High-Reliability, Modular Ocean Cable Termination

Abstract

One of the greatest challenges in underwater communications systems is in the area of terminating ocean cable. Cable design is relatively stable and families of cables consist of many similar attributes; however, the needs for terminations on these cables can vary widely and usually result in a custom design to suit a particular customer, connector type and/or application. There exists a need for a reliable way to terminate a cable such that it can withstand the rigors of deployment and long life service in the ocean environment where the mechanical and environmental conditions are hostile and can vary widely. A high-reliability cable termination has been designed, fabricated and tested to support a range of current system needs and can be readily adapted to future applications. The termination, described in this paper, is capable of integrating armored ocean cable with a variety of commercially available connectors and/or splice joints. The termination consists of polyethylene encapsulation of the conductor and armor wires contained in a sealed titanium pressure vessel with separate electrical and optical penetrators (feed-throughs) qualified to 10,000 psi hydrostatic pressure. In order to ensure reliability and meet the aggressive schedule, the design consisted of reuse, modification and integration of qualified subassemblies to leverage existing qualified technologies, processes and components. The qualification methods employed a requirements-based testing matrix which also mapped testing methods to each of the failure modes identified in the reliability analysis (Failure Mode and Effects Analysis [FMEA]) to a test method designed specifically to address each failure mode. The result is a robust design that can be readily adapted to suit a variety of cables, connectors and system requirements from short-life, shallow-water, transitory systems to long-life, high-voltage, deep-water, stationary systems.