No, I think trams were operating on 650VDC right from the beginning of electrification in 1897. We have a real mixture of power systems in public transportation here, 650VDC catenary (Tram), 750VDC catenary (subway line U6, former Stadtbahn, though the cars can operate on tram lines as well), 750VDC 3rd rail (other subway lines), 950VDC catenary (suburban train to Baden near Vienna, dual system cars to operate on both 650 and 950V), 15kVAC catenary (suburban train system operated by OEBB (railway company)). 650VDC seems to be pretty common for trams in continental Europe, Munich just stepped up to 750V about a year ago.
