A new method to analyse the speed power performance of operating ships and its implementation

Abstract

Ship operators need means to analyse their fleet’s performance in order to maintain their competitiveness. Important decisions such as voyage planning and scheduled maintenance, are all made based on a ship’s performance. However, there is no reliable method to estimate a ship’s performance. ISO19030 provides a means to measure the changes in performance but is only applicable to data collected over a relatively long period of time and is unsuitable for comparing the performance of sister ships. In this study, we implemented a software to analyse a ship’s performance. To meet the ship operator’s requirements, a new speed power performance analysis method based on ISO15016:2015 is proposed. The proposed method first evaluates the added or decreased resistance due to the environmental changes including wind, waves and water density first. Then, the measured shaft power is corrected by direct power method and finally corrected to reference displacement for comparison. The results of its implementation, a software called SPA, and its application to two ships, a 176K bulk carrier and an 8600TEU container carrier, are described herein.