South Australian Railways 700 class (steam)
| Company type | Steam locomotive class |
|---|---|
| Industry | Rail transport |
| Founded | 1925 |
| Founder | Fred Shea (designer) |
| Headquarters | South Australia , Australia |
| Products | Steam locomotives |
Number of employees | 10 (units produced) |
| Parent | South Australian Railways |
South Australian Railways 700 Class
The 700 class locomotives were a series of steam locomotives with a 2-8-2 wheel arrangement, utilized by the South Australian Railways. Designed by Fred Shea and constructed by Armstrong Whitworth in 1925, a total of ten units were produced, numbered 700 through 709.
These engines featured a gauge of 1600 mm and measured approximately 73 feet 2 inches in length with a height of about 13 feet 6 inches. The leading wheels had a diameter of 2 feet 9 inches, drivers were 4 feet 9 inches across, and trailing wheels measured 3 feet 6 inches. Each locomotive had an axle load of around 18 long tons, with the weight on drivers totaling approximately 70 long tons. The combined weight of the locomotive and tender was roughly 171 long tons in original configuration.
Fuel options included both coal and oil, with capacities of 17 long tons for coal and nearly 3,000 imperial gallons for oil. Water storage held about 5,900 imperial gallons. The boiler operated at a pressure of 200 psi, supporting a firebox area of 195 square feet and a combined tube and flue heating surface of around 2,400 square feet. Superheater surface area measured approximately 619 square feet.
Power was delivered via two cylinders sized at 22 by 28 inches, controlled by Walschaerts valve gear utilizing piston valves. The tractive effort generated was about 40,418 pounds-force, with a factor of adhesion rated at 4.11.
The first run for this class took place on April 27, 1926. They remained in service until withdrawal between 1959 and 1967. Of the original ten locomotives built, one unit—number 702—has been preserved, while the remaining nine were scrapped between 1962 and 1968.
Delivery
In 1926, as part of William Webb's efforts to modernize the South Australian Railways, Armstrong Whitworth from Newcastle upon Tyne supplied ten 2-8-2 steam locomotives. These engines were engineered specifically to function on broad gauge branch lines equipped with 60lb rail.
The initial unit, numbered 700, arrived at Port Adelaide by ship in March 1926. Its inaugural operation occurred in April 1926 during a test run north of Adelaide station. In May of the same year, locomotive 700 was involved in a minor incident when it collided with the rear of a freight train between Upper Sturt and Mount Lofty stations. By June 1926, it commenced regular service running between Adelaide and Murray Bridge, coinciding with the arrival of the remaining nine locomotives of the series.
While primarily assigned to freight duties, the 700 class engines were also deployed for passenger services.
In 1927, locomotive 706 underwent modifications that included replacing its original trailing bogie with a cast 'Delta' bogie and fitting it with a booster. Following this development, a batch of ten nearly identical locomotives known as the 710 class was produced in 1928 at the Islington Railway Workshops. These units incorporated boosters similar to those installed on number 706.
Track Restrictions
By 1931, locomotives from both the 700 and 710 classes equipped with boosters—including number 706—were prohibited from running on lines laid with 60lb rail due to the additional weight imposed by the boosters. To maintain operational capability on these lighter rails, boosters were removed from locomotive 706 and several 710s. This adjustment was necessary because the heavier 720 class locomotives were already banned from such tracks, creating a shortage of suitably sized engines.
Throughout the 1930s, both classes encountered progressively tighter limitations concerning speed, coal consumption, and water usage on 60lb rail lines. Eventually, they were excluded from operating on the Pinnaroo and Barmera routes but regained access in subsequent years. Additionally, after platforms on the Outer Harbor, Port Dock, and Semaphore lines were widened to accommodate Redhen railcars, these locomotives were permitted to run there. However, due to insufficient clearance between platforms and tracks for the 700 class engines to pass at full speed, they remained subject to stringent speed constraints.
Modifications
Early in their service life, the 700 class locomotives underwent minor adjustments to mitigate issues related to excessive axle loads and overheating bearings. Throughout the entire class, several other alterations were implemented, such as replacing the original sand domes with larger versions, installing blowdown mufflers during the 1930s, swapping out the flanged smokestacks for tapered ones, and repositioning the turbo generators. Additionally, some units had their single-stage air compressors substituted with single cross-compound pumps.
Initially delivered in a uniform black paint scheme, these locomotives were later finished with red buffer beams and red lining following William Webb’s retirement. However, the red lining quickly became obscured due to the natural weathering experienced during regular operation.
In 1945, locomotive 706 was involved in a head-on collision at Snowtown, resulting in significant front-end damage. Upon returning to service, it featured a notably different front design, including a centrally positioned headlight, a numberplate mounted beneath it, and a pressed-steel pilot replacing the original lattice-style pilot characteristic of Webb's designs. For a brief period, 706 was equipped with a fabricated smokestack resembling those on the 740 class locomotives before reverting to the standard tapered smokestack.
Following coal shortages after World War II, some locomotives were converted to oil burning, while others operated on a coal-oil mixture. Most were eventually reverted to coal firing except for number 708. Certain locomotives also received coal pushers. During the 1940s, all units had their buffers removed due to South Australia's transition to automatic couplers.
Withdrawal and Preservation
The initial withdrawals of this class occurred in June 1959 as 830 diesel locomotives began to replace them. The last unit in service was the class leader, number 700, which was retired following a series of farewell excursions known as 'Sayonara Mikado' held over the weekend of 1-2 June 1968. Locomotive 700 led the first farewell trip to Angaston and subsequently joined locomotive 718 on a second journey to Victor Harbor, substituting for a failed Rx224 unit. The two engines double-headed back to Adelaide, arriving in the early hours of 3 June after delays caused by locomotive 718 derailing on the Victor Harbor turntable. Both were retired immediately after this final run.
Preservation efforts have secured locomotive 702 at the National Railway Museum, Port Adelaide. It was initially transferred to the Mile End Railway Museum in June 1965 before relocating to its current home at Port Adelaide in 1988.
Class roster
| Number | Entry into Service | Retirement/Decommission Date | Distance Covered |
|---|---|---|---|
| 700 | 27 April 1926 | 3 June 1968 | 781,660 mi (1,257,960 km) |
| 701 | 28 August 1926 | 28 October 1966 | 864,438 mi (1,391,178 km) |
| 702 | 20 September 1926 | 9 July 1964 (Preserved) | 775,526 mi (1,248,088 km) |
| 703 | 10 September 1926 | 9 June 1959 | 1,068,326 mi (1,719,304 km) |
| 704 | 13 September 1926 | 14 April 1960 | 797,179 mi (1,282,935 km) |
| 705 | 4 October 1926 | 6 July 1961 | 738,250 mi (1,188,098 km) |
| 706 | 28 September 1926 | 7 September 1967 | 691,951 mi (1,113,587 km) |
| 707 | 16 September 1926 | 9 June 1959 | 958,431 mi (1,542,445 km) |
| 708 | 29 September 1926 | 28 October 1966 | 782,696 mi (1,259,627 km) |
| 709 | 7 October 1926 | 28 October 1966 | 694,798 mi (1,118,168 km) |
Image collection
-
The only remaining locomotive of this series, number 702 exhibited at the National Railway Museum in Port Adelaide
-
Number 700 leading the class and final operational unit during an ARHS excursion to Angaston in 1968Number 700 leading the class and final operational unit during an ARHS excursion to Angaston in 1968
-
Locomotive number 706 at Blackwood in 1952 with a centrally positioned headlight that distinguished it visually from its counterparts
-
Number 709 stationed at Mile End in the year 1952
-
Locomotive number 706 equipped with a booster unit in the year of its introduction (1927), which was subsequently removed
-
The class pioneer unit number 700 at Mile End circa 1926
.jpg){kind=link}
.jpg){kind=link}
References
