I enjoyed that very much, but you never addressed the issue of what kind of fuel the steam engines burn. I'm sure that it was originally coal, but steam engines can be modified to burn fuel oil. There always seems to be a good reason to pollute, but I would guess that these engines' days are numbered, particularly in Germany. People with nostalgia for steam engines are dying off.

According to trains.com, there are still over 150 steam engines operating in the USA, mostly hauling excursion trains.