My DTS, who are nearly 3yo, are really into Thomas the Tank Engine. Prior to having DTS, I knew nothing about Thomas or his friends. Now I know many of the characters and even the song. What I don't know, is the difference between the trains. On a basic level, I know that Diesel is a diesel engine and Thomas & Co are steam engines. However, how does Thomas differ from Gordon, apart from size? The trains, according to the song, perform different functions and I'm trying to understand if this is a reflection of how they differ in terms of construction, output etc. In addition, there are the narrow guages like Peter Sam.
I know nothing about trains but I'm conscious that because of the boys inquisitive minds, I will soon be facing a barrage of what, why and how about these engines.
I would be really grateful if someone would provide me with a basic understanding of trains in terms of how they differ and how this is reflected in the functions that they are assigned.
TIA