Reanalysis of the revised EEDI parameters for inland ships of Bangladesh

Abstract

A revision of the Energy Efficiency Design Index (EEDI) formulation was previously proposed to be useful for inland ships of Bangladesh. The study incorporated the shallow water effect using Schlichting’s method which has been developed in 1934 based on a large number of ship model tests to show how a ship’s resistance in shallow water deviates from that in deep water. However, the evaluation and presentation of Schlichting’s results did not cover all range of ship parameters. This reanalysis has considered the shallow water effect by actual measurement of 15 inland ships of Bangladesh. Later, the results of Schlichting’s method were compared with (a) actual investigation, (b) an improved version of Schlichting’s method proposed by Lackenby in 1963, and (c) a new method proposed by C B Barrass in 2004. It was found that the deviations of Schlichting’s results are much higher than Lackenby and Barrass’s methods in comparison to the investigated results. In a previous analysis of the inland ships of Bangladesh, the Maximum Continuous Rating (MCR) of the main engine was considered by using the Holtrop-Mennen method. As this method requires too much ship data, that analysis had assumed some unknown required ship data. This reanalysis has overcome that problem by the physical investigations of the same 15 inland ships of Bangladesh. The average MCR for inland cargo ships and oil tankers of Bangladesh are measured as 70% by the investigations, whereas it is 80% for passenger ships.