Experimental and numerical investigation on the load stability of coal cargoes during marine transport

Abstract: During marine transport of coal commodities, cargo slip or liquefaction failure scenarios within the hold may occur under cyclic ship motions. The resulting cargo shift affects the vessel stability, and subsequently endangers goods and crews on board the vessel. This study aims to investigate the coal cargo stability under marine transport conditions. A suite of six coal samples was selected to undertake a series of undrained cyclic triaxial tests to investigate their liquefaction resistance. Results were subsequently compared to the liquefaction threshold advised by International Maritime Organisation. It was suggested that finer coals were observed to be more susceptible to liquefaction. In addition, discrete element modelling of the coal cargoes was conducted to study the cargo slip susceptibility. Calibration was performed to ensure materials modelled in the numerical program reflected the physical behaviours. Results indicated coarser coal samples with lower moisture contents exhibited cargo slip failures under nominated rolling ship motion. Nevertheless, resulting centre of gravity shift from cargo slip exhibited negligible effect on the cargo stability. Outcomes of this study provided important safety guidelines on marine transportation of coal commodities. Graphic abstract: [Figure not available: see fulltext.].