Giant steampunk fortress train prototype in a big city

The Steampunk Fortress Train Prototype was a prototype train designed to test alternative methods of propulsion and used steam engines powered by boiling water in a nuclear reactor, the prototype ultimately failed and only one train was ever produced which is the one that is in the image. While it used technology that was identical to typical modern fortress trains, it never came about because of how much steam and energy was needed to simply get it moving. And plus steam power was not always available or needed, let alone popular in the Technoverse…