History of the Atlantic Cable & Undersea Communications
Making the 1865 Atlantic Cable
The Telegraphic Journal, Dec 24, 1864, pp. 306-307, reprinted from the Daily Telegraph
THE ATLANTIC CABLE
A circumstantial account of the commencement of shipping the Atlantic electric telegraph cable, published in an evening paper on the 18th inst., and copied by several of our contemporaries next day, is, though inaccurate in all the particulars, within a fortnight of probable truth as regards the main statement which it contains. The operation of transferring the cable from the factory at East Greenwich to the hulks Amethyst and Iris has not yet been begun; but, if all should go well, the preparations for this important step in the great enterprise may be concluded before New Year’s Day. Meanwhile, it is necessary to correct the utterly erroneous report which has appeared on the subject, and which seems to be indebted for its figures to the back numbers of a scientific journal. Those figures in reality represent no more than the prospective calculations of gentlemen superintending the works–that is to say, they refer to possibilities, not to accomplished facts; and in hardly one instance will the actual result verify the account which gravely purports to be a description of what has already been done.
The works of the Telegraph Construction and Maintenance Company, formerly Messrs. Glass & Elliot’s, are now the scene of as marvellously delicate a labour as ever yet taxed human intelligence and skill. The engineer and the electrician unite all their finest energies in the accomplishment of an end which must be universally pronounced the triumph of our century; and the combined process of fashioning this wondrous coil. and testing its uninterrupted conducting powers throughout the entire length, is an affair so complex as to baffle the understanding of any but experts, while even they will be moved to admiration by a sight of the means adopted to ensure a perfect result. Powerful machinery, by which some fourteen miles of the “core,” or gutta-percha-coated copper wire, are worked up into cable every day, is not the most important agency; for the tons of material, during manufacture, must undergo the trial of these exquisite instruments over which the man of science bends watchfully hour after hour, ready not only to detect a fault, but to apprise the engineers at what exact distance in the cable it has occurred. Moreover, the necessity of guarding against every slight inadvertence, every possible act of mischief, involves a constant inspection rarely exercised within the walls of a factory. The personal characters of all the workmen, and of the persons employed to cart the large reels of core from the Gutta-percha Works in the City-road to East Greenwich, are the object of rigorous inquiry; and in case of any defect in the cable being found, its exact point can actually and infallibly be identified, with the name of the workman responsible for that part of the work.
We shall now endeavour to give, as succinctly as possible, and from data afforded us by inspection of the works as well as by the courtesy of the chiefs of departments, an account of what is doing at Morden Wharf and a factory in its neighbourhood. At this last-named establishment the covering for the core is fabricated from iron wire and Manilla yarn, which is afterwards steeped in a seething compound of tar and gutta-percha. If a section of the perfected cable be examined, it will be found to measure an inch and one-eighth in diameter, the seven conducting wires lying close together in the middle. They are surrounded by layers of gutta-percha, the rings of which may be faintly discerned, though they form a substantial and practically homogenous coating, about a sixth of an inch thick. So far, we have the core, which is supplied from the gutta-percha works in the City-road, before leaving which place it has undergone the same tests which are afterwards applied during the process of covering at East Greenwich. In the section, we shall further perceive that the core is surrounded by a close mass, more than a quarter of an inch thick, in which are ten round spots of metal ; in other words, the sectional ends of rod iron wires. In fact, the protecting mass will be found to consist of ten closely-twisted strands of the soaked Manilla yarn, each strand having iron wire in the middle. It is at the separate factory, then, some hundreds of yards from the closing and coiling machinery at Morden Wharf, that this covering is manufactured, 50 tons of the iron wire being used every week, in combination with Manilla yarn at the rate of 6½ tons a day. The wire is received in coils from Birmingham, and, having been oiled, is stored until wanted; then it is joined very carefully by scarfed ends, or ends cut transversely and fitted together. The machinery by which the Manilla yarn is twisted round the wire is very ingenious, each machine being a long horizontal shaft or spindle, with alternate discs of perforated iron and bobbins of the gold-coloured yarn. In one set of machines the axis of the bobbins is parallel to or identical with the spindle, and the revolution is the same in rapidity as the fixed iron discs; but in an improved series of mechanism above stairs this arrangement is altered, the bobbins being set transversely with the shaft, and revolving very much more slowly. It is, indeed, a curious and rather perplexing sight to observe the difference in the two motions, the discs whirling so rapidly as to render almost invisible the threads of yarn passed eccentrically through the holes, while each thread unwinds itself in the coolest and most leisurely way from the bobbin. These machines will turn out 140 miles of Manilla-covered wire in a day. As it is twisted it goes through the hot solution above-mentioned, and it is then passed through a trough of water to cool it. These little details must be noted by the visitor by use of his own eyes; for during the time of his being inside this factory his power of distinguishing the sounds of the human voice, even if conveyed in a shout, is in abeyance. The noise of the machinery is, indeed, absolutely deafening, its effect on the drum of the ear being felt for a minute or two after any person unaccustomed to such enormous and indescribable din has left the building.
At the Morden Wharf factory another stage of operations is commenced. Here the core is received on large reels, and is sunk in circular openings, which are then filled up with water. From first to last, we may here observe, the cable is in all its processes of formation at this factory kept in water, that any flaw in the coating may the more quickly be made apparent. For twelve hours the coils of core are subjected to electrical tests, their continuity being ascertained and their complete isolation proved beyond a doubt. Malicious injury to the core in in transit from the Gutta-percha Works to Morden Wharf would thus be defeated in its purpose by prompt detection and remedy. The joining of the ends is, we need hardly say, about the most delicate operation in in the whole course of manufacturing the Atlantic or any telegraphic cable; and whenever the electrician proclaims a faulty transmission of the current, the chances are a hundred to one that the flaw will be found in one of the joints.
Before being worked into cable with the ten strands of wire and yarn, the core is wrapped in a twisted fold of jute, which may be just distinguishable in one of those sections that we have already alluded to, and which are in some request as souvenirs. The machinery by which the cable is twined occupies two floors. The closing machines are below, and they consist of large wheels or tables, revolving horizontally, with reels of the several strands so arranged on their margin as to maintain a relatively stationary position, instead of always keeping their axes pointed to the centre of motion. The strands, converging upward towards a small opening in the roof, meet, and are twisted round the jute-covered core, and so form the entire cable, which is conducted over grooved wheels to another and very noteworthy department. A visit to a large brewery is recalled by the appearance of this place, where platforms lead between huge tanks, or what would elsewhere be vats. They are eight in number, four being round and four oval. The round tanks are 34 feet in diameter, and the oval ones measure 36 feet by 27. Their depth is 12 feet, and they are intended as receptacles for the cable, which descends into them from the wheels overhead, and is coiled very neatly by manual labour. Each tank will conveniently hold 140 miles of the cable, but their capacity, if taxed to the utmost, would be found greater by some ten miles or more. A stream of water constantly falls over the edge of each tank, and, percolating the coils of cable finds its way into an open space which is kept clear in the middle, where it rises to a level with the coil. The water tests the efficiency of the protective covering; and the delicately adjusted batteries in the electrician’s room, into which the ends of all the cables are led in one bunch, proves the conducting power to be uninfluenced by any penetration from without. A measured force is being continually sent through the wires, and the least defect in the insulation can thus be registered with unfailing accuracy, even to its exact distance and degree. Hitherto the superintendents of this anxious work have been very fortunate; but it has sometimes happened that a great length of cable has had to be uncoiled, the defective joint cut out, and the whole made good. An account is kept of the daily progress, and there were 629 miles completed on Friday evening, to which another 12 miles would have been added by the end of the following short day’s work; so that, speaking tolerably “by the card,” we may state that the number of miles of finished wire at this time in the tanks at Morden Wharf is 641. The distance from the west coast of Ireland to Trinity Bay, Newfoundland, is 1,640 nautical miles. Two of the eight tanks are nearly full, and will soon be ready for embarkation by the Amethyst and Iris, two ghostly-looking hulks, which lie alongside near the wharf. The decks of these vessels have been knocked about considerably, and in great part got rid of, to make room for tanks in which the cable will be stowed in the same manner as at the factory. The hulks, when laden, will be towed to the Medway, where the Great Eastern is now lying, with three enormous tanks on board, occupying, by comparison with the surrounding bulk, so little space as to deceive experienced eyes as to their actual dimensions. The Iris and the Amethyst have each two tanks on board, the diameter of which is somewhat less than those at Morden Wharf, the depth being greater. They will have to make nine trips to get all the cable alongside the “big ship.”
Mr. Canning and Mr. Clifford, under whose control the operations have been conducted at East Greenwich, will accompany their precious charge on board the Great Eastern, and will direct the laying of the cable across the Atlantic Ocean. Our statement of the mileage of perfected cable gives but little idea of the length of all the materials taken separately. For example, to make up the 2,300 miles of cable which, allowing for various contingencies, will be required, 16,000 miles of copper wire are used. The insulating material is equal to an aggregate length of 18,400 miles; the jute, being in ten strands, will extend to 23,000 miles, which will also be the length of the iron wire; and as each wire is separately covered with five twists or strands of yarn, 135,000 miles of the latter will be worked into the cable; making together a length of material which amounts to 215,500 miles. What these figures really signify may be understood by reference to the astronomical fact that the distance of 237,000 miles is that from the earth to the moon.
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Last revised: 12 May, 2010