Structural design and sea trial results for a submarine optical-fiber cable joint box

A submarine optical-fiber cable joint box which can be disassembled and reassembled on shipboard in about 10 h has been realized. The joint box length is 1.7 m and the outer diameter is 19 cm. This paper describes the structural design and sea trial results. The main factors in designing the joint box, cable anchor structure, fiber storage structure, maximum joint box dimensions, and bending radius of cable adjacent to the joint box have been determined both theoretically and experimentally. A sea trial was conducted in Sagami Bay on board the Kuroshio-maru. It has been confirmed through the sea trial that the fabricated joint box is suitable for use with existing laying and recovery equipment and has excellent handling and mechanical properties, while causing little loss increase.