Angle of loll calculation by cubic spline

Abstract

Several years ago the Basque Government supported the programming of the software ARKITSAS in order to provideall existing vessels with a specific software to calculate stability, cargo and longitudinal strength data. The aim of thisarticle is to present the part of that research concerning the definition of the static stability curve by cubic spline in itsinitial end when the metacentric height is negative. Taking into account that the slope at initial end is known, the pre-cision of the results for low heeling angles may be improved and, in this way, the accuracy in the calculation of lollshould be enhanced. This method of calculation is compared to other traditional methods used for wall-sided ships bythe application to three different ships.