This story is a sequel to The Guild of Equestrian Railwaymen: Dual bands of steel through the hills

In the steep mountains of Northern Equestria, there is a railway through the hills that found itself in a bind. They needed a machine with more grunt and power than had ever been created in history before. Turning to a genius (or madpony) of steel and steam to help with this issue. They asked him to create a machine capable of satisfying their needs. What they were delivery, was a monster the likes of which had never been seen before.