CABLE, (cable, Fr.) a large, strong rope of a considerable length, used to retain a ship at anchor in a road, bay, or haven.
Cables are of various sorts and sizes. In Europe they are usually manufactured of hemp; in Africa they are more frequently composed of bass, which is a sort of long straw or rushes; and in Asia of a peculiar sort of Indian grass.
Cables, of what thickness soever, are generally formed of three ropes twisted together, which are then called strands: each of these is composed of three smaller strands; and those last of a certain number of rope-yarns. This number is therefore greater or smaller in proportion to the size of the cable required.
There are some cables, however, manufactured of four strands; which are chiefly the production of Italy and Provence.
All ships ought to be furnished with at least three good cables; the sheet cable, and the two bowers; best and small.
All cables ought to be one hundred and twenty fathoms in length; for which purpose the threads or yarns must be one hundred and eighty fathoms; inasmuch as they are diminished one third in length by twisting. Besides this length, it is necessary to splice at least two cables together, in order to double the length when a ship is obliged to anchor in deep water. For although it is not common to anchor in a greater depth than forty fathoms, yet if there is only one cable, and the ship rides in a storm and tempestuous sea, the anchor will of necessity sustain the whole weight and violent jerking of the ship, in a direction too nearly perpendicular. By this effort it will unavoidably be loosened from its hold, and dragged by the ship, which thus driven from her station, is in immediate danger of being wrecked on the nearest rocks or shallows; whereas it is evident, that if the cable, by its great length, were to draw more horizontally on the anchor, it would bear a much greater force. See Anchor.
The long cable is not so apt to break as the short one; because it will bear a great deal more stretching before it comes to the greatest strain: it therefore resembles a sort of spring, which may be very easily extended, and afterwards recovers its first state, as soon as the force which extended it is removed. 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.
By what has been said on this subject, we may see how very necessary it is to furnish a ship with sufficiency of cables, or what is called ground-tackle; and what an inconsiderate policy it is in merchants to expose their vessels to such evident dangers from the want of them. For we may venture to assert, without violation of truth, that many good ships have been lost only on account of a deficiency in this important article.
A cable ought neither to be twisted too much or too little; as in the former state it will be extremely stiff, and difficult to manage; and in the latter, it will be considerably diminished in its strength.