Specific Features of Determining the Mechanical Parameters of an Optical Cable Laid in the Ground
The article presents the modern design of Type OGD optical communication cable manufactured in line with its technical specifications and used by service providers for laying in the ground. The cable design is described, its main characteristics are given, and the predominant field of its application is indicated. The optical cable has an outer sheath and a core containing optical fibers which constitute the basis of any communication cable because it is exactly the optical fiber located in the core through which the signals are transmitted. The cable contains also a central dielectric strength member around which the optical modules and insulating cords are twisted. Each optical module contains from 2 to 24 optical fibers. The cable inner and outer sheaths are made of polyethylene. The inner sheath is superimposed with an armor made of one or two layers of galvanized steel wires or a layer of dielectric rods. Two design versions of Type OGD cable with an armor made of soft and hard galvanized steel wire are considered. The deformation force causing the same elongation for a cable with the armor made of hard wire is a factor of two higher than it is for a cable with the armor made of soft wire; i.e., the hard-wire armor makes the cable almost two times stronger than that with the soft-wire armor. The number of optical fibers, the size and weight of Type OGD cable withstanding the tensile force equal to 20 kN, and the sizes of hard and soft armor wire are given. The mechanical properties of cables of the considered designs were investigated. The test was carried out using the Type RRK-EK2 tensile and crushing installation. The results from measurements of signal power loss in an optical fiber depending on the value of tensile and crushing force acting on the cable are presented.