Robert Fulton the "Nautilus", the first practical submarine in history. Fulton is also credited with inventing some of the world's earliest naval torpedoes for use by the British Royal Navy. Fulton became interested in steam engines and the idea of steamboats in 1777 when he was around age 12 and visited state delegate William Henry of Lancaster, Pennsylvania, who was interested in this topic. Henry had learned about inventor James Watt and his Watt steam engine on an earlier visit to England. Robert Fulton was born on a farm in Little Britain, Pennsylvania, on November 14, 1765. He had three sisters –
Steam turbine used to conserve weight, and remained in use for all fast steam-powered ships thereafter. Since the 1980s, steam turbines have been replaced by gas turbines on fast ships and by diesel engines on other ships; exceptions are nuclear-powered ships and submarines and LNG carriers. Some auxiliary ships continue to use steam propulsion. In the U.S. Navy, the conventionally powered steam turbine is still in use on all but one of the Wasp-class amphibious assault ships. The Royal Navy decommissioned its last conventional steam-powered surface warship class, the , in 2002. In 2013, the French Navy ended its steam era with