A COMPREHENSIVE ASSESSMENT ON SHIP MANOEUVRABILITY

Having made many manoeuvrability investigations and collected data about manoeuvrability criteria, the essential criteria of ship's inherent, relative and closed-loop manoeuvrabilities are discussed. By using the theory of fuzzy mathematics, the authors established the membership functions of each essential manoeuvrability and give weighting factors for comprehensive assessment under different sailing conditions. Finally three grades of comprehensive assessment indices on ship manoeuvrability are proposed: ship's inherent manoeuvring quality, ship's relative manoeuvring quality and ship's closed-loop manoeuvring quality. The calculation results for many ships show that the comprehensive assessment given in this paper is not only effective and simple but can also be widely used in the optimisation of ship design, sailing permit analysis, waterways dredging, ship routeing, steering technique assessment and others.