Cable towed body dynamics

In recent years a large number of towed bodies for military and commerieal ocean engineering purposes have been put into service. A general trend in this activity is that towed bodies are getting larger, towing speed is getting faster and the operating depth of towed bodies is getting deeper. Towing vehicle, tow line and towed body are not only subjected to ocean wave, wind and current but also subjected to vibration excitation force due to flow around tow line and machinery of towing vehicle. In this paper the equilibrium attitude and altitude of towed body, and equilibrium configuration of cable when towing vehicle is advancing at constant speed is discussed. In addition, the dynamic characteristics of tow line due to tow point motion excitation is discussed. Finally, the considerations required to select a right tow line for the towing applications are listed.