Looking for Help Signalling Layout

[WolfofBadenoch]

I’m hoping someone will help me with the best way to signal a section of my layout. I think i've got a basic understanding of signalling on the mainline, but maybe not so much around junctions. I’ve included in a drawing of the layout and what i plan to have in terms of mainline signalling (correct me if it’s wrong please), but i'm not sure about subsidiary signalling which is where i’m really looking for help. Here’s a quick description of layout and my thinking.

The layout is based about 1987 (give or take a year or 2), and is based on an extension of the WCML north of Glasgow. Carstairs is an inspiration but instead of trains splitting and half continuing with original loco, and the other half leaving behind a diesel, i plan to run trains in from GLA on the left, and then the train leaves to KK with a new loco pulling it.

I plan to use 4 Aspect signals. All 4 lines through the station are bi-directional so the signals on each of the approaches to the station have theatre route indicators (black boxes on drawing), although the 2 to the left will be off scene. The 4 signals at the left end of the station have feather indicators to show which route the train will take on departure. The mainlines leading to INV are in the process of being electrified so any trains continuing that way have to change to diesel haulage. (Platforms are outlined in pink – ie 3 platforms and 1 loop).

The blue sidings are the loco stable, green sidings are for engineers, timber loading. I presume all these sidings would probably be controlled by a ground frame?
What sort of signal would allow trains to leave the sidings? Is a GPL enough? I plan light engines moving from the loco stable onto trains reversing direction at the station, but also engineer / timber trains would depart onto mainlines.

What sort of signal would be used to leave the headshunt onto the loop/ sidings? Is a GPL enough?

Would the 4 aspect on the loop need a subsidiary signal (as indicated) to allow access to the headshunt?

 

Thanks for any advice comments received.

[The Stationmaster]

That's a pretty impressive start.

 

The sidings will be wholly handpoints.

You really need a running signal (i.e main aspect) for leaving the sidings if trains are going to start from there considering you date and setting - both it and the loop signals would be far more likely to have theatre route indicators rather than JIs ('feathers')

Yes, the signal on the loop would need a sub to read towards the headshunt.

 

Also depending on your curvature if you're assuming a newish installation in 1987 you might need some more route indicators to take account of the Principle regarding provision of such things at divergences and running crossovers - but it does depend on the curvature etc.

Edited December 21, 2014 by The Stationmaster

[beast66606]

Have you missed a slip on the right hand end ? - the topmost platform appears to cross the next line at a diamond - a trailing single slip would be required as a minimum or a double for full flexibility

 

It's likely that trap points would also be provided at the yard exit.

[TheSignalEngineer]

If the bottom running line is a Goods Loop then a trap would be needed at the right hand end. If it is Passenger then traps would be needed in the sidinga and headshunt.

 

Agreed with Beast that there seem to be some bits missing on the right hand end of the running lines. is that a diamond or two back-to-back single leads?

 

If the speeds for through running (non-stop) trains are lless than 40mph, as most would have to be with the track layout, it would be probable that signals would have theatre indicators rather than PLJIs.

[WolfofBadenoch]

Well spotted! It shows me how good you people are that you can see my drawing is wrong and I couldn't, even with the track laid in front of me! Yes the RH end should have 2 points back to back! I've attached a corrected drawing and added a signal for exit from the sidings.

 

Theatre Indicators instead of JIs for departing the station - I don't plan on the lines being bi-directional after the crossovers leaving the station so would theatre indicators still be needed ? (Would non bi-directional running lines be incorrect for the location and era?) On the layout the GLA and INV lines have a maximum radius of Peco large radius points (852mm i think), KK lines are straight.

 

The main purpose of the loop is goods - would a lack of trap points on sidings + headshunt rule out any possibility of passenger stock using it? My other problem is the track's all laid and glued down so i'll need to think about getting trap points inserted! I should have checked the layout before now.

 

I forgot to ask in the original post - Should the approach signals to the station on each line (the ones i've marked A), have a subsidiary signal for any light loco that has run out from the sidings which then backs onto a train in the station? Or would a light loco always run out on the departure line, before backing into the station?

 

Thanks for the answers and knowledge given so far.

 

[kenw]

Theatre Indicators instead of JIs for departing the station - I don't plan on the lines being bi-directional after the crossovers leaving the station so would theatre indicators still be needed ? (Would non bi-directional running lines be incorrect for the location and era?) On the layout the GLA and INV lines have a maximum radius of Peco large radius points (852mm i think), KK lines are straight.

 

The lines being non-bidirectional don't affect this, and in '87 it's unlikely they would be bidirectional beyond the station, it's still uncommon. It's down to approach speed as Signal Engineer said, and also to some extent turnout speed, JI (feathers) normally being used in higher speed locations, given this layout theatre boxes instead being most likely. The top two platforms are entered through a crossover, so unlikely that approach speed s high enough to justify a 'feather'. Also, for top platform, the KK routes via a slip so would be slow speed, the GLA route through crossovers likely being the higher speed so bit of minefield which way a feather would point - safer with a theatre box here. The bottom platform route, being approached straight, could have a feather, though as diverging route KK is again through slips, and GLA also via turnout, perhaps unlikely.

 

 

The main purpose of the loop is goods - would a lack of trap points on sidings + headshunt rule out any possibility of passenger stock using it? My other problem is the track's all laid and glued down so i'll need to think about getting trap points inserted! I should have checked the layout before now.

 

Trap  protection's required between goods loops / sidings and passenger lines, so yes it would. Trap protection would also be needed at INV end of loop (the headshunt serves this purpose at other end).

If the loop is to be used by passenger trains then trap protection from sidings and headshunt is required, though traps are not normally provided on a passenger line so wouldnt be needed at INV end of loop. (note ;passenger trains, not stock)

 

 

 Should the approach signals to the station on each line (the ones i've marked A), have a subsidiary signal for any light loco that has run out from the sidings which then backs onto a train in the station? Or would a light loco always run out on the departure line, before backing into the station?

 

From the track layout, this appears unnecessary, so the locos would probably go out on departure lines before backing (well, changing ends!) into station. The facility to use the opposite lines could still be added for flexibility, though as these lines aren't bidirectional a 'limit of shunt' board would then be required to limit wrong direction movement. If this facility isn't provided then the 'subs' on the 4 INV direction departure signals would appear unnecessary.

Having subsidiaries on inward signals 'A' would also give flexibility in allowing a train to enter an already occupied platform eg two DMUs

Edited December 30, 2014 by kenw

[WolfofBadenoch]

Thanks for the further info Kenw.

 

So feathers were only used in higher speed locations? Theatre indicators it is then - and a budget increase!

 

I've also realised 4 of the signals are probably going to each need to a gantry of some sort as i don't think there's realistically enough space between lines for them to be placed correctly on the drivers side of the track - Another budget increase!

[kenw]

Yes, that would I'd say be the case in a layout such as this. Feathers are used to be read which route is being taken from a greater distance for a higher speed approach, at lower speeds the theater box is normally used. Remember the signal would be released under approach control to bring the train down to a suitable speed.

So feathers are more common in modern rationalised junctions with single lead crossovers and generally higher speeds.

 

Not sure where you have the space problems, but remember they don't always have to be on the driver's side for various reasons such as sighting, or even, space.

Especially in a more traditional layout such as this, the platform starting signals could all be on the platforms including the right-hand side ones. Just don't hide them behind a platform canopy or footbridge etc or your savings'll be lost having to put banner repeaters in!

The colour lights exiting INV end of Goods loop, and from Yard Sidings could both be ground mounted, and possibly the colour light from GLA end of goods loop also.

 

Hope this helps without costing you too much extra

Edited January 4, 2015 by kenw

[russ p]

Feathers don't have to be for high speed routes, Peterborough has them at both ends of platforms 4 and 5.

I'm curious to why you have sub's under both end platform starters? As all routes can go behind the GPL s you have provided to set back. If you want the subs you will need limit of shunt indicators on the wrong direction movements

[WolfofBadenoch]

Thanks for the further replies.

 

 

Not sure where you have the space problems, but remember they don't always have to be on the driver's side for various reasons such as sighting, or even, space.

Especially in a more traditional layout such as this, the platform starting signals could all be on the platforms including the right-hand side ones. Just don't hide them behind a platform canopy or footbridge etc or your savings'll be lost having to put banner repeaters in!

The colour lights exiting INV end of Goods loop, and from Yard Sidings could both be ground mounted, and possibly the colour light from GLA end of goods loop also.

 

Hope this helps without costing you too much extra

Measuring rail to rail i have about 32mm between lines. Placing a signal between these with rolling stock on each line is possible, but it looks very close to my eye. Looking at a link provided on another thread (http://www.railwaysarchive.co.uk/documents/DoT_ElectrificationBlueBook1977.pdf), the diagram on p17 states 1364mm from rail to nearest face of signal. So about 18mm from both rails (36mm in total), leaves no space to place the signal. I'll take your advice and probably have some right sided ones on platforms.

 

I'm curious to why you have sub's under both end platform starters? As all routes can go behind the GPL s you have provided to set back. If you want the subs you will need limit of shunt indicators on the wrong direction movements

Simple answer to this is i'm not very knowledgeable on subs, GPLs etc - hence my questions.

Here's the main scenario i'm thinking of. A train arrives from GLA into any of the platforms. It's uncoupled and runs forward light towards INV on departing line. Once clear of points (and GPL), it stops. It then backs along through the double slip down the loop into the headshunt and then accesses the sidings.

Based on that scenario, after uncoupling could the light engine depart the station on a single yellow knowing that it would only proceed until it's clear of the points (and GPL) or would that only happen using a sub?

Is a limit of shunt needed? I realise if the light engine proceeded along the approach line a limit of shunt would definitely be needed.

[russ p]

It would be perfectly acceptable for a light loco to depart the station on any main proceed aspect and stop over the GPL to reverse. No limit of shunt indicators would be required, they are for moves in the wrong direction when signalled by a sub or GPL

Hope this helps

[WolfofBadenoch]

That's a help Russ thanks.

 

Now i'm trying to work through all the scenarios i may come up and see if any of the platform starters would need subs. If not there's a big saving - that can go toward the theatre indicators!

[russ p]

Trouble with all the theatre boxes I've seen modeled is the all seem overscale

[WolfofBadenoch]

Looking for a bit more advice on this, so thought i'd resurrect the old topic rather than start a new one.

 

In the images below, for the two lines either side of the island platform would a twin signal (eg https://www.crsignals.com/product-page/oo-gauge-4-aspect-twin-platform-signal) be used or is it too far in front of where a train would be stopped to keep the points clear on the further away line. ie Should the signal be where the train can't go beyond, as shown by my crude drawing of a single signal, and hence use 2 separate signals?

 

Thanks

 

[Phil Bullock]

Yes two seperate signals... there should be a stop signal positioned to protect the merging routes , and the rearmost platform should also have its own signal.

 

Cheers

[WolfofBadenoch]

Thanks Phil.

 

Yes the rearmost platform will have a signal, as will the loop in the foreground  (i didn't bother mentioning them to try and keep it simple). It was just coming across the twin signal while researching that made me wonder.

[5BarVT]

How many signals would Sir like? !

All depends how tight you are for length and how fussed you are about blocking other things.

Minimum cost is a twin signal back level with ‘clear’ on the loop platform (your single signal)

Next is two signals each ‘clear’ of the relevant converging line.

Next up is both your signals as shown but level (a bit back actually) with the toes of the facing points - gives extra useable length in the platform with the 47 but at the expense of blocking the APT line.

Finally, three signals to give an extra 2” say on the main line. 

In big railway terms, how much can you afford and what facilities do you need.

The old platforms 11/12 at Paddington were an example of inner and outer signals: not really a problem when 12 was used for parcels vans most of the time.

Paul.

[TheSignalEngineer]

My take is much as Paul.

 

The essential signals at the red arrows. The top two are at the clearance point when the lines start to converge. At 4mm scale that would be at 45mm track centres plus any allowance needed for side and end throw.

 

The green arrow is an optional signal to make full use of the available platform length on the line where the 47 is standing. It would be 25mm back from the rail joint between the two sets of points. 

 

There are some instances similar to this at Birmingham New Street and I put one in at Euston when the old parcels platforms were signalled for passenger use.

[WolfofBadenoch]

Thanks Paul + Signal Engineer.

 

At the moment i'll go with the essential signals - if i discover in the future i need to use the whole platform length i can add in the 'optional' signal. 

 

It has been designed to hold 5*Mk3 carriages + a loco at each end, which i think doesn't look too bad, but i sometimes feel some of my freight trains  look short.

[WolfofBadenoch]

Thanks to the help at the start of the year i now have signals in place at one end of my layout :-) (Although the gantry isn't permanent yet!)

 

Half a Traintronics gantry with CR Signals signal heads + PLS and 2 CR Signals.

 

Now to work out interlocking!

 

[The Stationmaster]

Looks very nice but judging by the photos some interlocking would be a very good idea

[Grovenor]

And why have you ended up with position light subs that it was agreed you don't need?

[WolfofBadenoch]

On 16/06/2020 at 13:40, The Stationmaster said:

Looks very nice but judging by the photos some interlocking would be a very good idea

 

Thanks. Yes interlocking is planned, but for now i set up the first photo to show the different colours (i'm sure i've seen comments about variations between different manufacturers). The second photo i only noticed the conflict between the set route and the signals when i looked at the photo on the big screen!

 

On 16/06/2020 at 14:18, Grovenor said:

And why have you ended up with position light subs that it was agreed you don't need?

 

Stupidity! When i brought up this topic again i was concentrating on signal placement and didn't check back on answers given 4 years previously!

[The Stationmaster]

All you need is a properly positioned Limit of Shunt board/signal and your position light subsidiaries are all instantly justified

[WolfofBadenoch]

9 hours ago, The Stationmaster said:

All you need is a properly positioned Limit of Shunt board/signal and your position light subsidiaries are all instantly justified

 

They'll be added.... at some point!