Turbine waterwheels. Gas, steam, and water turbines have a casing around the blades that contains and controls the working fluid. Credit for invention of the steam turbine is given both to Anglo-Irish engineer Sir Charles Parsons (1854–1931) for invention of the reaction turbine, and to Swedish engineer Gustaf de Laval (1845–1913) for invention of the impulse turbine. Modern steam turbines frequently employ both reaction and impulse in the same unit, typically varying the degree of reaction and impulse from the blade root to its periphery. The word "turbine" was coined in 1822 by the French mining engineer Claude Burdin from the
Delaware River Iron Ship Building and Engine Works being not only America's first turbine-powered vessel, but also of eventually becoming the world's first helicopter carrier. The ship had a top speed of . The 3,750-ton sister ships "Yale" and "Harvard"—built in 1907 for the Metropolitan Steamship Company, which operated them between New York and Boston—had a top speed of and when first entering service were the fastest American-flagged vessels afloat. After the death of John Baker Roach in 1908, the Roach family heirs decided not to continue the business. The shipyard lay idle for some years until being leased in about 1913 by an engineer and former naval