Steam Locomotive

A steam locomotive is a self-propelled railway engine that moves itself and attached vehicles by the expansion of steam, burning coal, coke or oil to heat water in a boiler until it becomes high-pressure steam, which is then directed alternately into cylinders to drive pistons connected to the locomotive's wheels. Developed in the United Kingdom in the early nineteenth century, steam locomotives powered the first public railways and the inter-city rail networks that followed, and they dominated railway traction through the 1800s and most of the 1900s. Beginning in the early twentieth century they were gradually displaced by electric and diesel locomotives, and most were retired from regular service by the 1980s, though many survive and continue to run on heritage and tourist railways worldwide. The steam locomotive is closely associated with the Industrial Revolution and remained the backbone of global rail transport for nearly two centuries.