A Basic Study on Structural Strength Assessment for a Semi-Pocket Type Anchoring System

Vessels utilize anchoring systems to prevent collisions and other hazards, to maintain their position, to minimize movement, and to anchor safely. Among these systems, the bell-mouth is a key component that keeps the anchor stored safely without touching the hull. It is typically manufactured as a cast steel product using a mold. However, due to its complex shape, size discrepancies can occur between the design and the produced product, which can lead to problems when using the anchor. These issues increase both costs and safety risks, as they often require the re-production of the bell-mouth or necessitate field workers to perform dangerous modifications at height. This study aims to examine the feasibility of applying the semi-pocket type anchoring system as a replacement for the conventional bell-mouth type anchoring system on a Suezmax crude oil tanker. To apply this system, the bow structure of the existing vessel was redesigned, and mock-up tests were conducted to identify potential operational issues. Subsequently, structural strength evaluations were performed by applying the Minimum Breaking Load (MBL) of the anchor chain, confirming that the required strength criteria were satisfied. Through these steps, this study sought to verify the feasibility of applying the semi-pocket type anchoring system to large vessels such as Suezmax crude oil tankers.