Preserved Steam Locomotives Down Under

Pm 701

The Railway Museum, Bassendean

Class leader Pm 701 nicely presented in unlined green livery at The Railway Museum, Bassendean on 9 May 2002.

Builder

North British Locomotive Company,

Glasgow

Builder’s Number & Year

26545 of 1949

Wheel Arrangement

4-6-2

Pm 701 is the class leader of the Pm / Pmr class, built by North British Locomotive Company to meet post-war rebuilding demands and representing the final WAGR development of the Pacific locomotive type. The design was based on the earlier Pr class with enhancements including power reversing gear and roller bearings on the front bogie and trailing truck. There were 35 locomotives in Pm / Pmr class, the first 18 being Pm (I believe the ‘m’ denotes ‘modified’) while the final 17 locos (715 and 720-735) were further enhanced by roller-bearings on the driving wheels, hence ‘r’ denoting roller-bearings.

Although the Pacific wheel arrangement is normally associated with passenger duties, the Pm/Pmr class were found to be unsuited to that work due to adhesion issues and rough riding. They were quickly transferred to freight duties and found success on fast freight turns. Adrian Gunzburg provides a good explanation for the adhesion issues that impacted the class in his excellent book ‘A history of WAGR Steam Locomotives’. Despite these constraints the Pm/Pmr class were modern and capable machines that lasted to the end of WAGR steam, with records showing they were written off between 1970 and 1972.

Class leader Pm 701 entered WAGR service on 4 January 1950 and was officially withdrawn on 17 June 1971. It was selected to represent the class at The Railway Museum, Bassendean and transferred into the care of the Australian Railway Historical Society (WA Division) in June 1972. Today Pm 701 can be seen displayed within the display hall at Bassendean featuring the attractive green livery the class wore in WAGR service.

The WAGR was an early adopter of the Pacific wheel arrangement, providing both good speed and a lower axle load, and the type remained well represented in the WAGR steam fleet across the decades. The locomotive collection at Bassendean hosts several Pacifics, including early Es 308 (built 1902), P 508 (built 1924), Pr 521 (built 1938), U 655 (built 1942) and Pm 701 (built 1949). Alas the pioneering Ec class Pacifics (Baldwin Vauclain compounds, built 1901, later rebuilt to L class) and C class (Baldwin 1902, built 4-6-0 and rebuilt to 4-6-2 from 1908) did not survive into preservation – including the unfortunate scrapping of the last 4 Cs locos in 1964 following their final years in timber Industry service, and the last L-class lingering on the Midland Workshops scrap line until 1965. (I’ve included photos of these lost types on the page for Es 308.) While the pioneering Baldwin Pacifics are long gone, the webmaster suggests that perhaps the Bassendean collection could one day also provide a home for the very last WAGR Pacific, the currently derelict Pmr 735 - last built of the P/Pr/Pm/Pmr line?