围网渔船作业时的起网力矩及横摇计算

THE CALCULATION FOR HAULING MOMENT AND ROLLOF PURSE SEINER DURING THE PSOCEDURE

本文在实船测试的基础上，将渔船绞纲起网时的括纲视作一种呈悬链线状的柔索，由此求解产生于绞纲结束阶段的最大倾侧力矩和张力的方向角，同时考虑力的作用点位置等因素，推导出较为简化的最大倾侧力矩公式。起网时的横摇计算，应用了脉冲响应法求解横摇运动方程。在作计算修正时，还引入了横摇质量惯性矩Ｉｘ的修正系数Ｃ１和网具尺度比的修正系数Ｃ２。实例计算结果颇为满意。最后作者指出在风浪扰动力矩作用下，绞纲起网时，横摇幅值有成倍的增加，甚至出现危险情况。起网力矩和横摇角的公式计算法，对研究和设计围网渔船及其稳性校核很重要，并有益于进一步修订渔船稳性规范。

Based on the data of realtime records the tensile directions namely the angle between the tension line and the vertical line,while the incliningmoment ie up tO the maximum which normally occurs in the end of hauling,areanalyzed,when and the purse-line is supposed as a suspended flexible wire inthe water during hauling. On aecount of the amount and the point of tension andother factors,a simplified formula of maximum inclining moment is derived.The rolling of seiner is caleulated with the impulse response method according tO,the rolling equation. For different size of vessels and net specifications, the,adjustment coefficientg,O. and C2, are introduced into vessel's inertia moment.of the mass for rolling and for net specifications respectively in the calculation.In practice,the results from calculation are satisfaetory.In this paper, it hasindicated that rolling amplitude will increase many times if the fishing vesselsare effected by the moments caused by wind and/or wave during hauling, andthe vessels might be in danger. The calculation as mentioned above is practicallysignificant in tho designing of purse seiner and the checking of its stability.This method provides a basis for the further modification and adjUstment of theRules for stability of fishing vesselg.