Flickering Signal

[Deepgreen]

Last autumn I reported a signal fault to NR and received no response from them. The signal was RG88 - EB at Dorking Deepdene, which was flickering at frequent intervals and displaying no aspect at all during the severest flickers! Having had no reply last autumn, I assumed they had at least fixed the fault, but; no - when I was there again on Friday, the same fault was still evident! I have e-mailed NR again, but have, again, yet to receive a response or even an acknowledgement. Why is it so hard to get anything out of NR in the way of response? Of about ten messages on various subjects I have sent them over the last year or so, they have only replied to about three.
Has anyone else witnessed signal faults such as this?

 

[carriageline]

Who did you report it to and how? I dount you was the only person to have reported it, what aspect flickers, or is it all? Is it constant?

I imagine (could be wrong, depending on the area) a fault could of been logged automatically, depending on the signalling/interlocking system

 

[1e10]

How come a driver wouldn't have reported it? Is the line used if the fault is still there several months on?

 

[Deepgreen]

Reported via the NR web site's faults page. I have only witnessed the green aspect (which is by far the most often shown aspect at this location) flickering and going out, but this does not necessary mean the yellow and red aspects don't flicker too.
As I said, given that I first reported it last year, I'm amazed that nothing (apparently) has been done (and that NR didn't even respond).
I find it hard to believe that at least a few drivers haven't noticed it. Photo attached from Friday (from Flickr - appropriately!), and one I took of the same signal last year.

https://www.flickr.com/photos/deepgreen2009/14575156921/
https://www.flickr.com/photos/deepgreen2009/9725507728/

 

[Llanigraham]

Sorry, but all your photos show is a black signal!
Do you work on the railway?

 

[Muzer]

Sorry, but all your photos show is a black signal!
Do you work on the railway?

...a photo is hardly going to flicker, is it?

 

[Deepgreen]

Sorry, but all your photos show is a black signal!
Do you work on the railway?

A signal should never be without any aspect showing (i.e. appearing 'black') - that's the point.

 

[edwin_m]

You haven't by any chance only seen this on video? Some LED signals flicker too fast to be seen by the human eye but it can be picked up when it is close to the frame rate of a video recording.

Apologies if I'm saying something here that you already know!

 

[Llanigraham]

A signal shoud never be without any aspect showing (i.e. appearing 'black') - that's the point.

Really?
Have you a Rules reference to that?
Do you work on the railway?

 

[Deepgreen]

...a photo is hardly going to flicker, is it?

No, but it should be impossible to capture a signal without any aspect showing, because tungsten bulb units such as this one always show at least one colour even when changing aspect -e.g. when a train passes it will turn from green to red, and the green will still be visible for a fraction of a second after the red has lit.

 

[Muzer]

No, but it should be impossible to capture a signal without any aspect showing, because tungsten bulb units such as this one always show at least one colour even when changing aspect -e.g. when a train passes it will turn from green to red, and the green will still be visible for a fraction of a second after the red has lit.

Indeed - if you look at the post I quoted, he seemed surprised that your photo only showed a black signal. I wondered what exactly he was expecting to see, given the description of the problem and the fact that it's a photo

 

[edwin_m]

A signal shoud never be without any aspect showing (i.e. appearing 'black') - that's the point.

Certain signals are "approach lit" - they only light up when a train is detected approaching them. Early colour light schemes powered by batteries may have done this to save power, but is now mainly found at signals in loops where there is no adjacent signal on the through line so there would otherwise be the risk of confusing passing drivers. The signal in the photo doesn't fit this and I've no idea if it might be approach lit for other reasons.

 

[Deepgreen]

Really?
Have you a Rules reference to that?
Do you work on the railway?

Any active signal must display an aspect - it's an absolutely fundamental signalling principle.
No.
Yes.
--- old post above --- --- new post below ---

Certain signals are "approach lit" - they only light up when a train is detected approaching them. Early colour light schemes powered by batteries may have done this to save power, but is now mainly found at signals in loops where there is no adjacent signal on the through line so there would otherwise be the risk of confusing passing drivers. The signal in the photo doesn't fit this and I've no idea if it might be approach lit for other reasons.

It's not apparoach lit at all - it shows a green aspect that flickers on and off frequently, but irregularly. I don't know if other apsects are involved (to check would mean missing my departing train to observe!).

 

[Tomnick]

Any active signal must display an aspect - it's an absolutely fundamental signalling principle.

Approach lit, flashing yellow and flashing green signals would all seem to be contrary to that, and could all easily be photographed in an unlit state! I agree that this signal doesn't appear to fit any of those three though.

 

[OxtedL]

Reported via the NR web site's faults page. I have only witnessed the green aspect (which is by far the most often shown aspect at this location) flickering and going out, but this does not necessary mean the yellow and red aspects don't flicker too.

Have you seen it with your bare eyes, or just through a camera?

 

[headshot119]

Any active signal must display an aspect - it's an absolutely fundamental signalling principle.
No.
Yes.
--- old post above --- --- new post below ---


It's not apparoach lit at all - it shows a green aspect that flickers on and off frequently, but irregularly. I don't know if other apsects are involved (to check would mean missing my departing train to observe!).

Sorry but that's not correct.

Approach lit signals.
Flashing yellows
Flashing greens
And the emergency signals at RAF valley!

 

[GB]

I know Network Rail usually come in for some flack on this site but I find it hard to believe that if there is a problem they haven't done anything about it. How do you know this is not a separate fault from the original?

 

[carriageline]

Me too GB. Unless the fault was never escalated to the local fault teams (would not suprise me), but I would also suspect a driver or maintenance teams to of seen it. Not knowing much about the area, the engineers terminal could of logged a fault, plus signals could be going back if the lamp is being proved unlit.

I think there may be more to this, and I want to answer the same question, you saw this with your eyes yes?

As you say you work on the railway, there is definetlu better ways to report a fault (ie directly to the box), and im quite shocked you did it through the website (even more so if the signal was going blank),
.are you sure you work on the railway? Like I say, there are much better ways than using network rails site. But of course, you may not be rules trained so may not necessarily know that.

Could anyone let me know what box controls that signal? I'll see if I can raise it internally.

Sent from my iPhone using Tapatalk

 

[TOCDriver]

Pretty sure it's Reigate Signalbox

 

[Minilad]

I don't know if it's just me but that first picture looks like a green aspect is showing and its just not very bright. Zooming in shows a definite difference to the other two lights

 

[DownSouth]

Could anyone let me know what box controls that signal? I'll see if I can raise it internally.

Probably best to wait until the OP stops avoiding the question about whether they've seen it for real or just in photos/videos. As others have noted, this flickering effect is entirely normal for photos and videos of LED signals, but not visible to the naked eye.

If it is a real problem, you could depend on train drivers to report it through the correct channels as it is their lives that depend on it.

 

[Harbon 1]

Reported via the NR web site's faults page. I have only witnessed the green aspect (which is by far the most often shown aspect at this location) flickering and going out, but this does not necessary mean the yellow and red aspects don't flicker too.
As I said, given that I first reported it last year, I'm amazed that nothing (apparently) has been done (and that NR didn't even respond).
I find it hard to believe that at least a few drivers haven't noticed it. Photo attached from Friday (from Flickr - appropriately!), and one I took of the same signal last year.

https://www.flickr.com/photos/deepgreen2009/14575156921/
https://www.flickr.com/photos/deepgreen2009/9725507728/

The first image looks like the sun is shining directly onto it as there is no shadow across the track and the hoods are creating a shadow, thus making it more difficult (well, less easy) to pick the green aspect out. The Exif data shows it's a low ISO and a faster shutter time, so it must have been bright to get that photo.

The second image is also taken with a very low ISO and on a fast shutter speed, that's likely why you cannot see the green aspect.

There is a split second when you can get a photo of a signal showing no aspect, I know first hand, but this is different. The green is visible and if it is less visible then the AWS would confirm it, although if it goes out or gets too bad a driver would report it. (I have no idea where this line is so i don't know service patterns, T/FOCs that run over it etc)

I'd put this down to the camera settings as it doesn't appear to be an LED signal, unless the bulbs have been replaced with LEDs but in that case it would be brighter but it is certainly not blank.

 

[The Planner]

I thought it was possible for a splitting distant to show a black aspect?

 

[Tomnick]

I thought it was possible for a splitting distant to show a black aspect?

One of the individual heads might be black (if it's at danger, or possibly if there's no route set through the junction - not sure about the latter), but never the whole signal.

 

[Islineclear3_1]

If this is a filament signal, isn't there a second bulb that kicks in when the other fails? And surely this would show up as a fault in the signal box?

 

[Tomnick]

There's usually (?) a second filament, but auto signals (as this one is) aren't always repeated back in the box - though there will be controls to hold the signal in rear at danger or single yellow.

 

[Islineclear3_1]

There's usually (?) a second filament, but auto signals (as this one is) aren't always repeated back in the box - though there will be controls to hold the signal in rear at danger or single yellow.

Fair enough but a driver would have reported it to the relevant box if he approached it showing no aspect.

Another thought: sometimes a light may appear to flicker when leaves/branches get caught by the wind and their shadow falls on and off the light

 

[Railsigns]

Probably best to wait until the OP stops avoiding the question about whether they've seen it for real or just in photos/videos.

If you read each of the OP's posts (#13 in particular), it's clear that the flickering aspect was observed by the naked eye.

 

[Tomnick]

Yep, it'd almost certainly have been reported by now if it really was going black with any regularity, either because a driver would've observed it directly, or reacted to the effect on the signal in rear! It could well be repeated in the box anyway, it's just not always the case.

 

[Railsigns]

Yep, it'd almost certainly have been reported by now if it really was going black with any regularity, either because a driver would've observed it directly, or reacted to the effect on the signal in rear! It could well be repeated in the box anyway, it's just not always the case.

If the lamp was just flickering, as opposed to going out for any length of time, it wouldn't necessarily affect the signal in rear since lamp proving relays are designed to be slow to drop once de-energised, to avoid appearing as a fault each time a change of aspect occurs.