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
Gas turbine locomotive 18000 and 18100, were ordered by the Great Western Railway but completed for the newly nationalised British Railways. 18000 was built by Brown Boveri and delivered in 1949. It was a 1840 kW (2470 hp) GTEL, ordered by the GWR and used for express passenger services. 18100 was built by Metropolitan-Vickers and delivered in 1951. It had an aircraft-type gas turbine of . Maximum speed was . A third locomotive, the GT3, was constructed in 1961. Although built by English Electric, who had pioneered electric transmission with LMS 10000 locomotives, this used a turbine-mechanical transmission. The British Rail APT-E, prototype