郑和宝船实际吨位探析

A Study on the Actual Tonnage of ZHENG He’s Treasure-ships

郑和下西洋的大宝船据历史文献记载合今长 12 3米 ,宽 5 0米。按木帆船的结构规律和造船法式 ,(型、舱 )深应有 2 5米。这样 ,据阿基米德浮力定律 ,它的满载排水量高达 4万多吨。下西洋的大船队共有 2 0 8艘船 ,分超大型、大型、较大型、中型、小型五类。所以 ,总吨位多达 2 0 0万吨。这就有不少问题 :这么大这么多的巨舶 ,以当时中国的科技水平和综合国力造不出来 ;要完成下西洋的各项任务达到下西洋的各种目的也不需要这么大的巨船 ;古今中外也没有过那么大的木帆船 ,因为用木材造不出万吨级的船 ,那么大的船也不适合用风帆作推进装置。总之 ,当我们把研究思路从传统的尺寸转换为相应的吨位 ,问题就清楚多了。

The big treasure-ships of ZHENG He’s expedition to the Western Ocean are 123 meters long and 50 meters wide in terms of today’s measure system according to the data recorded in historical documents. Its depth of cabin should be 25 meters in accordance with the structure of a ship and the rule of ship-building. Thus, its full displacement could reach more than 40,000 tons according to Archimedes’ law of buoyancy. The great fleet of expedition to the Western Ocean had 208 ships in all, including super giant, giant, large-sized, middle-sized and small ones. Thus, its overall tonnage could reach 2 million tons. Problems arise here. Such big and so many giant ships couldn’t be built out with the level of productive forces,science & technology and aggregate national strength of China at that time; It was not necessary for such big ships to finish various tasks and to reach various aims of the expedition to the Western Ocean; Nor are there any such big sailing ships at all times and in all lands because ships above 10,000 tons can’t be built out with timber and the sail isn’t suitable to be used as propellant device for such great ships. In short, the question is much clearer when we shift our focus from the ships’ demensions to the ships’ relevant tonnage.