From the Maitland Mercury report:
Australian-built locomotive 3642 helped revolutionise rail travel before World War II and will carry passengers to Branxton on Saturday.
The loco entered service in 1926 – with the rest of the class – on mainline passenger service displacing the older 32 and 35 classes.
The 36 class was designed with less maintenance in mind and long range (water) tenders, which meant fewer stops.
Clyde Engineering at Granville built the loco as one of 10 engines that delivered shorter travel times on long distance journeys and ushered in new levels of passenger service.
Full article available at Maitland Mercury, April 17, 2015.