A locomotive is a mechanically-powered vehicle that travels on rails. After one was first tested in 1804, locomotives became ubiquitous in Britain, then from the 1830s, as railway technologies were exported, worldwide (Traffic and transport). Until the 20th century, propulsion was generally provided by high-pressure steam engines, usually fueled by coal, sometimes with wood, and later with heavy oil. The speeds attained by locomotives led to the triumph of the railways and brou…