Torpedoes and Torpedo Warfare / Containing a Complete and Concise Account of the Rise and Progress of Submarine Warfare

by Charles William Sleeman

The Formation of a Joint in an India rubber Insulated Cable.—In making a joint in any insulated cable, the very greatest care must be taken to keep the hands, tools, and materials clean and dry.

Remove the felt for about twelve inches from each end of the core by soaking it with mineral naphtha and then rubbing it off clean with the file-card. The cleaned surface sear with a red-hot iron, to burn off all remaining fibres of the felt. Wash these seared ends clean with naphtha.

Then cut off about four inches of the insulating material (taking care never to cut at right angles to the conducting wire for fear of injuring it) so as to leave enough of the conductor bare to join and solder in the manner described at [page 47].

After the conductor is jointed and soldered, clean again the seared parts of the insulator with the glazed side of the squares of cloth moistened with mineral naphtha, so as to leave a clean adhesiveness only; taper again the insulating material down to the conductor for about two inches on each side of the conductor-joint with a pair of curved and very clean scissors.

The tapering must be completed in such slanting way that the different layers of the dielectric are so far exposed as to enable a secure laying on of the new jointing material.

India rubber core consists chiefly of three layers of insulating material: the first layer next to the strand is called the pure or brown; the second layer is the white or separating; the third layer is the light red or jacket rubber.

Coat the conductor with a pure (brown) rubber tape tightly laid on in a spiral form, commencing at the spot where the separator (white) ends, across the corresponding place on the opposite side of the joint and back again in a contrary direction. The ends are fastened down by pressing a clean, heated searing-iron or a heated knife on them. By doing so the band will stick; the remaining portions of the band to be cut off with the scissors.

Lay on tightly the separating india rubber tape in the same manner, but beginning where the jacket or outer layer of rubber ends. One lap will be sufficient.

Complete the insulation by lapping on tightly two layers of red india rubber tape: the last lap must cover each end of the core to four inches on each side of the conductor-joint, or extend to the searing or tackiness, but not beyond it.