Bulk shipping: cargo carried loose in the hold

No packages means no piece count

Nothing can be counted, so quantity is established by measurement. For dry cargoes a draught survey compares the vessel's displacement before and after loading to infer the mass taken aboard, and shore weighbridges or belt scales provide a second reading. Small percentage differences between the two figures represent real commercial value, which is why independent surveyors attend both ends and why the measurement method is agreed in the contract long before the ship arrives.

The port call is defined by the loading equipment

Bulk handling is fixed infrastructure: conveyor systems and loading spouts for grain, grabs and hoppers for ore and coal, pipelines and pumps for liquids. The rate at which that equipment works determines how long the ship stays, and shore storage capacity determines whether it can work continuously. A terminal with limited silo space will pause loading regardless of how fast the conveyor could run.

Hold condition, compatibility and moisture

Holds are cleaned and inspected between cargoes, and a residue from a previous cargo can reject a hold for a sensitive commodity such as grain. Moisture behaviour is the serious safety concern: certain mineral concentrates can liquefy under vibration if loaded above their transportable moisture limit, causing catastrophic loss of stability. The international code governing solid bulk cargoes sets out the classifications, testing and precautions, and the maritime regulator publishes it.

Capacity taken by charter rather than by booking

Bulk cargo does not join a scheduled service; the ship is engaged for the cargo. A voyage charter hires the vessel for a specific passage, while a time charter hires it for a period with the charterer directing where it goes. The charter fixes an allowance of time for loading and discharge, and if the port takes longer the charterer compensates the owner for the delay. That single mechanism is why bulk shippers care intensely about shore equipment reliability.

Where bulk voyages go wrong

Contamination between cargoes, water ingress through imperfectly sealed hatches, cargo shifting because it was not trimmed level, disputes over measured quantity, and berth congestion that consumes the laytime allowance account for most of the trouble. Almost all of it is decided before the vessel sails.

Frequently asked questions

How is the quantity of a bulk cargo established?

By measurement rather than counting. A draught survey infers mass from how much deeper the vessel sits after loading, and shore scales give an independent figure. The contract states which measurement governs if the two disagree.

Why does moisture content matter so much for mineral cargoes?

Because some concentrates behave as a solid when loaded but can liquefy under the vessel's vibration if too wet, allowing the cargo to shift and destabilise the ship. Testing before loading is the control, and the international bulk cargo code sets out how it is done.