In the very early 1990s, announcements were made for a potential fleet of 15, 4 - car, <PERSON> double deck trains, for Melbourne's then two busiest lines/routes of Pakenham and, through Ringwood, Belgrave & Lilydale. One prototype, the ``4D'' train, was used to test the suitability of these trains. Seen on its launch weekend in March 1992, the train is on platform 1, with a Comeng train on platform 2, at Flinders Street Station. South Australia, Western Australia, Brisbane, Melbourne, Double Deck, Tasmania, Book Publishing, 1990s, Trains