How do trains work? Let us look at some of the ways a train gets its power, one at a time. First comes the steam locomotive. A steam locomotive burns coal as its fuel.

In a steam locomotive, the heat of a fire turns the water in a boiler into steam. Then high-pressure steam goes into cylinders and pushes pistons back and forth.

You may know the chuff-chuff sound of a steam locomotive. It is the sound of used steam escaping and leaving through the chimney.

You may have heard that a diesel locomotive's engine turns the wheels directly. In fact, it does not. A diesel locomotive's engine runs an electric generator. The electricity it makes powers motors that turn the wheels.

Electric trains take power from an overhead wire. To do this they press a metal frame called a pantograph against the wire. Look up and see where the wire runs.

Another kind of train does not roll on wheels. A maglev train floats above its track, lifted by the force of electromagnetism. Shanghai has one, and its maglev train covers its 30 km (18 mile) route between the airport and the city in about 8 minutes.

Words to know

• locomotive: engine that pulls
• boiler: water-heating tank
• pistons: pushing parts
• pantograph: wire-touching frame
• maglev: floating train