Commonwealth 4-6-0 Locomotives in Australia

Class C (Locobase 3323)

Data from Chris Drymalik's Commonwealth Railways "Commonwealth Railways Locomotive Information Standard Gauge C" page at [], last accessed 16 July 2018. Works numbers were 454-461.

Based closely on the New South Wales Railways' C36 (Locobase 15989) of 1925, the Cs were ordered from Walkers for 142,500 pounds. They were to supplant the G and GA class Ten-wheelers (Locobases 4187-4188 and 14229) as passenger haulers on the cross-continent line. Compared to the earlier engines, they had much more evaporative and superheater boilers and larger fireboxes and grates to supply the cylinder volume. The power system turned turning taller drivers

According to Chris Drymalik ([]), engineers on the Cs complained of smoke entering the cab. CR conducted a series of experiments with smoke deflectors and settled on a short smoke deflector (elephant ear) on either side of the stack. Drymalik's figure of 27 tons 17 cwt (61,396 lb) for the maximum axle load seems very high, given the C36's figure of 20 ton 10 cwt (45,884 lb)

Although the Cs succeeded in cutting Trans-Australian travel times by ten hours, they were rapidly supplanted by GM diesels in the early 1950s.

Class G (Locobase 4187)

See "Commonwealth Railways Locomotive Information Standard Gauge G/GA" on Chris Drymalik's Commonwealth Railways website at [], last accessed 16 July 2018. See also Leon Oberg, Locomotives of Australia 1854-2007 (4th ed) (Rosenberg Publishing, 2007), pp. 166-167.

Drymalik wrote that this class was the "backbone" of CR operations before World War II. The design followed closely the P class of the New South Wales Railway.

Although Baldwin offered the lowest bid and promised the engines eight months sooner, industrial policy eventually dictated that the engines would be built in Australia. Clyde Engineering was awarded the contract for the first four in February 1913 with anticipated delivery in July.

But problems implementing the contract meant delays. Demands on the line and the concern over the long building times broke the impasse over foreign imports and Baldwin won follow-on contract. Like the home-grown Gs, the American ten-wheelers had flat-topped Belpaire fireboxes. See Locobase 14229 for the specifications.

However, as Drymalik dryly notes: "Purchasing engines overseas was rather controversial, even un-Australian and had only been allowed as a special dispensation." So Toowoomba Foundry Co, Ltd won a contract for 8 engines in 1914. Alas for Australian armore propre, these too were so protracted in construction that Queensland Railways was asked to finish the boilers. Toowoomba had secured a contract for an additional two locomotives.

As it happened, the first three engines in service were Clydes, followed by several Baldwins, then the last Clyde. The first Toowoomba locomotive didn't make it onto the line until June 1916. Two more Gs were delivered by the end of the year and the last seven by October 1917.

On the occasion of the Baldwin deliveries, LM's report took issue with the anticipated loading gauge of the Trans-Australian. The author noted the recent practice of setting Indian railway double-track centers at 14 ft (4.27 m) and professed himself "astonished the engineers of the Commonwealth did not take the opportunity of giving a similar dimension" instead of the 12 feet (3.66 m) span between track centers being proposed.

Given that many railways in the British Isles suffered from tight loading gauges, LM's observation had a point.

Early troubles with sand in the axle journals caused frequent hotboxes. Oberg reports that the biggest maintenance headache for a while was the effect of high mineral-salt content water on the boilers. "The problem," Oberg says, was only arrested with the introduction of barium carbonate treatment plants at watering points." [Locobase wonders if humans could take advantage of the water softening ...]

These were overcome and the original plan to have four engines divide the Port Augusta-Kalgoorlie run (1,051 miles/1,692 km) could be supplanted by a practice of having one engine run Port Augusta to Cook (513 miles/826 km) and another cover the remaining 538 miles (866 km) to Kalgoorlie.

Most served through World War II and 6 were superheated and classified GA; see Locobase

Class GA (Locobase 4188)

Data from Chris Drymalik ([] . These were G-class Ten-wheelers (Locobases 4187 and 14229) that were superheated and fitted with larger cylinders. Besides those two features, very little else was changed. The Belpaire firebox, large truck wheels, and inside valves actuated by Allan link were untouched./

Seven were made over this way, two Baldwins and five Toowoomba-built engines. When the Commonwealth received General Motors diesels in the early 1950s, these were soon retired and all had been scrapped by the end of the decade.