The Atlantic Telegraph Cable
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THE ATLANTIC TELEGRAPH CABLE.
Has the breaking of the Atlantic Telegraph Cable thrown doubt upon the possibility of its being hereafter safely laid? is a question in which the public feel considerable interest. After carefully reading a great deal that has been written on the point, and giving the subject our best consideration, we are of opinion that it has not.
The cause and mode of the disaster are easily stated. It seems that while the Niagara was proceeding steadily and safely, paying out the cable at the rate of about four miles an hour, one of the engineers thought it was going out too fast, and in order to check it applied the brakes to the drums over which it was passing. Just at this moment the stern of the vessel, from which the cable was being paid over, was in the trough of the waves. The next instant the stern rose on the surface of a wave, thus straining the cable—when it suddenly parted. The cable, by experiments, had been proved equal to bearing uninjured a strain of four tons; its weight per mile was six tons. Allowing there to have been three miles length pending between the ship’s deck and the bottom of the sea, to stop the paying out was equivalent to placing nearly 18 tons—the weight of the quantity pending in the water—strain on the cable.
The opinions expressed by the press are various and contradictory as to how the disaster might have been prevented. The New York Times thinks it “apparent enough now that the true plan will be to let the Cable run out as rapidly as possible, without making any attempt to check it, at least until the ship has been stopped. The utility of the brake apparatus in any event is extremely doubtful,—while it is evidently a prominent source of danger.” The Evening Post considers that “if the steamer had sailed a little slower, or had the cable been permitted to run freely, it would not have broken.” The Herald believes that “if the speed of the vessel had been increased, instead of the descent of the cable being suddenly arrested, there is every probability that the fleet would be at this hour in Newfoundland, and the greatest feat ever attempted would have been triumphantly accomplished.”
There is some truth in all these theories, though none of them seem to grasp the whole matter. The remote cause of the disaster was the inadequate length of the cable. Only a few hundred miles had been allowed for divergencies, beyond the length of a straight line drawn from Ireland to Newfoundland. This allowance was much too small—one thousand miles extra is the least that should have been manufactured. Owing to the shortness of the cable the engineer was forced to put on the brakes. He dared not let the cable pay itself out so fast, for, owing to the drift of the waves, it was evidently laying itself in a curve instead of in a straight line. Hence three miles or more of cable would have been required for every two miles of the vessel’s sailing; and the whole would have been exhausted long before the fleet reached Newfoundland. The engineer’s idea in applying the brakes was that he could straighten the cable, and compel it to follow rigidly in the vessel’s course, instead of which as a moment’s reflection should have told him, he was throwing on the cable more of its own weight than it could bear. Had not the brakes been applied, and had the vessel continued to pay out the cable freely, the probability is that a still more mortifying failure would have occurred towards the last, by the premature exhaustion of the entire length.
It would have been of very little consequence whether the vessel was stopped or its speed increased. Neither of these expedients would have prevented the cable from paying out curvilinearly. The mistake all along was in supposing that, in calm or storm, the cable would lay right in the track of the ship, or that if not it could be straightened by applying the breaks. We do not despair of the success of another attempt, if it be conducted upon the theory that the cable cannot bear the weight of so much of its length as hangs between the ship’s deck and the ocean’s bottom, and therefore that the breaks must in no case be used, nor the paying out suspended. If this fact be borne in mind, and sufficient length be provided to allow of the divergencies which the drift of the water in any direction may cause, there is nothing in the recent disaster to discourage our hopes of the junction of the two hemispheres.