Cargo Handling and Stowage
This domain tests safe stowage, cargo documentation, dangerous-goods segregation, and bulk-cargo hazards. The examiner expects working knowledge of the IMDG Code, IMSBC Code, Grain Code, and CSS Code, not just definitions.
Stowage calculations
Stowage factor (SF) is volume per tonne. Broken stowage is space lost to shape and dunnage, commonly 5–15%. Cargo mass = available volume × (1 − broken stowage) / SF. Check the deck load limit in tonnes per square metre. IMDG segregation terms range from 'away from' to 'separated longitudinally by an intervening complete compartment or hold from'. IMSBC Group A cargoes may liquefy, Group B presents chemical hazards, and Group C presents neither.
Worked example
A hold has 1,200 m³ available. Cargo SF is 1.5 m³/t and broken stowage is 10%. Cargo mass = 1,200 × 0.9 / 1.5 = 720 t. If the tank top area is 300 m² and the load limit is 3.5 t/m², the allowable mass is 1,050 t, so volume controls. The same calculation prevents overloading a deck already limited by hatch-cover strength.
Traps
Using net tonnage instead of cargo mass; ignoring broken stowage; assuming a Group A cargo is safe because the surface looks dry; misreading the segregation table; and failing to check hatch-cover or tank-top strength. For grain, the heeling moment and assumed heel must be checked, not just total weight.