Signalling for modellers who don't know much about signalling

[Compound2632]

The French fermé and ouvert, closed and open, seem far more obvious as the generic term for the position of signals of all types though the British rule book's danger, caution, and clear is completely clear. 

 

I was though rather surprised to find in my 1961 edition of the 1950 BR rule book (as well as an earlier RCH rule book from 1933 that happened to be LNER ) umpteen references to stop signals being lowered to allow a train to proceed. e.g. rule 68 (b) "When a stop signal has been lowered for the passage of a train, it must not except.......be replaced at Danger before the train has passed...."   Replaced at danger is unambiguous but this lowering of signals looks rather as if the GWR got to write the rulebook. I assume it was a hangover from the days when most railways used lower quadrant signals but when most were upper quadrant I can't help but think that this must have caused some confusion to trainees if nobody else.

 

I should think that in 1933 lower quadrant semaphores were the norm, with the newfangled upper quadrant signals only just starting to appear. In most places, in 1933 you still had the pre-Grouping railway with a thin veneer of big engines and corridor coaches on the most main of main lines.

[keefer]

was just about to post the same thing David!

 

That siad, I find the rule book can be a bit confusing anyway - especially when it says you can/must (not) do something then inserts the exceptions and under what circumstances in the same paragraph.

By the time you get to the end and have just about understood it, you have to go back to the beginning and read it again

[Pacific231G]

I should think that in 1933 lower quadrant semaphores were the norm, with the newfangled upper quadrant signals only just starting to appear. In most places, in 1933 you still had the pre-Grouping railway with a thin veneer of big engines and corridor coaches on the most main of main lines.

Yes but they weren't newfangled in 1961 and the wording hadn't changed even though most of BR was by then upper quadrant. Surely, the one thing you should never have (but often will have) in any safety critical rule book is ambiguity. 

Edited October 16, 2017 by Pacific231G

[RailWest]

Yes but they weren't newfangled in 1961 and the wording hadn't changed even though most of BR was by then upper quadrant. Surely, the one thing you should never have (but often will have) in any safety critical rule book is ambiguity. 

Do not forget that, with a few exceptions, the BR(WR) lines still had LQ arms. So did many parts of the former L&SWR, where they remained until the respective lines were closed, and no doubt elsewhere in the country too.

By this time also there would have been increasing numbers of semaphore distant or stop signals having been replaced by colour-lights, which of course could be neither raised nor lowered (let alone 'turned off') :-)  Once you start talking along the lines of "...the signal must not be lowered, or raised, or - if a colour-light - changed to an aspect other than red (or yellow, if a distant signal).." then it all gets far too complicated !

[Chimer]

Do not forget that, with a few exceptions, the BR(WR) lines still had LQ arms. So did many parts of the former L&SWR, where they remained until the respective lines were closed, and no doubt elsewhere in the country too.

By this time also there would have been increasing numbers of semaphore distant or stop signals having been replaced by colour-lights, which of course could be neither raised nor lowered (let alone 'turned off') :-)  Once you start talking along the lines of "...the signal must not be lowered, or raised, or - if a colour-light - changed to an aspect other than red (or yellow, if a distant signal).." then it all gets far too complicated !

 

But "the signal must not be cleared" would work unambiguously for all those "or"s .....

[The Stationmaster]

was just about to post the same thing David!

 

That siad, I find the rule book can be a bit confusing anyway - especially when it says you can/must (not) do something then inserts the exceptions and under what circumstances in the same paragraph.

By the time you get to the end and have just about understood it, you have to go back to the beginning and read it again

 

One of the important parts of writing a Rule or Regulation is to first make as clear as possible what is permitted or what is not permitted.  The idea being that someone learning the Rules will see that first and it is the most important factor which has to be conveyed.

 

Having done that you proceed to add & explain any exceptions to the principle the Rule or Regulation has established.  The last thing you should do is start off by using wording such as 'except' or 'if'.  Thus for example in the 1950 Rule Book Rule 37 (a) stated 'Where starting signals are provided the home signal must not be passed at  except .... then listing the 5 exceptions.  Principle established first, then exceptions added and explained.  A badly worded Rule would have read 'Except as listed below the home signal must not be passed at danger where starting signals are provided - immediately informing the reader and student that exceptions exist - a poor attitude to create before the core principle is made clear. 

 

As far as use of the term 'lowered' is concerned it was replaced by 'cleared' in the 1972 major revision of the Rules and Regulations which was the first major revision of the 1950 Rule Book.  It had survived in the 1960 revision of the Signalling Regulations (and General Appendix) but that was almost certainly down to keeping it in line with the terminology used in the Rule Book which would itself have required major revision if the term were to be changed.  There were probably some very good reasons for avoiding major revision of the Rule Book at that time as the consequential alterations to numerous other documents right down to Local Instructions and Signalbox Special Instructions level would have been a major task on what was still a very complex and large railway network thatwas also having to cope with other changes such as rationalisation and modernisation which in themselves created major workloads for the people dealing with such stuff.

[iands]

Perhaps we can move forward from in the rear or in advance[/quote?

 

Officialy the railway industry has. I can't remember if it was the latter days of Railtrack or the earlier days of NR, but I remember one of the Ops Managers telling us on one of his "Block Regulation" training cources he used to run on a night after work (a latter day "mutual improvement class" for the non-footplate staff if you like), that the "Plain English Campaign" were being employed to assist with re-writing the Rule Book to make it easier to understand for those coming new into the industry (the railways had not long been privatised and people from other industries were coming "new" into the railways) and, like the general thread in the previous posts, were having some considerable difficulty in grasping the terminology. Suffice to say that I think the terms now used are "before" and "after" (but could be "before" and "beyond" - I haven't got my Rule Book with me to double check).

 

Hope this helps.

 

Regards, Ian.

[Junctionmad]

was just about to post the same thing David!

 

That siad, I find the rule book can be a bit confusing anyway - especially when it says you can/must (not) do something then inserts the exceptions and under what circumstances in the same paragraph.

By the time you get to the end and have just about understood it, you have to go back to the beginning and read it again

Actually , I personally find the rule books quite a model of clarity once you get your head around the peculiar construction of the paragraphs.

 

The main issue of course is the rule book was supplemented by so many local rules in places.

[37Oban]

For us mere mortals with only limited space for our model railways, signalling can be simplified, no need for in advance or to the rear!  Red means stop, yellow slow down and keep your eyes peeled and green carry on lad!

 

Roja

[Compound2632]

For us mere mortals with only limited space for our model railways, signalling can be simplified, no need for in advance or to the rear!  Red means stop, yellow slow down and keep your eyes peeled and green carry on lad!

 

Roja

 

All very well, but where are these signals in relation to the pointwork and other features?

[imt]

For us mere mortals with only limited space for our model railways, signalling can be simplified, no need for in advance or to the rear!  Red means stop, yellow slow down and keep your eyes peeled and green carry on lad!

 

Roja

 

Well there's your first mistake!  As I have had ground into me, railway signals are NOT traffic lights and do NOT mean the same things.  In the UK signalling is largely about routes not speeds (as much of the Continental signalling systems are - look at Swiss signalling which is fascinating and entirely different, like one starter for a 3 platform station).

[37Oban]

Well there's your first mistake!  As I have had ground into me, railway signals are NOT traffic lights and do NOT mean the same things.  In the UK signalling is largely about routes not speeds (as much of the Continental signalling systems are - look at Swiss signalling which is fascinating and entirely different, like one starter for a 3 platform station).

Which is why, in the real world, there is route training for drivers who need the knowledge before they are passed for that route!  For the majority of modellers, the traffic light anology works, after all, how many layouts have you seen at exhibitions where a train has passed a red signal and you've shook your head at such a transgression. The majority of modellers are hobbyists who can take it to whatever level they like, and concepts such as in advance and to the rear are confusing to someone new to the hobby who wants to signal a junction or whatever.  Most of us don't have the space to correctly site signals, much as I, for one, would like; what we model is a snapshot of just a small area.  For those who want to model a specific location signal diagrams are available and there is no excuse for getting it wrong.

 

Yes, if you want to go down the full knowledge of signalling route that's fine, but a lot of modellers don't have the time, or even the inclination, to study the subject to the depth it deserves, they just want something that says "here you need signal A, here you need signal B"

 

Roja

[jim.snowdon]

 

Yes, if you want to go down the full knowledge of signalling route that's fine, but a lot of modellers don't have the time, or even the inclination, to study the subject to the depth it deserves, they just want something that says "here you need signal A, here you need signal B"

 

Roja

And then, there are more than a few modellers who simply plant signals where they think, based on little knowledge, it looks good to have a signal.

 

Jim

[37Oban]

And then, there are more than a few modellers who simply plant signals where they think, based on little knowledge, it looks good to have a signal.

 

Jim

I agree, and it's those modellers who need something simple to guide them into greater knowledge, rather than expecting them to pick up every little nuance of the  prototype from the word go.   Once they grasp that then they can take it further if they want without feeling they are continually being judged.  After all, it is but a hobby which we do for our enjoyment and we can take signalling, or any aspect of what we model, as far as we like.  For some it's signalling, others it's locomotives, others it's landscape.  The hobby is a broad church!

 

Roja

[imt]

.....

 

Yes, if you want to go down the full knowledge of signalling route that's fine, but a lot of modellers don't have the time, or even the inclination, to study the subject to the depth it deserves, they just want something that says "here you need signal A, here you need signal B"

 

Roja

 

Well each to his own of course.  I expect these modellers you refer to don't care if their loco has the right number of rivets, their stock is painted the right colours or their buildings are inappropriate for the location, era or whatever.  Or maybe the bores that tell me those things are just mad signal freaks too?

 

Of course we all tend to "model" those things that interest us.  It just saddens me when I see beautiful scenery, carefully crafted buildings, exact replica locos etc. etc. Then you see unlikely stock rakes running past signals that don't work or are incorrectly sited.  Yes they get great enjoyment from what they do, and so they should.  But if you WANT a prototypical railway why not go the extra mile.

 

Mine is a mess but I just love the operational aspects.  I cannot make buildings for toffee, I cannot be bothered with static grass dispensers, but I like other aspects of the hobby.  The problems would arise were I ever to take my mess to an exhibition and try to pass it off as a model of a railway.

[TheSignalEngineer]

Actually , I personally find the rule books quite a model of clarity once you get your head around the peculiar construction of the paragraphs.

 

The main issue of course is the rule book was supplemented by so many local rules in places.

The RCH/Company and BR Rule Books are quite precise and logical in the context of the railway at the time when they were written. Unfortunately we now live in a 'txt spk' world where the correct construction and use of the language has largely disappeared. .

[RailWest]

>>>Most of us don't have the space to correctly site signals.....

 

To some extent I would agree, for example any distant signal at a proper scale distance would probably be outside the wall of your house! But to some extent you can take the compressed nature of a model layout into account and place at least a desirable minimum of signals in correct places. IMHO it does not need a lot of sophisticated signalling knowledge to avoid such howlers as a shunt disc at the exit from a siding being placed in advance of a trap-point which it supposed to protect! Did the layout builder not ask himself the simple question "what would happen if a train came to a stop at that signal at danger when the trap is open?"

[Junctionmad]

For us mere mortals with only limited space for our model railways, signalling can be simplified, no need for in advance or to the rear!  Red means stop, yellow slow down and keep your eyes peeled and green carry on lad!

 

Roja

 

While most ( ?) modellers understand signalling at that level ( even if it not quite correct ) , the real issues are incorrect siting of signals and then working incorrectly to those signals.  The example of the two trains at the junction stop signals being a classic example of a model railway " howler ".

[iands]

Hi all,

 

I find myself agreeing with both sides of this debate, the 'realism' for correct signalling and the need for practicalities in a layout due, in the main, to restricted space - so I'll remain firmly on the fence on this one. Purely as a matter of interest, I attach the photo below which shows how close modern colourlight signals can be. It is again a shot of the ELL (Up Line) at Hoxton looking towards Haggerston. Four green aspects can be seen, with the average spacing between them being only 263 metres. It is a passenger only line, operated purely by 5-car 378 units with a maximum line speed of 40mph, so the signalling was designed accordingly to suit. Not a very inspiring piece of railway for a model but it does demonstrate that signals can be placed closer together and still offer some sense of reality.

 

Regards, Ian.

[The Johnster]

For us mere mortals with only limited space for our model railways, signalling can be simplified, no need for in advance or to the rear!  Red means stop, yellow slow down and keep your eyes peeled and green carry on lad!

 

Roja

 

Not really.  Red means stop, but yellow does not mean slow down, it means that the next signal is red and must be stopped at, and green does not mean carry on lad, it means carry on as far as the next signal at line speed or train speed whichever is the slower if you can manage it and keep your eyes peeled; 'keep a sharp look out at all times'.  This sort of thing is part of the problem that makes it difficult to explain how signals are sited and what they do to people who do not already know and are only looking for a simple explanation; all the simple explanations assume that you have a level of basic knowledge, and attempts to communicate this sort of concept in any other way end up using incorrect terminology in a field where precise meanings are necessary, and become misleading.

[Chimer]

While most ( ?) modellers understand signalling at that level ( even if it not quite correct ) , the real issues are incorrect siting of signals and then working incorrectly to those signals.  The example of the two trains at the junction stop signals being a classic example of a model railway " howler ".

 

Can I ask for more info re the howler please?  I did before, but incautiously started a terminology war with a flippant P.S. and the actual question got lost ......

 

I have now learnt that, where trains are converging at a trailing junction and the "giving way" train arrives first, the "priority" train will not be cleared to approach the junction until the "giving way" train has come to a stand.  So the howler is two trains approaching the junction simultaneously, with one signal at stop and the other cleared.  But where is the priority train held?  And how are the stop signals protecting the junction described?  My best guess is that the signals at the junction are both homes and the "priority" train would be held at an outer home - if that's right, does that imply that all trailing junctions are protected by outer homes some defined safety distance in rear of the junction on both approaches?  Or is the train held at the previous box's starter/section signal?

 

The picture that started the original discussion is in post 124 on page 5.

 

Many thanks

 

Chris

[RailWest]

Can I ask for more info re the howler please?  I did before, but incautiously started a terminology war with a flippant P.S. and the actual question got lost ......

 

I have now learnt that, where trains are converging at a trailing junction and the "giving way" train arrives first, the "priority" train will not be cleared to approach the junction until the "giving way" train has come to a stand.  So the howler is two trains approaching the junction simultaneously, with one signal at stop and the other cleared.  But where is the priority train held?  And how are the stop signals protecting the junction described?  My best guess is that the signals at the junction are both homes and the "priority" train would be held at an outer home - if that's right, does that imply that all trailing junctions are protected by outer homes some defined safety distance in rear of the junction on both approaches?  Or is the train held at the previous box's starter/section signal?

 

The picture that started the original discussion is in post 124 on page 5.

 

Many thanks

 

Chris

 

>>>>So the howler is two trains approaching the junction simultaneously, with one signal at stop and the other cleared.....

 

The 'howler' is two trains approaching the junction simultaneously, where the signals in rear of the junction are not sufficient far away for the junction not to be within their Clearing Point. Even if both signals are at danger, it is still a howler.

 

1. It is probable that the 'priority' train would be accepted first, and the 'giving way' train declined if necessary.

 

2. Whether the signals protecting the junction are 'Homes' or 'Starters' will depend essentially upon the relative position of the signal-box to those signals, and whether or not they are the first stop signals for trains approaching that box.

 

3. If there is an Outer Home far enough out at the necessary distance to provide a Clearing Point that does not foul the junction, then a train approaching on that line will be accepted from the box in rear and allowed to run as far as the Outer Home. If there is no OH, then the train will be refused and held at the section signal of the box in rear. You may well have OHs on both lines, one line only, or neither line.

[TheSignalEngineer]

Hi all,

 

I find myself agreeing with both sides of this debate, the 'realism' for correct signalling and the need for practicalities in a layout due, in the main, to restricted space - so I'll remain firmly on the fence on this one. Purely as a matter of interest, I attach the photo below which shows how close modern colourlight signals can be. It is again a shot of the ELL (Up Line) at Hoxton looking towards Haggerston. Four green aspects can be seen, with the average spacing between them being only 263 metres. It is a passenger only line, operated purely by 5-car 378 units with a maximum line speed of 40mph, so the signalling was designed accordingly to suit. Not a very inspiring piece of railway for a model but it does demonstrate that signals can be placed closer together and still offer some sense of reality.

 

Regards, Ian.

378137 Hoxton Plat1 (Up) Signal EL216_(IS 091009).JPG

This close spacing is similar to what existed on Thameslink between Kentish Town and Farringdon when we improved the capacity in 1989, no-one having anticipated the popularity. We took the length of an 8-car 319, added the required overlap for the line speed, added a bit for standing back to give sighting if stopped and used that as the minimum spacing.  For the sections where the speed was 30mph it worked out at about 300 yards, but even that is nearly 12 feet at 4mm scale.. 

Edited October 24, 2017 by TheSignalEngineer

[Junctionmad]

Can I ask for more info re the howler please? I did before, but incautiously started a terminology war with a flippant P.S. and the actual question got lost ......

 

I have now learnt that, where trains are converging at a trailing junction and the "giving way" train arrives first, the "priority" train will not be cleared to approach the junction until the "giving way" train has come to a stand. So the howler is two trains approaching the junction simultaneously, with one signal at stop and the other cleared. But where is the priority train held? And how are the stop signals protecting the junction described? My best guess is that the signals at the junction are both homes and the "priority" train would be held at an outer home - if that's right, does that imply that all trailing junctions are protected by outer homes some defined safety distance in rear of the junction on both approaches? Or is the train held at the previous box's starter/section signal?

 

The picture that started the original discussion is in post 124 on page 5.

 

Many thanks

 

Chris

Given that many model railways may not have outer homes within the layout, and the junction stop signals will by necessity be close to the physical junction , the howler is both trains approaching the junction together , even if one is cleared and the other is approaching the stop signal. Where outer homes exist on the model, even close to their respective homes , it would be acceptable to run a train simultaneously to that OH. ( ie a compressed clearing point )

 

The correct approach on a model is one where one train is brought to a halt at the stop signal , then the other stop signal is cleared and that train proceeds onto the line and through the junction. ( from a fiddle yard or whatever ) at no time would both trains be moving towards their respective home signals.

 

The other " howler " is trains entering the signalled area passing a cleared stop signal only to then to stop at the next stop signal , ie set to " stop" . The correct way is that the train is first " checked " at the previous stop signal , which should be at " stop " , when the train has slowed or nearly stopped the signal is lowered/cleared and the train draws forward to the next stop signal which was always at" stop " this is encapsulated in old rule 39(a) ( I can't remember what number it is in the new modular one , 5 or 7 or some low number , I think ), hopefully you see what I mean, I've tried to remove any jargon words.

Edited October 24, 2017 by Junctionmad

[The Johnster]

Another common one is trains approaching a speed restricted turnout into a loop or junction for which the signal has been cleared; the more correct procedure would be for the signalman to bring the train to or almost to a stand before clearing the appropriate signal similarly to the example above.  In modern signalling, this sort of situation is 'approach lit' by the proximity and speed of the train; if it is approaching too quickly over more than one sensor, the signal will not clear and the driver has to phone the signaller to ask for the road; the same principle is employed.

 

This sort of thing is part of poor running practice generally on models operated by those not intimate with railway procedures, like running around a train and propelling the stock back into the platform without stopping, notwithstanding that the vacuum brakes are hard on, and the loco needs to stop for coupling, connection of vacuum (or air) hoses and the brake has to be blown off before the propelling can take place.  Don't get me started about train formations or locos without continuous brakes on passenger trains, or privately owned factory locos running around loose all over BR...

Edited October 25, 2017 by The Johnster