Cargo Handling and Stowage: Codes, Segregation and Draught Surveys
What this domain tests
The exam checks whether you can apply the IMDG Code, the IMSBC Code, the International Grain Code and the CSS Code to a real stow, and whether you can produce a trustworthy cargo quantity from draughts.
Core rules
- IMDG: stowage and segregation follow the class-based segregation table and the individual Dangerous Goods List entries; class 1 and class 7 have their own rules; never segregate from the table alone without checking the entry.
- IMSBC Group A cargoes may liquefy; a certificate of moisture content and transportable moisture limit is required, plus the can test before loading.
- Grain: heeling angle due to grain shift not more than 12° or the angle of flooding, whichever is less; residual dynamical stability at least 0.075 m·rad; initial GM at least 0.30 m, or the cargo is secured under the Grain Code.
- CSS Code: calculated strength of securing equipment is the MSL divided by 1.5; check the Cargo Securing Manual for the actual stow.
- Ventilation and sweat: dew-point rule for hygroscopic cargoes.
Worked example
Departure displacement from the hydrostatic table at 1.025 is 20,000 t, but the ship is in dock water of 1.015. Actual displacement = 20,000 × 1.015 / 1.025 = 19,805 t. Arrival displacement in salt water is 17,700 t with bunkers and stores unchanged, so cargo loaded = 19,805 - 17,700 = 2,105 t. Any change in bunkers, ballast or fresh water must be deducted as a separate line.
Traps
- Using TPC or displacement straight from the salt-water table while in dock water.
- Reading draughts at the marks without correcting for trim to the perpendiculars.
- Treating a Group A cargo as Group C because the stockpile looks dry.
- Signing a bill of lading figure without checking the ship's own draught survey.