Revision of Equipment Rule of Anchor Weight from the View Point of the Safety of Mooring at Anchor

Abstract

Anchor is an important equipment for the mooring safety of a ship. According to the standard rule for anchor equipment, the weight of the anchor is determined based on the equipment number (EN) of the ship. Under this standard rule, heavier anchor is required to be equipped against a ship with large EN such as VLCC, in spite of its safety while the ship is moored at anchor. On the contrary, lighter anchor is required against a ship with smaller EN such as PCC, in spite of its dangerousness while anchoring. The present standard rule for anchor equipment based on the EN involves such contradiction from the view point of the mooring safety. In the present paper, an improved criteria for the anchor weight to be equipped is proposed to solve the contradiction on the rule. And where, the new index of (EN/displacement) is introduced. The value of this index is proportional to the risk index of the mooring safety.