Steamship

A steamship is a seagoing, typically ocean-faring vessel propelled by one or more steam engines that drive a paddlewheel or, in later and more efficient designs, a screw propeller. Early steamships relied on paddlewheels, whose performance declined as a vessel's draft changed with added weight, until the screw propeller proved more efficient at any depth and less exposed to damage because it stayed fully submerged. The technology developed through the early nineteenth century, from the first working paddle steamer Pyroscaphe in 1783 through the SS Savannah's partly steam-powered 1819 Atlantic crossing, to fully reliable ocean-going steam propulsion later in the century. By freeing shipping from dependence on wind, steamships enabled regularly scheduled service between distant ports and are credited as a major driver of the first wave of global trade expansion between 1870 and 1913.