Design Method of Non-Rotational Torque Balance Cable For Deep-Sea Research Equipment

摘要

Deep-sea research equipment such as Water Sampler and Remotely Operated Vehicle (ROV) use long torque balance cable for power supply and signal transmission between the under water equipment and its support vessel.However, cable rotation occurs in almost all these equipment while paying in/out works of the cable, even if the torque balance of the cable is perfect. Moreover, there have been many accidents on these tether cables, such as kink or disconnection caused by rotation of the cable. In this research, calculation method of strand track of a torque balance cable over sheave was established. Applying this calculation method, the mechanism of this cable rotation was found to be the uneven change of track length between layers caused by bending of the tether cable over a sheave. In addition to the theoretical studies, a doubly layered torque balance cable with 17.4mm O.D. was fabricated, and its rotational characteristic was measured in the sea.