Non-armored fiber optic cable protection from the freezing water pressure in fiber optic cable duct

Today the «optical cable in the duct» technology at installation of cable lines is widely used. Distinctive feature of this technology is application of cables without armor at installation. The analysis of duct cable lines operating experience shows that at duct damage and loss of sealing water gets to a duct. The soil in winter time freezes to a depth of the duct laying and even more over large territory in Russia. It leads to freezing of an optical cable in ice if the duct had water filling. Thus the cable without armor can appear in more severe conditions than underground optical cable with armor which is traditionally used. There is a question how to protect an optical cable from ice loadings in case of damage of a duct. In article the existing ways of protection of a cable in a duct and possible difficulties of their realization are analyzed. It is offered to apply to protection of an optical cable the damping elements. Dampers can be used in a cable design or be laid together with a cable in a duct. It is offered to use the micro ducts as dampers. Diameters and number of dampers for various combinations of diameters of cables and ducts are calculated. At calculations possible extent of compression of a damper was considered. The received results of researches can be used at realization of the offered protection of an optical cable from ice loadings in a duct.