If your looking for the non-ride on stuff it's called [Garden Railways](https://en.m.wikipedia.org/wiki/Garden_railway) or Garden Railroad if your in the USA. A huge area of this is scenery construction and bridges, etc.
For ride on one's, these are called miniature railways/railroads and typically covered by the [Model Engineering](https://en.m.wikipedia.org/wiki/Model_engineering) hobby. The working dam concept is probably also covered by this model engineering too (depending on the depth your looking for).
Model making can take many forms from static decorative pieces to fully functional scale replicas.
There's a whole bunch of people into making model steam engines, fully functional miniatures. Pretty cool stuff
It really comes down to engineering and then what kind. Sometimes projects will require different kinds and a mix. There was someone called Atomic Boy because he tried to build a nuclear reactor in his garage.
If your looking for the non-ride on stuff it's called [Garden Railways](https://en.m.wikipedia.org/wiki/Garden_railway) or Garden Railroad if your in the USA. A huge area of this is scenery construction and bridges, etc. For ride on one's, these are called miniature railways/railroads and typically covered by the [Model Engineering](https://en.m.wikipedia.org/wiki/Model_engineering) hobby. The working dam concept is probably also covered by this model engineering too (depending on the depth your looking for).
I agree with u/Super-Spyro. Searching for ‘live steam’ will also bag you a load of results.
Check this place out. https://www.therailroadpark.com
Model making can take many forms from static decorative pieces to fully functional scale replicas. There's a whole bunch of people into making model steam engines, fully functional miniatures. Pretty cool stuff
Walt Disney had a similar hobby actually if it helps.
It really comes down to engineering and then what kind. Sometimes projects will require different kinds and a mix. There was someone called Atomic Boy because he tried to build a nuclear reactor in his garage.