Signalling for modellers who don't know much about signalling

[Compound2632]

Looking at signal-box diagrams "in isolation" is also fraught with problems. Many layouts were altered over the years, at different times with different standards/requirements in place, so it was quite common to find somewhere with shunt signals at some points and none at others. To 'understand' the signalling of a prototype you need to know more about its history. This is why two or three seemingly identical layouts on the same railway may appear to have been signalled in different ways.

 

True. Taking the Settle and Carlisle signalling diagrams I referred to, the diagrams were recorded in the 50s and 60s but in most cases the boxes and frames date from the 1890s; again in most cases the layouts didn't change but in some cases the signals were renewed (LMS tubular posts etc. and disc ground signals in lieu of Midland wooden posts and miniature semaphore ground signals.

 

On the general question of the complexity of the subject, my own view is that's what makes the hobby so interesting. It's rather like classical music: the basic attraction is the overwhelming emotional response but the more one engages with it the more one realises how much that emotional response (of the express thundering by, of the great orchestral climax) is built upon complexity and order. The opening sequence of Brief Encounter sums it up - nice signals too.

[PaulRhB]

This thread is very interesting but does not achieve the purpose of a simple guide to putting signals on a model railway. Perhaps the subject is too complex for that unless one is prepared to accept an over simiplified signalling arrangement. After all, so what if it is not quite accurate. Unlike the prototype no one's life depends on it.

The Signalling is simple but it does rely on several factors for the same track layout. How the line operates in the density and complexity of moves required even what goods pass through, which lines passenger trains use, the location and company.

To give one example Marchwood looks very sophisticated for a Station with one two coach platform. It has full bi directional Signalling with traps so you can run two trains in at the same time. It also has one side of the loop split in two for the junction into the MOD. The reason is it was primarily a freight line, with the majority of that freight classed as dangerous goods, that used to accommodate a limited passenger service. So the Signalling takes the high risk traffic into account with maximum protection for heavy dangerous trains but also offering the ability to move trains through faster as they only have to stop once if at all during a cross. Not having to stop and then restart on the home and then starter too with a heavy train makes the train handling easier and consequently safer.

If that same station just saw the same passenger service and local pick up goods you could probably eliminate six of the main signals and replace them with ground signals. That makes a significant difference to the look and operation.

This is the only real 'problem' you could show a branch station diagram and do four slightly different 'Big Four' versions, one with unique pre grouping differences and a light railway version.

The simple post quickly becomes four or five options for each layout. You could make a few basic assumptions first for passenger and normal goods and tell them that if you add x, y and z traffic you need to consider adding this or that. The topic would be a great way to compile and develop that but then once 'proof read' move the info to the first post as a final version?

[Reorte]

From what date? Monsal Dale, 1966, has none but the exit from the down siding to the up and the nearer exit to the down are right in front of the signalbox and the further exit is controlled by the ground frame, which you've explained. Leafing through the 1950s - 60s signalling diagrams in Anderson & Fox's Settle & Carlisle book, I see that there are ground signals controlling all exits onto the running lines, as you say, but not (usually) for setting back into sidings except in some cases (but not all) where the points are far from the signalbox - the choice might have to do with visibility?

Funny you should mention that. At least one ground signal for Kirkby Stephen seems to be in a different place on some photos and film I've seen of the station than it is on the diagram in that book. The dates aren't the same (less than 10 years apart though IIRC), so is that an inaccuracy in the diagram or were things changed in the interim? It's more things to consider at any rate, and also the point where having a forum like this with people who know what they're talking about is very useful, no matter how much you read up first.

[chaz]

Engine and brake backing up - not a SPAD...

 

 

Actually the N7 is stationary and hasn't passed the signal. Although in steam days they were rather less strict about passing signals at danger. A few feet beyond the signal post, provided there was no encroachment on another track seemed to be a fairly regular occurrence in some places. In this situation, where the line beyond the signal trails into a running line (a goods line, not modelled) a hundred yards or so on why would it matter? Local custom and practice and a blind eye turned!

 

Chaz

Edited September 2, 2017 by chaz

[vitalspark]

Interesting thread and just shows how complex accurate signalling can be.

 

A simple way around this is to model a prototype then from photographs and diagrams instal the signals.

 

Even if you don't construct buildings and other infrastructure to the letter as long as the basic track plan is used the end result is an accurate model displaying the correct type and siting of signals.

 

We built Alloa on these principles and all signals operate including a banner repeater in a cutting that only the operators can see however constructing in this way means that without needing to be signalling experts we have a properly signalled layout.

Signalling Society seemed to agree and gave us their award at Warley couple of years back.

 

The signalling part of the layout was interesting and enjoyable all the more so because we knew it was more or less correct.

 

Even with the knowledge that everything is in the right place there are still obvious 'moves' that we are unsure about and can only assume that in relation to setting back etc around the box and yard a great deal of hand signalling was performed.

We do take liberties with some of our movements like allowing an engine to take water at the box held by the starter while a  branch train crosses its path 100 yards ahead but it is an exhibition layout and we are there to entertain the public.

We also regularly hold a small shunter at the box at the junction from the harbour and waiting to cross the main line to the yard but this is ok as its catch point protected. 

 

The new layout is under construction and again signals will be built and placed from drawings and photographs including all the unusual pieces like yellow faced ground discs so correct type and accuracy is one less thing to occupy us.

 

It always surprises me that so much trouble is put in to building a fictitious scene when with a little research an actual prototype just like the one dreamt up is likely out there with of course all the answers to questions like what signals go where.

 

Good thread and informative.

 

Dave.

Edited September 2, 2017 by vitalspark

[runs as required]

Interesting thread and just shows how complex accurate signalling can be.

 

A simple way around this is to model a prototype then from photographs and diagrams instal the signals.

Even if you don't construct buildings and other infrastructure to the letter as long as the basic track plan is used the end result is an accurate model displaying the correct type and siting of signals.

We built Alloa on these principles ..

 

I had a similar attitude about this thread last night and began trawling for signalling diagrams from signal boxes.

One diagram I did find that interested me (because I knew it quite well being near where my parents lived in their latter years) was Dunton Green, illustrated here on the disused stations site

The diagram shews SR semaphores and DG station signal box (I imagine in the 1950s, still in the days of the Westerham branch). 

I wondered what our signalling cognoscenti might say to this being plausible enough to model as another BR Region location with its own patterns of signal posts and UQ/LQ  semaphores.

It represents a fairly intensive mainline, a branch train and a goods yard. 

dh

[beast66606]

We do take liberties with some of our movements like allowing an engine to take water at the box held by the starter while a  branch train crosses its path 100 yards ahead but it is an exhibition layout and we are there to entertain the public.

 

 

Provided the engine is stationary there's nothing wrong with that.

[phil-b259]

This thread is very interesting but does not achieve the purpose of a simple guide to putting signals on a model railway.

 

Possibly because it is trying to be all things to all people.

 

What may be more useful is separate threads to discus the varying signalling principles - NOT exact company practices. Once folk are familiar with these only then should we start going into regional specific variations as to what types of signal were used.

 

For example we could have a thread running called "Semaphore signalling - Absolute block principles" that uses the diagram in post 34 (or something similar as that does not cover the principle of shunting into block sections) to firmly establish the basics.

 

We could then have another thread called "Colour light signalling - Track Circuit Block principles" that covers that topic.

Edited September 2, 2017 by phil-b259

[Compound2632]

I had a similar attitude about this thread last night and began trawling for signalling diagrams from signal boxes.

One diagram I did find that interested me (because I knew it quite well being near where my parents lived in their latter years) was Dunton Green, illustrated here on the disused stations site

The diagram shews SR semaphores and DG station signal box (I imagine in the 1950s, still in the days of the Westerham branch). 

I wondered what our signalling cognoscenti might say to this being plausible enough to model as another BR Region location with its own patterns of signal posts and UQ/LQ  semaphores.

It represents a fairly intensive mainline, a branch train and a goods yard. 

dh

 

Coaley Junction, on the Midland's Bristol and Gloucester line, the junction for the Dursley branch, was broadly similar except opposite-handed.

[RailWest]

>>>A simple way around this is to model a prototype then from photographs and diagrams install the signals.....

 

With some caution :-)

 

Some examples from personal experience:-

 

1. A book of photographs, track-plans and signal-diagrams for a particular railway. You will be surprised (or maybe not) by the number of times puzzled modellers have queried why they can't seem to get information for their chosen station to 'match up', either oblivious to - or ignoring - the unfortunate fact that in many cases the photos, plans and diagrams all relate to different periods.

 

2. A junction station which once had two signal boxes, later replaced by one. At the same time the junction layout was re-modelled and the signalling altered accordingly. A well-known model of that station on the exhibition circuit had the signalling of one era superimposed on the track-layout of the other era!

 

3. A model of a particular station in the early 1920s, signalled entirely with UQ signals.

[Compound2632]

>>>A simple way around this is to model a prototype then from photographs and diagrams install the signals.....

 

 

3. A model of a particular station in the early 1920s, signalled entirely with UQ signals.

 

... and yellow distants?

[RailWest]

... and yellow distants?

...no, those were off-scene :-) I doubt they had green levers in the box interior though......

[micknich2003]

...no, those were off-scene :-) I doubt they had green levers in the box interior though......

Not all railways had Green Distant Levers, some were RED the same as STOP Signals. Lever colours another "Mine Field".

[Nearholmer]

Gentlemen

 

As a not-MIRSE, can I please court trouble?

 

I think that you are falling into a trap common among experts, which is to attempt to deal with every nuance, exception, if, but, maybe, local variation etc, etc, and in so doing are likely to 'blind with science' all innocent amateurs.

 

I strongly contend that "classic" block signalling, using semaphores, 'a la mode Britannique', is not complicated, and that, if you were to start with TYPICAL practice, using a few TYPICAL examples, which would be of relevance to a great number of railway modellers, much mystery might be dispelled, quite quickly.

 

After all, who is better qualified to explain something fairly simple, clearly, so that a raw novice can understand it, than a group of people who know very well what they are talking about?

 

If it helps, you could add a caveat to each posting, along the lines: what follows represents TYPICAL practice across all railways signalled according to 'classic' British block-signalling practice from c1890s onwards, and should not be read to apply to any particular location or date.

 

Kevin

 

PS: leave out shunting signals altogether, until the foundations are laid ...... they seem to have been applied on a "garnish according to taste" basis anyway.

Edited September 2, 2017 by Nearholmer

[phil-b259]

Gentlemen

 

As a not-MIRSE, can I please court trouble?

 

I think that you are falling into a trap common among experts, which is to attempt to deal with every nuance, exception, if, but, maybe, local variation etc, etc, and in so doing are likely to 'blind with science' all innocent amateurs.

 

I strongly contend that "classic" block signalling, using semaphores, 'a la mode Bretagnique', is not complicated, and that, if you were to start with TYPICAL practice, using a few TYPICAL examples, which would be of relevance to a great number of railway modellers, much mystery might be dispelled, quite quickly.

 

After all, who is better qualified to explain something fairly simple, clearly, so that a raw novice can understand it, than a group of people who know very well what they are talking about?

 

If it helps, you could add a caveat to each posting, along the lines: what follows represents TYPICAL practice across all railways signalled according to 'classic' British block-signalling practice from c1890s onwards, and should not be read to apply to any particular location or date.

 

Kevin

Exactly what I have said several times already Kevin.

 

It doesn't seem to have had an effect on this thread though.

[micknich2003]

 Following on from Kevin's suggestion, here is Absolute Block,Semaphore signalling at its most basic, a Home and a Distant, and signalling one line only.

 

[big jim]

My layout has no signals, that's the easiest scenario!

 

See enough of them in work to worry about them on the layout (yet!)

 

When I was doing my driver training a couple of trainees were struggling with absolute block so we went to my attic layout and set up some old Hornby semaphore signals up to show station limits, absolute block section etc and moved trains past them replacing signals to suit, helped them out a lot to grasp the basics

 

When it came to colour lights we just put some chocolate smarties next to the track and moved/eat them as a train past them

Edited September 2, 2017 by big jim

[PaulRhB]

When it came to colour lights we just put some chocolate smarties next to the track and moved/eat them as a train past them

Now there's an idea for the real thing  Driver sends waiting at Signal, we reply with wait and they have a snack handy if they get peckish.

 

I was once in the black Tower and saw a Brio set out on a table, I asked if it was the train planning department, didn't even get a smile

Edited September 2, 2017 by PaulRhB

[runs as required]

In casting around for diagrams relevant to this thread's OP, I stopped and dipped a little more into this PC-Rail Simulations site than I had before.

The page labelled  Summary of Functionality  claims:

PC-Rail simulation software provides detailed and realistic modelling of railway operations, accurately representing the running of trains on the corresponding real network, especially in areas of significant operational complexity.

The software is based on a general data model of railway networks and their operation (my emphasis)

 

I looked at both 'heritage' and 'steam era' and saw Machynlleth 1959  in 'heritage' and Sheffield Victoria 1968 in 'steam era'(!) and both were rated as 'moderate'

Sheffield Vic (£32.50) appealed to me because I'd enjoyed 'station improvements' responsibilities to the Stationmaster there long ago when working in the BR(E) CCE's Department at Kings+

Curiously PC-Rail Simulations describe S Vic as being in the 'North Eastern Area' (sic).

May I ask: has anyone any comments on the efficacy of these simulations?

dh

[vitalspark]

Provided the engine is stationary there's nothing wrong with that.

 

 

If that is correct its good news as I assumed we should be holding any train at the signal immediately before the box which is half way down the platform and not easy to view by the public.

 

From pic below I would have thought holding a loco at the box/water column with signal against to allow another train to pass from the branch was not practice but train would likely be held at signal in rear which is still in the station area.

Pic shows train coming off the branch although with no loco being held at the signal concerned which is at the column and adjacent to the box.  

 

Reverse of above shows a train held on branch to allow main line traffic to pass.

Again I would have thought that this train would likely be held at the signal in rear which is very close.

Again we hold trains here as it is in the public viewing area.

The A2 is Tony Wrights Tudor Minstrel which was 'visiting'.

 

The current layout under construction is Larbert and will be signalled as per diagrams of which below represents roughly one half of the layout.

 

I also note comments regarding diagrams not following actual pictures and yes we had this problem with Alloa and are experiencing it again with Larbert.

I would suggest this is down to the era..circa1962..when track layouts were rationalised and altered almost every other month.

Short of tying yourself down to a given date its something you have to accept.

We are happy to live with a few anomalies to allow a broader operating period and as said it is an exhibition layout and is there to entertain.

 

If I might add my experience of the 'finest of the finest' layouts where everything is exact from track plans to signalling and following actual operating practice..ie taking 10 minutes to drop a wagon in a siding.. usually ends up being run for the benefit of the operators with few viewing.

Our compromise is that although we hopefully accurately recreate the scene with correct track plan working signals and all locos and stock true to period and location we do run a far more intensive service that ever happened in real life.

Apologies for drifting off subject.

 

Dave.

[PatB]

I suspect that many modellers, particularly those outside the photorealistic finescale or signalling enthusiast/professional fraternities, would be happy with signal installations which are not howlingly wrong, even If not correct or complete in every detail and local nuance. There is a huge difference between this approach and a "just sticking signals anywhere" attitude. Those who really want to do it to full prototype standards probably already know how, or at least where to find out. Those needing to ask about the basics are probably at a stage where some compromise is almost inevitable.

 

I know I bang on a lot about CJ Freezer designs which many believe should be consigned to the dustbin of history, but, for the modeller who accepts a degree of compromise in their layout they can provide a useful guide. Many CJF plans are drawn showing appropriate running line signal placing (taking account of the often extreme distance compression involved) to protect junctions, control entry to and departure from platforms and sidings. Signal boxes are generally fairly sensibly placed overlooking junctions and station throats. Overall, most CJF signalling layouts appear to allow operation which is sensible and logical even if not completely in accordance with every detail of prototype practice.

[PaulRhB]

From pic below I would have thought holding a loco at the box/water column with signal against to allow another train to pass from the branch was not practice but train would likely be held at signal in rear which is still in the station area.

 

 

You probably wouldn't move a train forward only to stop again so soon unless it was long enough to be hanging back and fouling pointwork to the rear, a light loco using the water tower or short enough to allow the next train up to the signal behind because you need it out of the way too.

It's there so it's available to the Signalmen to regulate trains according to the traffic at the time. There are places we hold trains for a few minutes, where possible, on a signal even though the next section is clear because shuffling them up to the next one would mean restarting on an upgrade rather than the level or downhill. However if there's another train behind you have to shuffle it forward.

It's often about flexibility in how you use what you have.

[beast66606]

If that is correct

 

I wouldn't have posted if it wasn't, I'm not a "I don't know anything about this subject but I simply have to type something" person.

 

The interlocking would probably not allow the signal reading to the signal at the water column and the branch home to be cleared at the same time but it's perfectly possible to have a loco standing at the column with the signal at danger behind it. Local instructions may say that the branch signal must not be cleared until the move is at a stand, in fact it's no different from the train waiting at the branch home, as long as the move is at a stand (or the signal is at least 440yds from the junction) then the main line can have trains passing.

[TheSignalEngineer]

This nice example of an 0-6-0 with the empty vans for Cadbury's waiting at the Home signal on Lifford Curve while an express passes on the Up Main at Lifford West Junction

Lifford West Junction (pjs,0681) by geoff7918, on Flickr

[The Johnster]

OT a bit, but that's a lovely photo.  A grey rainy day, with the express blasting past and the safety valves lifting on the goods, as if they were not expecting to be held there and have been caught out with the boiler management slightly.  Dripping with atmosphere, as well as drips...

 

Britain before colour was invented; my childhood!