Flashing Yellows at Newton Abbot

"Deliberate oversight" is an interesting concept! Looking at the data it appears they were coded to flash but not linked to any route.

Thanks

Peter

Peter Bennet in post 118009 said:

"Deliberate oversight" is an interesting concept! Looking at the data it appears they were coded to flash but not linked to any route.

Thanks

Peter

By "deliberate oversight" I meant that the coders knew they were supposed to flash, but for some reason decided not to implement it. :)

In my experience, I have never come round the left-hand corner towards E84 (it isn't visible to drivers as they pass DM212) and found it to be STEADY double yellow with junction indicator 4 giving me the road across to the Up Main line.

lazzer in post 118005 said:

In my experience, I have never come round the left-hand corner towards E84 (it isn't visible to drivers as they pass DM212) and found it to be STEADY double yellow with junction indicator 4 giving me the road across to the Up Main line.

The normal rules for flashing aspects are:
* Hold the signal beyond the junction at red.
* Once the driver has had a chance to see the junction indicator lit, release the signal beyond the junction but limit the junction signal to double yellow.
* Once the train has passed the AWS magnet, release the junction signal to green (assuming the signals ahead allow that).

clive in post 118023 said:

lazzer in post 118005 said:

In my experience, I have never come round the left-hand corner towards E84 (it isn't visible to drivers as they pass DM212) and found it to be STEADY double yellow with junction indicator 4 giving me the road across to the Up Main line.

The normal rules for flashing aspects are:
* Hold the signal beyond the junction at red.
* Once the driver has had a chance to see the junction indicator lit, release the signal beyond the junction but limit the junction signal to double yellow.
* Once the train has passed the AWS magnet, release the junction signal to green (assuming the signals ahead allow that).

I don’t know how widespread that arrangement is, but the yellow normally steps straight up to a green in every example that I regularly encounter (some dating from the 70s, others very recent), well before reaching the magnet, obviously subject to signals in advance. It makes sense too - otherwise receiving a warning at the magnet would become routine for the diverging route, meaning that there’d be more chance of overlooking the junction signal only stepping up to YY or remaining at Y.

Note that some rules have changed over the years for flashing yellow sequences though. In the 1970s they were allowed for multiple routes from the same signal, then they decided only one route could use them, but now I believe it's been relaxed again to allow 2 routes, or possibly more.

lazzer in post 118005 said:

In my experience, I have never come round the left-hand corner towards E84 (it isn't visible to drivers as they pass DM212) and found it to be STEADY double yellow with junction indicator 4 giving me the road across to the Up Main line.

The normal rules for flashing aspects are:
* Hold the signal beyond the junction at red.
* Once the driver has had a chance to see the junction indicator lit, release the signal beyond the junction but limit the junction signal to double yellow.
* Once the train has passed the AWS magnet, release the junction signal to green (assuming the signals ahead allow that).

Uddingston Junction is slightly different (I think it's because it goes from 4 aspect to 3 aspect signalling on the Up Holytown). On approach to UDD (Providing that GMN186 (M186 pre-WSSC) is showing a proceed aspect, then GMN182 (M182) will show a single Y with route indicator with it stepping up to G when the train activates TC276 which, by observation every day, is when the train passes over the AWS magnet just before the platform ramp. Completely missing out YY.

Craig

Hap in post 118034 said:

Uddingston Junction is slightly different (I think it's because it goes from 4 aspect to 3 aspect signalling on the Up Holytown). On approach to UDD (Providing that GMN186 (M186 pre-WSSC) is showing a proceed aspect, then GMN182 (M182) will show a single Y with route indicator with it stepping up to G when the train activates TC276 which, by observation every day, is when the train passes over the AWS magnet just before the platform ramp. Completely missing out YY.

Craig

Same at Ashburys junction for trains running via Reddish

I think it does both thinking about it - normally my first sight of it is with Y and number 4 indicator, it then goes green around the AWS magnet. However there is a chance to get a brief view from further away and the signal does always seem to be on at that point, but it isn't easy to tell as it's a glimpse through foliage/OHLE.