Key data
| Stowage factor | 1.15–1.35 m³/t (typical 1.25)40.6–47.7 ft³/t (typical 44.1) |
|---|---|
| Form | Bulk |
| IMSBC group | A and B Cargoes that can both liquefy and carry a chemical hazard. |
| Angle of repose | ~35 |
| BCSN | COAL |
ft³/t values are per metric tonne (1 m³/t ≈ 35.31 ft³/t). Stowage factors are indicative — see note below.
Description
Coking, or metallurgical, coal is the premium grade prized for its ability to be baked into coke for blast-furnace steelmaking, rather than burned for power like thermal coal. Commercially it is a higher-value trade, but for carriage it is handled under the general coal regime and shares coal's range of behaviours. Its stowage factor sits a little below thermal coal on average, keeping it firmly in deadweight-cargo territory on most ships.
Stowage & loading
As with thermal coal, the parcel is loaded by conveyor or grab and trimmed level to limit the air available to feed any self-heating, and kept clear of heated structure. Because source and rank drive behaviour, the specific characteristics declared for the parcel matter far more than the label, and the loading temperature is logged as the reference point for monitoring during the passage.
Hazards & handling
Coking coal carries the same hazard profile as coal generally: self-heating toward spontaneous combustion, emission of flammable methane, depletion of oxygen in enclosed spaces, and the potential for finer, wetter parcels to liquefy. Lower-volatile coking coals may emit less gas than some thermal coals, but no parcel should be assumed benign without the declared characteristics to support that view.
Carriage & discharge
Temperatures and the gas atmosphere are monitored through the voyage, with surface ventilation managing methane while avoiding a draught that would accelerate heating; a climbing carbon monoxide reading is the early warning of a hot spot. Discharge is by grab or continuous unloader at steel-plant or trans-shipment terminals, after which spaces are ventilated, gas-freed and certified before entry.
Key hazards
- Self-heating that can lead to spontaneous combustion
- Methane emission producing a flammable atmosphere
- Oxygen depletion in cargo and adjacent enclosed spaces
- Liquefaction potential in finer, wetter parcels
Loading precautions
- Work to the declared characteristics of the specific parcel rather than assuming typical coal behaviour
- Trim level, keep clear of heated structure, and log a baseline temperature
- Set up gas and temperature monitoring and ventilation before departure
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.