A Study on Course Stability of Towing and Towed Vessels System under Wind Pressure
The author discusses the problem on course stability of towed ship under severe wind pressure. The characteristic equation to assess the stability on course, is derived from sway and yaw coupled motions of towing and towed vessels with wind effect. Through the numerical calculation on course stability of towing and towed vessels system, the relationship between the course stability of a towed ship and wind direction or towrope length, is clarified with the parameter of wind speed in terms of Beaufort number. Two types of towed vessel, such as a bulk carrier and a passenger liner, are applied and examined. The major results are as follows. The course stability of towed vessel under wind pressure depends on the inherent course stability of the vessel herself. The towed vessel will be much unstable for the range from beam to quarter wind in relatively high wind speed. The length of towrope has also great infulence upon the stability. Long towrope will be able to stabilize for all range of wind direction in relatively low wind speed or for the head wind in relatively high wind speed.