An experimental investigation of motion control devices for truss spars

Abstract

This paper presents the results of an experimental study carried out on a model truss spar in regular and irregular waves. Each bay of the truss of the model was spanned by a horizontal plate. The bottom bay was instrumented so that the vertical loading could be measured. Four different types of plate were fitted to the model and the responses of the spar to the wave loading were recorded for each type. Two of the plate types were perforated and two were solid. The response amplitude operators, and the force coefficients in the vertical direction, are presented and the performances of the different types of plate are assessed.