ON THE BASIC DESIGN OF SINGLE POINT MOORING SYSTEMS, 1ST REPORT: APPLICATIONS OF THE DYNAMIC STABILITY ANALYSIS TO THE PRIMARY PLANNING OF THE SYSTEM

The slow oscillation, or weather vane motion, of a single point mooring (SPM) is a critical consideration when designing such a system. This is because the cost performance of an SPM, from the viewpoint of its rate of operation, is affected by the excessive mooring forces that such oscillation induces. As an approach to the problem, theoretical dynamic stability analysis has not yet been much used in practical SPM design work despite the simplicity of the techniques involved. The main reason is that such analysis cannot give the amplitude of the oscillation or mooring force, but only shows the stability of the moored vessel--in other words, indicates whether the slow oscillation will or will not arise. The author suggests that for practical purposes, even this limited information can be useful. Practical applications of dynamic stability analysis to the primary planning of an SPM system are discussed.