The WAGR Pm and Pmr classes were two classes of

4-6-2 Under the Whyte notation for the classification of steam locomotives, represents the wheel arrangement of four leading wheels on two axles, six powered and coupled driving wheels on three axles and two trailing wheels on one axle. The locomotiv ...

tender engine

steam locomotive A steam locomotive is a locomotive that provides the force to move itself and other vehicles by means of the expansion of steam. It is fuelled by burning combustible material (usually coal, oil or, rarely, wood) to heat water in the locomot ...

s operated by the

Western Australian Government Railways Western Australian Government Railways (WAGR) was the operator of railway services in the state of Western Australia between October 1890 and June 2003. Owned by the state government, it was renamed a number of times to reflect extra responsi ...

(WAGR) between 1950 and the early 1970s.

History

With the WAGR suffering from a shortage of locomotives and having a backlog of repairs deferred from

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

, authorisation was granted for the construction of 35

locomotives. Initially it was planned that

Midland Railway Workshops The Midland Railway Workshops in Midland, Western Australia, were the main workshops for the Western Australian Government Railways (WAGR) for over 80 years. History The first railway workshops in Western Australia were located at Fremantle an ...

build 10 with the balance built externally. However capacity constraints at Midland saw the order for the full 35 placed with the

North British Locomotive Company The North British Locomotive Company (NBL, NB Loco or North British) was created in 1903 through the merger of three Glasgow locomotive manufacturing companies; Sharp, Stewart and Company (Atlas Works), Neilson, Reid and Company (Hyde Park Wor ...

Glasgow Glasgow ( ; sco, Glesca or ; gd, Glaschu ) is the most populous city in Scotland and the fourth-most populous city in the United Kingdom, as well as being the 27th largest city by population in Europe. In 2020, it had an estimated popul ...

.Pm Class Steam Locomotive
Rail Heritage WA Nineteen were built as the Pm class with plain bearings on the coupled axles and

roller bearings In mechanical engineering, a rolling-element bearing, also known as a rolling bearing, is a bearing (mechanical), bearing which carries a load by placing rolling elements (such as balls or rollers) between two concentric, Groove (engineering), g ...

on the carrying axles. The other sixteen were built as the Pmr class with roller bearings on all axles. One Pm was later converted to a Pmr at

. All entered service in 1950. Although intended to operate passenger services, their independently sprung driving wheels gave a rough ride meaning they could not maintain schedules, hence they were quickly relegated to fast freight trains on the

Eastern Goldfields The Eastern Goldfields is part of the Western Australian Goldfields in the Goldfields-Esperance region of Western Australia, covering the present and former gold-mining area east of Perth. Extent and name origin The region encompasses the town ...

and Great Southern lines and associated branches. Later they were concentrated on the Great Southern and South Western lines. All were withdrawn between 1970 and 1972.

Classes list

The numbers and periods in service of each member of the Pm and Pmr classes were as follows:

References

Notes

Bibliography

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External links