The first steam railway journey ran into trouble. On 21 February 1804 the world's first railway journey, with a steam locomotive built by Richard Trevithick, ran in south Wales. The locomotive weighed about five tons, and it was so heavy that it broke the cast-iron rails it ran on.

A steam locomotive burns coal as its fuel, and the heat of the fire turns the water in a boiler into steam. High-pressure steam goes into cylinders and pushes pistons back and forth, and the chuff-chuff sound is the sound of used steam escaping and leaving through the chimney. The engineer is the person who runs a train's engine.

A diesel locomotive's engine runs an electric generator, and the electricity it makes powers motors that turn the wheels, while electric trains take power from an overhead wire by pressing a metal frame called a pantograph against it.

Train wheels are not flat cylinders, because the tread of a railway wheel is shaped like a shallow cone, wider on the inside next to the flange and narrower on the outside, and hunting is a dangerous oscillation of a train's trucks that comes from the cone-shaped wheels and can lead to a derailment.

George Stephenson's railways used rails 4 feet 8.5 inches apart, a width later called standard gauge, and the clickety-clack of older trains came from the gaps, or joints, between sections of rail.

A maglev train floats above its track, lifted by the force of electromagnetism. At speed, Japan's SCMaglev does not touch the track: magnetic force between its superconducting magnets and coils on the ground lifts it about 10 centimetres (4 inches).

George Westinghouse invented the compressed-air brake for railway trains in 1869, and his triple valve turned the railway air brake into an automatic brake and sped up its action.

Many railways keep trains apart by dividing the track into blocks and letting only one train be in each block at a time, while in moving-block signalling, the safe zone around each train moves with the train and is worked out by computer in real time.

Before the railways, it did not matter much that towns kept different local times, but fast railway travel changed that, because trains ran to timetables. In 1852 Greenwich began sending accurate time signals over the electric telegraph wires, and the railways used those wires to pass Greenwich time to stations across Britain. By 1855 nearly all public clocks followed this 'railway time'.

On November 18, 1883, American railroads began using four standard time zones. In 1918 Congress passed the Standard Time Act, which made time zones the law 35 years after the railroads began using them.

London's Metropolitan Railway, which opened in 1863, was the world's first underground railway to carry passengers.

New York City's first subway line opened on October 27, 1904, and it was about nine miles long, and on its first day it carried more than 100,000 riders, each of whom paid a nickel (five cents).

One freight train can carry as much freight as 280 or more trucks. As of November 2026, according to the freight railroads, a train can move one ton of freight nearly 500 miles on a single gallon of fuel, on average.

The longest freight train on record ran in Western Australia on 21 June 2001; it was 7.353 km (4.57 miles) long, with 682 ore cars. The BHP train that set the record weighed about 99,732 tonnes, and a new control system let one driver in the front locomotive control the other engines.

Words to know

• timetables: printed schedules
• telegraph: wire messaging
• standard: agreed common
• cylinders: steam chambers
• pantograph: overhead pick-up
• tonnes: metric weight units