Abstract:

In order to further evaluate stability of carriers with solid bulk cargo that may liquefy, a correction method for ship stability was proposed considering dynamic instability of cargo. Firstly, based on dynamic coupling between ship's posture and cargo performance, including its moisture content, density, compaction and pile surface, surface effect of high density slurry, which jeopardized ship stability, was analyzed. Then, critical slurry density and critical moisture content were obtained through dynamic instability experiment of bauxite and approximate calculation of ship stability, and moreover, risk control measures were presented to suppress the surface effect. The results show that the initial stability height of bauxite carriers would not meet minimum requirements and be at severe risks of capsizing disaster in the condition where moisture content exceeds 14.5% and slurry density reaches 2.0 t/m³, or moisture content at 19.5% and slurry density at 1.5 t/m³. The term and concept of "surface effect of high density slurry" put forward in this paper extend boundaries of liquid density, and can be utilized to correct initial stability height of bulk carriers with non-viscous cargo that may liquefy, and furthermore to evaluate their stability and safety, improving risk prevention ability.

Key words: dynamic instability, ship stability, correction method, surface effect of high density slurry, cargo that may liquefy, bauxite