The recent increase in crude oil trading has led to an increase in the workings of SPM for crude oil carriers. VLCCs generally encounter difficulty entering port due to limitations in terms of sea depth and maneuverability. The SPM is a system that allows mooring to the buoy located in the outer sea for such vessels. However, the buoy is more affected by relatively external forces because of their offshore location. Therefore, the safety assessment of SPM is particularly important as it can lead to large oil pollution disasters in the event of SPM accidents. Despite this, in the implementation of the Marine Traffic Safety Audit Scheme in Korea, there exists no guidance for SPM. In this study, a SPM mooring safety assessment is performed using OPTIMOOR, a numerical analysis program, so as to understand the mooring characteristics of SPM. As a result, it is confirmed that the tension of mooring lines and hull movement in the SPM are greatly affected by the encounter angles with external forces. In addition, it is found that the maximum tension of the mooring line is elevated as the water depth becomes shallower through sensitivity analysis. According to SPM characteristics, which has a large influence on the encounter angle, this study has proposed an amendment to setting criteria in the implementation of the Maritime Traffic Safety Audit Scheme which could improve the reliability and accuracy of mooring safety assessments.

VLCC SPM 작업이 주로 이루어지는 외해에서는 기상상태 및 파랑 영향을 많이 받고 있다. 기상악화로 인한 비상 이안시에는 강한 바람과 높은 파고로 도선사의 승선이 불가능하고 예인선을 사용할 수 없는 경우가 대부분이다. 현재 울산항에서는 기상악화로 인한 VLCC의 SPM 비상이안이 빈발하고 있으며, 신항만 건설로 SPM 주위에 방파제가 건설됨에 따라 SPM 이안 선박의 조종영역 기준을 제시할 필요성이 대두되고 있다. 현재 우리나라에는 SPM 설치 기준이 없으며, 외국의 설치기준을 참조하고 있지만, 이 기준들이 일관성 및 근거가 부족한 실정이다. 따라서 울산항의 SPM 비상이안 선박들의 조종영역 실태를 AIS 항해 테이터를 이용하여 파악하고 선박의 조종영역 기준을 제안하고자 한다.