This is a steam engine.
This steam engine is a little like Gordon.
It's called a steam engine because steam is what makes it go.
Look at the white clouds of steam puffing from the engine's funnel.
You can see steam engines coming from a long way away.
But how does a steam engine make steam?
[ENGINE WHISTLES]
Steam is made from water.
Before every journey, the engine is filled with water.
The big water tank on the front of the steam engine holds lots and lots of water.
[WATER DRIPS]
Lots and lots of water will make lots and lots of steam.
[ENGINE WHISTLES]
The fireman shovels coal into the engine's firebox and carefully sets it on fire.
He must be very careful.
The fire makes the water very, very hot.
The engine needs a lot of coal to keep the water very, very hot.
Once the engine has lots of water, lots of coal and a very hot fire, the water is soon bubbling and boiling.
And the boiling water turns into steam.
Lots and lots of steam.
The steam travels through lots of pipes to the pistons.
The pistons push the wheels round and round.
The wheels make the engine puff forwards and backwards.
That is why steam engines are called steam engines.
Subtitles by SteamTeamExtra
