An optical-fiber cable has been developed which has a superior performance; which has high reliability; which can be installed in lengths of 1 km or more by direct burial or in ducts without additional protection; which can be handled with the equipment and personnel regularly employed for conventional wire cables; which will withstand the rough treatment normally encountered in a field environment. The paper describes cable construction; measured results; methods of installation, splicing, testing and pressurization; specialized hardware; instruments and tools developed for field use. Several systems employing this type of cable have been installed and have been placed under observation with automatic monitoring equipment.

Interest is increasing in thermoplastic insulated and jacketed cables that are filled to minimize the entry and flow of water within the core. Such cable designs provide reliable, stable transmission characteristics, particularly for the increasingly popular pulse-code modulation (PCM) systems. This paper explores the primary and secondary electrical parameters of filled telephone cables in the voice and carrier frequency range. In addition, data are presented on nearend and far-end crosstalk.