| With the prosperity of Chinese economy and the increasing demand of the touring ship diversity, archaize sail boat, one of the symbols of the Chinese ancient traditional culture and one branch of tourist industry, is able to enjoy its rapid development. The sail boat differs from general ships for its overlarge wind area and overhigh center of wind pressure, therefore its stability checking method is other from general ships. Moreover, there is not yet a clear and specified regulation for the checking of sail boats. Consequently systematic and uniformed regulations to check the stability of sail boat has not been proposed by now. However, these factors has hindered the development of archaize sail boat and restricted the publicity of Chinese age-old culture of boat greatly. Meanwhile vast quantities of sea damage data has indicated that a boat which meets the stability regulation and has a good navigation performance may not reach the same performance level when it sails in wave. It was mentioned on the seventh conference of International stability meeting that nearly90%of ship’s stability accident is due to pilots’ lack of the cognition and acknowledgement of stability variation of ship in wave. Since ships sails mostly on the turbulent sea surface, researchinging the request of ship’s static stability checking in wave and the stability variation condition is extremely significant to the safety of sail boat and has definite instruct meaning to the development of Chinese archaize sail boat. Additionally, the improvement of the checking regulation of sail boat’s safety and performance ensures the safety of personal life and asset safety. And the study of the law may provide the ship pilot with practical reference material.This paper concentrates on the study of domestic and overseas’checking request and regulation of sail boat and analyses to choose suitable checking request as the reference of stability calculation. At the same time, based on the pure stability loss principle of wave stability, the stability of an archaize sail boat is calculated through programming, the stability variation law of the ship in wave is discussed and several exceptional cases which are most likely to happen in waves is analyzed and listed. In basis of the analysis above, sevel notes for sail boat sailing in wave was concluded in combination with the feature of Chinese archaize sail boat, sail pattern and navigation. The main content and conclusions of the study are as follows:Firstly, this paper sums up the test conclusion of domestic and overseas researchers and some countries’regulation for sail boat and finds suitable stability checking basis by comparing and analysising those materials.Secondly, this paper studies the variation behavior of righting arm of the ship sailing in regular waves. Setting up three coordinate systems of ship and wave, the intersection point between them can be obtained by the transformation of coordinate systems. Meanwhile, utilizing the general calculation method of ship’s immersed area and the center of buoyancy as well as combining the mutual balance of buoyancy and gravity and the instantaneous balance equation when trimming arm equals zero, relatively precise coordinate of intersection point of ship and wave is ascertained. Thus ship’s instantaneous immersed area and corresponding position of the center of immersed area can be obtained as well. Then based on Froude-Krylov hypothesis righting arm of ship in waves is calculated through programming and thus rule restoring variation in waves is obtained.Thirdly, the design of sail boat and the navigation decision of the sail boat sailing in wave are provided through calculating the law of the stability curve variation of the ship sailing in wave, in combination with the feature of Chinese sail patterns, sail boat patterns, navigation feature and stability checking basis discussed above. |
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