Western Australian Government Beyer-Garratt Locomotives in Australia

Class M (Locobase 535)

Data from Wiener (1930); corrected and supplemented by Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005); and A[rthur] E[dward] Durrant, Garratt Locomotives of the World (revised edition) (Newton Abbott, UK: David & Charles, 1981), pp 67-68,. Works numbers were 5477-5482

Durrant noted several "firsts" in the history of Garratt-type locomotive owned by this class. These six Double Mogul Garratts were the first to be of "a main-line natu re", the first to be ordered in series quantity, and only the third Garratt design to be produced, and, later, the first Garratt design to be produced in the Southern Hemisphere. A more technical first occurred when Beyer-Peacock produced long connecting rods to drive on the third axle, "instituting," Garratt wrote,"a standard infrequently strayed from [by the builder]."

Wiener noted that the line had severe gradients of up to 4 1/2 percent and line curvatures of as little as 328 ft (100 m). Ms mostly ran on branch lines of southwestern WA, which meant rural and forest settings. Like most Garratts, the M class used Belpaire fireboxes, and short-lap Z-ported piston valves.

Only one M-class Garratt received a superheater and joined the Ms class described in Locobase 536. The five other M Garratts remained in service well into the century.

Class Ms (Locobase 536)

Data from Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005); and "Western Australia Railway, Design No. 0557", Beyer-Garrrat Patent Articulated Locomotives (Manchester, England: Beyer-Peacock & Company Limited, 1931), archived on flickr's Historical Railway Images at [], et seq, p. 34.. See also "Pioneering in Nyasaland" archived at Mike's Railway History, last accessed 3 January 2015. Works numbers were 5665-5671 in 1913.

Superheated version of class M (Locobase 556). Follow-on to first Western Australia Double Mogul Garratts, these being fitted with superheaters. Small, closely space drivers in each engine unit with the typical short, thick boiler heated by a Belpaire firebox.

Class Msa (Locobase 6847)

Data from Gavin Hamilton's excellent compilation of Garratt data posted at []

(6 September 2005). See also Bobbie Oliver, The Locomotive Enginemen: A History of the West Australian Locomotive Engine Driversñ, Firemenñs and Cleaners' Union (Black Swan Press, 2016), no page numbers.

Obviously based on the pre-World War I Ms class supplied by Beyer, Peacock (Locobase 536), this set of Double Mogul Garratts came from the WAGR's own shops as works #46-55. In her study of the union, Oliver provides several details about the Msa design. "Record" wheat harvests prompted the WAGR to bolster its hauling power. Instead of going back to Beyer Peacock in England, Fred Mills, Chief Draftsman (later Chief Mechanical Engineer) at the Midland Workshops modified the Ms design and turned out these somewhat heavier engines.

The grate size grew while the boiler was unchanged. The class was rated to haul 302 tons up a 1 in 45 (2.2%) grade. Claiming the distinction of being the first locomotives manufactured entirely in Western Australia, the class used cast steel frames supplied by Hadfields from their Bassendean foundry. They were the most powerful locomotives in Western Australia. As they required "large amounts of coal and water", the union was able to negotiate an extra half-hour of preparation time before the engines left the shed.

Class Msa (Locobase 20933)

Data from Gavin Hamilton's excellent compilation of Garratt data posted at [] (6 September 2005): "W.A.G.R. C.M.E. No. 4356 Loco Class Msa-General Arrangement Elevation & Plan" at [], last accessed 19 August 2021; and "WAGR Msa class" in Wikipedia at [], last accessed 19 August 2021.

The WAGR found themselves sufficiently pleased with the trio of Ms Garratts delivered in 1912 (Locobase 536) that they produced ten more very similar engines in their own shops beginning in 1930. The most signficant changes occurred in the firebox, which now held a larger grate.

Boiler pressure increased by 20 psi (1.38 bar). Herein may have lain the cause for Wikipedia's report of "Hearsay evidence suggests that the poor quality of the boilers in the Msa rendered some inoperable by the late 1940s.". If the boiler's construction didn't change, the extra tractive power may have come at a cost. On other other hand, Wikipedia's own table shows the entire class was withdrawn in 1963. (The two bits of information do not necessarily contradict each other.)