PB15 No.732

The Workshops, Ipswich


No.732 stored in the running shed area of ‘The Workshops’ railway museum, Ipswich. 8 October 2004.



Walkers Limited, Maryborough



Builder’s Number & Year

379 of 1926



Wheel Arrangement




No. in class

203 (Stephenson valve gear)

  30 (Walschaerts valve gear)


The PB15 class were conceived as a passenger version of the earlier B15 class 4-6-0 freight locomotives dating from 1889, hence the ‘P’ prefix. A key difference was the larger diameter driving wheels, being 4’ for the PB15 class as opposed to the original 3’ diameter of the B15 class. The classification otherwise followed the Queensland Government Railways (QGR) naming convention of ‘B’ for 6-coupled locomotives and ‘15’ to designate 15-inch cylinder diameter. The first PB15 class locomotive entered service in 1899, 10 years after the B15 class. The PB15’s proved to be useful locomotives in addition to their handsome, well-proportioned looks, and the class had grown to 202 examples by 1912.

As a testament to the utility of the PB15 design, the Ipswich Railway Workshops constructed an additional unit in 1924 for the Aramac Shire Tramway; this locomotive later passed into QGR stock in 1958 becoming No.12. When the Queensland Railways administration of the early 1920’s identified a need for additional mixed traffic locomotives for light lines, the proven PB15 design was selected with a further 30 units built by Walkers Limited, Maryborough between 1925 & 1926. These ‘1924 design’ PB15’s featured Walschaerts valve gear instead of the original Stephenson gear, together with other modifications and modernisations.

The PB15 class found extensive used on mail and passenger trains, lightly-laid main lines (such as the Main Range route from Cairns to the Atherton Tableland) and country branch lines, together with suburban passenger and shunting turns. A number were withdrawn in 1942 and 1943, but the balance lasted to the end of QGR steam operations, being withdrawn between 1967 and 1970.

PB15 No.732 entered service with Queensland Government Railways in March 1926 and was written off in March 1970 after a working life of 44 years. Following retirement, No.732 was retained in operational condition for the QR Heritage Fleet, although the more powerful BB18¼ and C17 locomotives have predominated in heritage & tour train duties. I believe No.732 is currently awaiting overhaul and is exhibited in the running shed area at The Workshops railway museum, Ipswich.

Excellent references for further information about the PB15 class are ‘Locomotives in the Tropics - Volume 1 (Queensland Railways 1864 - 1910)’, which covers the original Stephenson valve gear locos, and Volume 2 (Queensland Railways 1910 – 1958 and beyond) which covers the 1924 design / Walschaerts valve gear locomotives. The Wikipedia page for the PB15 class also contains useful technical data.



Armstrong, J. 'Locomotives in the Tropics - Volume 1

(Queensland Railways 1864 – 1910)’,

published by the ARHS Queensland Division, 1985.


Armstrong, J. 'Locomotives in the Tropics - Volume 2

(Queensland Railways 1910 – 1958 and beyond)’,

published by the ARHS Queensland Division, 1994


‘Locomotives of Australia 1854 to 2010’ (Fifth Edition, 2010),
by Leon Oberg, published by Rosenberg Publishing Pty Ltd.


Wikipedia page for PB15 class, retrieved 28 September 2020.

Page updated: 6 December 2020

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