 The first locomotive was completed at the Islington Railway Workshops in 1936, with the last completed in 1938.Class leader 620 was also notable for being Australia's first streamlined locomotive, the smokebox being covered with a chromed steel grille similar to those fitted to motor cars of the period, and painted Hawthorn green with yellow stripes.The press of the time described 620's appearance as 'a bit of fluff'.