Improved Water Barriers for Outboard Electrical Cables

The Navy uses a wide variety of cables to provide power and control signals to shipboard systems. The Vertical Launch System (VLS) uses cables containing between 3 and 85 conductors. These cables must withstand the underwater environment and be resistant to mechanical damage when passing through ballast tank penetrators. Current cable jacket materials either lack toughness or have insufficient water resistance. The two most common failure modes for outboard electrical cables are connector short-circuit due to water seeping in through a cut or gouge and wicking axially along the cable length to the connector; and connector short-circuit due to cathodic delamination of the polyurethane strain relief which causes the water seal to debond at the connector and allow water to seep in. Foster-Miller proposes to improve the water barrier characteristics of these cables by utilizing biaxially oriented liquid crystal polymer (LCP) films as the inner jacket of a dual jacket system. The use of a strand block will further improve the water impermeability. LCP films will also be incorporated in the cable connector to prevent cathodic delamination.