Abst 膃 ct Fiber ropes have recent 正 y bee【1 drawing attention as alternative materia 工 s for mooring lines or towing hawsers . The advantage of the fiber ropes is that they are lighter in weight than the conventional steel chains or the wire ropes , They also have better characteristics in the corros 三 〇 n resistance and the flexibiIity 。 It is known , however , that most of the breaking of fiber ropes occurred at the points where they rub against something such as fairleaders , bollard or bitt

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... . Therefore in order to use the fiber ropes for mooring lines or hawsers, the fatigue strength and the abrasion characteristics should be fully examined . In this paper the effect of abrasion on the decrease of the strength of fiber ropes is investigated exper 正 mentally , The residual strength of 皿 odel ropes were measured after they were rubbed aga 正 rlst arotating steel drum for certain periods . 8 strand ropes made of nylon were used and 5 different ameunt of tensions were i皿 posed on the rQpes . From the study the following conclusions were obtained . ( 1 ) tension vs residual strength The residual strength decreases in pr 。 portion to the tension when the number of abrasion is constant . ( 2} nulnber of abrasion vs residual strength The residual strength decreases in proportion to the logarith 皿 of the number of abrasion when the tenSiOn iS eOnStant . From these results it can be said that the effect of tensions on the decrease of the residual strength of fiber ropes is much larger than that of the number of abrasion . Therefore a sufficient safety factor should be taken into account for the tens 三 〇 n acting on the fiber ropes .