BR(S) Colour light signalling help please...

[ikcdab]

Although I think I know a lot about semaphores, my understanding of MAS is a little bit thinner.

The scenario is southern region, late1960s. My layout is here. 

The track diagram is shown below. The approach homes (3) and platform starters (1 and 2) all have route indicators (theatre style) that allow routing to any other feasible line. So a train leaving P1, can be routed via signal 2 to the UM or DM. As I imagine that the lines are fully track circuited, I assume no further running GPLs are required as once signal 2 has been cleared and the track circuits occupied by the departing train, all the pointwork is locked.

A train shunting from (say) P3 to (say) P2, could depart P3, run beyond signal 3 on the DM, then is routed from signal 3 back into P2. Equally feasible, it could depart P3, through crossover 12 and beyond signal 3 on the UM. Then signal 3 routes it back from the UM into P2. Track circuiting takes care of all the point locking and I haven’t planned for any running GPLs.

Points marked H are intended to be “hand worked”.

So my questions.

1.       I assume I need a GPL at A. When crossover 10 is normal, trains in the yard can shunt to and fro as much as they want. When they need to be routed onto the DM, crossover 10 is reversed and the GPL cleared. Is this GPL a “normal” one, or is it something special with yellow lights allowing it to be passed at caution when the route is set into the headshunt?

2.       Pretty much the same question applies to the GPL at B. when shunting from the goods reception (GR) into the goods sidings, GPL B needs to be passed at caution and is only cleared when the route is from GR to the main lines.

3.       Do I need a GPL on the DM at the toe of points 10? As I have organized it so far, an engine shunting from P3 to the loco sidings (LS) needs to run out beyond signal 3 and then be routed from signal 3 back into the LS. If I had a GPL at the toe of 10, the loco need only run just beyond the GPL to allow crossover 10  to be reversed. If I do that, is this GPL a running one which clears for both positions, or does it only clear when the route is set into the LS. If one GPL covers both routes, how does the driver know which route is set, apart from looking at the points?

I know that with signalling, there is rarely one definitive answer and it can be subjective. Also, this is a model railway, I am  not trying to signal a real life location, so simplification is possible. 

I have  been looking at the DCC concepts steam era GPLs which come in a pack of 4, so I am happy to use up to 4 GPLs if needed!

The reason the two signals at 2 both share the same number, is that both signals are worked from a single control knob on the panel. Same goes for the two signals at 3.

Many thanks

Ian

 

 

[ikcdab]

I should add that I am aware that br(s) terminals with colour lights at this period outside London were rare beasts, but rule 1 applies and I am keen on having colour light signals. The rest of the layout is semaphore!

Ian

[iands]

Just for starters, not sure why you would need theatre routers on platform starters, surely the only route would be to the Down Main? 

Edited October 18, 2020 by iands
Added missing word.

[roythebus]

From right to left, the signal facing the platform on the DM would be  a shunt signal with theatre indicator with 6 options, not a main aspect. the DM is not a reversible line and no passenger movements in the Up direction.

 

subsidiary signal A? will be a yellow/white ground signal showing 2 whites when the road is set to DM; similarly B? with 2 routes UM or DM.

 

The "arrival" signal at UM will have theatre indicators for the route setting plus a subsidiary signal for entering an occupied platform for coupling units up or light engine onto train.

 

There would also be stop boards at the top headshunt for moves from the headshunt to LS1 and LS2 and bottom sidings GS1-3 to GR, "STOP do not pass without shunter's permission" or similar.

 

There will also be subsidiary signals below all the platform starters for shunt moves towards UM,  a train could shunt onto DM towards the advance starter using the main proceed aspect. 

 

There must be a subsidiary on P1 and P2 starters for shunt moves towards UM, a wrong line move, and a Limit of Shunt board a "safe distance" away from signal 4 on UM.

 

But then I'm not a signal engineer, I just drove trains on the Southern for years.

Edited October 18, 2020 by roythebus

[roythebus]

Add to my previous comment that the platform starters would only be capable of showing a "proceed" aspect without route indication when the road is set towards DM. Any move to UM would be a wrong line shunt move.

[bécasse]

1. There was no bidirectional signalling of normal running lines on the Southern in the 1960s.

2. The platforms are numbered the wrong way round, the Southern standard was that the left hand platform as viewed from the concourse was platform 1.

3. The Up Main should just be the Down line and the Down Main should just be the up line (unless this is meant to be a central London terminal à la Holborn Viaduct - but the use of "line" rather than "Main" still applies). The Southern, where there was more than a single running line in each direction, used the terms "Through Line(TL)" and "Local Line (LL)", although these may have been changed (under BR standardisation) to Fast Line and Slow Line by the end of the 1960s.

4. The "approach" signal would have been three aspect with a theatre type indicator, clearing to green for a clear platform or yellow for a partially occupied platform.

5. There would have been a w/r-w gpl as an approach signal on the departure line to permit shunting, not a running signal. It almost certainly wouldn't have any route indicator and it would have been located close to the toe of no.11 points.

6. The two gpls that you do show at the exit from the sidings either side would both have been y/w-w, only clearing when exit from the sidings was required.

7. If the installation of colour light signals predated c1964, the gpls would have been motor-worked floodlit discs. Yellow discs had a black background, red discs a white background, the attached photo shows (bottom right) a floodlit disc at Sheerness (installed 1959).

Edited October 18, 2020 by bécasse
Information about ground signals amended.

[iands]

22 hours ago, roythebus said:

From right to left, the signal facing the platform on the DM would be  a shunt signal with theatre indicator with 6 options, not a main aspect. the DM is not a reversible line and no passenger movements in the Up direction.

I agree this signal should be a GPL, but suggest there are only 5 routes as there is a set of hand points that won't be detected in the Signalling controls. Alternatively, this set of points need to be power operated and detected to give you the 6 routes. 

Edited October 19, 2020 by iands
Added missing word.

[Oldddudders]

I foresee big problems when the first freight train arrives as it is unable to run round to depart, other than light engine. 

[The Stationmaster]

It is perhaps pertinent to ask the date when this layout was resignalled with colour lights because that would seriously impact the sort of ground signals used - i/.e would they be discs or would they be GPLs

[Nearholmer]

1 hour ago, bécasse said:

There was no bidirectional signalling of normal running lines on the Southern in the 1960s.

Are you sure?

 

I thought there was a three track section (maybe on the route into Holborn Viaduct?) that was signalled Up, Reversible, Down from some time pre-war.

 

Possibly not strictly bi-directional, in that the reversible was used for ‘tidal flow’, being switched to Up or Down, rather than used interchangeably on a fast-paced basis.

 

Werent there other ‘reversibles’ too?

[Oldddudders]

1 hour ago, Nearholmer said:

Werent there other ‘reversibles’ too?

East Croydon to South Croydon certainly had one. But any such facility tended to be a short section in an intensively-trafficked area. This terminus is not apparently thus.  

[Oldddudders]

2 hours ago, The Stationmaster said:

It is perhaps pertinent to ask the date when this layout was resignalled with colour lights because that would seriously impact the sort of ground signals used - i/.e would they be discs or would they be GPLs

Certainly the 1959-62 resignalling for Kent Coast Electrification used discs. 

[The Stationmaster]

1 hour ago, Oldddudders said:

Certainly the 1959-62 resignalling for Kent Coast Electrification used discs. 

Checking through notices - which of course don't necessarily cover everything it looks like position light subsidiaries to read to sidings were being installed in new work in 1965 but the use of GPLs instead of illuminated discs didn't get underway in new work until 1966 and the SWML resignalling.

[RailWest]

<pedantic hat on>

Surely, strictly speaking, this is not 'MAS signalling' anyway, but just a 'traditional' signalling installation done with C/Ls rather than semaphores? Are you assuming also all points to be motor-worked rather than mechanical?

<pedantic hat off>

 

>>>The reason the two signals at 2 both share the same number, is that both signals are worked from a single control knob on the panel. Same goes for the two signals at 3.

Well, that might work for 2 but not for 3 as the layout allows for parallel moves, eg a shunt move from DM to P3 at the same time as a running move from UM to P2 or P1 etc.

[Oldddudders]

9 minutes ago, RailWest said:

<pedantic hat on>

Surely, strictly speaking, this is not 'MAS signalling' anyway, but just a 'traditional' signalling installation done with C/Ls rather than semaphores? Are you assuming also all points to be motor-worked rather than mechanical?

<pedantic hat off>

 

True. And that is something the Southern Railway did in places in the late 30s. Dorking, Horsham, Arundel - maybe others - were all resignalled with colour lights and power points - but trains were run between boxes under Absolute Block. 

[ikcdab]

2 hours ago, RailWest said:

<pedantic hat on>

Surely, strictly speaking, this is not 'MAS signalling' anyway, but just a 'traditional' signalling installation done with C/Ls rather than semaphores? Are you assuming also all points to be motor-worked rather than mechanical?

<pedantic hat off>

 

>>>The reason the two signals at 2 both share the same number, is that both signals are worked from a single control knob on the panel. Same goes for the two signals at 3.

Well, that might work for 2 but not for 3 as the layout allows for parallel moves, eg a shunt move from DM to P3 at the same time as a running move from UM to P2 or P1 etc.

Hi Chris, your pedantic hat must be worn out!

Well it is MAS inasmuch as the colour lights have multiple aspects. I have assumed that this is a local installation worked from a local signalbox. The points have been converted to point machines (Mike H on the WSR tells me that is the correct term, not point motor) and it has been fully track circuited. The mainline junctions remain semaphore worked.

Ian

[ikcdab]

10 hours ago, iands said:

Just for starters, not sure why you would need theatre routers on platform starters, surely the only route would be to the Down Main? 

Point well made, I guess I was looking fur maximum flexibility.

Ian

[ikcdab]

9 hours ago, Oldddudders said:

I foresee big problems when the first freight train arrives as it is unable to run round to depart, other than light engine. 

Actually this is deliberate. It is, if course, an enlarged Minories, and the intention is to have a station pilot for loco release. An excuse to make operations more interesting.

Ian

[ikcdab]

10 hours ago, bécasse said:

1. There was no bidirectional signalling of normal running lines on the Southern in the 1960s.

2. The platforms are numbered the wrong way round, the Southern standard was that the left hand platform as viewed from the concourse was platform 1.

3. The Up Main should just be the Down line and the Down Main should just be the up line (unless this is meant to be a central London terminal à la Holborn Viaduct - but the use of "line" rather than "Main" still applies). The Southern, where there was more than a single running line in each direction, used the terms "Through Line(TL)" and "Local Line (LL)", although these may have been changed (under BR standardisation) to Fast Line and Slow Line by the end of the 1960s.

4. The "approach" signal would have been three aspect with a theatre type indicator, clearing to green for a clear platform or yellow for a partially occupied platform.

5. There would have been a w/r-w gpl as an approach signal on the departure line to permit shunting, not a running signal. It almost certainly wouldn't have any route indicator and it would have been located close to the toe of no.11 points.

6. The two gpls that you do show at the exit from the sidings either side would both have been y/w-w, only clearing when exit from the sidings was required.

7. If the installation of colour light signals predated 1959, the gpls would have been motor-worked floodlit discs.

Thanks for the comments which are very helpful.

[ikcdab]

9 hours ago, The Stationmaster said:

It is perhaps pertinent to ask the date when this layout was resignalled with colour lights because that would seriously impact the sort of ground signals used - i/.e would they be discs or would they be GPLs

 You may ask,  but as its all entirely fictional, who knows. I have set the layout in mid to late 1960s, so the resignalling would have been done before that!

Sounds like discs might be more appropriate than GPLs. Is the disc a standard br(s) one with a flood light over it? If so, any pics?

Ian

[bécasse]

10 minutes ago, ikcdab said:

 You may ask,  but as its all entirely fictional, who knows. I have set the layout in mid to late 1960s, so the resignalling would have been done before that!

Sounds like discs might be more appropriate than GPLs. Is the disc a standard br(s) one with a flood light over it? If so, any pics?

Ian

I have added a picture to my previous post. The Southern had used similar floodlit round discs, red/white or yellow/black, as part of colour light installations since Waterloo (terminus) box was opened in 1937(?), having previously used miniature light signals.

[RailWest]

48 minutes ago, ikcdab said:

Hi Chris, your pedantic hat must be worn out!

 

My wife bought me a new one for my birthday :-) 

[Nearholmer]

Hope to goodness she chose exactly the right one.

 

 

Edited October 18, 2020 by Nearholmer

[ikcdab]

11 hours ago, bécasse said:

4. The "approach" signal would have been three aspect with a theatre type indicator, clearing to green for a clear platform or yellow for a partially occupied platform.

Thanks for your comments. Are you certain about this? My understanding (though I now cannot find the quote) was that as the next "signal" is the permanent red light on the buffer stop, then this signal should only show red/yellow. Of course, this might be a date thing where practice has changed.

 

12 hours ago, bécasse said:

7. If the installation of colour light signals predated c1964, the gpls would have been motor-worked floodlit discs. Yellow discs had a black background, red discs a white background, the attached photo shows (bottom right) a floodlit disc at Sheerness (installed 1959).

Thank you, great photo, i wonder what was causing all the attention around the point machine.

Ian

 

[ikcdab]

Thank you all for your helpful replies. I now have some thinking to do.

I still quite like the idea of having working GPLs even thought they might be out of timeframe. I like the look of these:

https://www.dccconcepts.com/product/4x-2-wire-lms-br-ground-signal/

It says they have been in use since the 1930s, bit I guess not on the southern where you say they only appeared from 1960s.

If I do use these, I guess I can paint over the white LEDs with yellow nail varnish to give the yellow aspects. Has anyone done this?

Ian