A study of CTD cables and lowering systems

Abstract

This study first reviews both the electrical and mechanical modes and causes of failure of electromechanical (E/M) cables used to lower deep sea sensors, such as CTD instruments, from oceanographic ships. It then outlines measures or steps that could be taken to correct some of the deficiencies observed and improve the systems presently used. These measures include quality control, tests, operational limits, improved handling and maintenance, improved machinery. The study then surveys alternative cables for lowering the sensors and convey the information from the sensors back to the ship. These alternatives include strength members other than steel (Kevlar)and signal carriers other than conventional copper conductors (fiber optics). The final section - Conclusions - summarizes the recommendations, based on this study, for improving the reliability of present and future CTD lowering systems.