Whether you use Freightlink often or maybe just a couple of times a year, unless you’re moving via the Eurotunnel the chances are you’re moving your freight on a ferry.

Have you ever wondered just how do ferries float? These mighty structures made of iron and steel simply shouldn’t float on water, right?

Let's look at some basic science so you can impress your driver friends when you’re sat having a coffee on your next Dover-Calais crossing...

Sink or Float?

Whether an object sinks or floats on water is called ‘displacement’. Displacement is when an object 'displaces' or pushes aside water. Think of a full glass of water. If you drop an ice cube into the glass some water spills out. The amount of water that spills out will be equal to the amount of space that the ice cube takes up. If you get in the bath when it’s too full, water goes everywhere. But this water will be the same as the space that you take up when you get in the bath.

It's all About the Buoyancy

Ships are designed to displace as much water as possible. They tend to be really wide, especially freight ships as they need to be able to take more weight. Buoyancy refers to how well something floats or sinks. If something is able to float then its classed as buoyant.

Even though ferries are really large they are also hollow and not as heavy as you would think. The golden rule is, something will sink if it's heavier than the water it is displacing. Therefore, a bowling ball would sink, but a football would float. In the case of a ferry, gravity pushes down on the boat, but buoyancy helps it stay afloat as it’s not as heavy as the space it's taking up.

So there you have it, some basic science from Freightlink. To see how buoyancy works in real life, book your next Ferry crossing today