The E127 Napier Nymph was Napier’s first single shaft gas turbine propellor engine. Design was carried out from as early as May 1945 was rated at 500 shp and was proposed as a light prototype unit. The project was only bench tested; its turbines were required to produce 1500 bhp in order to provide 500 shp for its propellor shaft.
In 1956 an E146 Napier Oryx was converted into a single shaft turbo prop engine with a three stage turbine becoming the E226 Napier Nymph. This was for a fixed-wing aircraft application with a take-off rating of 715 shp.