Abstract
Marine disasters which cause serious environmental pollution occur frequently. Disabled ships due to marine disasters must be removed from the sea route as soon as possible. Generally disabled ships are towed by tugboats. Concerning the towing problems with tugtowed ships systems, some factors such as the length of the towing ropes, the location of the towing point and the condition of the disabled ships, etc. should be considered. However, these important factors have been left to the knowledge and the experience of towing operators up to the present time. In order to tow disabled ships safely, we need to develop the optimum method of towing systems from the viewpoint of navigational safety.
As the first stage of this research, we carried out captive model tests to measure the hydrodynamic forces acting on disabled ships. For the conditions of the disabled ships, we considered the ship which has immersed bow due to large trim angle.
Finally, applying the results of the captive model tests, we calculated the manoeuvring motions of tug and towed ships, then estimated the course stability in towing conditions.
