An upper quadrant motor-worked semaphore mounted on a 30ft tubular steel post. The semaphore can take 3 positions over the upper quadrant: horizontal (STOP), 45 degrees (CAUTION) and vertical (PROCEED).
Home and distant 2-position automatic semaphore signals appeared in NSW in the 1900s. Later (1920s?) a 3-position variant for use in areas with higher traffic densities started to appear. These were double-light semaphore signals where the lower light was a white-light lamp with a red/green spectacle arm or a 2-colour electric light in place of a distant semaphore. The semaphore had 3 positions but the 3 spectacles showed only 2 colours (red, green, green). By day, CAUTION was indicated by the semaphore at 45 degrees, while at night the light indication was green over red.
If the signal was automatic, it was controlled by a nearby relay hut ('NSWGR automatic signal relay hut', kuid:368725:20070) in which track-circuit detections were converted into signal-motor instructions to set the semaphore position.
This signal has a shunt-ahead banner semaphore mounted below the lower light of the main signal. Since the shunt ahead semaphore cannot be set automatically, the signal was always under the control of a signal box, or the signalman could override the automatic setting of the main signal.
The model was created for use in sessions where it is under the control of a signal box. If used in a session with typical fully-automatic signal operation, then the shunt ahead banner signal will be inoperable.