Ultimate low-loss electro-optical cable

Claim 1

A deep ocean cable having essentially no voids therein for transmitting power and data comprising: at least one optical fiber axially extending for optically transmitting control and data signals; a tube-shaped solid conductor having a coaxial bore sized to encase, isolate and hermetically seal the at least one optical fiber for electrically transmitting d.c. power through the deep ocean cable; a tube-like dielectric cylinder coaxially disposed about the tube-shaped solid conductor for encasing it and dielectrically insulating the tube-shaped solid conductor from the surrounding seawater; means coaxially disposed about the tube-like dielectric cylinder for armoring the at least one optical fiber, the tube-shaped solid conductor, and the tube-like dielectric cylinder and for tensiley bearing the load imposed by the cable, the armoring and bearing means further guards the tube-like dielectric cylinder from abrasion and penetration; and means coaxially disposed about the armoring and bearing means for protecting it from the leaching action of seawater and to defocus externally originating concentrated forces, the tube-shaped solid conductor and the armoring and bearing means are selected from materials and dimensioned to provide a stress safety factor of about two in combination and, with the other means, to have a specific gravity of about one point five, the tube-shaped solid conductor and the armoring and bearing means are selected from materials that, when simultaneously strained a pretermined percent, share the load of the cable; further including means interposed in contact with the at least one optical fiber and within the tube-shaped solid conductor for buffering the at least one optical fiber to help isolate stress therefrom and the coaxial bore of the cylindrically-shaped solid conductor is sufficiently sized to receive the buffering means without any voids therein; the optically transmitting means is at least one optical fiber and the electrically transmitting means is a cylindrically-shaped solid conductor having a coaxial bore sized to receive the optically transmitting means and the buffering means to make a one-way d. c. path along the cable; the tube-like dielectric cylinder is a high density plyethylene; the armoring and bearing means is a multitude of aromatic polyamide filaments in an annular resin matrix; the tube-shaped solid conductor is fabricated from materials to share equally in the tensile load imposed by the cable when both the tube-shaped solid conductor and the aromatic polyamide filaments are strained to a one percent strain; the aromatic polyamide filaments are disposed in a contrahelix configuration with a relatively long lay length for torque balance; and the outer and inner diameters D 3 and D 2 of the tube-shaped solid conductor, the outer diameter of the tube-like dielctric cylinder D 4 and the outer diameter D 5 of the armoring and bearing means have the following relationship upon said one percent strain: S(1%)=(π/4)S.sub.c (D.sub.3.sup.2 -D.sub.2.sup.2)+S.sub.k (D.sub.5.sup.2 -D.sub.4.sup.2) where S c is the tube-shaped solid conductor ultimate tensile stress at 1% strain of 4500 KGF/CM 2 and S k is the armor and bearing means tensile stress at 1% strain of 11250 KGF/CM 2 .