OPGW Sub Station Work
Aerial cables (as self-supporting cables, suspended on towers of the existing overhead power lines, under the conductors, wrap on cables, wrapped on the ground wires of the existing overhead power lines, lashed cables, fixed to the ground wires of the existing overhead power lines using some kind of tapes, and optical cables incorporated into the ground wires of overhead lines). Common name for self-supporting, wrap-on and lashed cables that is sometimes used is retrofitted cables because these solutions are applied on existing O/H lines, hence, these cables are added afterwards. Each option has its advantages and disadvantages in comparison with other ones, both from technical and economic point of view. It is necessary to note that single mode optical fibers are now predominantly used because of larger transmission capacity and lower attenuation than multimode fibers. In the optical cable construction, as the best way to protect the fiber mechanically and to give the fiber enough space for free moving, the loose buffer technique is favored over the tight buffer one.
Underground FO cables
Case of direct burial of the cable, installation works are comprehensive because they include trench excavation and backfilling for cable and joint closures, mechanical drilling and excavation of obstacles at crossings of roads and water-ways. According some experience, total cost of link implemented by underground fiber optic cable is 2.5 times higher in comparison with cost of FO cable itself. Furthermore, the way leave problem has to be overcome, especially in urban areas.
Self-supporting FO cables
Self-supporting cable is suspended between towers, below conductors. This cable should contain a high proportion of a metallic strength member to achieve the necessary strength of the cable. This would, however, significantly increase the load on towers both directly and when combined with wind load.
Wrap-on FO cables
Attaching an optical cable to the existing conductor (wrap-on cable) is a quick way how to install fibre cables on an overhead line but the cable is exposed to the wind and ice loadings (in climate conditions where applicable).
