Queensland PB15 class locomotive
| Company type | Steam locomotive class |
|---|---|
| Industry | Railway transport |
| Predecessor | B15 class |
| Founded | 1899 |
| Founder | Henry Horniblow, LW Piggott |
| Defunct | 1970 (retired) |
| Headquarters | Ipswich , Australia |
Area served | Queensland, Australia |
| Products | Steam locomotives |
Number of employees | 233 (total produced) |
The Queensland Railways PB15 class represents a significant series of 4-6-0 steam locomotives that were operated by Queensland Railways. Conceived by Henry Horniblow alongside LW Piggott, this class was constructed from 1899 through 1926, totaling 233 units. Production was carried out by several manufacturers: Evans, Anderson, Phelan & Co (70 units), North Ipswich Railway Workshops (1 unit), Kitson & Co (20 units), Toowoomba Foundry (20 units), and Walkers Limited (122 units).
These locomotives ran on coal and initially operated with a boiler pressure of 150 psi, which was later increased to 160 psi. They featured two outside cylinders sized at 15 by 20 inches and were equipped with either Stephenson or Walschaerts valve gear depending on their year of manufacture. Capable of reaching speeds up to 102 mph and generating a tractive effort of 12,750 lbf, the PB15 class proved to be a reliable and adaptable asset for Queensland Rail.
The locomotive’s weight was approximately 32 tons, with tenders weighing around 24 tons, carrying up to 4 tons of coal and holding 2,500 imperial gallons of water. This class remained in active service until its retirement in August 1970. Presently, five locomotives from this series have been preserved by various heritage organizations.
History
The PB15 class was engineered to fulfill the need for more powerful passenger locomotives. Designed under the guidance of Locomotive Engineer Henry Horniblow together with LW Piggott, the classification PB15 follows Queensland Rail’s system: 'P' signifying passenger service, 'B' indicating three driving axles, and '15' representing the cylinder diameter in inches. The design closely mirrored that of the B15 class engines.
Walkers Limited from Maryborough delivered the initial PB15 units in December 1899. By 1912, production had reached 202 locomotives manufactured by Walkers (122), Evans, Anderson, Phelan & Co (70), Kitson & Co (20), and Toowoomba Foundry (20). These early models utilized Stephenson valve gear. In May 1918, locomotive number 411 was modified into a tank engine classified as the 6D15 at North Ipswich Railway Workshops but was converted back to its original tender configuration by 1922 due to unsatisfactory performance.
In 1924, a single locomotive was constructed at North Ipswich Railway Workshops for the Aramac Shire Tramway; this engine later became part of Queensland Railways’ fleet in 1958.
Between 1925 and 1926, Walkers produced an enhanced batch of 30 PB15 locomotives featuring larger tenders and Walschaerts valve gear; this subset became known colloquially as the Walschaerts variant.
In 1932, a number of PB15 engines stationed at Ipswich depot received an additional sandbox mounted at the rear to assist with sanding during shunting operations on colliery branch lines. Locomotives fitted included numbers 351, 508, 567, 574, 587, 591, and the Walschaerts-equipped no. 750. Subsequently, rear sanding equipment was removed from no. 591 and installed on no. 525.
Preservation
A total of five PB15 locomotives have been preserved:
- No. 444 is exhibited at the Workshops Rail Museum located in Ipswich.
- No. 448 runs on the Queensland Pioneer Steam Railway at Swanbank and carries the name RV Armstrong in honor of a founding member of the preservation society.
- No. 454 is currently undergoing restoration work at the Bellarine Railway in Queenscliff.
- No. 732, a Walschaerts type engine built in 1924, is held in storage at the Workshops Rail Museum.
- No. 738, also a Walschaerts model from 1924, is displayed at the Rosewood Railway Museum.
Representation in Media
- The PB15 locomotive is featured as a digital model within the Trainz simulation series.
External Resources
- PB15 class Queensland Railways Interest Group