Cargo Handling, Stowage and Care of Cargoes
Stowage fundamentals
Stowage factor, broken stowage, dunnage, and the difference between measurement and weight cargoes govern how a hold is filled. Learn the IMDG segregation terms and their distances: away from 3 m, separated from 6 m, separated by a complete compartment or hold 12 m, separated longitudinally by an intervening complete compartment 24 m. The segregation table and the individual dangerous goods list entry override general assumptions.
Cargo care
Hygroscopic cargoes release moisture; steel and non-hygroscopic cargoes condense it. Ventilate only when the dew point of the outside air is lower than the dew point of the air in the hold - that is the practical test, not outside temperature alone. Ship sweat forms on the ship's structure, cargo sweat on the cargo surface. Watch for caking, tainting, condensation under tarpaulins, and heating of coal, grain and fishmeal.
Documents and operations
Bill of lading as receipt, evidence of contract and document of title; mate's receipts, letters of protest, hold cleanliness surveys. Grain needs the stability booklet and an approved loading plan; timber deck cargoes need lashings, uprights and free drainage.
Trap: applying ventilation rules on temperature alone, and assuming a stow is safe because the table says only away from.
Worked example: a hold of 1,200 m³ filled to 85 per cent efficiency with cargo of stowage factor 2.5 m³/t carries 1,200 × 0.85 ÷ 2.5 = 408 t.