We have such a train in Zürich as well. It's called the Forchbahn [1]. It switch...

We have such a train in Zürich as well. It's called the Forchbahn [1]. It switches from 600v to 1200v half way through it's trip. There is also the Uetliberg Bahn (but that can't be considered a Tram) which has an offset pantograph[3] in order to travel all the way into the city as one is AC and the other is DC. [2]