South Australian Railways '520' class 4-8-4

Designed by Chief Mechanical Engineer Frank Harrison.
Built at Islington Railway Workshops 1943-1947.

CYLINDERS (2) 20½ ins X 28 ins (521mm x 711mm)
COUPLED WHEEL DIAMETER 66 ins (1,676mm)
TOTAL HEATING SURFACE 3,105 square feet. (288.5m²)
(including superheater)
GRATE AREA 45 square feet (4.2m²)
BOILER PRESSURE 215 PSI (1,482 kpa)
TRACTIVE EFFORT 32,600 lbs (14,787kg)
TOTAL WEIGHT 200.5 tons (203.72 tonnes)
LENGTH OVERALL 87 feet 4½ ins (26,632mm)

The '520' class was South Australia's most successful locomotive, twelve being delivered with a further eight planned but never built.
The first three were painted hawthorn green with cream striping and applied overall streamlining inspired by the Pennsylvania Railroad's 'T1' class duplex 4-4-4-4's of 1942. The remaining nine locomotives were finished in black with silver striping and modifications to the smoke box casings.

Being one of only two 4-8-4 types ever designed and built in Australia the '520's' light axle loadings enabled them to run on the secondary line network as well as the main lines. Basically described as a 'mixed traffic' type they proved their versatility by hauling expresses, country passenger trains, and suburban locals. They were frequently rostered on freight workings handling them with ease.

However, they are mainly remembered for their sterling performances on the 'East West Express' from Adelaide to Port Pirie. With a load of 500 tons they were able to run at 70 mph on some sections of this line.
The '520's' stood tall as diesels started being introduced in 1952 and most of them saw service well into the late 1960's, the last one being condemned in September 1971. Fortunately two still remain, 523, on display at the National Railway Museum, Port Adelaide and 520 with The Steamranger Tourist Railway at Mount Barker.