The Barlow Boy
Member
- Joined
- 29 Aug 2010
- Messages
- 696
I think what the other posters are trying to say is that the main and subsidiary aspects together count as one signal. If the position light says you can proceed then the signal as a whole is not "at danger" regardless of what the main aspect says.
RalphChadkirkhas now realised it.
A Driver must obey a red signal and stop at it. If the subsidiary (dictionary definition of subsidiary is "supplementary to") signal is then cleared the driver is then authorised to pass the main aspect at red - which remains illuminated at red. The main aspect must and will remain at red because:
i) technically - both by interlocking and rules - it cannot be cleared because
the section of line to the next stop signal and the overlap beyond is
occupied and
ii) to remind the driver that the train is entering an occupied section
That is why if such a move is being made at a location where there is no subsidiary provided the signalman will verbally authorise the driver to pass the signal at danger. The subsidiary signal takes the place of that signalman's verbal instruction/permission.
