木帆船时代船蛆防治与多重外板结构

The method of anti-teredo in wooden sailing era and multiple exterior planks

船蛆对海洋木船的危害极大,防治船蛆可以通过钉锅铁、金属包覆等办法延缓、隔阻其侵入,或通过烘烤船底、驶入淡水等进行杀灭,但都有一定的局限性。木帆船时代远洋航行依靠季风,往南洋、西洋方向的航程往返耗时需大半年甚至一年半,其间如何抵御船蛆蚕食木质外板是一项挑战,尤其是对比较缺乏船队保障和海外基地的民间海商而言。中国古代木帆船的多重外板结构,利用船蛆“隔板不蛀”的特性,兼有远洋航行时抵御船蛆之效,这种情况在以民间海商为主导的宋元时期更为多见。

The Teredo is extremely harmful to the marine wooden ships.It can be prevented by nailing the pot iron,coating with a protective metal layer and so on to delay and block its invasion.It can also be killed by roasting the bottom of the boat and sailing into fresh water.But there are certain limitations.Ocean sailing in the wooden sailing era mainly relied on the monsoon,and the voyage took six months or even a year and a half.During this period,how to resist teredo is a challenge,especially for civilian maritime merchants who lack fleet protection and overseas bases.The multiple exteriorplanks structure of ancient Chinese shipsutilized the characteristics of the teredo—"partitions no worm"to resist teredo during ocean voyages.This kind ofsituation was more common in the Song and Yuan dynasties which were dominated by civilian maritime merchants.