I believe the steam trains you're referring to are model trains based off the Rev. W. Awdry's The Railway Series. The books were best known in Britain but the characters gained popularity in the United States through Shining TIme Station and the likes of narrators Ringo Starr, George Carlin, and later Alec Baldwin. The series is now Thomas and Friend, a widely popular preschool program that has strayed far from the original Shining Time Station and texts of Awdry, featuring little realism.
I grew up with Shining Time Station and it was my absolutely favorite show when I was a kid, and the complete collection of Awdry's Railway Series books was my favorite book growing up. It's easy for me to say that Thomas the tank engine and his friends ignited my interest in railroading