The completion of the South Australian Railway (SAR) broad gauge route between Adelaide and Port Pirie created a need for a fast, light passenger locomotive to haul this service, as well as other traffic on the lightly laid 60 lb/yd (29.8 kg/m) rail branch lines of the SAR.

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,[2] painted in resplendent Hawthorn Green and Silver.

This was the first and only time a South Australian Railways steam locomotive had worked east into Victoria and with the gauge conversion imminent, the tour would also be the last.

The train travelled as far east as Bacchus Marsh, due to the locomotive being too wide for the stations situated along the Melbourne suburban railway system.

The locomotive combined with R761 for the majority of the tour from Wolseley in South Australia to Bacchus Marsh in Victoria.