[John Webb]

Junctions and stations - two important functions here:
1) stop trains colliding with each other by preventing 'conflicting movements'.
For example, where two lines merge, only one train can be allowed to proceed at a time and the trains must be stopped a little before the junction to give a safety margin.
2) confirm to the driver which route he is to take when he comes to a 'facing point' where he can take one of two routes - or maybe more if there are further points beyond the first one.

The signals used are of two types:

The 'feather' indicator is OK anywhere - but can only signal a maximum of 7 routes (straight ahead and three each side). The 'theatre' indicator is capable of showing more routes, but is restricted to stations where trains always approach at slow speed, so is used mostly at termini or major stations where all trains stop.

In the model world however we have an even smaller choice. No 'off the shelf' theatre indicators at all and three and four aspect signals with only position 1 or position 4 'feather' indicators! So unless you want to try and build your own there's not much choice! I'll look at this when we start planting signals on the layout.

Both the feather and theatre indicators will not show the route if the signal shows the Red 'Stop' aspect. If the route to be taken leads into a dead-end - the bay platforms in particular on your layout, the signal will only clear to the Yellow 'Caution' aspect. (Don't forget there will be a fixed red signal just in front of the buffers.)

Next instalment a bit later today, I hope.

Regards,
John

 

[John Webb]

Shunting signals. In semaphore signalling days there were a number of forms of signal relating to shunting movements. These included small arm signals indicating the train was running into a siding or goods loop, there were various 'ground discs' and such things as 'calling-on' arms and 'shunt ahead' signals. All is simplified with colour lights:

The ground signal with two reds is the more recent LED (light emitting diode) version of the 'Ground Position Light' (GPL) signal, the older one having a common white bulb to both the 'Stop' and 'Clear' aspects. (With LEDs it's a great deal easier to make two colours in the one position.)

The Ancillary signal is the 'Clear' aspect of the GPL signal mounted under the main signal. It will only show the clear aspect if the main aspect is showing Red.

GPLs and Ancillary signals are used where a siding is to be entered, or a train is to enter a platform in which there is already a train standing. The meaning of the 'Clear' aspect is 'proceed with caution and be prepared to stop before the next fixed signal'. Where a GPL allows a train to proceed on any one of two or more routes, a stencil indicator or a small theatre indicator will show which route the train is taking. I'll try and dig a photo up of one of these sometime.

The rectangular black plate below the signal will have it's identity number on, telling drivers which signal they are at. This may be very important information for the driver to relay by phone or radio to the signalling centre if there are problems of any sort. The arrow shows to which line the GPL applies - they are small units and can safely sit in the 'six foot' gap between pairs of tracks and without the arrow there could be confusion.

In the modelling world there is at least one 'off the shelf' GPL signal available, and it can be worked either with the red/white or the red/red danger aspect. There is no model ancillary light available as far as I am aware, and this may mean a compromise by using a GLP instead.

Regards,
John

 

[John Webb]

Here's a redrawn plan of your layout incorporating the revisions and with possible signal positions marked.
It is the custom to label signals for trains moving in one direction with the Odd numbers and those for trains moving in the opposite direction with Even numbers - this helps the signaller know in which direction the train is moving if the driver phones or radios in.

You may want to download and enlarge - I thought it would come out bigger!

And this is an explanatory list:

It's only in locating the signals I've realised the North Bay platform causes a problem - any chance of extending it to come off closer to the other points?

The big problem is Signal S12 which would need three 'feather' indicators when I know we cannot get them off the shelf!

Potential sources of model signals are the Berko/Eckon range - have a look at www.gaugemaster.com who are their main distributors; they are the same items, just one lot's ready-made, the other is in simple kit form. There's also Traintronics, a relative new-comer to the scene, but I can't find their URL.

Regards,
John

 

[Edwin]

I think I'd omit S17, as it is very close to S7 and would have to have an irregular aspect sequence. The only instances of this I can think of in platforms are in termini or areas with very low permitted speed. This may compromise the length of train that can fit in the northernmost through platform, and I agree it would be helpful to move the bay point further east.

I'd also suggest moving S3 further back from the station if there is room to do so. Similarly with S12 - in fact if you could move this so far back that it is off scene it would solve your feather problem! Only at very busy stations with low speeds and four-aspect signalling would the station controlling platform entry be right up against the pointwork. Few models achieve anything like prototype signal spacings but just to give you an idea you should have over 1000m at 50mph and over 2000m at 125mph between each three aspect signal and the next one.

For more details: http://www.rgsonline.co.uk/docushare/dsweb...397/Rt0034a.pdf and go to Appendix A.

 

[John Webb]

Thanks for the suggestions, Edwin, and for reminding me that the current rules are on-line. I had looked at them some time ago but lost the URL.
It's always a problem on model railways getting the signals reasonably spaced because most models are compressed in length. Jason hasn't made clear what the 'East' end of the layout is going to - if a storage area then the suggestion about S12 may be feasible.

The Model Railway Journal Issue 171 (published late 2006) has a fascinating article about constructing modern colour light signals that are used on the layout "Widnes Vine Yard". This article includes 'Feather' indicators made with surface mount LEDs on circuit board and ancillary signals scratch-made from 'Plasticard' and similar material.

Regards,
John

 

[jk1]

Sorry I haven't replied in a while! Have been held up completing a project over the weekend for uni, being marked today so I can relax! Thank you for all the information, I have a basic understanding now to where, why and what signals I should use! I tried to save your diagram and view it larger but it distorted too much, I have re-drawn the track plan with tracing paper this time and have added your numbers to it. Please correct me if I have miss placed some signals! I have also altered the position of the North Bay point to the east and therefore hopefully corrected the signals as suggested.

I have shown on the diagram my intended final layout, subject to completing the first section! This may help with decision about S12.

I was thinking of the Berko/Eckon range, the prices seem reasonable. Traintronics signals are available from express models which the website is here:

Traintronics

Traintronics signals are a bit pricy for a student, and my modelling skills will allow me to purchase the kit versions of Berko/Eckon signals (which ever way around the kits are!).

Thankyou for your help and suggestions.

Regards Jason

 

[jk1]

I am drawing myself up a signalling diagram at the moment to help me visualise which orientation each signal will have and how that makes the layout operate (which way trains run through platforms etc). When it comes to the type of signal I am aware that 4 feather means R/H etc as shown on your previous diagram but what aspect signalling will I use? Will all signals be either 3 or 4 aspect? or do different signals have different aspects!? Also where you have 'Main/GPL' is this a combination or one or the other of these types of signals! I guess the easiest question to ask is given that I will be using the Berko/Eckon range of signals, which signal is which from their range!?

This is a steep learning curve for me! Never have I gone into this much depth in signalling but don't get me wrong I am enjoying its complexities! Many thanks for your help and I hope I am not taking up to much of your time!

Regards Jason

 

[Edwin]

John has posted drawings of the various types of signal in a previous post. I agree with his recommendation of three-aspect signalling (where the main signals have three lenses) since the more complicated four-aspect signals are rare west of Bristol.

You need a couple more three-aspect signals in each direction round the rest of the layout so that trains can follow each other round the layout. Unless you have DCC you will probably only have one train going round in each direction, but best to put at least two more signals on each track. That way each signal can change from red through yellow and back to green before the train comes round again.

It looks like you have plenty of room to move S12 back from the points. Ideally it should go back a scale 180m from where it is now, but on a model you could get away with moving it less far.

 

[John Webb]

Glad to know I've been of help.

I'm aware that there is a separate 'Feather' kit in the Eckon/Berco range and it might be possible to use this to make up a second feather to give you at least positions 1 & 4 for signal 12 as a partial solution to this position.

Regards,
John

 

[jk1]

Just to clarify on this I have drawn up three diagrams showing each major signalling area. The diagrams show exactly the type of signal in that position and underneath I have added the information that John kindly provided and then a code number for the Eckon/Berko kits. Where John you had 'Main/GPL' I assume that would be an ancillary signal but as you suggested these aren't available. I have shown them as separate Main and GPL signals but if i ever wanted to model the ancillary part of the signal they could be added at a later date.

Please correct me if I have done anything horribly wrong!

Regards Jason

 

[Edwin]

You've drawn S6 and S4 to the right of the lines. Normally they would be on the left unless there was a particular problem with the driver seeing them in this position. Also as drawn the "straight on" route from S3 is into the bi-directional line - if this is so then it would have a position 1 indicator applying to the through line, either instead of or as well as the one shown. I think however the actual turnout configuration suggests a main route into the through road.

Do you actually need S13? I may have lost track of this thread but I thought the two through tracks were uni-directional.

I think you need a signal in the siding above S8, even if this is out of use. If it was out of use when the signalling was installed then the siding would have been removed to avoid the complication of including the point in the signalling. If it went out of use later then there would almost certainly still be a signal there (probably another GPL). There are places that haven't seen a train for years, maybe decades, where the signal is still there and still lit. Sometimes the signal is still lit even if the point has been removed!

I think I see what you are intending to do with the subsidiary (ancillary) aspects - have a GPL at the foot of the main signal. This would work better if you could lift it up to the correct height about half way up the main signal. I'm not familiar with Eckon/Berko but I have a feeling the workings for the GPLs may be buried underneath the baseboard in which case this wouldn't work. In this case you might be better just making a dummy subsidiary aspect and sticking it to the signal. If you do have a lighted subsidiary aspect then it only ever lights with two white lights, not white/red or red/red which only appear on GPLs that are separate from main signals. Aren't there other places where subsidiary aspects are needed, not just the east end platform starters?

 

[John Webb]

All noted - bit busy for the next few days but will get back when I can.

For information - yes, the Berko/Ekcon GPLs are ground mounted and use either a plastic or fibre-optic 'light guide' from the LED light sources underneath to the lenses, so regretably they cannot be stuck up the main signal post. But Edwin's right - if they are by a main signal they would not show the 'Stop' aspect, only the 'Clear'.

Regards,
John

 

[jk1]

Ok thank you John. The cost of having both GPL and main signal is quite high considering its not prototypical. Having a browse through the net Knightwing produce kit plastic signals that have the 'Ancillary' part attached to them! If only they had them as a separate piece. This could be added but not working to a standard Berko/Eckon kit. What about electrifying their kits though!? They also do kits with feathers. Could use the main parts etc but replace the pole with brass tube etc. I think it might be worth investigating. My grandfather is very good at micro electronics he could maybe help me out. Something to research anyway!

Regards Jason

 

[jk1]

Edwin, yes I made a mistake, should have put them on the left ooops. About S3 hopefully John will be able to help their! I see what you mean though about which is the straight on route and whether the other is 1 or 4 feather. S13 does not seem to be required as this road I guess is supposed to be an anti-clockwise route, with the bi-directional above and clockwise route above again.

Adding a signal above S8 on the siding would be easy enough. And hopefully ancillary questions will come to light, I am very pleased with all the comments and help received from both John and you, it's very much appreciated and I hope I have better understanding about signalling, enough to not hassle anyone when it comes to extending my layout!

Regards Jason

 

[John Webb]

Hi - quick look-in while passing through.

Those ancillary signals in your posting above are ideally the ones you need. But I suspect they are solid plasic and therefore not easy to modify. You might just be able to fit 1.8mm LEDs by drilling through their bodies, but I'm not very certain of that.

As you appear to have someone who might be able to help out, do try and get hold of a copy of the "Model Railway Journal" Issue 171 and look at the article in that about making colour light signals. May be available from the publishers: Wild Swan Publications Ltd., 1-3 Hagbourne Road, DIDCOT, Oxon., OXC11 8DP, tel 01235 816478.
(no e-mail address given)

It will be Weds next week at the very least before I can get round to looking afresh at the diagrams above.

Regards,
John

 

[John Webb]

Hi - quick look-in while passing through.

Those ancillary signals in your posting above are ideally the ones you need. But I suspect they are solid plasic and therefore not easy to modify. You might just be able to fit 1.8mm 'Top Hat' LEDs by drilling through their bodies.

As you appear to have someone who might be able to help out, do try and get hold of a copy of the "Model Railway Journal" Issue 171 and look at the article in that about making colour light signals. May be available from the publishers: Wild Swan Publications Ltd., 1-3 Hagbourne Road, DIDCOT, Oxon., OXC11 8DP, tel 01235 816478.
(no e-mail address given)

It will be Weds next week at the very least before I can get round to looking afresh at the diagrams above.

Regards,
John

 

[jk1]

Thats not a problem John. I phoned Wild Swan Publications today and they still have back issues so I have sent a cheque.

Regards Jason

 

[Richard Johnson]

***Hi Jason, John, Edwin

I want to say what an amazingly useful and helpful thread this has been ... in all aspects, it is a real pleasure to read and follow!

Being so far away its hard to get an appreciation of modern UK signalling application/conventions and all contributions from start to finish have been exceptionally clear and easy to understand. The combined wisdom of John and Edwin plus Jasons step at a time reposting of images as it progressed has been a great qualifier for the written word!

As one who has greatly enjoyed reading this thread so far and has really appreciated learning much more about the subject... thanks!

Richard

 

[jk1]

Thank you Richard for you nice comments, I am sure John and Edwin will appreciate them as well! After all they have done the hard work! I agree with you also, reading through John and Edwin's replies it has much improved my understanding!

I have been conducting my own research into how these prototypical signals would be located in the real world. As I will probably install the base of these signals first and complete all scenery around them before finally fitting them, I wanted to see how these items are served in respect of electrical power and data. I found a great picture of a GPL on the photo sharing website 'flickr'. It also has a theatre indicator fitted above and is of the new LED version.

(Reference:GPLKevin R Boyd 26/04/2008)

Well worth visiting the reference site above as he has other interesting detail photos of signalling equipment used on the mainline.

Hopefully I will be able to model and create all the wiring runs and power boxes etc. I'm planning on creating as many of these items myself as purchasing enough of them from Knightwing or Ten Commandments to serve my layout will be a costly affair!

Regards Jason

 

[John Webb]

Jason - the indicator with the GPL signal in your photo above is actually a 'Stencil' indicator. Behind the front is, in this case, probably two compartments each with lights in. (Maybe in this case even LEDs as the GPL is a modern LED type.) Between the front screen and the lights is a cut-out 'stencil' with the route descriptions (in a brief format) which can be made visible by turning on the lights behind it - hence the name.
A 'Theatre indicator' is like a 5 by 7 dot matrix digit.

Thanks for the link to the site - but I regret there is a small error in it. The author has highlighted the items on the right and labelled one of them as 'Rail Contact'; this is wrong. It is actually an 'Axle Counter' and detects the passage of each wheel by magnetic means as a train passes. These devices are replacing track circuits for a number of reasons in many places.

I can't recall mentioning it before but there is a book by C J Freezer "Model Railway Signalling" published by PSL in 1991 (ISBN 1 85260 174 4). It's not up to date in the sense of having currently available models in it, but is a good reference to the prototype (except axle counters!) as well as to possible model-making. No longer in print, it often turns up on stands at model railway exhibitions and swap-meets.

Regards,
John