section_path: Motive power/Steam
section_name: Steam
paragraph_text: Steam
  
  Steam locomotives work by burning coal, wood or oil fuel in a boiler to heat water into steam, which powers the locomotive's pistons which are in turn connected to the wheels. In the mid 20th century, most steam locomotives were replaced by diesel or electric locomotives, which were cheaper, cleaner, and more reliable. Steam locomotives are still used in heritage railways operated in many countries for the leisure and enthusiast market.