The EMD GP50T was a proposed turbocharged or "tunnel motor" diesel locomotive design by the Electro-Motive Division.
Ideas for the design:[]
The EMD GP50T was designed to reuse the same design of the GP50 but would be a turbocharged or "tunnel motor" variant of the GP50 and it was supposed to be built by the Electro-Motive Division for the Denver and Rio Grande Western Railroad after the success of the EMD SD40T-2, in which the radiators were expanded for better engine cooling in mountainous areas.
Why wasn't it built?:[]
The reasons to why it wasn't built was because, before the Denver and Rio Grande Western Railroad could put an order for EMD's GP50T, they had tested EMD's relatively new SD50, which ironically despite its later to-be-discovered reliability issues from the 645F3B V-16 engine, the SD50 had performed pretty well when in tunnels thus rendering the Tunnel motors obsolete