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Signalling "Nessie": a space limited take on Inverness


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  • RMweb Gold
This is my take on Inverness which I want to control "in a railwaylike manner" despite the fact that trains will be short because the space available is constrained. I am using colour light signals because I can buy them in and set them up with DCC easily(!?). I am also signalling the main line for bi-directional running since the crossover is "offstage". Platform 1 is for the Highland Far North and Kyle branches, with some cross movements onto main Aberdeen/Perth lines. Trains leaving platforms 3 and 4 will have to go out on the Down line (normal incoming line) to the junction. By the bye, I have got some WTTs for the late 60s early 70s period to help design the timetable for the layout.
 
I have followed this Group avidly for some time, and was enthralled by the discussion on "Bradfield" - which really started this all off for me. I have tried to learn from what I have read, but I am not confident in what (I think?) I have learned. I attach a signalling diagram in a condensed form with a separate sheet of examples of what I think the signals should look like. I would really like some peer review if anybody has the time.
 
Now I have probably made many mistakes that need correction, so please tell me when you spot them, however I have some questions myself:
 
1. A key one is signalling shunt moves (or calling on) from signals with feathers or the Route Indicator.  Is it permissable to use the feather or the RI to show the direction of the shunt. So the Down Home (DH) shunt signal (DHS) would show OFF with the RI showing (say) 3 indicating calling on to stock in Platform 3?
 
2. Where do pls go on a signal post, in front, to one side, does it matter?
 
3. The Parcels siding is small and will only hold a couple of GUVs or some vans, the gpls is only to stop any pilot loco that does go in from coming out against another movement.  Is this right? No trains will be formed or depart from this line.
 
4. At bottom left gpls SR3 (signalling entry to the run-round) would be stacked above SP1 (signalling shunt into Parcels). I have used yellow since traffic needs to run past them to the TMD.
 
5. I am considering how to signal from Platform 2 - currently I am assuming exit will only be to the UP line, whether for ECS movements or departing trains. Otherwise presumably a feather like P1 would be needed (assuming I got that one right!).
 
6. I have put a couple of catch points in from the TMD line and from the goods facilities - do I really need more?
 
7. I don't really know how to signal crossover 10 (top left). The goods area would (I have presumed) be under shunter control, so there is a ground frame. I have protected the run round from the good facilities with SG2. Does there need to be a reciprocal signal by 10a to hold locos on the run-round until the  goods line is free or would a shunter just hand signal it?  SR4 is really intended for holding a loco on the run-round whilst ECS is drawn out, before the loco follows it out to the P1S platform starter. But then there is a red signal to pass if a loco is to go into the goods facilities to run round(???).
 
All observations and constructive comments gladly received.

 

Inverness Signal Box Diagram.pdf

Required Signal Shapes.pdf

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Here's an extract of a diagram for a terminus..

 

post-4034-0-25542100-1386696171_thumb.jpg

 

7a 3 aspect R/Y/G

7b 3 aspect R/Y/G

25 3 aspect R/Y/G

43 2 aspect R/Y

 

43 reads to the platform ends an can only show red and yellow. I very much doubt Scottish Region practice is much different.

 

Edit to add.. Whole diagram here..

 

http://www.flickr.com/photos/pwayowen/6618711569/sizes/o/in/photolist-b5SCmH-b5SCmk-b5SCm6-b8yZep-bd9LJX-bdaoTP/

Edited by LNERGE
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  • RMweb Gold

Here's an extract of a diagram for a terminus..

 

attachicon.gifKLJ(extract).jpg

 

7a 3 aspect R/Y/G

7b 3 aspect R/Y/G

25 3 aspect R/Y/G

43 2 aspect R/Y

 

43 reads to the platform ends an can only show red and yellow. I very much doubt Scottish Region practice is much different.

 

Edit to add.. Whole diagram here..

 

http://www.flickr.com/photos/pwayowen/6618711569/sizes/o/in/photolist-b5SCmH-b5SCmk-b5SCm6-b8yZep-bd9LJX-bdaoTP/

 

Thank you very much for replying. I think that, because my little pictures look a bit like yours, you misunderstand my level of understanding of signalling! So I am not sure what you are telling me. I think you are suggesting that my DH should be red/yellow only, which is fine.  I am assuming that the black square on top of the post for 43 is a Route Indicator with 4 possible indications?  I would love to know why 19 is shown on the signal post and 6B to one side.  Is the RI over 6B only read for 6B or does it apply to 7B too?

 

I'd be grateful for more of your guidance if you can spare the time.

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My apologies. I am a new works signalling tester (but fairly new at it) but have been involved in signalling for many years. I only had a quick look at your layout and signal drawings. The first thing that struck was they all seem to be red/green. This is not prototypical. The object of showing KLJ was to show a similar 'ish' layout and what the signals were capable of displaying.

 

The black box is a route indicator. On 43 lever it reads into 3 locations, platform 1, platform 2 and the sidings to the west of the platforms. By using 19 lever a fourth route is available over 12/13 points up to 15/16 signal. The indicator can display 1, S, 2, and G all of which can display with the two white lights call on signal. Only 1 and 2 can display with the yellow aspect.

 

post-4034-0-27679000-1386775940_thumb.jpg

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  • RMweb Gold

PLEASE don't apologise for helping!  Thank you for sticking with it.  Your answer moves me a bit further forward.  I understand your point about everything being green/red and wondered at the time whether that was good.

 

I now understand that pls can read with the Route Indicators - though what may show may be limited by locking or logic. Does the same apply to feathers? i.e. can the pls operate with the feathers on a signal (again the ones that will illuminate I guess can be restricted).

 

Finally could you tell me why the pls on 6b/7b is to the left with the RI above 6b.  Is this because 7b only reads to a single route anyway or am I just misunderstanding.

Edited by imt
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6A/B signals were arranged as they were for clearance purposes..

 

post-4034-0-51423900-1386788840_thumb.jpg

 

One downside of being off work because Mrs. P is expecting is that when i made a call to a colleague regarding a PLSG coming off with a PLJI was he assumed i was making THE call about the new arrivals. I think he had rung a goodly number of people before ringing me back only to find a non event <G>

 

The upshot of the eventual conversation was yes a PLSG can come off with PLJI but we can't think of where there is one.

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  • RMweb Gold

Oh! Even more thank you's for taking the time.  My very best wishes to Mrs. P.  Thanks for the above.  I am using Junction Indicators in preference to RI solely on cost grounds. CR Signals (who have been very helpful) can do a reasonably priced 2-aspect plus pls with a JI (feather) whereas Absolute Aspects prices for an RI signal are eye watering. OK for one (my DH signal) - but 3 is out of the question. So I am likely to give you the only known combination for ECS/light engines out of or into my my platforms 1 and 2!

My thanks again and very best wishes! 

Edited by imt
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I'm twiddling my thumbs to be honest. It's like watching a kettle boil. We walked out across the fields for something suspect on Realtimetrains earlier. Timed to 60 mph, 715 tons Southall to Norwich which turned out to be 47580, coaches and Union of South Africa chuffed backwards on the rear. She thought the walk had started off but no. Where's me dets?..

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6A/B signals were arranged as they were for clearance purposes..

 

attachicon.gifKLJ6.7G.jpg

 

One downside of being off work because Mrs. P is expecting is that when i made a call to a colleague regarding a PLSG coming off with a PLJI was he assumed i was making THE call about the new arrivals. I think he had rung a goodly number of people before ringing me back only to find a non event <G>

 

The upshot of the eventual conversation was yes a PLSG can come off with PLJI but we can't think of where there is one.

 

It was certainly a case with the BW(W) RRI interlockings as originally installed that when a subsiduary draw ahead'aspect was located under a main aspect and they read to the same place, that the route indication was the same for the draw ahead as it was for the main aspect - be it feather or theatre box. This is a historic practice and definately not one we are allowed to install on a 'new works' job now.

 

Looking at the current inverness locking sketch, then it certianly the case  that both main and draw ahead aspects on the same post utilise the same theatre box indication. There are only a couple of feathers and and subs at Inverness, and from what i can find, these do not use the feather for route information, or the signalling is set up in such a way that the draw ahead reads only to a running shunt which then provides routing information.

 

Hope that helps a little and doesn't muddy the waters or confuse at all.

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  • RMweb Gold

It was certainly a case with the BW(W) RRI interlockings as originally installed that when a subsiduary draw ahead'aspect was located under a main aspect and they read to the same place, that the route indication was the same for the draw ahead as it was for the main aspect - be it feather or theatre box. This is a historic practice and definately not one we are allowed to install on a 'new works' job now.

 

 

 

So how do you now signal a passenger train into a platform which is already occupied?

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  • RMweb Gold

So how do you now signal a passenger train into a platform which is already occupied?

 

Thanks! Couldn't have put it better myself! By the way Stationmaster any chance of your expert comments on my earlier questions?

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So how do you now signal a passenger train into a platform which is already occupied?

 

If its a new signal, where there are multiple draw ahead routes from the same signal then a stencil indicator must be provided, it can't use the feather or theatre indicator associated with the main aspect to provide routing information. If its a theatre on the main aspect, and the draw ahead reads to the same destination, then the same letter shall be displayed in the stencil.

If it is works on an existing signal, then generally a new stencil will be provided for routing information. There are still examples of main aspect routing being used with draw ahead aspects, but these will gradually get less as more and more boxes get swallowed up in the ROC's.

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6A/B signals were arranged as they were for clearance purposes..

 

attachicon.gifKLJ6.7G.jpg

 

One downside of being off work because Mrs. P is expecting is that when i made a call to a colleague regarding a PLSG coming off with a PLJI was he assumed i was making THE call about the new arrivals. I think he had rung a goodly number of people before ringing me back only to find a non event <G>

 

The upshot of the eventual conversation was yes a PLSG can come off with PLJI but we can't think of where there is one.

Oxford North Junction, 15 signal (i am pretty sure it is 15) has a feather with a draw ahead.I am sure there are still others lurking about the former Western power boxes too.

I know its a little off region, but there are still existing examples about.

I had a wee look at Inverness locking sketch in more detail and i can only find 2 signals that contain feather and draw ahead, and none use the feather for routing on the draw ahead. There are however, plenty of theatre boxes with draw aheads.

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  • RMweb Gold

Just in case anybody does have time to look, I enclose an updated plan (the new layout plan is in the Layouts Thread).  After comments on the structure of things I have revised matters to remove the "reception siding" and include a link to the goods yard from south/east mainline (albeit "Wrong road").

Inverness Signal Box Diagram Mk IX.pdf

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  • RMweb Gold

If its a new signal, where there are multiple draw ahead routes from the same signal then a stencil indicator must be provided, it can't use the feather or theatre indicator associated with the main aspect to provide routing information. If its a theatre on the main aspect, and the draw ahead reads to the same destination, then the same letter shall be displayed in the stencil.

If it is works on an existing signal, then generally a new stencil will be provided for routing information. There are still examples of main aspect routing being used with draw ahead aspects, but these will gradually get less as more and more boxes get swallowed up in the ROC's.

 

Thanks - although it does seem to me to be the use of an excessively complicated, and seemingly over large, hammer to crack a near non-existent nut by presenting Drivers with yet another set of signal indications when a very simple one already exists.  It would be very interesting to see the risk assessment which led to this change as I must admit to never having heard of a mis-reading case in consequence of the past - very long established - arrangement on 'splitting' colour signals.  

 

Interestingly, although probably increasingly irrelevant, it also puts colour light signalling practice in conflict with semaphore signalling principles which strikes me as a not entirely good idea - but then there seem to be such ideas around nowadays which pay little attention to either the consistency of long established, and entirely safe, principles or indeed to the practicalities of the operational railway by presenting Drivers with yet more signal indications.

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  • RMweb Gold

Coming back to the OP can we establish please (or maybe I'm missing it?) what period the layout is meant to portray and when it is assumed that it was resignalled with colour light signals as we appear to have advanced in some respects to recent practice - which might not be appropriate for the model.  For example the 'real' Inverness was resignalled in 1987 and obviously would not at that time reflect any changes to Principles etc which have been introduced subsequently.

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  • RMweb Gold

Coming back to the OP can we establish please (or maybe I'm missing it?) what period the layout is meant to portray and when it is assumed that it was resignalled with colour light signals as we appear to have advanced in some respects to recent practice - which might not be appropriate for the model.  For example the 'real' Inverness was resignalled in 1987 and obviously would not at that time reflect any changes to Principles etc which have been introduced subsequently.

 

Thanks.  What I am envisioning is the WTT of late 60's early 70's.  I realise that colour lights were not used at that time, however I can buy them in to use.  Constructing appropriate semaphores and making them operational are beyond my manual and visual abilities.  I would like to use the colour lights in a reasonably realistic way.

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  • RMweb Gold

Thanks.  What I am envisioning is the WTT of late 60's early 70's.  I realise that colour lights were not used at that time, however I can buy them in to use.  Constructing appropriate semaphores and making them operational are beyond my manual and visual abilities.  I would like to use the colour lights in a reasonably realistic way.

 

So ideally ScR colour light practice to suit that period then - much more straightforward (probably).  Presumably you won't use theatre style route indicators that also show an indication on the back?

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  • RMweb Gold

So ideally ScR colour light practice to suit that period then - much more straightforward (probably).  Presumably you won't use theatre style route indicators that also show an indication on the back?

 

To be honest I didn't know there was such a thing! Ignorance as they say is bliss. I'll try to find examples on the 'net.  I am sure you will understand that I am fascinated by this subject but have no background in it to call upon.  I have a couple of modelling books on the subject an the Ian Allan "Modern Signalling Handbook" plus all the things I have read in this group.  So I am driving blind. Any crumbs will be welcome ....

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  • RMweb Gold

To be honest I didn't know there was such a thing! Ignorance as they say is bliss. I'll try to find examples on the 'net.  I am sure you will understand that I am fascinated by this subject but have no background in it to call upon.  I have a couple of modelling books on the subject an the Ian Allan "Modern Signalling Handbook" plus all the things I have read in this group.  So I am driving blind. Any crumbs will be welcome ....

 

Such as my Inverness colour light signal pics when I can find them?

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I'm twiddling my thumbs to be honest. It's like watching a kettle boil. We walked out across the fields for something suspect on Realtimetrains earlier. Timed to 60 mph, 715 tons Southall to Norwich which turned out to be 47580, coaches and Union of South Africa chuffed backwards on the rear. She thought the walk had started off but no. Where's me dets?..

The thumb twiddling stopped abruptly on Sunday night. We have been joined by Henry, 7lb3oz and Charlotte, 6lb14oz Mrs LNERGE is 'relieved' that bit is over...

 

I'll take another look at the thread when i get a moment when my thoughts are my own.

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