    the 4d was a prototype double deck electric multiple unit built for the public transport corporation, victoria, for operation on the melbourne railway system. it remains the only double deck train ever to have run in melbourne. ==design== thumb|interior of the 4d train|left built by a goninan & co, broadmeadow it was delivered by rail in december 1991."interstate rolling stock" railway digest february 1992 page 73 the train's design was based on the tangara train being built by a goninan & co for cityrail in sydney, however it was similar only in terms of interior and exterior bodywork; the train's electrical system was much closer to that of the comeng sets. the design was further modified for use on melbourne's broad gauge track, and its contr
Double-decker_EMUs Electric_multiple_units_of_Victoria_(Australia) Melbourne_rail_rollingstock