Journal of The School of Marine Science and Technology,Vol.7 No.1
－On the Hull Form Study of Okinawan Majian Ships－
Hikaru YAGI and Hiroshi KAWABE
Abstract
Since ancient times,Ryukyu has developed their own shipbuilding technology.One of the traditional ships is the‘Majian’, which had been used for sea transportation around the Ryukyu islands and Japan. The ship is sometimes called ‘Yambaru’as well. At the present, there are no actual ships in commercial use, and therefore a very few shipwrights pass down the traditional technology from generation to generation.
Historically, it is understood that the shipbuilding technology of the ‘Majian’is very much influenced by the
Chinese ships called ‘Tribute ships’which were used for the voyages between Ryukyu and the Ming and Quing from
1372to 1876.Such ships were originally built in China and given to Ryukyu.There is evidence that some tribute ships
were built in Ryukyu around 1557 by permission of the Ming Dynasty. The technology obtained in those days is
thought to have spread out to Ryukyuan shipwrights and was developed to meet the local requirements.
In the Marine Cultural Museum in Uruma City,Okinawa Prefecture,large size model ships built by a shipwright
Mr. Goeku, who is a living intangible city asset, are exhibited for the public education of their own traditional
technology.Furthermore,another large size model was also built by him.The study was conducted by measuring the
detail hull form using a Laser Total Station System under the full cooperation of the Marine Cultural Museum and
Mr. Goeku.
In this paper, the result of the survey is briefly mentioned, followed by the successive technical investigations
using the model and theoretical tools for the grasp of hydrodynamic performance such as resistance and ship motion
in waves etc. In relation to the Chinese technology, a comparison is made about the hull form and ship motion in
waves.
Finally, this type of survey recording an intangible cultural asset by digitizing the traditional ship form and
studying the performance by use of modern technology will contribute to pass down the invaluable traditional
shipbuilding culture to future generations.