Stowage Factor: Definition, Conversion and Use
Stowage factor and its reciprocal relationship with bulk density, the IMSBC section 12 conversion tables, broken stowage, and the cube out against weigh out decision.
The stowage factor is the volume a unit mass of cargo occupies as stowed, conventionally in cubic metres per tonne, and it is the number that decides whether a ship fills before she loads to her marks. It is the reciprocal of bulk density once the units are reconciled, which is why the IMSBC Code prints both for each cargo and carries conversion tables in section 12.
The full article will cover the definition and its measurement basis, including the fact that the figure is an as-stowed volume including the voids between particles rather than the solid density of the material. It will cover broken stowage for cargoes that do not fill the space they occupy, and the difference between a schedule range and a declared figure for a specific parcel.
It will also work through the operational decision the number drives: whether a cargo cubes out or weighs out on a given ship, what that implies for the vertical centre of gravity and the resulting stability, and why using a schedule midpoint rather than the shipper’s declared density is a recurring source of loading plan error.