Development of intact stability weather criterion applicable to river-sea vessels

Abstract

Inland vessels, in general are not allowed to navigate in seas and thus there is a need to solve the missing link between minor inland ports to major ports. River-sea vessels are proven models now in many countries to move cargoes in order to solve this missing links in waterway systems. These vessels are intended for inland navigation waterways and suitable for restricted navigation at sea, with significant wave height limited to 2m. For these vessels, suitability for restricted navigation at sea should be proven by the compliance with appropriate Rules of a recognized classification society as well as with applicable local/national statutory Regulations. For stability assessment, these Regulations refer to the IMO code for intact stability, difficult to meet for inland vessels. Also as statutory regulations may not always available, classification rules are expected to include those vessel designs generally prescribed by administrations. The research follows on to define appropriate requirements related to intact stability weather criterion from the study of local meteorological data and the results of the seakeeping analysis. Simulating navigation condition is done using accepted time-series analysis and spectral analysis techniques. The nonlinear relationship between excitation and response of structures is to be done and in this context, wave conditions that produce rare events are to be defined. Through this paper validation of requirements developed is done for roll amplitude and relative wave elevation along with design criteria regarding the evaluation of vessel intact stability.