Key data
| Stowage factor | 0.29–0.42 m³/t (typical 0.34)10.2–14.8 ft³/t (typical 12.0) |
|---|---|
| Form | Bulk |
| IMSBC group | C Cargoes that neither liquefy nor carry a chemical hazard. |
| Angle of repose | ~35 |
| BCSN | IRON ORE |
ft³/t values are per metric tonne (1 m³/t ≈ 35.31 ft³/t). Stowage factors are indicative — see note below.
Description
Iron ore is the single largest seaborne dry bulk trade, feeding the world's steel mills. Lump and coarse ore is inert and is carried as Group C, distinct from the fines, which can liquefy. It is so dense that a ship reaches her deadweight with the holds barely a third full, so this is the deadweight cargo against which the whole concept is usually explained.
Stowage & loading
Because the cargo is so heavy and concentrates low in the hold, the binding constraint at the berth is hull stress rather than space. Loading follows the ship's approved loading sequence and manual to avoid overstressing the structure as alternate holds fill, and the high tank-top loading is respected throughout. The stow is trimmed reasonably level once the sequence is complete.
Hazards & handling
Coarse iron ore is chemically inert and low-hazard in itself; the real risks are structural and operational – overstressing the hull through an incorrect loading sequence, and the heavy local loads on the double bottom. Dust is a housekeeping and visibility issue during handling. The key distinction to keep in mind is that the fines, not the lump, are the cargo that liquefies.
Carriage & discharge
An inert ore parcel makes for an undemanding passage, with routine checks for water in the holds and bilges. Discharge is by heavy grab or continuous unloader at dedicated terminals, and the abrasive residue is washed down on completion. The main operational care on discharge is again structural, easing the ship's loads as the holds empty in the planned order.
Key hazards
- Hull overstress if the approved loading or discharge sequence is not followed
- Very high point loading on the tank top from a dense, low stow
- Dust during loading and discharge (a housekeeping and visibility concern)
Loading precautions
- Load and discharge strictly to the ship's approved sequence and loading manual to control hull stress
- Confirm tank-top strength limits for the concentrated, heavy stow
- Do not confuse inert lump ore with liquefiable iron ore fines – check what the parcel actually is
Stowage factors are indicative and vary with grade, origin, moisture and packing. Always verify against the shipper's cargo declaration and the applicable IMSBC Code schedule before fixing or loading. This is general information, not professional or safety advice.