| South Australian Railways A class locomotive | |
| Powertype: | Steam |
| Builder: | Robert Stephenson and Company |
| Ordernumber: | 1827, 1828, 2108 |
| Builddate: | 1868 |
| Totalproduction: | 3 |
| Rebuilder: | Islington Workshops |
| Rebuilddate: | 1889 (no. 1); 1883 & 1911 (no. 19) |
| Numberrebuilt: | 2 |
| Uicclass: | 1'B T |
| Leadingdiameter: | 39abbr=offNaNabbr=off |
| Driverdiameter: | 60inches |
| Minimumcurve: | 18abbr=offNaNabbr=off |
| Wheelbase: | 7feet |
| Over Bufferbeams: | 26feet |
| Width: | 7feet over running board[1] |
| Height: | 3912mm |
| Frametype: | Plate |
| Leadingbogie/Pony: | 8LT |
| Coupled All: | 10LT |
| Locoweight: | 30LT loaded |
| Fueltype: | Coal |
| Fuelcap: | NaNLcwt |
| Watercap: | 225impgal |
| Fireboxtype: | Round-top |
| Firearea: | 11.17square feet |
| Pitch: | 6feet |
| Boilerpressure: | 1300NaN0 |
| Safetyvalvetype: | Salter spring balance |
| Totalsurface: | 817.4square feet |
| Tubearea: | 751.6square feet |
| Fireboxarea: | 65.9square feet |
| Cylindercount: | Two |
| Cylindersize: | 14x |
| Valvegear: | Stephenson's |
| Coupling: | Hook and screw |
| Tractiveeffort: | 7940lbf |
| Operator: | South Australian Railways |
| Operatorclass: | A |
| Numinclass: | 3 |
| Fleetnumbers: | 1, 19, 20 |
| Firstrundate: | September 1868 |
| Withdrawndate: | 1893 (no. 20), 1923 (no. 19), 1924 (no. 1) |
| Disposition: | All scrapped |
The first two of what later became the South Australian Railways A class of locomotives, built by Robert Stephenson and Company, England, arrived at Port Adelaide for the South Australian Railways in September and October 1868. A third, final locomotive arrived in 1873.[2]
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. The main difference between the locos supplied to Victoria and those supplied to SouthAustralia was the size of the cab, with the Victorian locos having a very much smaller cab, with no side plates. Even then, the two windows on each side of the A class cab remained unglazed.[3]
The three locomotives were the first broad gauge locomotives to be fitted with outside cylinders.[2]
The drawings show locomotive no. 1 in its final form with fully enclosed cab, complete with glazed side windows, a boiler the same diameter as the firebox, a dome that is smaller in diameter but taller than the original, and a new funnel with a more conventional shape. Not evident is the alteration to the front spectacle plate by which two circular windows replaced the three windows originally supplied.[3]
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] New F class locomotives, which entered service later in the month, took over the task.[4]
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. Subsequently the three engines were allocated to suburban passenger and goods services around the Adelaide metropolitan network.[5] [6] In 1923 the A class were listed as being able to work on the North Terrace to Glenelg line with either freight or passenger trains; Mile End to Port Adelaide with freight trains; Port Adelaide to Dry Creek;Dry Creek to Stockade (Northfield line); Adelaide to Brighton; and Strathalbyn to Milang. Other work included shunting from Port Dock station to numerous wharfs in the area, in Islington Workshops and the Adelaide yards, and at Milang.[3]
Refurbishing of two of the locos, including replacing the boiler, took place after about 15 years' service: no.19 in 1883 and again in 1911, and no.1 in 1889. No.20 missed out on a rebuild and, as a consequence, was the first to be withdrawn, in 1893.[3] No. 19 was condemend in 1923 and no. 1 in 1924.[3]