South Australian Railways 'S' class 4-4-0

Designed by Chief Mechanical Engineer Thomas S. Roberts.
Built by James Martin & Co. Gawler 1894-1903

CYLINDERS (2) 18 ins x 24 ins (457mm x 610mm)
COUPLED WHEEL DIAMETER 78 ins (1981.2mm)
TOTAL HEATING SURFACE 1,138.24 square feet (105.74m²)
GRATE AREA 17.37 square feet (1.61m²)
BOILER PRESSURE 150 PSI (1,034.25 kpa)
TRACTIVE EFFORT 12,711 lbs (5,765.71 kg)
TOTAL WEIGHT 82.1 tons (83.41 tonnes)
LENGTH OVER ALL 57 feet ½ in (17,388.6 mm)

Eighteen of these elegant locomotives were introduced to replace the smaller 'Q' class of 1885. Displaying splashers over their 6'6" drivers and inside cylinders employing 'Stephenson's motion', they certainly had a distinctive English appearance.
The 'S' class became South Australia's frontline express passenger locomotive working both the northern services to Terowie and Kapunda and the Southern mainline from Tailem Bend to Serviceton. Double-heading became necessary as loadings increased, particularly on the 'Melbourne Express' and it was not unusual to see two 'S' classes or an 'S' and a 'Q' teamed up.
The 'eight wheelers' became victim of Webb's rehabilitation scheme, firstly in 1924 with the acquisition of twelve '55' class 'Tin Hare' railcars from Service Motors Inc., Wabash Indiana and in 1926 a further thirty five larger '75' class 'Barwell Bull' railcars purchased from J.G. Brill and Co.

Also the big '600' class Pacifics were being introduced at this time. Unlike the other small powered locomotives the 'S' class was unsuitable for more mundane duties such as shunting and suburban passenger services. Their opportunities to show their true worth quickly diminished and once the '620' class light Pacifics were introduced in 1936 the 'eight wheelers' found themselves relieved of most of the remaining country passenger services they had continued to operate. However they struggled on, six being scrapped in 1956 with the remainder disappearing by 1961. Once again shortsightedness at the time prevented one from being preserved.