Answer
As Chief Engineer, loading cargo with a density (1.24 g/cm^3) exceeding the maximum structural limit specified in the vessel’s Certificate of Fitness (CoF) (1.04 g/cm^3) is a major structural hazard.
Immediate Action: Issue an immediate Letter of Protest (LOP) to Port Agent, Shippers, and Charterers. Refuse to load or stop cargo operations immediately.
Technical Calculations: Refusing to load is mandatory because a higher density cargo increases the static and dynamic heads on the tank bottom plating and bulkheads, risking catastrophic structural deformation or a structural failure at sea.
Managerial Steps:
Inform the Designated Person Ashore (DPA) and the vessel’s Classification Society.
Check the vessel's Stability Booklet and the class-approved Loadicator. If partial loading is proposed (e.g., filling tanks only to a lower volume percentage to keep total weight identical), this must be verified on the Loadicator to check that localized stress, bending moments, and shear forces remain within permissible limits.
Crucial Condition: Partial filling of cargo tanks creates a significant Free Surface Effect (FSE), severely compromising the vessel's transverse stability (GM). Do not accept this unless the arrangement is explicitly cleared by the Class/Flag State and a revised loading plan is provided.