UNDERSEA BRANCHING METHOD OF OPTICAL SUBMARINE CABLE

PURPOSE:To branch an optical submarine cable at the most geographically advantageous point and to minimize the influence of a fault even if the fault occurs by opening a switch and releasing a feed path from being grounded in the sea when the feed current of the feed path exceeds a specific current value. CONSTITUTION:Relay contacts rla and rlb are made when no current is fed. When the feed currents of feed paths 5 and 6 attain to the specific current value after the feeding started, the contacts rla and rlb are broken and the feed paths 5 and 6 between A and B are disconnected from O.G to perform both-terminal feeding from A and B. A feed path 7 is used invariably for one-terminal feeding from C. For example, if a fault occurs between D and B, the feeding from the points from A and B is stopped temporarily and the path is initialized between A and B. Therefore, the time when the feeding is stopped is only the required time when the contacts rla and rlb are released. Then, the feeding from the point A is started to constitute the feed path 5 in the order of A, RLa, D, rlb, and O.G, and the one-terminal feeding from the point A is performed to allow a communication between A and C.