MINIATURIZATION OF HEAD OF EXISTING LARGE-SCALE BOLLARD TO IMPROVE EFFICIENCY OF MOORING WORKS

In recent years, large-scale bollards (tractive force: 1500 kN and 2000 kN), which are not described in the Japan’s Standard Specifications for Port & Harbour Works, have been installed at quay walls because of enlarged ships especially cruise ships calling in Japanese ports. The main opinion of mooring workers is that the head of large-scale bollards is too large and too tall, and that’s a big burden and a cause of deterioration of work efficiency. In this study, we first organized the design concept for the head of large-scale bollards based on the existing method. Also, we carried out a survey on the use of large-scale bollards for mooring workers. We studied a miniature head, which is expected to improve work efficiency in mooring work, while ensuring safety during mooring for the bollards. As a result, we clarified that the bollards with a tractive force of 2000 kN can be made the same outer size as the conventional 1500 kN commercial type or smaller than that.