Posted 3 years ago
I would think that ABT Rack Railway=West Coast Wilderness Railway
The Abt system was devised by Roman Abt, a Swiss locomotive engineer. Abt worked for Riggenbach at his works in Olten and later at his IGB rack locomotive company. In 1885 he founded his own civil engineering company.
During the early 1880s, Abt worked to devise an improved rack system that overcame the limitations of the Riggenbach system. In particular, the Riggenbach rack was expensive to manufacture and maintain and the switches were complex. In 1882 Abt designed a new rack using solid bars with vertical teeth machined into them. Two or three of these bars are mounted centrally between the rails, with the teeth offset. The use of multiple bars with offset teeth ensures that the pinions on the locomotive driving wheels are constantly engaged with the rack. The Abt system is cheaper to build than the Riggenbach because it requires a lower weight of rack over a given length. However the Riggenbach system exhibits greater wear resistance than the Abt.
Abt also developed a system for smoothing the transition from friction to rack traction, using a spring-mounted rack section to bring the pinion teeth gradually into engagement.
The first use of the Abt system was on the Harzbahn in Germany which opened in 1885.
The pinion wheels can be mounted on the same axle as the rail wheels (as in the picture at right), or driven separately. The steam locomotives on the Mount Lyell Mining and Railway Company had separate cylinders driving the pinion wheel as do the 'X' Class locomotives on the Nilgiri Mountain Railway.
Looks like PBR approaching Gembrook.