Signal questions

[Llanigraham]

You wouldn't necessarily know if just the blade was missing, leaving the spectacle plate and mechanical grubbing intact, until someone stopped to report it! I suppose you'd be able to work normally in darkness though, as the nighttime indications would remain. If the spectacle plate went missing too, you'd know about it, as that's what the arm detection is attached to. The latter serves to indicate the position of the arm where the signal's not visible from the box (and sometimes, for example if the block controls check that the home signal is at danger before allowing a 'line clear' to be given, even if it's clearly visible), so you know either by that or by direct observation if a signal failed to return to danger.

Arm detection? Really? Not fitted on any of the signals in my area!
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If the driver saw the blade was missing but was expecting it to be clear from the distant signal, would they have to stop the train immediately at the signal and notify you or do it as soon as reasonably practicable?

Yes, immediately. Either using GSM-R, the SPT or their mobile.
--- old post above --- --- new post below ---

If the driver saw the blade was missing but was expecting it to be clear from the distant signal, would they have to stop the train immediately at the signal and notify you or do it as soon as reasonably practicable?

Yes, immediately. Either using GSM-R, the SPT or their mobile.

 

[Tomnick]

Arm detection? Really? Not fitted on any of the signals in my area!

You don't have any repeaters (i.e. 'on', 'wrong', 'off') for any of your semaphore signals?

 

[Llanigraham]

As said before, No.

 

[Tomnick]

Must be a bit of a rarity then! I've never come across a box without any repeaters for semaphores, even one of ours with just one stop signal for each line (so all clearly visible).

 

[6Gman]

What would happen if a semaphore lost its arm by some means? (weather damage, vandalism, little green men beaming it up whatever)
The automatic protection mentioned for colour lights wouldn't work here, I'm guessing.

Would it be treated the same if the whole arm was gone or just the sticking out bit, with the spectacles remaining?

And if the rodding froze/got jammed with the signal showing a proceed aspect (ie the physical link to the box doesn't want to move when the signaller tries to revert the signal to danger?)

Gerard Fiennes (I think!) tells a story in his book of a signal arm falling off shortly before a Royal Train departure from Liverpool Street. Chap carried it back up and held it proudly in the 'off' position to prevent delay.

Best not to try this these days .....