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Signalling Advice


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Hi,

Just wondered if anyone coud advise re the signalling on the following layout.

The top points would be operated by a signal box further down the line with the lower ones being hand operated (unless some would be operated by motors?)

 

Appreciate any advise.

 

 

 

 

 

 

post-29767-0-75036800-1490526526_thumb.jpg

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IMO, it would be better if the track plan at the station throat was altered a little as per the following diagram.

However, either way, your main line signals are ok with the exception of the one leading out of the sidings.

This would be better as a ground signal (the light blue open circle) AND adding in a trap point to protect the main lines.

The signal in the tunnel on the approach to the station should have a route indicator to show which route was set -

1 or 2 for the platforms (or however you have numbered them) and maybe S for sidings. Of course, these need not work,

indeed if the signal was in the tunnel, it wouldn't be seen anyway!

post-7160-0-01189100-1490529538_thumb.jpg

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Many thanks for that dave55uk :-)

 

Unable to change that plan as the track is already laid but should be able to fit a trap point in.

 

For the ground signal would this be a shunt signal type? I'm using Berko / Eckon signals.

 

Cheers Ian.

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The signal exiting the tunnel should be red/yellow not red/green if your era is mid-1970s or later.  It also really needs to have a subsidiary aspect (two white lights lit with the main red aspect).  This denotes that the train should be driven slowly enough to stop short of any obstacle.  It would be used for any move into the sidings as the signalling does not "know" whether the sidings are occupied.  It could also be used for calling on moves to the platforms if you wished to stack up more than one train in the same platform (including coupling a loco to a train waiting to depart).  If used for more than one purpose it would either have its own stencil route indicator or light the main route indicator. 

 

I think a main signal for the moves out of the sidings rather than a shunting signal would be acceptable, especially if the next signal on the main line isn't encountered for a long distance, which is likely to be the case if the platform starter signals are two-aspect as shown.  Otherwise the departing train would have to run very slowly until reaching that signal. 

Edited by Edwin_m
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As you are using colour light signals, then one of the Eckon ground signals would be ideal.

Again, the one in the tunnel wouldn't be seen so need not actually be there - if you get my drift :-)

Edited by dave55uk
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Adding to Edwin_M's post, the signal in the tunnel leading to the station would only be a red/yellow one.

Agree with the addition of the subsidiary signal.

Disagree though with the signal having a feather.

 

All a moot point actually, as if it's in the tunnel, it won't be seen ;-)

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Cheers fellas much appreciated as I you can gather I'm no expert with signalling :-)

 

So coming out of the stabling sidings I have the following that I can use if one of them is acceptable?

 

A three aspect ground signal

Red / Green Standard

Light Ground Signal (2 Whites 1 Red)

 

 

post-29767-0-62328000-1490533506_thumb.jpg

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Cheers fellas much appreciated as I you can gather I'm no expert with signalling :-)

 

So coming out of the stabling sidings I have the following that I can use if one of them is acceptable?

 

A three aspect ground signal

Red / Green Standard

Light Ground Signal (2 Whites 1 Red)

 

The '3 aspect ground signal' is NOT a 3 aspect signal (even if it does have 3 lamps). It is a Ground mounted Position (GPL) light signal showing 2 white lights at 45 degrees for a 'proceed' indication and either one red and one white (or two red lights for the LED type) in the horizontal position for stop.

 

As to which type to use, I know of a 1980s signalling scheme where all three options were used (albut in different physical locations). The most common type is the GPL, followed by a ordinary signal head up on a post, with the 3rd used where clearances were tight and it was not thought worth the expense of putting in a gantry structure.

 

As one TV gameshow used to say "The choice is yours"

Edited by phil-b259
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Thanks phil-b259.

 

Not sure if you saw the one in the last picture I posted (the one actully on the layout in front of the two boxed ones).......as far as I'm aware its a Red / Yellow / Green signal

 
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Thanks phil-b259.

 

Not sure if you saw the one in the last picture I posted (the one actully on the layout in front of the two boxed ones).......as far as I'm aware its a Red / Yellow / Green signal

 

 

 

Thanks for the clarification - however one thing is an absolute no-no in signalling terms is mixing 2/3/4 aspects where they all lead to a common destination signal*. If your platform starting signals are 2 aspect, the same MUST apply to your signal at the exit of the sidings - unless you use the GPL (which stands outside the scope of 2/3/4 aspect signalling principles)

 

*Note where a signal has two possible destination signals to route trains then you can end up some oddities - e.g. a 4 aspect fitted at the exit to a platform where their is a choice of onward routes (one route using 4 aspect signalling with the other using 3 aspects for example) adjacent to a signal that can only send trains along the 3 aspect route (so only has a 3 aspect head).

Edited by phil-b259
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Thanks phil-b259.

 

So updated my diagram forgetting anything beyond the bridge.

 

Would the ground signal had the arrow on pointing to the left?

 

Ian.

 

I'm not sure what you are getting at here, however....

 

Some GPLs had a arrow sign attached to them (or included on the signal ID plate) which should point to the line to which the signal applies (which would vary between left and right depending on where the signal was placed).

 

This was done to prevent driver confusion, not all GPLs had this feature - if it was obvious that the signal could only apply to one line then no confusion could result.

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I'm not sure what you are getting at here, however....

 

Some GPLs had a arrow sign attached to them (or included on the signal ID plate) which should point to the line to which the signal applies (which would vary between left and right depending on where the signal was placed).

 

This was done to prevent driver confusion, not all GPLs had this feature - if it was obvious that the signal could only apply to one line then no confusion could result.

 

I think I'm getting there slowly :D

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however one thing is an absolute no-no in signalling terms is mixing 2/3/4 aspects where they all lead to a common destination signal.

Ive seen schemes that have a four aspect signal signal (on a main line) and a three aspect signal (out of a siding) read to a 4 aspect signal. As long as the transition between them allows for the aspect sequence to be correct and there is the braking distance between first caution and red then there's not a problem.

 

Simon

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Ive seen schemes that have a four aspect signal signal (on a main line) and a three aspect signal (out of a siding) read to a 4 aspect signal. As long as the transition between them allows for the aspect sequence to be correct and there is the braking distance between first caution and red then there's not a problem.

 

Simon

 

None of which contravenes the point I was trying to make.

 

In the case of this particular layout the platform starters are 2 aspect signals - so from that we must infer the next signal on must be a yellow / green repeater - it cannot be anything else as of it was capable of showing a red platform starts would have to be 3 aspect as well.

 

Thus if the exit signal from the sidings was a 3 aspect (but the platform starters 2 aspect) then said yard exit signal would never get to show its yellow aspect - because a single yellow on a 3 aspect signal cannot lead on to a yellow at a Y / G two aspect repeater - it is not a valid aspect sequence as a Yellow on a 2 aspect repeater always comes after a Green on the previous signal

.

If the platform starters were 4 aspect then the yard exit could indeed be 3 aspect as you state - but its more likely all main signals would be 3 or 2 aspect rather than 3 / 4 aspect.

Edited by phil-b259
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None of which contravenes the point I was trying to make.

 

In the case of this particular layout the platform starters are 2 aspect signals - so from that we must infer the next signal on must be a yellow / green repeater - it cannot be anything else as of it was capable of showing a red platform starts would have to be 3 aspect as well.

 

Thus if the exit signal from the sidings was a 3 aspect (but the platform starters 2 aspect) then said yard exit signal would never get to show its yellow aspect - because a single yellow on a 3 aspect signal cannot lead on to a yellow at a Y / G two aspect repeater - it is not a valid aspect sequence as a Yellow on a 2 aspect repeater always comes after a Green on the previous signal

.

If the platform starters were 4 aspect then the yard exit could indeed be 3 aspect as you state - but its more likely all main signals would be 3 or 2 aspect rather than 3 / 4 aspect.

I see, I thought I was missing something in your point!

 

Simon

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  • 1 year later...

Sorry to bring this one up again but the layout has changed a little to single track.

 

So does the ground signal out from the stabling sidings remain or should it be a different signal in the same position?

 

Thanks Ian.

 

 

post-29767-0-40655800-1524388364_thumb.jpg

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