Study of Sailing Performance of a Tall Ship - Sailing Speed Ratio of the Kaiwo Maru under the Heavy Weather -

Abstract

 The sailing performance of sail training ships Nippon Maru and Kaiwo Maru have been analyzed under the moderate weather since those actual services. As the result of the analysis, we have confirmed that the maximum speed can be observed in close-hauled sailing and the maximum sailing speed ratio is 75% in sharp up yards when receives the wind from 5 points of relative wind direction under the full sails. Furthermore, other sailing performance¹⁾²⁾ also has been observed.

 On the other hand, the sailing performance under heavy weather has not yet analyzed. In 2016 and 2017, sail training ship Kaiwo Maru carried out training voyages from Tokyo to Honolulu,USA and to Richmond,Canada. In those voyages, We analyzed the sailing speed ratio under the heavy weather which was 6 in beaufort wind scale.

 

As the result of analysis, we got knowledge as follows;

1)The sailing speed ratio was 64% in sharp up yards when recieved the wind from 5 points of relative wind direction under the 77% of sail area.

2)The sailing speed ratio was 56% in 3.5 p’t yards when recieved the wind from 6 points of relative wind direction under the 78% of sail area.

3)The sailing speed ratio was 54% in 2p’t yards when recieved the wind from 8 points of relative wind direction under the 80% of sail area.

4)The sailing speed ratio was 45% in square yards when recieved the wind from 12 points of relative wind direction under the 63% of sail area.