大型帆船の帆走性能に関する研究 －冬季北太平洋における日本丸の最適航路選定について－

抄録

 Some papers had been published on Analysis of Navigation Record and Sailing Performance of NIPPON MARU and KAIWO MARU. And around 10 years has passed since latest one was published. Therefore We reanalyzed them adding the latest 9 times data of Navigation Record. The results are follows;

1. In comparison low latitude route voyages with high latitude route voyages, the sailing speed and the sailing rate in high latitude route voyages are higher than in low latitude route voyages.

2. The success rates of landfall on sailing is almost no difference. between low latitude route and high latitude route, It is impossible to say definitely that high latitude route have advantages.

3. In recent voyages, the low latitude route are prefered to the high one. Because unusual weather what often occurs in recent years were took warning.

4. The relationship between ENSO(El Nino and La Nina) and success rates of landfall is definitely. The success rate of El Nino term is 86% Unsuccess rate in La Nina term is 83%.

5. When Zonal Index is low, the atmospheric depression develops in middle North Pacific Ocean and be apt to proceed eastward more than ordinary. And during this term, migratory anticyclone tends to proceed to the lower latitude than ordinary.

6. The area where perils of the sea and heavy weather occurs easily is within the limit of 30~35N , 140~160E.

 According to the above, we suggested a possible route to keep out of rough sea and gain moderate wind to reach Hawaii only sailing. The route is composed following 4 part;

1. Choosing a suitable starting point of sailing.

2. Selecting the possible route to reduce the risk in rough sea.

3. Selecting optimum route to get good sailing speed.

4. Choosing a southward route to reach Hawaii.