Gas turbine on and off to run it only at high efficiency. The emergence of the continuously variable transmission may also alleviate the responsiveness problem. Turbines have historically been more expensive to produce than piston engines, though this is partly because piston engines have been mass-produced in huge quantities for decades, while small gas turbine engines are rarities; however, turbines are mass-produced in the closely related form of the turbocharger. The turbocharger is basically a compact and simple free shaft radial gas turbine which is driven by the piston engine's exhaust gas. The centripetal turbine wheel drives a centrifugal compressor wheel through
Gas turbine by a gas turbine. The "Auris" operated commercially as a tanker for three-and-a-half years with a diesel-electric propulsion unit as originally commissioned, but in 1951 one of its four diesel engines – which were known as "Faith", "Hope", "Charity" and "Prudence" - was replaced by the world’s first marine gas turbine engine, a open-cycle gas turbo-alternator built by British Thompson-Houston Company in Rugby. Following successful sea trials off the Northumbrian coast, the "Auris" set sail from Hebburn-on-Tyne in October 1951 bound for Port Arthur in the US and then Curacao in the southern Caribbean returning to Avonmouth after 44 days