|Total Number of Engines Built||203|
|First Engine Built||1899|
|Last Engine Built||1924|
|First Engine Written Off||1941|
|Last Engine Written Off||1970|
This class was the most significant and successful of the locomotives designed in the nineteenth century. The design resulted from a need for more powerful engines for passenger trains. Initially designated as “Passenger” B15, they were later better known as PB15.
They spent many of their early years hauling important passenger trains around the state. With the strengthening of the main lines they were relieved of most of these tasks by more powerful locomotives. Later they were relegated to lesser duties on branch lines and in shunting yards. Engines attached to Wooloongabba and later at Mayne were used on “Southside” suburban passenger trains until 1968.
A number of modifications including cab alterations and fitting of electric headlights were carried out during their lives. Tenders on engines constructed at Toowoomba Foundry and the one at Ipswich had increased water capacity. Some engines based at Cairns had additional boards on their tenders to enable additional coal to be carried. Several engines were fitted with an additional sandbox and electric light on the tender for working on branch lines where no turning facilities were available. In May 1918, Ipswich Workshops converted N°411 into a tank engine. Evidently the results were not completely satisfactory as the engine returned to its original form in March 1922. In the late 1920s, the boiler pressure was increased from 150psi to 160 psi.
They could run on all parts of the system except the Etheridge line, the isolated Normanton and (now closed) Cooktown Lines.
One engine was built in 1924 for the Aramac Shire Council. This engine was subsequently purchased from the Council when the Aramac Shire Tramway was dieselized in 1958. Numbered A1 in Council service, it first ran on QR in February 1958 as N°1052 but was renumbered N°12 in June of that year. This was the only engine of the class to be constructed at Ipswich Workshops.
In 1924, increasing traffic on lines that could not carry C16 engines resulted in orders being placed for an engine of similar proportions but fitted with Walschaerts valve gear. These engines became PB15 (1924) Class.
In November 1969, nineteen members of the class were still operating; eleven in the Mackay District, and four at Maryborough and four at Ipswich.
*Originally 8 x 7½. The larger pumps were fitted between 1928 and 1942
EAP – Evans, Anderson, Phelan & Co, Brisbane, Qld
Ipswich – Ipswich Workshops, Qld
Kitson – Kitson & Coy, Leeds, UK
Toowoomba – Toowoomba Foundry Ltd, (Southern Cross Works) Toowoomba, Qld
Walkers – Walkers Limited, Engineers, Maryborough, Qld