4-6-2 Steam Locomotives in Australia

Class M (Locobase 8580)

Data from [], and [], all accessed 14 July 2007.

Pipe-festooned Pacific based on the Indian Government Railway's YB class that fulfilled all the requirements for this twisting, hilly narrow-gauge line. Like the Vulcan Foundry H-class 4-8-2s described on Locobase 8579, these Pacifics (works #7421-7430) had cast-steel SCOA-P drivers and roller bearings on every axle including the 4 under the tender, the main (connecting) rod, and the side (coupling) rods. Unlike the Hs, however, these engines had Belpaire fireboxes.

The Hobart-Launceston passenger service needed light but powerful engines, notes OS Nock (RWC VI, pl. 106), so this design used welded construction for such components as the inner steel liner to the Belpaire firebox, ashpan, and parts of the tender's tank. Line curvature is as tight as 330 ft radius, "and personal observation from the footplate has confirmed that they do ride these severe curves both smoothly and comfortably."

Four were rebuilt as MAs for freight work; see Locobase 2872.

Retirements came in the early 1960s, although M5 remained in service until 1971 as a suburban-traffic, special-service engine.

Class MA (Locobase 2872)

Data from [], and [], accessed 14 July 2007.

In 1957-58, four of the M-class Pacific engines were retrofitted with 48" drivers taken from Garratt locomotives and smaller pony-truck wheels. A change in weight distribution added a little more than 1 long ton to the adhesion weight. Tractive effort went up, but they were had a significantly lower factor of adhesion.

These were designated MA 1-4 and were the ex-M8, M1, M6, and M2, respectively. They tackled the more challenging North East line.

Class R (Locobase 21253)

Data from "Tasmanian Government Railways R class" in Wikipedia at

[], last accessed 23 March 2025). See also "The Railways of Tasmania", Locomotive Magazine, Volume XXVIII [28] (14 October 1922), pp. 88-91 (15 November 1922), pp. 323-326.. (Thanks to Oz Pete (Peter Dunn) for his 23 March 2025 email supplied the general arrangement drawing.)

Based on the Q class 4-8-2s delivered the year before (Locobase 21251) Its "neat arrangement" of the radial constant-lead valve gear actuated 9" (229 mm) inside-admission piston valves and drove the second coupled axle. In addition to the taller drivers, differences included a shorter wheelbase and shorter tubes.

Iniitally, the quartet served trains on most of Tasmania's rail lines--

Main from Hobart on the south coast headed north about which flows north to George Town on the Bass Strait between Tasmania and Australia's Victoria State.

Western from Western Junction 11 miless (18 km) south of Launceton northwest to Deloraine and ultimately to Devonport and Burnie on the Bass Strait west of the Tamar estuary.

Just north of Hobart, the Derwent Valley line headed westerly from Bridgewater up the Derwent.

The Fingal Line left the Main Line at Conara Junction heading east through Fingal to St Mary's on Tasmania's east coast.

R3 and R4 joined the streamliner fraternity in 1938 when the TGR fitted smooth sheaths over the boiler and smokebox, masked the running boards with deep valences striped alt the way back to the tender and dedicated coaches, and fitted casings over domes and safety valves on top of the boiler.

The pair retained the cosmetics until the late 1940s as they hauled Hobart-Launceton expresses.

All four retired in 1956-1957 and went under the torch in the early 1960s.