Unstable Cargo

The stability of a ship requires the cargo to remain in its loaded position. Nonetheless, under some circumstances cargo can move while the ship is underway.

A bulk cargo of solid powder can liquefy at a specific water content under the stimulus of vibration and motion of a ship underway enabling it to flow to one side or other of the cargo hold. Such cargoes, include finely divided coal, which can liquefy with absorption of ambient moisture in this way to produce a free surface effect, which can cause capsize.

Even grain cargoes can slide because, since grain settles during a voyage and creates extra space between the top of the cargo and the top of the hold, allowing the cargo to move from one side to the other as the ship rolls.

Unstable packaged cargo has also been discussed in the section stability. Unstable cargo may result in other dangers than just loss of stability. The crew could be struck could get hit by ‘flying’ packages or packages could get damaged, releasing their content.