Cargo Handling and Stowage
This domain tests whether you can load a ship safely and prove it on paper: bulk cargo hazards, grain stability, IMDG segregation and stowage, hold cleanliness, deck cargo securing under the CSS Code, and draft surveys.
Bulk cargo hazards (IMSBC Code)
- Group A: cargoes that may liquefy, such as iron ore fines, nickel ore and mineral concentrates. Load only if the moisture content is below the transportable moisture limit (TML); the shipper supplies the declaration and test certificates.
- Group B: cargoes with a chemical hazard. Coal is Group B, giving off methane and carbon monoxide and liable to self-heating; it needs surface ventilation and gas monitoring.
- Group C: cargoes in neither group, such as many ores and grains.
Grain
The International Grain Code needs a Document of Authorisation and either filling each compartment (98 per cent or more) or trimming and securing. You compare the actual heeling moment from grain shift with the tabulated allowable heeling moment for that loaded condition and KG.
Dangerous goods
IMDG segregation levels run from away from, through separated from, to separated by a complete compartment or hold, up to separated longitudinally by an intervening complete compartment. Class 1 requires magazine stowage; Class 7 requires calculated separation distances.
Worked example
A hold tank top is rated at 3.0 t/m². The cargo has a stowage factor of 0.50 m³/t, so its density is 1 ÷ 0.50 = 2.0 t/m³. Maximum cargo level = 3.0 ÷ 2.0 = 1.5 m. Stowing deeper overloads the tank top, so spread the load with dunnage over a larger area or load less.
Traps
- Treating stowage factor as if it were density, which inverts the loading height calculation.
- Omitting deductibles (fuel, ballast, fresh water, constants) in a draft survey, or reading drafts away from the perpendiculars.
- Accepting a can test in place of the certified TML and moisture content.
- Securing deck cargo without checking the CSS Code lashing calculations and the ship's cargo securing manual.
- Signing a bill of lading for a quantity you have not verified.