The linearization of mooring load distribution problem

This paper presents a novel step forward in finding the loads of particular mooring ropes that balance the steady environmental excitations for a ship staying at berth. The industrial static equilibrium method for a rough assessment of ship mooring safety is considered to be well-established. The static loads are directly related to the rope’s MBLs (minimum breaking loads) while applying a certain safety margin (usually 50%). The problem is reduced to a set of linear equations that may be solved analytically. The generality in terms of arbitrary horizontal and vertical angles of mooring ropes is preserved. All derivations are provided to enhance trust in the very simple yet absolutely accurate and fast linear solution. The accuracy is studied both analytically, throughout all the development stages, and finally by comparison to the exact numerical solution of the original nonlinear equilibrium equations for an exemplary mooring pattern. A discussion of selected effects in load distribution is also given. Using the approach presented, for instance, we can efficiently test mooring safety when any mooring rope of the set is accidentally broken.