Signalling Saltfleet - on the bench

[Dave-5-5-7]

Thought I'd start a dedicated signalling post to supplement my layout post. 

Saltfleet on Sea's controlling signal box, being Moss Street PSB is based slightly on Pasture Street in Grimsby. A BR Type 19 box converted to a Panel in the late 70s. Signal is a mixture of 2 and 3 aspect signalling. Initially the panel will be an IFS panel, but the plan is to convert it to N-X once all the track circuits are working. 
Full interlocking is being incorporated using traditional Relays and TTL/CMOS circuitry. Initially signals will be train tech, with a view to moving to absolute aspect signals as the finances permit. 

The control plan is that the fiddle yard will be able to switch over to independent control for a second operator. In this instance signalling to Austin Fen Signal box will be Absolute block (diagram required amending) and signalling to Rimac Road SB will be track circuit block with acceptance switches. 

Signalling diagram. (Note, given the design of panel, the signalman only sees whether or not the signal is showing stop, or proceed, they do not see which proceed aspect. 

 

Signal MS940 under construction

 

Cabinet A1/B1 taking shape. 

 

LOC SFLEETN (A2) This holds the CDUs for the station pointwork 1768/1769A+B/1770/1771/1772A+B/1772/1773

Any questions, queries or suggestions welcome. 

Edited April 2, 2020 by Dave-5-5-7

[bigP]

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Edited February 1, 2021 by bigP
Deleted

[St. Simon]

Hi,

 

Dave, as Paul says, this is very very interesting, I will be following it closely.

 

I do have a couple of questions / comments on what you are doing:

 

1 - When you say full interlocking, are you basing it on prototypical practice? I.e. SW67, Westpack, E10K, etc? You are very brave to attempt a proper interlocking in relays, especially as BR930 aren't suitable for model railways (as they are very expensive!). I applaud you with attempting it and I hope that you succeed!

 

2 - On your diagram, I haven't seen any diagrams which detail route indications and I can't see the symbols for the overlaps? Is this a regional / era specific practice for the area / period you are modelling? It looks great and you certainly know what you are doing!

 

Can't wait to see it develop!

 

Simon

[Dave-5-5-7]

5 hours ago, bigP said:

Hi,

 

This looks veeeeeeeery interesting indeed.

Looking forward to seeing this develop.

 

Thanks,

Paul

 

Thanks Paul

 

41 minutes ago, St. Simon said:

Hi,

 

Dave, as Paul says, this is very very interesting, I will be following it closely.

 

I do have a couple of questions / comments on what you are doing:

 

1 - When you say full interlocking, are you basing it on prototypical practice? I.e. SW67, Westpack, E10K, etc? You are very brave to attempt a proper interlocking in relays, especially as BR930 aren't suitable for model railways (as they are very expensive!). I applaud you with attempting it and I hope that you succeed!

 

2 - On your diagram, I haven't seen any diagrams which detail route indications and I can't see the symbols for the overlaps? Is this a regional / era specific practice for the area / period you are modelling? It looks great and you certainly know what you are doing!

 

Can't wait to see it develop!

 

Simon

 

Hi Simon, thanks for your questions. 

At the minute the diagram is still in technical stages. The final "on panel" diagram will not show route indications. Overlaps are being put in to the diagram at the minute along with a correction with TCs 289, 291 and 293 which need to realigned after I moved the CCTV crossing. 

Interlocking isn't really based upon a prototypical system, however the functionality will be there. Point not detected, signal won't clear, TC or relevent overlap showing occupied, Signal won't clear or TC showing occupied, PL will drop in instead of the main aspect, crossing not down or clear, signals won't clear etc etc. To the operator it will be fully interlocked, to the technician it will be electrical insanity, on veroboard. I do need to add that in my professional context I am a signaller for Network Rail, and I hold an HND in electrical and electronic engineering.

Edited April 4, 2020 by Dave-5-5-7
correction

[Titanius Anglesmith]

Also following with interest. 

 

I also considered relays (not BR930!) for my own interlocking but discounted them on the grounds of expense. Even widely available 4 pole C/O relays would be prohibitively expensive. I then thought about logic gates but settled on programming an Arduino instead. I’ve “relocked the frame” a few times now to incorporate different ideas; it would have been much more difficult if I had to change physical wiring. 

[LNERGE]

Split tracks in the platforms? Line Street control?

 

Looking very interesting. 

 

The traintech signals are my weapon of choice..

 

 

 

Edited April 4, 2020 by LNERGE

[Junctionmad]

Forgive me, why would one use relays to switch model railway led colour lights ? 

 

Dace 

[The Stationmaster]

4 hours ago, Junctionmad said:

Forgive me, why would one use relays to switch model railway led colour lights ? 

 

Dace 

Why not?  It's something they are very good at and relay logic and interlocking is very easy to understand.  Yes they take up more room and yes they cost money but they do have the big advantage of simplicity because if all else fails you can see precisely where the current and how it is being switched.   I built an NX panel using relay interlocking and, obviously, control of points and signals when I was in my mid teens although today there are other emans which some might chose.

[Dave-5-5-7]

4 hours ago, Junctionmad said:

Forgive me, why would one use relays to switch model railway led colour lights ? 

 

Dace 

Well, the most general answer is, "because I  have a big box full of relays so it's effectively free" ha ha. Also it's a lot of fun to do (for me anyway). 

 

[LNERGE]

Relays for me too. You can see what they are doing. Several of my signals read to multiple routes. The circuitry needs to look forward through point detection and track circuits a to get the HR but also the HHR and DR need to read the correct signal ahead via point detection.

[Junctionmad]

I still don’t get it , 8 way open collector driver chips are about 10p each ! 
 

dave 

[LNERGE]

Learning to use them would be my problem. I am my railway's locking fitter twelve inch to the foot scale. I build relay interlockings too. I do try to embrace new stuff but I simply don't have time (9 kids/wife, NR job/heritage railway job/four signalboxes at home/garden railway and indoor 00 railway)

 

 

[The Stationmaster]

11 hours ago, Junctionmad said:

I still don’t get it , 8 way open collector driver chips are about 10p each ! 
 

dave 

But can you see what electricity is, or isn't, going where & when at certain states of the circuit?  That is the beauty of working with relays - ok they are very 'steam age' in some respects but like many other things from the steam age they have the benefit of simplicity.  All a matter of horses for courses but whatever ever you use the first part is to make sure that your circuitry and controls are both designed to do the correct job and actually do the correct job.  And if the circuitry doesn't do the correct job finding out why and then putting it right.  

 

For example I have seen numerous examples of folk using solid state controls for colour light signalling on layouts and they haven't even got the aspect sequences correct (there are obviously also examples of those folk who have got the sequences right).  Getting correct aspect sequences using relays is a doddle.

[Titanius Anglesmith]

12 minutes ago, The Stationmaster said:

That is the beauty of working with relays - ok they are very 'steam age' in some respects but like many other things from the steam age they have the benefit of simplicity.

 

+1.  On my patch of "real" railway we have a mixture of relay interlocking and electronic.  The electronic systems keep us entertained with a variety of problems that relays are simply immune to.  The relay sites "just work".

[Junctionmad]

9 hours ago, Titanius Anglesmith said:

 

+1.  On my patch of "real" railway we have a mixture of relay interlocking and electronic.  The electronic systems keep us entertained with a variety of problems that relays are simply immune to.  The relay sites "just work".

As an EE I can design electronic switches that outperform  and outlive any “ relay “. If you wished it could survive conditions that would have extinguished all life on Earth. 
 

It’s all a matter of spec ( and cost ) I used to work in space and defense 

 

to me it doesn’t make sense to use relays to switch semiconductor leds !!!! 
 

buy hey as they say whatever floats your boat. 
 

To me relays are less suitable , require more assembly and wiring ( hence unreliability ) etc 

 

dave 

Edited April 6, 2020 by Junctionmad

[St. Simon]

54 minutes ago, Junctionmad said:

to me it doesn’t make sense to use relays to switch semiconductor leds !!!! 
 

buy hey as they say whatever floats your boat. 
 

To me relays are less suitable , require more assembly and wiring ( hence unreliability ) etc 

 

dave 

Hi,

 

There are many many relay based interlockings which are used to control LED Signals on the real railway very very reliably.

 

Equally there are loads computer based / solid state interlockings which require relay inputs and outputs to interface with different bits of equipment

 

I prefer relay based interlockings from a design point of view as I am more familiar with them (Ironically I’m most familiar with SW67 type interlockings even though I work in the design office that effectively invented, and are almost sole experts in E10K interlockings, which I know hardly anything about!). However, I would say that you can do far more with an SSI / CBI in terms of controls and ancillary items such as Train Describers, ARS, Information screens etc. 
 

Both types (relay / electronic) interlockings are safe and reliable, however they do have different failure modes and conditions. Relay interlockings are more prone to mechanical and electrical failure, but electronic interlockings are more prone to interference and have a finer tolerance. I would say that across the network, the split of failures between the two is roughly equal.

 

I don’t see the problem with Dave-5-5-7 using relays to switch his signals, I would do the same if I already have the relays and a simpler layout.

 

Simon

Edited April 6, 2020 by St. Simon

[micknich2003]

Just to throw a spanner in the works, I will stick with this.

[Flying Pig]

6 hours ago, Junctionmad said:

to me it doesn’t make sense to use relays to switch semiconductor leds !!!! 

 

You do realise it's only a model and not Crossrail 4 ?????

 

The layout thread says it's set in the late 80s to early 90s, so the real signals would likely have traditional filament lamps and the leds are pretending to be said lamps !!!!!!

 

As it's a model !!!!!!!

 

So there's no contradiction, provided we keep pretending !!!!!!!!

 

And the OP has a big bag of crabs here box full of relays so it's effectively free !!!!!!!!!

 

And he likes relays !!!!!!!!!!

 

Seems like win-win to me.  And it's only a model.

[LNERGE]

I'm looking forward to seeing more posts. I'm glad I'm not alone in using relays.

 

I may try and incorporate a few real signalling relays just for the fun of it in the near future. I have a few non remax shelf types I wasn't planning on using on a big railway project...

[43110andyb]

Relays for me also! Made this small interlocking for our club terminus layout (which reminds me I need to post it up here as a thread one day).

[micknich2003]

To prove I actually made it, here are a few pictures.

[Mallard60022]

Why is there always someone that has to 'have a dig' when this poster is obviously having a whale of a time and loves his wires and whizzy things? If you know about other things then be generous, not condescending. I for one am envious of this particular project. My signals, if they ever get to work, are Semaphores so will probably be operated by bits of string and some wire!

Phil

[LNERGE]

44 minutes ago, micknich2003 said:

To prove I actually made it, here are a few pictures.

 Beautiful.

 

[LNERGE]

59 minutes ago, micknich2003 said:

To prove I actually made it, here are a few pictures.

 Sorry Dave closing with locked starters. Seeing Mick's tray reminded me of this I came across recently..

 

A 'you are not moving this lever any more lock'...

 

 

 

Edited April 7, 2020 by LNERGE

[Dave-5-5-7]

On 06/04/2020 at 02:10, LNERGE said:

Learning to use them would be my problem. I am my railway's locking fitter twelve inch to the foot scale. I build relay interlockings too. I do try to embrace new stuff but I simply don't have time (9 kids/wife, NR job/heritage railway job/four signalboxes at home/garden railway and indoor 00 railway)

 

 

Looks like a McKenzie & Holland Type 13. I know what you mean thought. I have 3 kids, other half,  00 gauge railway, NR job and heritage rail job. Don't have the room for a signal box hence why I'm tying the two together. I do have a mate who has a signal box based on a miniature frame, 5 inch garden railway.