Cable (marine)

“ Besides all this, a ship will ride much smoother with a long cable, and be less apt to pitch, or plunge deep in the water with her fore-part.
On the contrary, the short cable, being too nearly vertical to the anchor, cannot bear such a strain, because it is charged with a greater effort; and, as it will not bear stretching, may break at the first violent tug. The ship also rides with much greater difficulty, labours extremely, and often plunges all her fore-part under water. ”

“ Thus the end of a reef-line is pointed, so that, being stiffer, it may more readily penetrate the eye-let holes of the reef; and the ends of the strands of a cable are occasionally pointed, for the greater conveniency of splicing it to another cable, especially when this task is frequently performed. The extremities of the splice of a cable are also pointed, that it may pass with more facility through the hause-holes.
POINTS, garcettes de ris, short flat pieces of braided cordage, tapering from the middle towards each end, and used to reef the courses and top-sails of a ship. ”

“ The constant slipping of this drum sets up great heat, which is dissipated by currents of air. As the sacks of coal arrive on the man-of-war they are automatically detached from the cable, and fall down a chute into the hold.
In the Temperley Miller Marine Cableway the load is carried on a main cable kept taut by a friction drum, and the hauling is done by an endless rope which has its own separate winches. In actual tests made at sea in rough weather sixty tons per hour have been transferred, the vessels moving at from four to eight miles an hour. ”

“ The stoppers of the cables have a large knot, and a laniard, at one end, and are fastened to a ring-bolt in the deck, by the other. They are attached to the cable, by the laniard, which is fastened securely round both by several turns passed behind the knot, or about the neck of the stopper; by which means the cable is restrained from running out of the ship, when she rides at anchor. See also Bits and Ring-rope.
The stoppers of the shrouds have a knot and a laniard at each end. They are only used when the shrouds are cut asunder in battle, or disabled by tempestuous weather ”

“ The breadth and thickness of all the planks of a 74 gun ship, as also of her wales and thick-stuff, are exhibited in the midship section, plate VII.
PLAT, garcette de cable, a sort of braided cordage, formed of several strands of old rope-yarn, twilled into foxes. It is used to wind about that part of the cable which lies in the hause-hole, or against the fore-part of the ship, where it would otherwise be greatly injured by the continual friction, produced by the agitation of the ship in stormy weather. See the articles Freshen and Service. ”

“ 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. ”

“ There was a strange, unnatural silence in the ship. Men paced the deck with soft and muffled{66} tread, speaking only in whispers, as if a loud or heavy footfall might snap the vital cord. So much had they grown to feel for the enterprise, that the cable seemed to them like a human creature, on whose fate they themselves hung, as if it were to decide their own destiny.
“There are some who will never forget that first night at sea. Perhaps the reaction from the excitement on shore made the impression the deeper. There are moments in life when everything comes back to us. ”

“ The Great Eastern now proceeded six miles to the eastward, and commenced a new drag, for raking the ocean bed with 2,400 fathoms of wire rope. About eleven o’clock at night the grapnel came to the surface with the cable caught on two of the prongs. Boats were quickly in position alongside the grapnel. Shortly afterward they were endeavoring to secure the cable to the strong wire rope, by means of a nipper, when the grapnel canted, allowing the line to slip away from the prongs—like a great eel—and disappear into the sea. ”

“ It consists of an exchange of currents sent alternately every ten minutes by each ship. These not only serve to give an accurate test of the continuity and insulation of the conducting-wire from end to end, but also to give certain signals which it is desirable to send for information purposes. For instance, every ten miles{121} of cable paid out is signalized from ship to ship, as also the approach to land or momentary stoppage for splicing, shifting to a fresh coil, etc. The current in its passage is made to pass through an electromagnetometer, [34] an instrument invented by Mr. Whitehouse. ”

“ The ship seemed as if made by Heaven to accomplish this great work of civilization. The paying-out apparatus was a piece of mechanism to excite the enthusiasm of an engineer, so smoothly did its well-oiled wheels run. The strain never exceeded fourteen hundred-weight, even in the greatest depths of the Atlantic. And as for the cable itself, it seemed to come as near perfection as it was possible to attain. As before, the insulation was greatly improved by submergence in the ocean. With every lengthening league it grew better and better. ”

“ Nearly all the officers of the ship and of those connected with the expedition stood in groups about the coil, watching with intense anxiety the cable as it slowly unwound itself nearer and nearer the joint, while the workmen worked at the splice as only men could work who felt that the life and death of the expedition depended upon their rapidity. But all their speed was to no purpose, as the cable was unwinding within a hundred fathoms ”

“ All cables of any great length are worked by reverse currents. A modification (known as the cable code) of the ordinary single needle alphabet is used; that is to say, currents in one direction indicate dots and in the other direction dashes.
The general principle on which the instruments for working long submarine cables are based is that of making the moving parts very light and perfectly free to follow the comparatively slow rise and fall of the electric impulses or waves. The simplest form of receiving instrument (formerly much used) is known as the “mirror.” ”

“ The regulation of the United States Navy for chain cables, is one inch and a half for a sloop of war, and one and a quarter for brigs and schooners. In the merchant service, a ship of 400 tons would probably have a best bower cable of one and five sixths, and a working bower of one and a quarter inches. A ship of 700 tons would have a best bower of one and five eighths, and a working bower of one and a half inches. Chain cables have a shackle at every fifteen fathoms, and one swivel at the first shackle. ”

“ The science of making, testing, and laying cables has so much improved that an undetected fault in an insulated wire has now become literally impossible, while so much are the instruments for signalling improved, that not only can a slight fault be disregarded if necessary, but it is even easy to work through a submarine wire with a foot of its copper conductor stripped and bare to the water. This latter result, astonishing as it may appear, has actually been achieved for some days past with the whole Atlantic cable on board the Great Eastern. ”

“ 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. ”

“ That the steamship Great Eastern, from her size and constant steadiness, and from the control over her afforded by the joint use of paddle and screw, renders it possible and safe for her to lay an Atlantic Cable without regard to the weather. That the egress of a Cable in the course of being laid from the Great Eastern may be safely stopped on the appearance of a fault, and with strong tackle and good hauling-in machinery, the fault may be lifted from a depth of over 2000 fathoms, and cut out on board the ship, and the Cable respliced and laid in perfect condition. ”

“ 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. ”

“ ELECTRICAL GRAPNEL FOR SUBMARINE CABLES AND TORPEDO LINES. By H. KINGSFORD.
All those who are acquainted with the cable-lifting branch of submarine telegraphy are well aware how important a matter it is in grappling to be certain of the instant the cable is hooked. This importance increases, of course, with the age and consequent weakness of the material, as the injury caused by dragging a cable along the bottom is obviously very great. ”

“ 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. ”

“ As an instance, even at a comparatively recent period, Captain Marryat, R.N., the famous nautical author, writes of the sea: “What a mine of wealth must lie buried in its sands. What riches lie entangled among its rocks, or remain suspended in its unfathomable gulf, where the compressed fluid is equal in gravity to that which it encircles.” [13]
To obviate this non-existent difficulty, it was gravely proposed to festoon the cable across, at a given maximum depth between buoys and{45} floats, or even parachutes—at which ships might call, hook on, and talk telegraphically to shore! ”

“ The result of this is nowadays to practically double the carrying capacity and earning power of the line, the effective speed in either direction remaining virtually the same as in “simplex” working, provided the cable is in good condition. [73] The armor of this cable (Fig. 43) is also a good example of present-day practise, each wire (usually covered with compounded tape) butting against the next; this is found to be the most durable form for a deep-sea cable.
In 1898 another French Atlantic line of a similar type to the above was laid. ”

“ It was necessary to bring up the ship, holding the cable by stoppers until it was again properly disposed around the pulleys. Some importance is due to this event, as showing that it is possible to “lay to” in deep water without continuing to pay out the cable, a point upon which doubts have frequently been expressed.
Shortly after this the speed of the cable gained considerably on that of the ship, and up to nine o’clock, while the rate of the latter was about three knots, by the log, the cable was running out from five and a half to five and three-quarter knots. ”

“ Even a punt will not turn if she has no way on her, and it takes a good deal of way—more than she could get with safety to the Cable—to give steerage to the Great Eastern. As she slowly drifted and came round by degrees quite imperceptible to those who did not keep a close watch on the compass, the wire rope was payed-out; and at last, as the ship’s bows turned, it was taken in over the machinery, and was passed aft through the drums, and the picking-up apparatus coiled it in very slowly away till the end of the Cable was hauled up out of the sea. ”

“ 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. ”

“ It has been proved beyond a doubt that no obstacle exists to prevent our ultimate success; and I see clearly how every difficulty which has presented itself in this voyage can be effectually dealt with in the next.
The cable has been laid at the expected rate in the great depths; its electric working through the entire length has been satisfactorily accomplished, while the portion laid, actually improved in efficiency by being submerged—from the low temperature of the water and the increased close texture of gutta-percha thereby effected. ”

“ Bright and the two energetic engineers, Mr. Canning and Mr. Clifford, who acted with him, it could not have been done at all. Men were kept at the wheels of the machine to prevent their stopping (as the stern of the ship rose and fell with the sea) , for had they done so, the cable must undoubtedly have parted. During Sunday the sea and wind increased, and before the evening it blew a smart gale. ”