As the designation suggests, the QR class C16 was a steam locomotive with four driving axles and a cylinder diameter of 16 inches. 152 of this 4-8-0 mixed-traffic locomotives were built by Australian manufacturers between 1903 and 1918, although three 0-8-0 locomotives built in 1882 by Baldwin also deserved the designation C16. The new class was mainly used for livestock and mail trains and had drivers with a diameter of only 45 inches. All were built with saturated boilers. 

In the twenties, ten locomotives were tested with a superheated boiler. This was no success due to problems with the slide valves and it was decided to remove the superheaters again, without rebuilding these locomotives to piston valves. Soon, the C16 was replaced by the superheated C17 in the most important roles. From 1945, they gut AAR-type smokeboxes, what increased their power despite still being saturated. In their last years, they were used for heavy shunting services. No. 106 is the only one that has been preserved. Its restoration was completed in 2021 and it can be found at the DownsSteam Tourist Railway & Museum.