PURPOSE: To make it possible to retrieve the relative position of a cable to a movable body, which has non-directional magnetic field detectors mounted at fixed intervals, in a short time and with a little labor by moving the movable body to a retrieval point with the retrieved cable fed with a current.
CONSTITUTION: In case that a fault is occurring due to a short circuit of a conductor at fault point 14 of cable 12 laid on the sea bottom, feeding a retrieval signal current from cable terminal 15 on the ground provides a signal magnetic field around cable 12. Magnetic-field detectors 4, 6, 8, and 10 fixed to mavable body 2 capable of moving freely under the water through the control from a mother ship senses a retrieval signal magnetic field corresponding to a distance from the cable. For the purpose, signals from respective magnetic field detectors are extracted to obtain an amplitude ratio among the extracted signals and this amplitude ratio is used as a parameter to calculate position information of the cable, thereby displaying the position information of the cable on display part 30 on the basis of the arithmetic result.
FUKUI TAKAAKI
IWAMOTO YOSHINAO
SHIRASAKI YUUICHI
FUJISE MASAYUKI
