I wonder how much current the loco's use? Including the headlight and smoke generator.
O-scale train set I had, it was powered by a Louis Marx 1209 toy transformer. LV AC variac, no circuit breaker or fuse that I remember. It seems to have been a Marx train set, I'm not sure.
Made quite a few sparks on the tracks. Tried cleaning them with steel wool, uncle's idea. That lit up and started burning. Scared the shit out of me.
Then the figure-8 crossover shorted out intermittently and the track got red hot and smoked. The train set from hell lol. A manly model train, that's for sure.
Years later went N then HO and that was plastic baby in comparison.