Applicability of Current Statutory Rules for Stability Requirements of Bangladesh Inland Passenger Vessels
Authors: Islam Muhammad Rabiul , Barnil A. K. M. Samiu Haque , Rahman Md. Shaidur , Hossain Khandakar Akhter 
Published: September 2022

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Applicability of current Bangladesh inland vessels stability rule has been investigated for the local passenger vessels. Bangladesh inland vessel’s stability rule is exactly the same as international stability code (2008), despite of the different environmental load in navigational routes. The restricted waterways limit the dimension of the vessels. It has been found that domestic passenger vessels have changed their dimensions considerably from the year 1974 to 2009. But analysis shows, still most of the domestic passenger vessels exceed the dimensional ratio range that is specified in both the righting lever-based criteria and weather criterion of international code. The part of the weather criterion, specifically estimation method for the angle of roll due to wind and wave action has been studied in details. Different nationals have adopted values of governing parameters for extended range of vessel dimensions, which can also successfully cover all the Bangladesh domestic passenger vessels. As per the code 2008, for ships with values outside of the addressed range, the angle of roll may be determined with model experiments of a subject ship as alternative weather criterion. Bangladesh is still lacking both in facility and infrastructure for carrying model tests. This study shows that computer simulation can be used in exchange of experimental setup where the simulation result can be validated by Parameter Identification Technique, which is described as an alternative approach in the interim guideline of International Maritime Organization (IMO).

Introduction
Passenger vessel accident is a persistent phenomenon in Bangladesh inland waterways. Thousands of people have passed away due to these catastrophic incidents. The major two modes of failure that are responsible for accidents in waterways are identified as structural failure and stability failure (Islam et al. 2015a). Structural failure like collision also leads to stability failure (Damage Stability). Iqbal et al. (2008a, 2008b) analyzed the Bangladesh inland passenger vessels accident data of 25 years and found that in 49% cases, the failure was due to lose of intact stability. Raiyan et al. (2017) have done event tree analysis of marine accidents in Bangladesh taking initial condition as overloading. Literature study (Awal 2006; Awal et al. 2007; Awal et al. 2014; Islam et al. 2015b; Rahman 2017) shows that researchers have proposed many general recommendations from different point of view to prevent the passenger vessel accidents. But still now, no attempt has been made to analyze the currently applicable statutory rules for ensuring the safety in inland waterways, which is mainly Bangladesh Inland Vessels Stability Rule including Weather Criterion (Zulfikar 2005). Stability rules of inland vessels are to be governed by standard localized condition of the subjected parameters. The socioeconomic condition, local environment, as well as infrastructural development like availability of model test facilities need to be considered for smooth and proper application of stability rules which then can only ensure the safety of local vessels. This implies that the individual efforts of concern country in research and analysis are of great importance for the development of practicable stability rules of inland vessels.