Submarine telegraph cable

“ The Atlantic telegraph, it is said by some, was a failure. Well, if it were so, replies Mr. Field, I should say (as is said of many a man, that he did more by his death than by his life) that even in its failure it has been of immense benefit to the science of the world, for it has been the great experimenting cable. No electrician ever had so long a line to work upon before; and hence the science of submarine telegraphy never made such rapid progress as after that great experiment. ”

“ Countries far apart, and isolated by oceans, have, by means of deep-sea cables, been brought into intimate relation, and made sharers of one another’s intelligence, enterprise, and civilizing instincts. What the overland telegraph has done toward bringing local states and communities into contact, the submarine cable has done for the remote nations.
In form, an ocean cable differs much from the simple wire which constitutes the conductor of an overland or even underground telegraph. ”

“ The practical working of a submarine cable differs in many respects from that of a land telegraph line. The currents used in submarine telegraphy are extremely small, contrary to the popular impression. An insulated cable acts like a Leyden jar, in the sense that it accumulates electricity and does not quickly part with it, as does a bare overhead wire. In the case of a very long cable, such as one across the Atlantic, a current continues to flow from it for some time after the battery is disconnected. ”

“ It was in 1851 that an electric cable was actually laid in the open sea, and worked successfully; and the wire which then connected Dover with Calais was beyond question the first important line of submarine telegraph ever attempted. In the year 1850, Mr. Brett obtained a concession from the French Government for effecting this object,—an object regarded at the time as one purely chimerical, and decried by the press as a gigantic swindle. The cable which was made for the purpose consisted of a solid copper wire, covered with gutta percha. ”

“ In 1903 an American cable was laid to the Philippines from San Francisco by way of Hawaii. Thus, by means of the overland telegraph and the submarine cable, it is now possible to transmit a message in a few hours to almost any country on the globe.
Submarine Cables are laid on the bottom of the sea. They require not only good insulation, but great tensile strength, else they will not support their own weights when lowered from the vessel to the bottom of the sea. This tensile strength is acquired by wrapping the guttapercha insulation with a sheathing of steel wire. ”

“ It may be well believed that the Directors have not decided upon a matter so all-important to success, without availing themselves of the most eminent talent and experience which could be commanded. The practical history of submarine telegraphs dates from the successful submersion of the cable between Dover and Calais in 1851, and advantage has been taken of whatever instruction this history could furnish or suggest. Of the submarine cables heretofore laid down, without enumerating others, the one between Dover and Calais weighs six tons to the mile ”

“ Submarine cables have multiplied recently, and almost every ocean flows over the mysterious wires which flash intelligence beneath the rolling waters from point to point of the civilized world. By a telegraph-cable, which is partly submarine, the India Office in Westminster is united with the Governor-General and his Council at Calcutta. ”

“ In the French Atlantic cable no current can be detected by the most delicate galvanoscope at America for the first tenth of a second after it has been put on at Brest; and it takes about half a second for the received current to reach its maximum value. This is owing to the phenomenon of induction, very important in submarine cables, but almost entirely absent in land lines. In submarine cables, as is well known, the copper wire which conveys the current is insulated from the sea-water by an envelope, usually of gutta-percha. ”

“ Thus the carrying capacity of the wire is in practice nearly doubled, and recorders are busy writing at both ends of the cable at once, as if the messages came up out of the sea itself.
We have thus far followed out the recorder in its practical application to submarine telegraphy. Let us now regard it for a moment in its more philosophic aspect. We are at once struck with its self-dependence as a machine, and even its resemblance in some respects to a living creature. All its activity depends on the galvanic current. ”

“ EVENTS FOLLOWING THE CIVIL WAR.
THE ATLANTIC CABLE.
Original
ARLY [318] in October, 1851, the first effort at laying a cable for a submarine telegraph was begun by the United States brig Dolphin, which carried a line of soundings across the Atlantic. At that time there were but eighty-seven nautical miles of submarine cable laid, while now there are nearly 200,000 statute miles. Some of these cables merely connect islands with the main shore, others are thousands of miles long. A cable is laid so far below the surface that neither storms, tides or currents can disturb it. ”

“ No insulation of a submarine cable is ever so perfect as to withstand the influence of these electrical phenomena, which correspond [Pg 286] in some particulars to storms in the ordinary atmosphere, their direction generally being from east to west. Their action is immediately communicated to all conductors of electricity, and a struggle set up between the natural current and that used artificially in sending messages. ”

“ Thomson became a man of public note in connection with the laying of the first Atlantic cable. After Cooke and Wheatstone had introduced their working telegraph in 1839; the idea of a submarine line across the Atlantic Ocean began to dawn on the minds of men as a possible triumph of the future. Morse proclaimed his faith in it as early as the year 1840, and in 1842 he submerged a wire, insulated with tarred hemp and india-rubber, in the water of New York harbour, and telegraphed through it. ”

“ The High Contracting Parties agree to insist, as far as possible, when they shall authorize the landing of a submarine cable, upon suitable conditions of safety, both as regards the track of the cable and its dimensions. ”

“ To have been the pioneer par excellence in this great work should be most gratifying to yourself and your family, and no one can take from you this proud position.”
It would have seemed a strange prophecy if the above had been predicted in 1856, when it was declared that the object of the Atlantic Telegraph Company was “To continue the existing line of the New York, Newfoundland, and London Telegraph Company to Ireland, by making or causing to be made a submarine telegraph cable for the Atlantic.” At the close of the year the contracts for the manufacture of the cable were signed. Messrs. ”

“ Mr. John Watkins Brett, who was also honourably connected with the initiation of submarine telegraphy, stated in 1857 that [Pg 188] he was ignorant until three or four years previously that a line across the Channel had been suggested years before by that talented philosopher, Professor Wheatstone; and he exhibited at the Royal Institution the original plans of Wheatstone drawn in 1840 for an electric telegraph between Dover and Calais. The cable he then designed was to be insulated by tarred yarn and protected by iron wire ”

“ One can never be sure when the line may be unfit for duty. Sometimes from storms, sometimes from the assassination of the operators in wild districts through which the land wires pass, and sometimes from the destruction of lines out of pure mischief, the telegraph is often beaten by the mail.”
“There seems, indeed, much need for a cable direct,” said Sam, “which will make us independent of Turks, Persians, Arabs, and all the rest of them. By the way, how long is your cable?” ”

“ The present Convention shall be applicable, outside of the territorial waters, to all legally established submarine cables landed in the territories, colonies or possessions of one or more of the High Contracting Parties.
Art. 2
The breaking or injury of a submarine cable, done willfully or through culpable negligence, and resulting in the total or partial interruption or embarrassment of telegraphic communication, shall be a punishable offiense, but the punishment inflicted shall be no bar to a civil action for damages. ”

“ Hence the line is separated from the poles by glass. The poles are about one hundred and thirty-two feet apart, making forty to the mile. The wires are usually galvanized iron one sixth of an inch in diameter. Copper conducts six times as well as iron, and is now replacing iron in the lines.
Morse laid a submarine telegraph line in New York Harbour and suggested a cable across the [65] ocean. But that gigantic undertaking had to await the masterful intelligence of Lord Kelvin and the indomitable will of Cyrus W. Field. A submarine cable was laid across the Strait of Dover in 1850. ”

“ It seemed as though a great and valued friend lay at the point of death.
The submarine hill, with its dangerous slope, was passed in safety, and the 'telegraph plateau,' nearly two miles deep, was reached, when suddenly the signals from Ireland, which told that the conductor was intact, stopped altogether. Professor Morse and De Sauty, the electricians, failed to restore the communication, and the engineers were preparing to cut the cable, when quite as suddenly the signals returned, and every face grew bright. ”

“ Owners of ships or vessels who can prove that they have sacrificed an anchor, a net, or any other implement used in fishing, in order to avoid injuring a submarine cable, shall be indemnified by the owner of the cable. ”

“ The owner of a cable who, by the laying or repairing of that cable, shall cause the breaking or injury of another cable, shall be required to pay the cost of the repairs which such breaking or injury shall have rendered necessary, but such payment shall not bar the enforcement, if there be ground therefor, of article 2 of this Convention.
Art. 5
Vessels engaged in laying or repairing submarine cables must observe the rules concerning signals that have been or shall be adopted, by common consent, by the High Contracting Parties, with a view to preventing collisions at sea. ”

“ Communication by wireless cannot be interrupted by a belligerent. With a submarine cable it is otherwise. The possibility of cutting the cable exists, and if a belligerent possesses naval superiority the cable is cut, as was the German cable near the Azores by one of Germany's enemies, and as was the British cable near Fanning Island by a German naval force. Since a cable is subject to hostile attack, the responsibility falls upon the belligerent, and not upon the neutral, to prevent cable communication. ”

“ Owing to the small currents received and to prevent interference from earth currents it is necessary to use a complete metallic circuit. If an overhead line could be employed no difficulty would be experienced in working a distance of over 1000 miles, but a line of this length is impossible—at least in this country—and if transmission is attempted with any other country, a certain amount of submarine cable is essential. ”

“ Mr. Field was despatched to England, as there were no firms established for the manufacture of submarine cables in the United States, to order the necessary work to be done, and to raise money. He previously ordered specimens of cable to be made, so that when he landed in England they were ready for his inspection; and soon after his arrival he entered into a contract with Messrs. Küper & Co. (subsequently Glass, Elliot, & Co.) for a cable to be laid across the Gulf of St. Lawrence. He held interviews with eminent engineers and electricians, among whom were Mr. ”

“ In all there are more than 150,000 miles of submarine cable under the waters of the globe, and there is a fleet of forty ships, large and small, fitted out solely for the purpose of laying and repairing submarine cables. Nowadays the laying of an Atlantic cable attracts no attention, and the fishing up of a slender rope less than an inch thick from the floor of the ocean, 12,000 or 15,000 feet down, is a thing done a dozen times a year. ”

“ The engineers were fast learning the rigorous conditions of submarine telegraphy; in its essentials the Dover-Calais line continues to be the type of deep-sea cables to-day. The success of the wire laid across the British Channel incited other ventures of the kind. Many of them, through careless construction or unskilful laying, were utter failures. At last, in 1855, a submarine line 171 miles in length gave excellent service, as it united Varna with Constantinople; this was the greatest length of satisfactory cable until the submergence of an Atlantic line. ”

“ Before laying a submarine cable between the proposed places it is extremely important to take soundings and otherwise survey the ocean, so as to determine the exact route the cable should take. A cable is too costly to be flung away anywhere on the sea-bottom, and the sea-bottom is sometimes of a very unfavourable character. ”

“ According to recent statistics, the North Atlantic Ocean is now crossed by no less than 17 cables, the number of cables all over the world being 2937, with a total length of 291,137 nautical miles.
Before describing the actual working of a submarine cable, a few words on cable-laying may be of interest. Before the cable-ship starts, another vessel is sent over the proposed course to make soundings. Galvanized steel pianoforte wire is used for sounding, and it is wound in lengths of 3 or 4 nautical miles on gun-metal drums. ”