Ship stability: cargo on deck and in the hold
Two identical boats are heeled over. Cargo high on a mast capsizes one, cargo in the hold rights the other.
2D
Age 9+15 min
Fluids & floatingStability
Loading simulation…
Press “Run”. Bodies move by the laws of physics: gravity, friction, elasticity.
What the experiment shows
Water pushes the boat up at the centre of its submerged part. With a low centre of gravity that push turns the boat back when it heels. With a high one it tips it over.
How to run it
- Press “Run”: both boats start heeled at 18°.
- Which boat came upright?
- Make the mast cargo lighter — at what weight does the boat stay up?
Questions to discuss
- Why does a sailing yacht have a heavy keel?
- Why is it dangerous when all passengers stand on one side?
The science
Stability is a ship’s ability to return upright. It depends on the distance between the centre of gravity and the metacentre: the lower the cargo, the stronger the righting moment.
Try it at home
Float a plastic box in the bath and put coins on its bottom, then on a tall lid ‘mast’.
What to change in the editor
- Make the hull wider.
- Add a wave: push the boat from the side.