[1] The A class design was very similar to the 2-4-0 WT (well tank) locomotives that Stephenson supplied to the Melbourne and Hobson's Bay Railway Company between 1854 and 1871.

[2]: 04‑686 When the railway line from Roseworthy to Forrester's (now known as Tarlee) was opened on 5 July 1869, it was intended that a pair of 2-4-0WT locomotives, not yet classified as A class, would operate on it.

The rails were lightweight – 40 pounds/yard (20 kilograms/metre) – and soon after the line's opening in September 1869 it became evident that the locomotives were too rigid in their wheelbase and too heavy for the track.

[3] The pair were then placed in service on the Port Adelaide line, where they proved to be a much more valuable asset, so much so that a third locomotive was ordered from Robert Stephenson and Company, arriving in 1873, by which time they had become the A class.

Other work included shunting from Port Dock station to numerous wharfs in the area, in Islington Workshops and the Adelaide yards, and at Milang.