A simulation model for a mooring positioning system of a vessel in presence of wind, current and waves

Abstract

During positioning of a floating craft by means of a mooring system different kinds of displacement of the vessel are generated due to the sea exciting forces: quasistatic displacement, first order motions (of high frequency) and second order motions (of low frequency). The corresponding loads in the lines of the anchor mooring system of the vessel are generated following the displacement of the vessel. The motion equations of the ship equipped with the anchor mooring system are presented in the paper. Their solution is presented with regard to non-linear terms of the equations and the random exciting forces, in the form of numeric simulation in the time domain. The sample calculations were peformed for a geological vessel fitted with the 4-line positioning system.