Failure implies that it will no longer be capable of providing electricity to the load. Such a low resistance path could allow sufficient current, termed fault current, to flow in the cable to cause the protective fuses at the power pole to open the circuit. This type of degradation is very slow, and based on the low power transfers and low operating temperatures expected, it is unlikely there would be any measurable deterioration in 40 years . The submarine cable, in combination with the protective devices, is designed to keep the water around the cable from becoming energized before, during, or after such a fault occurrence due to the redundant construction of the cable armor and overall jacket. Should this cable become exposed to physical stresses, the stresses available may potentially hasten the process described above.
Physical stresses are part of every cable installation process.
They are minimized with proper installation techniques. Okonite publishes recommended minimum bending radii, maximum pulling tensions, minimum conduit sizes, receiving, handling and storage procedures. If the cable becomes incapable of carrying current, the island will be without power until the cable is replaced. The NESC is the code book that electric utilities must abide by for both overhead and underground installations. These rules contain the basic provisions that are considered necessary for the safety of utility employees and the public.