Steel cable

“ Then the wire is attached and the rods are pulled out and detached one at a time and with the last rod the wire is through. At least No. 14 galvanized iron or steel wire should be used, for any smaller size cannot be used a second time, as a rule. In starting to pull in the draw rope a wire brush should be attached to the wire and to this again the rope, and when the brush arrives at the distant end of the duct it very likely will bring with it a miscellaneous collection of material which for the good of the cable had better be in the manhole than in the duct. ”

“ The first Atlantic cable failed principally on account of imperfect manufacture, in a great measure arising from undue haste and urgency, but largely owing to insufficient experience. The cable was not tested under water, for fear of rusting the small steel wires of the external covering, and small wires have never since been used; large wires, the larger the better, is now a principle. The copper was not all good. ”

“ Intermediate piers support the trusses in the side spans. The cables are 183⁄4 in. in diameter; each weighs about 1116 tons, and has a nominal breaking strength of 22,320 tons, the actual breaking strength being probably greater. The saddles are 332 ft. above the water. The four cables support a dead load of 7140 tons and a live load of 4017 tons. Each cable is composed of 37 strands of 208 wires, or 7696 parallel steel wires, No. 8 B.W.G., or about 3/16 in. in diameter. The wire was required to have a tensile strength of 89 tons per sq. in., and 21⁄2% elongation in 5 ft. ”

“ It was known, to journalism especially, that the cable would never be laid and that the enterprise was absurd. But it was like the laying of the first land line. There was a way to do it, existing in the brains and faith of men, though at first that way was not known. From this third meeting the two ships again sailed away, the Niagara for America, the Agamemnon for Valencia Bay. This time the wire did not part, and on August 29th, 1858, the old world and the new were bound together for the first time, and each could read almost the thoughts of the other. ”

“ Armoured Cable Wiring.—Where a conduit system cannot be conveniently installed, armoured cable is used. Armoured cable is made by winding steel strips over the insulated conductors, the latter being permanently retained inside the steel casing. Armoured cable is manufactured in long lengths, the actual lengths being determined by convenience in handling. ”

“ A spool of wire on the gear was carried around with it, winding the wire around the cable. A brake on the spool kept the wire under a constant tension. After the wire was wound, a steel sheathing made in half-sections was bolted about the cable. “Every so often” a collar was applied to the cable, and suspender cables were attached to them. To these suspenders, floor beams and girders were to be fastened, and on them the double deck of the bridge was to be built up. ”

“ The cable may run on a level—as when it spans some great gorge between two mountain peaks—or it may be strung up to any incline not too great to make precarious the grip of the grooved overhead wheels of the basket. I was not able to learn what this limit is, but I have never seen a cable run at an angle of over forty-five degrees. Wherever a cable does not form a single great span it has to be supported at varying intervals by running over steel towers to prevent its sagging too near the earth.
A teleferica has never more than its two terminal stations. ”

“ Lead is put on the outside of the paper in a press, which has dies through which the cable passes, and is covered with a uniform coating or tube of lead, forced into the dies and around the cable by hydraulic pressure. Steel tapes are in some cases used to armour cables and protect them from external injury ”

“ The weights of material used in this cable are: copper wire, 495 tons; gutta-percha, 315 tons; jute yarn, 575 tons; steel wire, 3,000 tons; compound and tar, 1,075 tons; total, 5,460 tons. The telegraph-ship Faraday, specially designed for cable-laying, accomplished the work without mishap.
Electrical science owes much to the Atlantic cables, in particular to the first of them. At the very beginning it banished the idea that electricity as it passes through metallic conductors has anything like its velocity through free space. ”

“ When large bodies of water must be crossed, tensile strength is a prime requirement. Thus a 142-mile line from Colgate to Oakland, in California, crosses the Straits of Carquinez in the form of steel cables, each seven-eighths of an inch in diameter and 4,427 feet long. Steel wire was selected for this long span, probably because it can be given a greater tensile strength than that of any other metal. Annealed iron wire has a tensile strength between 50,000 and 60,000 pounds per square inch. ”

“ The cable was made about 25 miles longer than that. It was composed of a vast number of strands of tremendously tough steel wire and put together in the most marvelous way, for they were in small bundles insulated from each other as to the attraction of gravitation and also insulated by sections of their length. ”

“ They refuse to become slaves until they are once and for all utterly subdued, and then they are docile forever. Yet the malice truly lies in the inaptitude and inexperience of men. Had Field and his associates known how to make and lay an Atlantic cable in the beginning as well as they did in the end, the first one laid would have been successful. The years were passed in the invention of machinery for laying, and in improving the construction of each successive cable. Many have been laid since then, certainly and without failure. Men have learned how. ”

“ And it is going to take many multiplications by twenty to raise us from the hopeless shortage that kept us standing still last year, spending flesh and blood in a desperate endeavour to make up for the lacking steel and iron, and holding our bare own, to raise us from that to being an irresistible force capable of advancing and breaking through miles of trenched and barbed-wired and fortified positions, through hordes of well-armed, unbeaten men, through a flaming barrier of shells and bombs, through liquid fire and gas and machine-gun and rifle bullets. ”

“ Therefore the advantages in point of price of iron wire over copper in the first place, would be greatly overbalanced by the increased cost of insulating and sheathing it. It is of the greatest importance that the copper wire of the cable should be as pure as possible, for the slightest trace of arsenic or other foreign element is sufficient to hamper, in some mysterious way, the swift course of the subtle current, and very materially to weaken the conducting power of the wire. ”

“ The attempt to insulate more than one conducting-wire or medium would not only have increased the chances of failure of all of them, but would have necessitated the adoption of a proportionably heavier and more cumbrous cable. The tensile power of the outer or wire covering of the cable, being very much less than that of the conductor within it, the latter is protected from any such strain as can possibly rupture it or endanger its insulation without an entire fracture of the cable. ”

“ The special properties of every knot or mile of the core are chronicled, so that a complete account of every part of the cable is preserved during its progress of manufacture. And after it is made, it is tested electrically every day, to see that no change takes place in its electric qualities. These electric tests are three in number: For resistance—the resistance of the copper wire to the passage of the current. For inductive capacity—the amount of charge or quantity of electricity which the cable will take up. For insulation resistance—the insulating power of the gutta-percha coating. ”

“ In 1850 a cable twenty-five miles in length was laid from Dover to Calais, only to prove [Pg 40] worthless from faulty insulation and the lack of armour against dragging anchors and fretting rocks. In 1851 the experiment was repeated with success. The conductor now was not a single wire of copper, but four wires, wound spirally, so as to combine strength with flexibility; these were covered with gutta-percha and surrounded with tarred hemp. As a means of imparting additional strength, ten iron wires were wound round the hemp—a feature which has been copied in every subsequent cable (Fig. 58) . ”

“ He described 'high tension cables for 3,000 volts' having paper insulation impregnated 'with a rather thin liquid, oily and not too resinous mass' with cable joints bound with linen tape first boiled in oil so that it is completely saturated, with the wrapped joint inclosed in a lead sleeve, soldered to the lead sheath of the cable. Through a hole cut in the top of the sleeve or socket 'hot insulating mass is poured into the socket. ”

“ Drivers and gunners are spruce and neat and clean, the horses are sleek and well fed and groomed till their skins shine like satin in the sun, the harness is polished and speckless, bits and stirrup-irons and chains and all the scraps of steel and brass twinkle and wink in bright and shining splendour. ”

“ Who has not seen men in the streets dragging huge pipes of lead through the open manholes from big wooden spools? These are the cables you talk over. They have been papered and clothed—and tarred and feathered, maybe—and then encased in lead by a process that is so easy as to be laughable, and yet as ingenious as any one thing the wire miller does. Unrolling slowly from its spool, the heavy cable moves up to a machine built strong and four-legged from the floor. ”

“ The Board of Trade in 1859 had appointed a committee of experts, including Professor Wheatstone, to investigate the whole subject, and the results were published in a Blue-book. Profiting by these aids, an improved type of cable was designed. The core consisted of a strand of seven very pure copper wires weighing 300 lbs. a knot, coated with Chatterton's compound, which is impervious to water, then covered with four layers of gutta-percha alternating with four thin layers of the compound cementing the whole, and bringing the weight of the insulator to 400 lbs. ”

“ The natural increase in the number of aerial wires created a demand for better insulation and grouping in cables. Hundreds of miles of No. 12 iron wire were braided and dipped in suitable compound for this use. The annoyance from induction soon made a call for anti-induction cable. This want was supplied by a tin-foil cable so called, in which each conductor, after being insulated, was enclosed in a strip of this tin-foil. Cotton-covered wires to the extent of 50 or 100 were cabled together, and after being saturated with paraffine were placed in a lead pipe. ”

“ A triple coating of gutta percha, to keep the sea from sucking out the electricity, and a thick coating of iron wire, to sink the cable to the bottom and give it strength, were added to the copper rope, and then the cable was complete. No less than 325,000 miles of iron and copper wire were woven into this great cable,—as much as might be wound thirteen times round the globe ”

“ This combination for the length involved was based on Professor Thomson’s law for the working speed of a cable, as depending inversely on the resistance of the conductor as well as on the electrostatic capacity of the core. The armor consisted of a combination of iron and hemp, each wire being enveloped in manila yarns. The object of incasing the separate wires in hemp was (1) to protect them from rust due to exposure to air and water, and (2) to reduce the specific gravity of the cable, with a view to rendering it more capable of supporting its own weight in{181} water. ”

“ A furnace-door slams open, and a burst of glaring light glows fiercely over the shop; long irons plunge into the flaming gap, and poke and prod and hook hastily about the fire; a lump of glowing steel rolls out, tips over, and thumps down on the inclined floor in front of the furnace.54 There is a babel of yells, the rush of flying feet, the clatter of a truck-barrow, and the red-hot billet of metal is pounced upon, snatched, and twisted on to the hand truck, rushed to where men wait its coming grouped about a lumbering press whose massive bulk towers aloft into the misty gloom. ”

“ The design of the cable was a subject of experiment by Professor Morse and others. It was known that the conductor should be of copper, possessing a high conductivity for the electric current, and that its insulating jacket of gutta-percha should offer a great resistance to the leakage of the current. Moreover, experience had shown that the protecting sheath or armour of the core should be light and flexible as well as strong, in order to resist external violence and allow it to be lifted for repair. ”

“ So long as these are connected with the ground, he prefers that the projecting rod should be of round iron of considerable length and in one piece, and the conducting cable should wind round it as a collar, and be strongly attached to it by set screws and soldering. He does not advise that all the masses of metal within a building should be connected with a conductor, especially if they are in proximity with human beings, but with a well-made conductor he considers it safer to leave them isolated. ”

“ It is made of hemp, of steel wire, or of iron links.
2. A rope of steel wire, or copper wire, usually covered with some protecting, or insulating substance; as, the cable of a suspension bridge; a telegraphiccable.
3. (Arch) A nolding, shaft of a column, or any other member of convex, rounded section, made to resemble the spiral twist of a rope; Ð called also cable molding.
Bower cable, the cable belonging to the bower anchor. Ð Cable road, a railway on which the cars are moved by a continuously running endless rope operated by a stationary motor. ”