Measuring Submarine Optical Cable Tension from Cable Vibration

Abstract

A new tension measuring system for submarine cables utilizing the lateral vibration frequency of cables to calculate their tension with sufficient accuracy, has been proposed. Cable bend stiffness, the pay out/recovery velocity of cables and response time of the measurement have been examined on land and out-at-sea. The new tension meter thus developed is a handy system consisting of an optical vibration detector, conventional filter and an F/V converter and recorder, and covers a wide range of tension from 10kN up to more than 100kN within an error of 10%. In conclusion, the new system was found to improve the reliability of submarine cable pay-out and recovery operations as well as to offer a safer and more accurate tension measuring method, in general, for elongated substances.