What are these sensors for in Pearse station?
Saw this relatively clean little box bolted to the inside of the right rail of the north bound tracks in Pearse station. It just says "smart wheel sensor" but am curious what about the wheels is being sensed?
Looks like there could be a small window on top of the box but with all the grime that gets thrown on the tracks I'd be surprised if it was optical-based.
Best guess is a magnetic sensor for detecting when / where wheels pass by but I don't know why that'd be valuable enough for a dedicated sensor.
Train position is determined by the drivers and could be checked by CCTV, I don't see how wheel wear could be accurately measured, and surely the spacing of the wheels is determined by the solid axles connecting them and is thus unlikely to change?
Any IE/IR insider knowledge appreciated!