PB15 No.448

Restored & operated by the Queensland Pioneer Steam Railway


PB15 No.448 sits at Bundamba Racecourse platform as the crew prepare to couple to her train, having already run four shuttle trips that day.

This image is dated 5 April 2015 and was kindly contributed by Jarrod Mitton.




Walkers Limited, Maryborough



Builder’s Number & Year

93 of 1908



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 use 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 A number were withdrawn in 1942 and 1943, but the balance lasted to the end of QGR steam operations, being withdrawn between 1967 and 1970.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.448 entered service with Queensland Government Railways in October 1908 and was written off in October 1969 after a working life of 61 years. Following retirement, No.448 was sold to the Pioneer Valley Amusement Park at Kuraby. Alas that venture did not succeed and No.448 was subsequently purchased by group of railway enthusiasts, becoming the flagship locomotive for the Queensland Pioneer Steam Railway (QPSR) at Swanbank, near Ipswich. Here it wears an attractive navy blue livery and operates a tourist service around the ‘loop line’, a branch which originally served local coal mines.

No.448 was stopped for overhaul in 1997 and subsequently received a complete rebuild by the QPSR, with the boiler being overhauled and a replacement tender tank constructed. It returned to operation in 2009 after 12 years of repair and renewal. Several photos on this page date from this overhaul, as seen during the webmaster’s visit to Swanbank on 24 October 2006.

This locomotive has also been reported as being No.446 (Walkers B/N 91 of 1908) but wearing the number plates of sister No.448. I have received a very authorative email from Andrew Rodgers of the QPSR who states it is actually No.448 and explains how the confusion arose:

"Many people seem to think that we renumbered Locomotive PB15 446 with 448. I can categorically inform you that this is incorrect. The locomotive is in fact 448 and can be found stamped into the frame, cylinders, rods, fittings, etc.

To give weight to my claim, the following was conveyed to me by the late Ron Armstrong, founder of the locomotive plus who was a QR Driver who actually towed 448 to Kuraby and stowed it into what was Pioneer Park as part of QR’s shunt workings on the south side.

He stated and is in many writings by Ron, that the locomotive was placed at Kuraby with 448 plates attached, these plates were then stolen and so they didn’t have a loco sitting there on display, as Ron actually had the locomotive operating at Kuraby before finally purchasing it with a small group of friends, without plates. 446 plates belonged to a friend of Ron’s and these were attached, these plates were changed in following years when the society could afford to have new plates poured and machined and that is what is seen today on our operational PB15 448."

A spare PB15 boiler is also stored by the QPSR at Box Flat, as seen in the photo below. Another interesting artefact at the QPSR is a hand-operated crane, built by QR on the 4-wheel tender frame of an early QR steam locomotive. A friendly fitter at the QPSR told me they still used it around the workshops!

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 contains useful technical data for these locomotives. In addition, the QPSR website includes some history for the Swanbank branch line, together with a fine series of photos of No.448 in tourist railway service.

No.448 runs around her train at Racecourse siding. This view has kindly contributed by Tony Hassam and is dated 9 October 2016.

A second view of No.448 running around its train at Racecourse station on 9 October 2016. Phot credit: Tony Hassam

This view show No. 448's boiler perched on a flatcar during overhaul; 24 October 2006.

No.448's restored tender (including a new welded superstructure) in the running shed; 24 October 2006.

This hand-operated workshop crane is fitted on an ancient 4-wheel tender frame; 24 October 2006.

This spare boiler is also held by the QPSR; I believe it is a PB15 type. 24 October 2006.

No.448 in operation on the Queensland Pioneer Steam Railway during 1991.

This much earlier view was kindly contributed by Ken McHugh from an original photo by Bill Blannin, with his permission.



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.


Queensland Pioneer Steam Railway website,
viewed 8 May 2010 & 5 November 2020.


Wikipedia page for PB15 class, retrieved 28 September 2020.

Page updated: 6 December 2020

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