Early steam engines burned wood instead of coal. Many of these old locomotives are now in train museums. To warn people and animals to stay away from the tracks, some locomotives had bright headlights and loud whistles. Others had bumpers in front, called cowcatchers, which kept the tracks clear of debris. Most locomotives today are run by diesel fuel or electricity.
Many electric trains get power from a special electric rail that runs along the tracks.
Others use overhead electrical cables like these. Repair cars have high platforms where workers can stand when they have to fix the cables. A special car carries big spools of new cable. Speedy electric commuter trains take people from small towns to work in big cities. In a tunnel, a red signal light tells the engineer in the cab to stop.