Signal Sighting (not Siting)

[iands]

Not long after the Shard was officially opened (and all the scaffolding, cranes, etc. removed) a problem became apparent that (probably) no-one would have imagined. Easy to see how the suns glare/reflection can cause problems for drivers spotting signals. One signalling problem that the modellers don't need to worry about!

 

 

Regards, Ian.

[imt]

OOPS! That looks terrible, how do the drivers cope?  Actually it is a problem for modellers.  Since I like to drive to the signals on my layout, I have to move the window blinds so that the tiny lights are actually visible!  Not that much different - but nobody dies on my model railway if I get it wrong.

[TheSignalEngineer]

I don't know what the current situation is with Network Rail, but about 40 years ago when i was responsible for processing Signal Sighting Forms on a BR Division I used to receive copies of all Planning Applications in the vicinity of the railway within our area. These were assessed as to whether the work fell in line of sight of the railway or nearly so, colour and intensity of illuminated signs, large windows or shiny surfaces. Similar rules applied to street lighting and road signs being put up by local councils. If we thought it could be a problem a meeting of the Local Signal Sighting Committee was convened to go out and view the situation, in some cases from the front of a convenient DMU or 'borrowing' a trip loco. I remember on one occasion recommending a particular type of lantern on a new stretch of road to reduce light spill towards the railway on a curved approach to a signal and on another the shielding of a set of traffic lights and providing an intensified electric light for a semaphore signal where there was a crossroads on top of a railway bridge.

Edited November 18, 2017 by TheSignalEngineer

[The Bigbee Line]

I don't know what the current situation is with Network Rail, but about 40 years ago when i was responsible for processing Signal Sighting Forms on a BR Division I used to receive copies of all Planning Applications in the vicinity of the railway within our area. These were assessed as to whether the work fell in line of sight of the railway or nearly so, colour and intensity of illuminated signs, large windows or shiny surfaces. Similar rules applied to street lighting and road signs being put up by local councils. If we thought it could be a problem a meeting of the Local Signal Sighting Committee was convened to go out and view the situation, in some cases from the front of a convenient DMU or 'borrowing' a trip loco. I remember on one occasion recommending a particular type of lantern on a new stretch of road to reduce light spill towards the railway on a curved approach to a signal and on another the shielding of a set of traffic lights and providing an intensified electric light for a semaphore signal where there was a crossroads on top of a railway bridge.

I have a feeling that a lot of this common sense type of stuff has gone out of the window (sadly).  It must be an age thing, I often think 'what is the world coming to...

[timbowilts]

Being five weeks away from retiring from the signal engineering proffession, mostly on the new-works side of things, my impression is that Network Rail are more reactive than pro-active these days. It only gets looked at if there is an “operating incident” or if the SME happens to be out on his patch at the right time of day

 

Tim T

[iands]

Being five weeks away from retiring from the signal engineering proffession, mostly on the new-works side of things, my impression is that Network Rail are more reactive than pro-active these days. It only gets looked at if there is an “operating incident” or if the SME happens to be out on his patch at the right time of day

 

Tim T

 

I think NR are still "pro-active" with such things as Signal Sighting when it is there design and they are in control of the "project". However, if it is a non-railway development that is away from the railway "boundary", I think you are right in that only a cursory look at the proposals is given.

 

Regards, Ian.

[iands]

I don't know what the current situation is with Network Rail, but about 40 years ago when i was responsible for processing Signal Sighting Forms on a BR Division I used to receive copies of all Planning Applications in the vicinity of the railway within our area. These were assessed as to whether the work fell in line of sight of the railway or nearly so, colour and intensity of illuminated signs, large windows or shiny surfaces. Similar rules applied to street lighting and road signs being put up by local councils. If we thought it could be a problem a meeting of the Local Signal Sighting Committee was convened to go out and view the situation, in some cases from the front of a convenient DMU or 'borrowing' a trip loco. I remember on one occasion recommending a particular type of lantern on a new stretch of road to reduce light spill towards the railway on a curved approach to a signal and on another the shielding of a set of traffic lights and providing an intensified electric light for a semaphore signal where there was a crossroads on top of a railway bridge.

 

I agree with your sentiments re "that is how it used to be done", and still is to some extent regarding a "signal sighting committee" being convened (if it is a wholly owned NR project). But taking your example, it would be somewhat difficult to try and replicate or predict such an occurrence physically until the building was completed, by then of course it is a bit late to change things. Perhaps there is an opening for someone out there to develop a bit of clever computer software that could simulate such occurrences. Also bearing in mind how often would "all the ducks be in a row" to provide such an occurrence (e.g. correct time of day, train in correct position, sun actually shining, sun at correct angle, etc.). I know it only takes one instance when all these things line up to cause a disaster when all manner of investigations would ensue, but with more and more glass covered buildings being developed these days, particularly in large urban areas, it might be worth an investment for some entrepreneur out there? 

 

Regards, Ian.

[big jim]

Signal sighting nowadays seems to comprise of someone who doesn’t know what a train looks like sat in front of a computer looking at the ‘computer model’ of how far apart the signals should be then simply adding the data to a straight line map without knowledge or understanding of things like gradients, curves, structures etc

 

I know that opinion ‘upsets’ some on here but honestly I see new signals going up and wonder did Stevie wonder get the job designing them!

 

The new (as yet to be commissioned) signals between soho and perry Barr are a recipie for disaster for either sliding past them or not getting away from them in low adheadion conditions

 

Regards the original post, dropping into Salop from Gobowen up until very recently had a similar thing where the signal ‘disappeared’ into the lighting located behind, you would see the distant and it wasn’t until you were say 1/4 mike from the stop semaphore you would see the aspect (oil lit lamp), annoyingly the lighting that interferes with it was the canopy lights on platform 3 in shrewsbury station, as I say it’s been changed now, must have swapped the lights as well as fitting LED lamps to the signal and you see the stop signal a good 2 miles back now!

[TheSignalEngineer]

We were already experimenting with sighting by computer when City Thameslink was first being designed. I had a set of computer generated artists impressions which were done from the architects drawings with our proposed signal positions plotted on them. 

Nowadays this is much easier to do. I remember that somewhere posted a while back there is a simulation of the flyover at Norton Bridge which was produced before the signals were erected. The only problem is that you still have to know what you are looking at and check it on site. In that particular case to my mind there is one signal located in a very poor position from an operating viewpoint.

A former 'Old School' engineer who was head of Signalling Projects on BR at one time was firmly of the opinion that the quickest way to a ****-up was to rely on what was produced on the drawing board.

 

Regarding glass buildings, windows have provided a problem for years. I remember a phantom aspect  appearing when a new colour light signal was commissioned near Stafford Road Junction c1969. It was caused by one of the few remaining windows in the derelict loco works. Needless to say no-one asked questions when it disappeared the same night.

[iands]

Signal sighting nowadays seems to comprise of someone who doesn’t know what a train looks like sat in front of a computer looking at the ‘computer model’ of how far apart the signals should be then simply adding the data to a straight line map without knowledge or understanding of things like gradients, curves, structures etc

 

I know that opinion ‘upsets’ some on here but honestly I see new signals going up and wonder did Stevie wonder get the job designing them!

 

The new (as yet to be commissioned) signals between soho and perry Barr are a recipie for disaster for either sliding past them or not getting away from them in low adheadion conditions

 

Regards the original post, dropping into Salop from Gobowen up until very recently had a similar thing where the signal ‘disappeared’ into the lighting located behind, you would see the distant and it wasn’t until you were say 1/4 mike from the stop semaphore you would see the aspect (oil lit lamp), annoyingly the lighting that interferes with it was the canopy lights on platform 3 in shrewsbury station, as I say it’s been changed now, must have swapped the lights as well as fitting LED lamps to the signal and you see the stop signal a good 2 miles back now!

 

Hi Big Jim,

 

I can't speak for all projects but I do know that for the original TfL East London Line project (and subsequent additional phases) some signal sighting was generated by 3D design software by the designers, BUT every signal position had to be reviewed and verified by an Independent Signal Sighting Chairman. Needless to say that some changes were required at the final design stage and IIRC a few minor tweaks were required at the test running/commissioning stage.

 

Regards, Ian.

[timbowilts]

Just to clarify my post #5 I was talking about existing signals where development outside the boundary fence has taken place since commissioning of said signals

 

Regards,

 

Tim T

[big jim]

Just to clarify my post #5 I was talking about existing signals where development outside the boundary fence has taken place since commissioning of said signals

Regards,

Tim T

A prime example of that, and I have highlighted it to authorities, is Trent jn, around 2015 they built some houses on the sharp curve coming from long Eaton to Trent which now impinge in the sighting of the signal protecting the Jn, you now don’t get a view of said signal until practically on the magnet, all it needs is a banner repeater adding and the problem would be solved, beforehand you got a pretty good view of the signal when you looked left out of the side window of the loco

[royaloak]

A prime example of that, and I have highlighted it to authorities, is Trent jn, around 2015 they built some houses on the sharp curve coming from long Eaton to Trent which now impinge in the sighting of the signal protecting the Jn, you now don’t get a view of said signal until practically on the magnet, all it needs is a banner repeater adding and the problem would be solved, beforehand you got a pretty good view of the signal when you looked left out of the side window of the loco

I take it the signal was fitted with a normal filament head because you cant really view an LED signal from anywhere but head on.

 

We have a few sited on corners that we used to be able to see from a couple of miles away, now they have been fitted with LED heads it is from about 300 yards away, we complained only to be told 'it is compliant with the standard'.

Edited November 18, 2017 by royaloak

[big jim]

It’s an LED type now (bulb fitted to a ‘normal’ signal) not a flat panel type signal

[caradoc]

An occasional problem during my railway career was temporary traffic lights for roadworks, on overbridges or where the road ran alongside the railway, resembling signals. Liaison with the local council usually addressed the issue.

[uax6]

I take it the signal was fitted with a normal filament head because you cant really view an LED signal from anywhere but head on.

 

We have a few sited on corners that we used to be able to see from a couple of miles away, now they have been fitted with LED heads it is from about 300 yards away, we complained only to be told 'it is compliant with the standard'.

 

I'm guessing that a couple of spads will have to occur before anyone takes any notice sadly... or do the other thing and get all the drivers to crawl upto it and put time in to the service. Rack up enough time and something will happen...

 

Andy G

[The Pilotman]

Whilst not wanting to make light of the situation (no pun intended) as outlined by the OP, I am guessing that the sun's reflection as shown would only affect a relatively small area for a relatively short space of time on a few days of the year, and then only with a clear sky. Given the number of glass structures on and around the railway these days, the occasional flash of the reflected sun must, I would have thought, be viewed as an unavoidable and short-lived nuisance.

Edited November 23, 2017 by Western Aviator

[iands]

Whilst not wanting to make light of the situation (no pun intended) as outlined by the OP, I am guessing that the sun's reflection as shown would only affect a relatively small area for a relatively short space of time on a few days of the year, and then only with a clear sky. Given the number of glass structures on and around the railway these days, the occasional flash of the reflected sun must, I would have thought, be viewed as an unavoidable and short-lived nuisance.

Hi Western Aviator,

 

Yep, you're guessing correctly, hence my point in earlier post above about an opportunity for some really clever person somewhere to develop some neat software. Yes it is a relatively short-lived nuisance, but can be a significant one if it ever results in an incident. If that should ever occur I'm sure that something would be done to make it "avoidable" thereafter.

 

Regards, Ian.

[jim.snowdon]

I take it the signal was fitted with a normal filament head because you cant really view an LED signal from anywhere but head on.

 

We have a few sited on corners that we used to be able to see from a couple of miles away, now they have been fitted with LED heads it is from about 300 yards away, we complained only to be told 'it is compliant with the standard'.

How far away do you need to see the signal, as against how far away would you like to see it?

 

The braking distance is, after all, calculated from the signal, not some distance before you reach it.

 

Jim

[big jim]

It’s all dependent on the route, certain signals I like to see way ahead so I know whether to keep the power open, shut off, check the route etc

 

It’s a very rare situation where I’d actually be passing a caution signal at line speed then shutting off and braking for the stop signal, anything could happen between those points, low adheasion, wheel slide etc, I like to have plenty of ‘get out time’ should something go awry, I’be normally got the brake in way before passing the caution

 

Of course there are signals you don’t want to be reading through as that’s as bad as not being able to see ones that apply to you

[phil-b259]

How far away do you need to see the signal, as against how far away would you like to see it?

 

The braking distance is, after all, calculated from the signal, not some distance before you reach it.

 

Jim

 

IIRC modern rules dictate that drivers must be able to see the signal aspect for 10 seconds at a minimum when traveling at line speed (reduced to 7seconds for older pre 2000 installations). For the last 5 seconds that view must NOT be interrupted by structures (e.g. OLE masts, platform canopies, bridges, etc.)

 

Where sighting times cannot be met then banner repeaters MUST be used or the line speed reduced so as to bring the time the driver has to observe the signal to within the guidelines.

[iands]

How far away do you need to see the signal, as against how far away would you like to see it?

The braking distance is, after all, calculated from the signal, not some distance before you reach it.

Jim

IIRC the red aspect (for colour-light signals) was "aligned/focussed" to be viewed at its "fullest" by the driver from the AWS magnet which is 200 yards (180 metres) on the approach to the signal. The fact that the signal may still be seen from a much greater distance (subject to curves, structures, etc.) is perhaps an advantage of colour-lights over semaphore signals.

 

Regards, Ian.

[big jim]

IIRC the red aspect (for colour-light signals) was "aligned/focussed" to be viewed at its "fullest" by the driver from the AWS magnet which is 200 yards (180 metres) on the approach to the signal. The fact that the signal may still be seen from a much greater distance (subject to curves, structures, etc.) is perhaps an advantage of colour-lights over semaphore signals.

 

Regards, Ian.

 

new LED signals are very hard to judge distance wise, last night for example i was doing a rail drop on the halton chord, i had to draw the train forward to drop the rail and having already passed the distant for halton the red was in view, both myself and the ES questioned whether the distance had been measured correctly as the red looked to be 100m or so ahead (despite not having got to its magnet), when the ES went out to check he measured it at 300+ meters away, in fact i even questioned the position of the worksite marker boards he'd put out as they looked to be beyond the signal but they were in fact 50yds my side of it 

[43110andyb]

May be of interest- Signal sighting distance chart from NR SMS part Z

 

[iands]

new LED signals are very hard to judge distance wise, last night for example i was doing a rail drop on the halton chord, i had to draw the train forward to drop the rail and having already passed the distant for halton the red was in view, both myself and the ES questioned whether the distance had been measured correctly as the red looked to be 100m or so ahead (despite not having got to its magnet), when the ES went out to check he measured it at 300+ meters away, in fact i even questioned the position of the worksite marker boards he'd put out as they looked to be beyond the signal but they were in fact 50yds my side of it 

Hi Big Jim,

 

Very interesting to hear the "end users" views regarding the LED signals. Although I work in the railway industry, I'm not a (train) driver. I find it difficult sometimes driving at night to judge the distance of on-coming vehicles when all you can see are the headlights, I imagine this is similar to what you experience. I'm not suggesting the "lamp lit" signals were easy to judge the distances at night, but what you seem to be saying is it was at least a bit easier to judge the distance (relatively speaking).

 

Regards, Ian.