English: Preserved GWR/BR(W)/Brown Boveri 2,500 hp A1A-A1A Gas Turbine prototype No.18000 in 1956 BR(WR) green livery with orange stripe, at the Didcot Railway Centre, 26/05/14. As in so many elements of railway design, the GWR did things differently when contemplating a replacement for steam in the immediate post-war years. Whereas the LMS and SR went for diesel electric, and the LNER and SR went for electric locomotives, the GWR typically decided to follow its own path and chose gas-turbine power - a very daring decision for the late 1940's. No.18000, after a protracted design and construction period, was not finally completed until 1950, two years after the demise of the GWR; it was the first of two prototypes, neither being delivered until after Nationalisation. The second prototype was built by Metropolitan-Vickers and of a very different design. Though innovative, neither locomotive showed Gas Turbine power to be the answer to replace steam!