Submarine optical fiber cable with grooved plastic core and manufacture thereof

Abstract From the Canadian patent

An optical fiber submarine cable having only a central rope for withstanding the stresses to which the cable is subjected a, plastic core with interrupted but closed or substantially closed grooves at its outer portion, at least one optical fiber in each groove, a sheath around the core, and a substantially incompressible fluid filling all otherwise empty spaces within the sheath including any such spaces between the wires of the rope and in the grooves. The grooves are separated by ribs and, before the sheath is applied the diameter of the core at the ribs is greater than the diameter of the inner surface of the sheath and the sides of the ribs are separated to provide grooves opening …