Victorian Government Rlys 2-4-0 Locomotives in Australia

Class B (Locobase 10650)

Data from [], last accessed 12 July 2009 and Wikipedia article on the B class, [], last accessed 12 July 2009.

The first seven of the class were produced by R & W Hawthorn in a design based on one delivered to the British Isles' Great Northern Railway. The guiding requirement was a need to haul passenger trains along relatively steep profiles that included stretches of 1 in 50 (2%) grades. They were nicknamed "Overarmers" because of the outside cranks and coupling rods, which Locobase suspects reminded some of a cricket delivery.

20 of the 22 remaining locomotives in the class were built by Beyer, Peacock (works numbers 231-237 in 1861, 261-266 in 1862, 1034-1039 in 1871-1872, and 1267 in 1874), with the railway's Phoenix Works completing the class with two in 1880.

According to Wikipedia, these locomotives were built with the unusual Cudworth double-firebox, apparently because it was useful for handling wood fuel. The two firebox chambers were separated by a water leg that effectively acted as a thermic syphon and thus improved boiler efficiency. As the wood fire burned in one of the fireboxes, the fireman could be preparing the next charge for the other.

The class was a success and remained in service for several decades. They were delivered with 16" diameter cylinders, but were refitted in the 1880s with the 17" cylinders shown in the specs. They also were pressed to 130 psi, a value increased to 140 psi as the class was rebuilt. Withdrawals began in 1904 and were completed by 1917.