Pressure resistant optical fiber cable

Claim 1

A submarine, telecommunication cable comprising: an axially disposed and extending armor comprising a strand of wires, said strand having, by itself, a tensile strength sufficient to withstand the tensile stresses to which the cable is subjected during laying and recovery thereof; a plurality of tubes helically wound around and contacting said armor in circumferentially spaced relation to each other; a substantially incompressible fluid disposed in and filling-up any spaces within said armor including any spaces between said wires; at least one optical fiber loosely received in each of said tubes; a substantially incompressible fluid disposed in and filling-up the spaces between the interior of said tubes and said optical fibers; and a water tight sheath of plastic material around said tubes and said armor, the innermost surface of said sheath of plastic material contacting said tubes and said armor and said sheath filling the spaces between said tubes, said water tight plastic sheath, by itself, having a resistance to compression which is insufficient to withstand the compression forces to which the cable is subjected during use; said cable being without armor externally of said sheath of plastic material which, by itself, can withstand the mechanical stresses to which the cable is subjected in use; whereby said cable is able to withstand hydrostatic pressures to which it is subjected when submerged without any armor outwardly of the optical fiber or fibers which by itself can withstand such pressures.