Submarine cables have more possibility of serious mechanical troubles by ship's anchor or equipments for fishing, more than conventional underground cables. Detecting these troubles in submarine cable before electrical breakdown is very useful technology to improve the reliability of submarine transmission line, considering these laying circumstance. We have developed the mechanical-damage-detectable-sensor applied by optical fiber. Actual 66kV XLPE submarine cables composite mechanical-damage-detectable-sensor were manufactured and were subjected to various mechanical tests. Press down test for the sensors by optical fiber units showed a good detectability to mechanical deformation by sample tests. The actual cable by 66kV XLPE cable were subjected to mechanical test by CIGRE recommendation, press down test where the cables were deformed by mechanical pressure and electrical breakdown test under the mechanical deformation. These data provided that the developed 66kV XLPE cable has the mechanical-damage-detectability and the required properties.
The cable will be installed in actual field on April in 1992.