The Pt Class was used from 1978 to 2016 mainly on line U5, where the platforms were too low to accept the regular trains used on the other lines. As the line was gradually upgraded with high-level platforms as used on the remainder of the network, the Pt class cars are in limited service on tram lines 15, 17 & 20, whereas the Ptb, which was used for underground service, was withdrawn in 2016.
