TRANSIENT-BEHAVIOR OF TOWED MARINE CABLES IN 2 DIMENSIONS

This paper presents a numerical solution for the transient motion of m arine cables being towed from a cable ship which is changing speed. Th e cable ship is assumed to move rectilinearly, hence the cable configu ration is two-dimensional, The solution methodology consists of dividi ng the cable into n straight elements with equilibrium relationships a nd geometric compatibility equations satisfied in each element. A syst em of n non-linear ordinary differential equations is derived from thi s and then solved by fourth- and fifth-order Runge-Kutta formulations with the dynamic axial tension calculated iteratively because it is it self dependent on the solution. Results are presented for the cable-to p tension and element angles as functions of time and for transient ca ble geometries when the towing velocity is linearly or parabolically i ncreased (or decreased). It is shown that the results from this analys is compare reasonably well with full-scale experimental data from Hopl and (Proc. Int. Wire and Cable Symp., 1993, pp. 734-39).