Electrical reliability of dc-operated submarine telecommunications cables

The results of a research program carried out to quantify the reliability of joint moldings for dc operation in submarine telecommunications cables are reported. The region of the bulk insulation most at risk of electrical failure has been identified as the amalgamation zone of the molding, which is believed to be associated with additional electrical stress-enhancing defects present at the conductor-insulator interface. In addition to factory tests implemented to eliminate moldings with severely hazardous defects, a quality assurance sampling test procedure is proposed to optimize the manufacturing quality.