>>1095250>>1095275>>1108352You're all wrong. They were literally tram-trains. A tram within the city, then gets on a ROW and becomes a train.
In Zurich line S21 is an interurban tram. It uses tram rolling stock, uses tram tracks within the city, and then gets on its own ROW. Also it's lettered like a suburban train with an S, unlike trams which just have a number.