Colour Light Signalling for Model Railways (Out Now)

[St. Simon]

Hi,

 

Based on the responses on here, I've gone away and done a little more thinking.

 

I think a possible way of tackling it would be to do an introduction to colour light signalling (a short history), and then base each chapter on a different situation, so one chapter on signalling plain line, another on how to signal a busy terminus, another on depots / interfaces, another on single lines etc. etc. In those I would go through how it's broadly done on the real thing (focusing on the principles rather than the detail of individual details), with some pictures etc and then go on to signal a track plan for a layout based on those principles. I would cover the layout of signals, safety systems, points, track work, etc. The finishing off with some stuff about control and models etc.

 

To help with the above, I've posted a question in the layout design section about popular track plans: http://www.rmweb.co.uk/community/index.php?/topic/124061-popular-track-plans/

 

I hope that sounds like a sensible solution and covers most of what people have asked for. Also, thank you to all the people that have contact me offering me help and guidance, it is very much appreciated, once I have an idea of when I'll start, I'll contact you again!

 

Simon

[Nearholmer]

Simon

 

For what it's worth, I think you've hit upon the best way to tackle the topic, although I notice in another thread that one of the obvious alternatives is being reiterated.

 

I look forward to being informed, educated, and entertained.

 

Kevin

[uax6]

I've recently borrowed the NER Socs book on NER signalling, and they have a good section on example of how various places were signalled, and I though that this would be a perfect method for you to show how to do it. Its just under 30 quid, and very well written (including a section by Mick Nicholson from here....)

 

Andy G

[Dungrange]

Based on the responses on here, I've gone away and done a little more thinking.

 

I think a possible way of tackling it would be to do an introduction to colour light signalling (a short history), and then base each chapter on a different situation, so one chapter on signalling plain line, another on how to signal a busy terminus, another on depots / interfaces, another on single lines etc. etc. In those I would go through how it's broadly done on the real thing (focusing on the principles rather than the detail of individual details), with some pictures etc and then go on to signal a track plan for a layout based on those principles. I would cover the layout of signals, safety systems, points, track work, etc. The finishing off with some stuff about control and models etc.

 

I think this is probably the best way to cover the topic.  Each chapter can then be based on how a layout would be signaled in the Network Rail era (which is the period that you know most about), whilst acknowledging that there may be alternative arrangements that may have been used in the past (ie regional variations) to achieve the same outcome.  

 

Ah - but you shouldn't tackle it quite like that because 'done like this' was pretty conditional (on region/era etc) in the first place so it was more a  matter of A did it like this while B did it like that.  Thus starting with principles makes a lot of sense as you get the right things in to someone's head before they ask the question of how to do what and then they can answer it themselves or look at a Regional variation if they want to adopt one.

 

That seems to be exactly what David ('Dungrange') has done in establishing how a freight train would be signalled into a loop - he clearly understands the basics and now all he might, or might not, want to ask is how the ScR did it in schemes put in at the time he has chosen for his signalling.  And some of the questions he is asking relate as much to operational principles as they do to signalling equipment - such as the engine which has runround  (basically main aspect to run into an empty signal section - with a clear overlap at the next signal).  Again it comes back to understanding the basics before hanging the signals on to suit the basics.   Not so good if you don't understand what signal section or overlap is - dead simple once you do.

 

I think that your introduction needs to cover some basic operating principles.  Whilst some things may seem bleeding obvious to you (and possibly many that have contributed to this thread - particularly those who have worked on the railway), they clearly aren't obvious to all railway modellers, some of whom don't seem to understand what a signal is or what it is for (based on where I have seen some signals 'placed' on layouts).

 

I think it is fair to assume that most of your readers will have driven a car, but probably few of them will have driven a train.  However, I think it is important that the reader understands that there is one fundamental difference between driving a train and driving a car.  The road network is largely uncontrolled, whereas the railway is a controlled network.  A car driver can start their journey at a time of their choosing, follow the route of their choice and if necessary stop whenever they want.   By comparison, a train driver makes none of these decisions, as these have been predetermined by the train planners and set out in the timetable.  A car driver may give way when entering a roundabout or joining a main road and may have to wait for a gap in oncoming traffic to make a right turn, but again the car driver is free to decide which gaps he will accept.  By comparison, a train driver makes none of these decisions, as these are made by the signalman, who controls the passage of trains through the network.  Consequently, a signal is fundamentally a devise used by a signalman to give an instruction or provide information to a train driver.  

 

The way that I tend to think about signalling is that the location of signals are governed by the positions at which a train driver needs information.  Once I've identified the location that the driver needs information (and therefore the preferred position of the signal), the next step is to think about what type of information is required and what speed the train is travelling at.  Once I've ascertained that, it's possible to take an educated guess at the correct type of signal, whether that be a three aspect colour light signal or a Position Light Signal or something else.  I think the key point is that you can't really signal a track plan without some understanding of the likely train movements and I think that is where some modellers go wrong.

 

Of course I realise that it's not always possible to place signals at the locations that I have identified, because there are various clearance distances, overlaps, sighting considerations etc, that means a signal may be further from the junction than may initially be thought, but this is where the greatest differences will be between the prototype and a model, insofar as modellers tend to compress distances.  As such, whilst a signal may be x metres in advance of a junction, in model form it may be visually acceptable to place that signal a scale y metres from the junction.  As such, with regards overlaps etc, whilst you need to cover the actual distances, you probably also need to provide some guidance on what sort of distances may be visually acceptable in model form, albeit I realise that is a little subjective.

 

Anyway, I look forward to hearing your progress.

[PaulRhB]

Probably a good appendices is worth doing including forums such as this to get specific details on regional differences.

I don't think that undermines the book as I bought books on US and German signalling to understand the basics, so I knew what I was looking for in many cases, and was then able to ask online to clarify details and sort out what some of the unique items were.

Only my RhB research was done wholly online but I learnt the basics from one very thorough website on SBB systems and was fortunate enough to have corresponded with a RhB driver to sort the details.

[St. Simon]

Hi,

 

Just a small update on this, I have had the time over the past couple of days to draft a contents list, and this weekend I'll be going out to find interesting stuff and take some research pictures.

 

I'm going to run the contents past some of colleagues who have kindly offered help with the project before I release it on here

 

Simon

Edited August 3, 2017 by St. Simon

[Dungrange]

Simon,

 

I'm not sure what others think, but in my search for information on signalling matters, I came across an IRSE Exam Study Guide titled "Signalling the Layout".  You may be aware of this, but if not it can be found at http://www.irse.org/membership/membersdocuments/IRSE%20Exam_Module%202%20Study%20Guide_v1.0%20FINAL%20052016.pdf

 

It strikes me that your contents page could be very similar to this. The IRSE document itself isn't particularly easy reading for a railway modeller with only a passing interest, but the overall content seems appropriate if presented in a more easy to read format with more or better diagrams.  Many sections have an 'activity' which is either to research how something is signalled in your area or to work through an example such as calculating headways.  Clearly within your book you would need to simply state how Network Rail would do something (ie you are presenting your research of your own organisation) or alternatively present worked examples rather than asking questions.  You could then have some worked examples as to how what the reader has (hopefully) learned can be applied to a model.

 

One point that is possibly worth making is that a lot of model railway books on signalling cover multiple aspect signalling on plain line reasonably well (ie I can understand it), but are usually a bit short on detail when it comes to the specifics of signalling junctions and station approaches, which is where I think the gap is.  Few railway modellers have the space to model working block signalling properly, so it would be more useful if you were to focus on signalling around stations or freight facilities, where shunting and / or other permissive moves may be required, as this is what we railway modellers tend to want to represent.  The method of calculating the headway and signal spacing would be interesting from a general knowledge point of view, but perhaps less useful to your target audience.

 

Anyway, I look forward to seeing what you hope to cover.

[St. Simon]

Hi David,

 

I had only seen that particular document in passing as I'm studying for my IRSE Module 2 Exam in October, the problem with that is the IRSE has to take into account principles from around the globe, so it doesn't go into too greater detail of UK principles.

 

Actually I'm basing my contents around the sessions that I have created as part of a study session of the IRSE exam that I have been running in the office. My idea is basically to split the book into broadly five sections. The first would be giving a brief history of colour light signalling. Next would be a sectional outlining the requirements to start thinking about signalling. Then it would move onto explain the different types of the signals and indicators, this would also cover the hard and fast rules that we use (covering for very slight regional / era variations, such as the combinations of indicators that are permitted). Probably the bulk of the book would have scenarios, such as junctions, single lines, termini etc etc, with one or two examples, prototype examples and explanations. Finally I would close up with stuff about safety systems, level crossings and control.

 

I want to make it as general as I can, this will prevent me writing 'my way of signalling' and to allow modellers to do their own research as to get specifics for their era and area, which would also reduce the amount of research I would have to (I won't have to research every variation for every company, which would take me years).

 

I will cover how the real railways cover headway calcs, signal spacing and TPWS Calculations, but only breifly for information and how it relates to models.

 

Simon

[The Stationmaster]

Simon,

 

I'm not sure what others think, but in my search for information on signalling matters, I came across an IRSE Exam Study Guide titled "Signalling the Layout".  You may be aware of this, but if not it can be found at http://www.irse.org/membership/membersdocuments/IRSE%20Exam_Module%202%20Study%20Guide_v1.0%20FINAL%20052016.pdf

 

 

 

Talk about making a meal of it  - I'm sure Simon can do a considerably better job than that!  (even I was hard put to understand some of it and I've been involved with the subject in its various ways for very many years - I even used to teach things like headway!)

[Dungrange]

I'm also confident that Simon can write a much more readable text than the IRSE, although to be fair to the IRSE, the document is not intended to be an easy read for a layman and as Simon points out has to take into account different practises from across the globe. Unfortunately, this makes it cumbersome and lacking in detail in relation to current UK practise. I was only really only highlighting this document with regards the contents page (ie the subject areas covered and the order in which they are covered).

 

Despite the IRSE documents lack of readability, it does have a couple of figures which presented the clearest details I could find on fouling points and clearance points (p19) and I now understand the concept of an 'overlap' from the description in the glossary.  It's not all bad.

[St. Simon]

Hi,

 

Having had chance to have a discussion with colleagues over my proposed contents and make some amendments based around their feedback, I thought I'd upload a basic contents list to show people what I intend to cover (yes, it will happen eventually) for people to have some discussion and suggestions on it.

 

PROPOSED BOOK.pdf

 

I'll be putting a 'standards freeze' on the book as well, so I'm not continually updating it as I write to new standards that may come out soon, but I'll decide the moment I 'freeze' it when I start writing.

 

I have been out doing some research and photography as well, so I've got some interesting stuff to into the book!

 

Simon

[njee20]

Sounds good, would likely buy it based on that.

 

Think I've said it before - but please get someone to proof read it though, you seem to like random capitals based on your contents

[cal.n]

Looks great, I would also buy based on that.

[The Stationmaster]

Oops - you seem to have fallen into the trap of using the term 'Single Line Working' in respect of the 'signalling of single lines'; they are two totally different subjects

[St. Simon]

Oops - you seem to have fallen into the trap of using the term 'Single Line Working' in respect of the 'signalling of single lines'; they are two totally different subjects

 

Hi Mike,

 

You make a good point, in this case it would be mostly signalling of single lines, but it could cover single line working as well, but probably as an information bit as I don't think we've invented the 4mm scale working human to be the pilot just yet!

 

Sounds good, would likely buy it based on that.

 

Think I've said it before - but please get someone to proof read it though, you seem to like random capitals based on your contents

 

You are totally correct on the last point, I have noticed a tendency to capitalise randomly, but don't worry, it will be proof read, but for spelling and grammar and for technical content.

 

Simon

[PaulRhB]

I don't really see the need to cover single line working, as it's only used in failures or engineering, unless you group it with other methods of working in a failure situation in a separate chapter. I just think it will confuse people if it's in with Working of Single Lines.

[PaulRhB]

I was involved in the rewriting of the internal assessments for the Wessex and Scottish trial and we had a very active proof reading system for the questions where it went to a fairly large trial group to iron out the vague and downright wrong. (It got binned despite being an apparent success as the system changed again before it went national).

Might be worth getting couple of novices on board and see if they can signal a two or three locations using your guide.

It teaches you a lot about what those of us in the know take for granted.

[St. Simon]

I was involved in the rewriting of the internal assessments for the Wessex and Scottish trial and we had a very active proof reading system for the questions where it went to a fairly large trial group to iron out the vague and downright wrong. (It got binned despite being an apparent success as the system changed again before it went national).

Might be worth getting couple of novices on board and see if they can signal a two or three locations using your guide.

It teaches you a lot about what those of us in the know take for granted.

 

Now there's an idea, I like that, thank you. I think I can rope a couple of people in...

 

Simon

[The Stationmaster]

I don't really see the need to cover single line working, as it's only used in failures or engineering, unless you group it with other methods of working in a failure situation in a separate chapter. I just think it will confuse people if it's in with Working of Single Lines.

 

Very sensible point - as Single Line Working has nothing to do with the provision and siting of signals (but simply how certain of them are or aren't worked when SLW is in operation it makes far more sense to leave it out completely.  Otherwise you create something of an imbalance by covering one area of failure/unusual situation working without covering the others (and I'm not suggesting you should include them!!).

[Dungrange]

Is "Singe Line Working" the term used for bi-directional working on one line of a multiple track formation due to disruption or engineering works on the other line(s)?   If that is the case, then I agree that it's not really relevant to the location of signals and other infrastructure, which is what i think most modellers require information / guidance on and what I think your book should cover.  I'd therefore agree that this should probably be highlighted as being out of scope.

 

Also, make sure that all of your acronyms are explained on first use.  I hate reading reports that I have to try and figure out what LOR, IECC, ROC, etc might mean.  They may be obvious to those in the industry, but not clear to the layperson.  Although I know some of the acronyms you've used (ECS, LED, TCB, SPAD, etc) there is no guarantee that all of your readers will know all of them.  When writing reports and even some e-mails at work (because they are often forwarded to others), I usually work on the premise that someone won't know what some of the acronyms that are obvious to me mean and therefore write them out in full.  I usually tell the graduates that work for me that I want something that they think their grandmother would understand!

[The Stationmaster]

Is "Singe Line Working" the term used for bi-directional working on one line of a multiple track formation due to disruption or engineering works on the other line(s)?   If that is the case, then I agree that it's not really relevant to the location of signals and other infrastructure, which is what i think most modellers require information / guidance on and what I think your book should cover.  I'd therefore agree that this should probably be highlighted as being out of scope.

 

Also, make sure that all of your acronyms are explained on first use.  I hate reading reports that I have to try and figure out what LOR, IECC, ROC, etc might mean.  They may be obvious to those in the industry, but not clear to the layperson.  Although I know some of the acronyms you've used (ECS, LED, TCB, SPAD, etc) there is no guarantee that all of your readers will know all of them.  When writing reports and even some e-mails at work (because they are often forwarded to others), I usually work on the premise that someone won't know what some of the acronyms that are obvious to me mean and therefore write them out in full.  I usually tell the graduates that work for me that I want something that they think their grandmother would understand!

 

Technically and operationally bi-directional working is not Single Line Working (SLW).  The pure terminology of SLW means that traffic is worked over a single line of rails - where it would normally be worked over double or multiple lines - under a procedure set out in the Rule Book and there is no fixed signalling provided to enable it to take place.

 

A bi-directional line could obviously be a single line which is fully signalled for trains travelling in either direction or it could be a line, usually at a major station, which has a predominant direction of travel but is fully signalled to enable it to be used by trains travelling in the opposite direction.   However the term is also used nowadays to cover lines which are reversibly signalled which is slightly different from full bi-directional signalling as in most cases the number of signals for the 'wrong' direction' are reduced compared with those provided for the normal direction of travel - reversible signalling was in fact originally devised (on the WR as it happens) as what might best be described as 'signalled SLW' which was intended to save on manpower and more importantly enable reversible working to be introduced very quickly.  For quite a number of years in the past bi-directional signalling and reversible signalling were effectively quite different from each other operationally as the relevant Rules and Instructions reflected their very different purposes.

[Dungrange]

The pure terminology of SLW means that traffic is worked over a single line of rails - where it would normally be worked over double or multiple lines - under a procedure set out in the Rule Book and there is no fixed signalling provided to enable it to take place.

 

Thanks - that's what I thought.  I think the key point is the section I've highlighted in bold.  Since there is no fixed signalling provided, I think it should probably fall out of scope.  However, lines that are designed for bi-directional operation on a regular or normal basis (ie single track branch lines and the like), should definitely fall within the scope of Simon's book.  Reversible signalling is a term that I've never heard of before and seems to be more of a grey area.  If reversible signalling has infrastructure associated with it, then perhaps that should fall within the remit of Simon's book depending on how common such arrangements are.  That is, Simon's chapter on working of single lines (7a) could highlight the key differences between Reversible signalling and full bi-directional working if appropriate.  What I don't know is whether Reversible signalling would be common on the types of layout that most of us try to create, which is where Simon should focus his teaching.

[Suzie]

The key feature of reversible lines is the use of 4-aspect distants in the reverse direction (which are otherwise very rare) due to the longer block lengths when running in reverse. Important to know about when modelling modern double track main line like the Great Eastern with all the yellows and double yellows showing quite predominantly.

[PaulRhB]

A glossary is a good idea and referring people to the RSSB website where they can read the rule book itself to understand any other methods of operation in full, probably mentioning forums like this to get clarification

 

Don't try to cover too much or it will end up as big as the real rule book and many just won't read it

 

Simple diagrams showing examples of a variety of plans with a explanation of the Signalling would be my favourite route. Typical stations of various sizes, junctions, a quarry, yard, MOD depot, unit / loco depot or port interface with the mainline railway as they are popular subjects. Just a few ideas

[The Stationmaster]

Thanks - that's what I thought.  I think the key point is the section I've highlighted in bold.  Since there is no fixed signalling provided, I think it should probably fall out of scope.  However, lines that are designed for bi-directional operation on a regular or normal basis (ie single track branch lines and the like), should definitely fall within the scope of Simon's book.  Reversible signalling is a term that I've never heard of before and seems to be more of a grey area.  If reversible signalling has infrastructure associated with it, then perhaps that should fall within the remit of Simon's book depending on how common such arrangements are.  That is, Simon's chapter on working of single lines (7a) could highlight the key differences between Reversible signalling and full bi-directional working if appropriate.  What I don't know is whether Reversible signalling would be common on the types of layout that most of us try to create, which is where Simon should focus his teaching.

 

The problem with reversible signalling is how it has developed and changed which creates quite a lot of ground to cover.  The initial WR installations (which was where the idea originated as aUK application) was quite extensive and generally - but not always replicated the signal positions for right direction signalling on the opposite line.  However this idea didn't last overlong as it was incredibly expensive to install, especially for something which had finished up as 'mechanised Single Line Working' and (due to industrial relations problems) could not be used for what is known in France as 'banalisation' (effectively bi-directional working on each line allowing faster trains to overtake slower moving trains).

 

So the Wr then moved on to 'Simplified Bi-Directional Signalling' (known by the acronym SIMBIDS) which greatly reduced the number of signals in the reverse direction - although they were still parallel to right direction signals - and kept the number of aspects down to what was actually needed instead of what was nice to have.  The latter meant that usually the signal immediately in rear of a 3 aspect signal at a crossover was only 2 aspect (yellow/green) and there was usually no need to have a signal in rear of that showing double yellow due to the reduced speed in the reverse direction.  Thus all later WR schemes were based on the SIMBIDS principle and at least one which was constructed on the ground to the original standard (even including occasional 4 aspect signals) never had the necessary interlocking provided so was never commissioned.  Incidentally virtually WR reversible signalled lines are in 3 aspect territory with only occasional 4th aspects which are there solely to provide the second yellow.dfor braking purposes.

 

So it is a complex history and probably best avoided beyond a relatively brief historical explanation.