F C CROSS SECTION OF A MODERN SUBMARINE 1 B K A SUBMARINES electrical firing was used, the mines being connected to a station on shore by cable. In recent years, however, guncotton has been replaced by trinitroto- SUBMARINES vane." This consisted of two "otters" towed by wire ropes from the side of a vessel. The otters were fitted with sawlike jaws, and a mine would glide along GUN IN USE GUN IN RECESS DECK OF SUB- MARINE WATERTIGHT DOOR SUBMARINE'S GUNS luene (T. N. T.) and the North Sea barrage referred to above is said to have contained more than 21 million pounds of this explosive. Much of the wartime development was concerned with rendering explosion more certain and more easily brought about. The American navy was especially successful along these lines. The details of manufacture are necessarily kept a close secret, but it is known that both British and German mines were of the so-called "horn type," being fitted with leaden horns, which projected from the mine. When these horns were struck and broken by a passing ship, or any other body, the explosion of the mine was brought about. The American mine was invented shortly after the United States entered the war. It was long antenna which fitted with a stretched above the mine. When this antenna was struck by a ship the explosion of the mine followed. It is obvious that the radius of action of a mine fitted with such a device is very much greater than that of the horn type.
Moreover, the explosion depended upon electrical action, and it was only necessary for a piece of metal to make contact with the antenna for an explosion to follow. Mines are destroyed by "sweepers." A heavy wire is attached to the stern of two vessels, and the wire is kept at a sufficient depth by means of a pipe. The vessels sail through a suspected mine field, and when a mine is caught in the sweep wire, it is dragged along until the wire which holds it to its anchor breaks. The mine then rises to the surface, and can be destroyed by gunfire. Another protective device against mines invented by the British navy during the war was the "parathe length of the wires until it reached the otter, when the wire would be cut and the mine destroyed .
Submarine Navigation. Under-water vessels had never been used in warfare to any appreciable extent until the European War of 1914-1918. Many attempts at submarine navigation have been made, however, during the last 300 years. One of the earliest inventors to meet with anything approaching was Cornelius Drebbell, a Dutchman, who built a boat manned by twelve rowers, and navigated it on the River Thames. This was at the beginning of the 17th century. In 1744, another inventor named Day, built a boat which he claimed could remain under water for twelve hours. He lost his life, however , in an attempt to prove the truth of his assertion, being drowned in his own boat in Plymouth Sound. In the following year, Bushnell, an American, invented a submarine vessel which met with considerable success. Some of the . principles employed by him are still used in modern vessels. His boat was fitted with "oars on the principle of a screw," and submerged by admitting water through a valve, the water being pumped out when it was wished to rise to the surface. The next inventor was Robert Fulton, who, in 1800, remained under water for four hours, at a depth of 25 feet, in an egg-shaped vessel of his own devising. He indicated future possibilities in this line by attaching a charge of explosives to an old hulk off the coast of France and blowing her up. In 1830 a German named Bauer made some unsuccessful experiments with a boat which sank, but was later recovered and pre- SUBMARINES served in the Berlin Naval Academy.
The same inventor experimented for the Russians during the Crimean War. In 1851, an American of the name of Phil- SUBMARINES the surface or awash. The vessel was armed with a spar torpedo, but it achieved no great success. The other "David" carried out a successful attack ARMORED CONNING TOWER WITH 12 inch GUN 1140.
BRITISH SUBMARINE lips demonstrated the possibility of remaining beneath the water by spending a day with his wife and family at the bottom of Lake Michigan, and Delaney, another American inventor, experimented in 1859 with a boat similar to that of Robert Fulton's. During the American Civil War attempts to use submarine boats were made by both Federals and Confederates. Two boats, both known as "The David," were built by the latter. The first was a steam vessel driven by a screw propeller, the funnel protruding above the surface of the water, but the boat proper being below upon the Housatonic, which she sank, but she herself was swamped and sank with her crew. In 1876, G. W. Garrett, an English clergyman invented a submarine which gave promisingly successful results, but a larger model, built on similar lines, was lost off the Welsh coast. He entered into partnership, however, with a Swedish inventor named Nordenfeldt, and they built two submarines, and sold one to Turkey and the other to Greece.
A third was built for Russia, but was wrecked and sunk while attempting to sail to Petrograd. All these boats were driven by vertical propellers, and were FORPEDO SUBMARINE FIRING TORPEDO SUBMARINES propelled by steam. The French navy in 1896-97, built four submarines, driven by electricity, and fitted with compressed air reservoirs. From that time onward the submarine grew rapidly in importance. Inventors were many, among them being the Frenchmen, Goubet, Zédé, and Peral, and the Americans, Simon Lake, J. P. Holland and others.
Modern submarines are of four types, coast defense, cruising, fleet and minelaying. While generally similar, they necessarily differ in details according to the work they are called upon to perform.
Those used for coast defense require only a small cruising radius, since they can readily return to their base for fresh supplies of fuel, food and ammunition.
For a similar reason, quarters for officers and crew need be only of the simplest SUBMARINES necessarily be larger than the coastal type, and even berore the war boats of 800 to 1,200 tons had been built. During the war, both the United States and Great Britain built several of 1,500 to 2,000 tons, and similar large boats were owned by Germany. On the average, the submarine cruiser is 250 to 300 feet long, with a beam of 18 to 25 feet or more. They are swifter than the coastal type, and can attain a speed of 20 knots on the surface, and 14 to 15 knots submerged. More recent vessels have a cruising radius of 10,000 miles. Their armament has steadily increased, and some of the larger boats are equipped with two 5-inch or even 6-inch guns. In the earlier years of the war the German boats were fitted with one or two 3-inch guns, to which very soon was added an Submerged-Steering by Periscope.
Completely Submerged Steering by Clock and compass All Ballast Tanks Filled For Resting on Ocean Floor SUBMARINE kind. Compared with the cruising type they are small, varying from 250 to 600 tons, being 150 to 200 feet long with a beam of 15 to 20 feet. They can attain a speed of as much as 16 knots on the surface, but when submerged this is reduced to 8-11 knots. They have a cruising radius of 1,000 to 2,000 miles, and are usually armed with one 3-inch gun, and sometimes with an anti-aircraft gun in addition. They carry also from four to eight torpedo tubes.
The Submarine Cruiser was the type which showed probably the greatest development during the war. These formed the most active branch of the German navy, and the enormous destruction of Allied and neutral shipping was carried out by them. Because they are away from their base for several days, or even weeks, they must contain sleeping and living quarters for officers and crew, with space for the preparation and cooking of food. In addition, they have to carry a comparatively large number of torpedoes and other needed n supplies. It follows that they must anti-aircraft gun. These were, of course, in addition to the torpedo tubes, which numbered as many as eight. They carried a crew of from 40 to 50 men. The Fleet Submarine, as its name implies, is intended to accompany the fleet in action. Its radius of action need not necessarily be high, as it can be accompanied by a mother ship carrying supplies of fuel, extra ammunition , food for the crew and other necessities .
This type can therefore be smaller than the cruiser, but it must be speedy and also possess seaworthiness. The submarine mine-layer was a type evolved by Germany during the war, and proved of great value to her in laying mines off the coast of Great Britain. They carried 16 mines in inclined tubes, which were open at the lower end. The tubes were loaded from the deck, the mines being liberated by a special device under water at the open end.
All types of submarines are now driven by Diesel or gasoline engines when traveling on the surface, but rely on electric motors when submerged. The current SUBMARINES for the motors is supplied by storage batteries. An arrangement is made similar to that on the ordinary automobile (see "Electric Battery"), by which the storage batteries can be recharged from a generator driven by the Diesel or gasoline engine gine when the boat is traveling on the surface. The newer types of cruising submarines can travel upward of 100 miles on a single charge of the batteries. It will be seen, therefore, that even they can remain beneath the surface for comparatively short periods of time, even if other considerations permitted them to keep submerged for any greater period. One of the most difficult problems which confronted early inventors was that of keeping the boat on an even keel. This is now accomplished by means of ballast tanks and horizontal runners, or by means of the gyroscope. But the matter still remains one which requires constant watchfulness. It will be clearly seen that under the conditions existing in a submarine, where the vessel is so to speak in a state of delicate balance, the moving of equipment or of torpedoes, presents problems of peculiar difficulty. and especially the discharge of torpedoes, As indicated above, the problems have to a large extent been solved, but the stability of the submarine still leaves room for improvement. Submerging is effected by admitting water into tanks specially designed for the purpose. Conversely, the boat is brought to the surface by expelling the water from these tanks either by means of compressed air or with the aid of pumps. The speed with which a boat can submerge or rise has increased considerably in recent years, but even now it varies somewhat with conditions. On the average, from one and one-half to three minutes are required for a boat to emerge sufficiently far from the water to use her guns. The periscope, by means of which the observing officer can watch what is taking place on the surface of the water while the boat remains almost completely submerged, is an essential part of submarine part equipment, and the principle of reflecting mirrors, on which it depends, is familiar to all. Submarines are costly to build; ton for ton they cost more than twice as much as surface battleships or cruisers.
The pre-war cost was estimated at, approximately, $1,000 per ton, but it is certain that the cost of those built under war-time conditions was much higher than this.
Submarine Merchantmen. - The first (and possibly the last) submarine merchantman was the "Deutschland," which crossed the Atlantic with a valuable cargo of dyestuffs from Germany SUBMARINES and reached the United States in July, 1916. She is believed to have had a sister ship known as the "Bremen," and this is supposed to have been captured or sunk by the British. The utility of the submarine for carrying cargo is obviously small. Its comparatively slow speed, its high cost of construction, its small capacity and its general inconvenience, render it not worth consideration as a cargo carrier. It is inconceivable that it will ever be used as such in the future, except by a country which finds itself situated as Germany was in the late war, with its main fleet impotent and its mercantile vessels swept from the seas.
Previous to the European War there were many to be found, even among the highest authorities, who prophesied that the submarine had rendered the surface war vessel useless and impotent. In the early months of the war, when German submarines scored heavily against British and French cruisers, it seemed as though their prophecies were to be fulfilled. As the power of the submarine grew, however, the means of fighting it grew more rapidly, and in the later years of the war almost its only success was against the unarmed or lightly armed merchantman. Deadly though it may be, the submarine, by its very nature, is vulnerable. Many methods of destroying it were devised, some of which have become known, while others still remain secret.
One of the earliest schemes was the construction of huge nets, two lines of which were placed across the Straits of Dover, from the coast of England to the coast of France, thus providing a comparatively safe space between the two lines. The construction of the vast mine fields in the North Sea has already been dealt with in the early part of this article.
Another device that was perhaps more dreaded by the submarine than any other was the "depth charge." This was a huge bomb, weighing 600 pounds or more.
One or more of these bombs would be dropped from the stern of a destroyer where a submarine was last seen to submerge. They They would explode at or near the bottom, and the enormous concussion would bring about the complete destruction of the submarine. The hydrophone was another useful device invented during the war. This was a special type of telephone, by means of which the position of submarines could be detected by noises transmitted through water. These, and other devices, have greatly lessened the deadliness of submarines in legitimate warfare. None the less, they are still recognized as a powerful weapon of both defense and offense, and form an important adjunct to all modern navies.
SUBMARINE TELEGRAPHY