Simmering-Graz-Pauker Type U is the older stock on the U bahn.
The U 4 pops out into view at this famous location.
A Type U is seen on the U 4 on the Zollamtsbrücke bridge These were the first cars on the U Bahn.
A Type V is seen on the U 4 on the Zollamtsbrücke bridge. The U Bahn system compliments the trams and is quite extensive.