Basic Research on Breakage of Mooring Ropes on Ship Mooring

Abstract

There seems to be end of the number of breakage of mooring ropes on ship mooring. In ports facing to the open sea, they are occuring under severe weather conditions. In the past, strength of mooring ropes themselves was researched, however, the strength was not investigated under the condition where the ropes were moored on the ship. In this paper, the strength of mooring ropes was examined through a roller in order to estimate the fair leader effect. The obtained results are summarized as follows : (1) Breakage of mooring ropes occurs near a fair leader, even if the turn of the roller is smooth. (2) Through the fair leader, rope of one side pulling is easier to break than that of two sides pulling. (3) In the case of one side pulling, the rope tends to break at the part where the rope of pulling side contacts at first with the roller. In the case of two sides, the rope tends to break near the eye sprice.