Design of Torque-Free Cables Using a Simulation Model

Torque-free operation is an essential performance requirement in today's ocean cable constructions. Torsional information is needed to properly select, design and specify cables. The fastest and most economical way of obtaining such information is by model simulations. Several models have recently been developed for specific purposes. One of these models, the helical model TAWAC developed by CEL, applies to both single and multistrand steel cables. For a given twist and elongation, TAWAC yields the corresponding torque and tension. An example is given to demonstrate the usefulness of TAWAC in cable selection, design and specification. Two multistrand cables with steel armors are simulated by TAWAC and the torsional response was found to be inadequate for the intended applications. By varying the pitch lengths nearly true torque-free designs were achieved.