Signal plan

[SteveJF]

Hi,

 

I'm new to the forum, joined yesterday, and I'd really like some opinions on my signal plan. I've been planning to build a layout for more years than I can remember and over the years have amassed a collection of OO locos, coaches, wagons and various other items. However, I now have enough spare time and a bit of space to finally build a layout but I'm not sure how prototypical my plan is. I would appreciate any hints and tips.

 

 

 

 

Thanks

Steve

[phil-b259]

Can i just point out to all those who request help with signalling their layout, This is exactly the sort of diagram we need to be able to give assistance in signal positioning.

 

As a generalisation, images of layout planning software are far too messy to use for the purposes of signalling design. A line drawing like this (even if hand drawn with pen and paper) is far superior.

[ADK92]

I'm not too hot on signaling diagrams but your layout looks very similar to one I intend on building of Upton and Blewbury Station on the Didcot Newbury & Southampton Line, almost a mirrored image. 

 

Here's a link to the signal diagram of Upton and Blewbury Signal Box:

http://www.uptonvillage.co.uk/2014/02/upton-blewbury-signal-box-diagram/#prettyPhoto

 

Hope it might be of some use. 

 

Regards,

ADK

[dave55uk]

Nice clear diagram, only the signal arms are back to front and the colours are reversed :-)

 

Signals 6 and 21 are unnecessary. The main signal arms will suffice.

 

Question. What is the distance (in number of wagons) between signals 13 and 16?

 - not a problem for up trains but for down trains, detached wagons would have to fit

 between these signals so the train loco could run round and shunt them (unless you have

 a separate shunting loco which would be unlikely in a small station like this).

 And knocking off a wagon or two at a time from the down line would be time consuming.

 OK for a model where the operator wants to play but unlikely in real life.

 

Signals 9 & 10 could have an additional signal, reading 'set back onto down main', OR

 9 could read 'shunt to up main or good yard' and 10 reading 'set back onto down main'.

 

What is the distance (again in wagon lengths) between signals 15 & 17?

 Again, if too short, you would have the problem of only attaching/detaching one or two wagons at a time.

 (I'm aware of signal 17 - but see below).

 

Re signal 17. I have mixed feelings about this. My personal preference would be to have an additional up advance starter on the single line

 but within the down outer home. Thereby signal 17 would not be needed, signal 3 giving permission to shunt forward.

 I don't think an additional shunt signal reading 'down single line to up line' would be needed, as the interlocking between signal 3 and

 4 points would hold the points (signal 3 only being replaced to danger once the loco is back in rear of it).

 

To further compound matters, IF the distance between 13 & 16 AND between 15 & 17 is short, then signals 3 & 17 could be removed altogether

 (signal 2 acting as protection for 4 points) and then have the up advance starter (3) on the single line as mentioned above.

 

Furthermore - if the distance between 4 points and signal 22 is short, then signal 22 itself could be abolished - I have already removed signal 21 :-)

Edited August 27, 2018 by dave55uk

[RailWest]

A few random thoughts/questions:-

 

1. The usuals :-) What company/region, time period etc? This could impact for example the use of yellow discs or not...

 

2. Why that particular- and IMHO unusual -  numbering arrangement of crossover 7 and the slip 11?

 

3. I would suggest it much more likely that 20.19 would be 4.5 and 4.5 would be 19.20 - but actually, if there was a SA 17 then it would be 4 in a 'typical' sequence, so your current 20.19 would be 5.6 (given the disc 6 is not needed).

[bécasse]

The layout looks like a reasonably standard (ex-)GWR single passing loop station. If that is in fact what is intended then you should look at a handful of erstwhile prototype locations and copy what was installed there - particularly useful for getting the lever numbering right.

[iands]

I would agree with just about everything in the responses above. Signal 21 is unnecessary. Similarly, signal 17 is unnecessary and I suggest signal 3 is moved further along the curve towards 4 points. However, if you want to retain 3 and 17 (and it's your layout, so Rule One applies) in the current position, I would provide a "Limit of Shunt" board halfway between 3/17 and No. 4 points.

 

Regards, Ian.

[The Stationmaster]

I would agree with just about everything in the responses above. Signal 21 is unnecessary. Similarly, signal 17 is unnecessary and I suggest signal 3 is moved further along the curve towards 4 points. However, if you want to retain 3 and 17 (and it's your layout, so Rule One applies) in the current position, I would provide a "Limit of Shunt" board halfway between 3/17 and No. 4 points.

 

Regards, Ian.

 

Yer wot guv?   I do agree with everything you said until you got to dispensing with 17 and then mentioned a 'Limit of Shunt ' (LoS) board.  Now I know one Signal Engineer who has installed a facing LoS board on a 'leisure railway' but there is no such facility for such a thing in normal signalling that I have ever come across - LoS boards are there to limit shunting movements made towards the rear into a section, and not to limit them if they are made in the facing direction into a section.  NB in this context 'section' can be a block section or a signal section.

 

I agree wholeheartedly with moving Signal 3 towards No.4 points and it could readily be sited just in rear of the fouling point for those points.  Logically it could (perhaps even 'should') have a subsidiary shunt ahead arm (No.17) as it would be quite likely to have to be passed for shunting purposes.  Such arms weren't always provided, even on the GWR, but they tended to be installed where it was necessary to make regular shunting moves in advance of the Section Signal (No.3) - as such the 3/17 combination and its situation matches almost exactly (albeit without the tunnel) the signalling at one end of Chipping Norton and absolutely matches one of the Section Signals there.

 

There seems to be some confusion in respect of shunting movements into single line sections and the placing of signals or what signals are needed to ensure safety.  The traditional single line passing place very rarely had either Outer Home Signals or Advanced Starting Signals, even if a lot of shunting took place there.  If a shunt was needed onto the single line section it was block signalled as a shunt outside the Home Signal (e.g No 23 in this instance) and then either handsignalled or a subsidiary Shunt Ahead Signal or ground disc (depending on which line it was coming from) was used.  There was normally no fixed signal at all to limit the movement, that relied on those making the movement to go only as far as was necessary for the shunt.  the regulations permitted such moves to be made into opposite ends of a single line section simultaneously and a shunt to be made into the section behind a train going away from the place where the shunt was made - even the latter could be signalled using a ground disc or Shunt ahead depending on which line the shunt was coming from but the last time I did it we used a hand signal as we only had a running signal - taht was to shunt a 10 coach passenger train into a section following a departing dmu - all 100% legitimate within the Rules & Regs.

 

The idea of an Outer Home Signal sufficiently far beyond an Advanced Starting Signal towards which the shunt would be made seems a fairly modern one - in fact even stations where passenger train sections were regularly shunted into a single line section didn't have such lavish signal provision, basically because it was unnecessary unless there was a need to accept a train while a shunt was being made onto the single line.

[iands]

Yer wot guv?   I do agree with everything you said until you got to dispensing with 17 and then mentioned a 'Limit of Shunt ' (LoS) board.  Now I know one Signal Engineer who has installed a facing LoS board on a 'leisure railway' but there is no such facility for such a thing in normal signalling that I have ever come across - LoS boards are there to limit shunting movements made towards the rear into a section, and not to limit them if they are made in the facing direction into a section.  NB in this context 'section' can be a block section or a signal section.

 

I agree wholeheartedly with moving Signal 3 towards No.4 points and it could readily be sited just in rear of the fouling point for those points.  Logically it could (perhaps even 'should') have a subsidiary shunt ahead arm (No.17) as it would be quite likely to have to be passed for shunting purposes.  Such arms weren't always provided, even on the GWR, but they tended to be installed where it was necessary to make regular shunting moves in advance of the Section Signal (No.3) - as such the 3/17 combination and its situation matches almost exactly (albeit without the tunnel) the signalling at one end of Chipping Norton and absolutely matches one of the Section Signals there.

 

There seems to be some confusion in respect of shunting movements into single line sections and the placing of signals or what signals are needed to ensure safety.  The traditional single line passing place very rarely had either Outer Home Signals or Advanced Starting Signals, even if a lot of shunting took place there.  If a shunt was needed onto the single line section it was block signalled as a shunt outside the Home Signal (e.g No 23 in this instance) and then either handsignalled or a subsidiary Shunt Ahead Signal or ground disc (depending on which line it was coming from) was used.  There was normally no fixed signal at all to limit the movement, that relied on those making the movement to go only as far as was necessary for the shunt.  the regulations permitted such moves to be made into opposite ends of a single line section simultaneously and a shunt to be made into the section behind a train going away from the place where the shunt was made - even the latter could be signalled using a ground disc or Shunt ahead depending on which line the shunt was coming from but the last time I did it we used a hand signal as we only had a running signal - taht was to shunt a 10 coach passenger train into a section following a departing dmu - all 100% legitimate within the Rules & Regs.

 

The idea of an Outer Home Signal sufficiently far beyond an Advanced Starting Signal towards which the shunt would be made seems a fairly modern one - in fact even stations where passenger train sections were regularly shunted into a single line section didn't have such lavish signal provision, basically because it was unnecessary unless there was a need to accept a train while a shunt was being made onto the single line.

Re the LoS suggestion, you're quite right Mike, what was I thinking! In my defence, I had been busy painting a wagon and the fumes must have got to me. I've now opened the window for a bit of ventilation.

 

Regards, Ian.

[Nick Holliday]

When I first saw the diagram I thought that the single slip, 11, was redundant, since the main loop would have been sufficient. Looking at Stephen Williams' book on GWR branches, he shows five stations on the Didcot, Newbury and Southampton Railway which had a similar layout, but without the single slip, just a diamond crossing across the upper running line. However, he does also illustrate Dymock station, which is almost exactly as drawn, complete with a single slip. There is a signalling diagram for Dymock in R H Clark's book of station diagrams, which has fewer signals than the OP has shown, with only three ground signals, but with an up starter and an up main advanced starter. However, Dymock was unusually (?) signalled so that the down line, the one further from the goods yard, was a reversible line, presumably so that the signal box could be shut, without disrupting services too much, which would make an interesting variation and a talking point for signalling aficionados.

A final comment, I wonder if point No 8 would be controlled from the box, being operated by the shunting team as required.

[RailWest]

I would agree about 8 being just a hand-point.

 

It would appear that Dymock could switch-out, hence the bi-directional signalling. Perhaps more unusual still was South Molton, which had bi-directional  on the Down but could not switch-out. Allegedly this provision was for the convenience of passengers (wot? never!), as the town was on that side of the line, so it was convenient for passengers returning from Barnstaple when there was not a Down train to cross.

 

Bishops Lydeard was another location which once had a slip (on the connection in to the goods shed), so I suspect it's really up to the builder to decide whether or not to have one. 

[bécasse]

more unusual still was South Molton, which had bi-directional  on the Down but could not switch-out. Allegedly this provision was for the convenience of passengers (wot? never!), as the town was on that side of the line, so it was convenient for passengers returning from Barnstaple when there was not a Down train to cross.

 

 

It is more likely to have been provided because it facilitated the handling of parcels and mail (or, perhaps even more likely, milk churn) traffic.

[SteveJF]

Hi Everyone,

 

Thanks for all the feedback it will certainly help. In answer to the questions and observations:

 

Dave,

Signal arms back to front and colours reversed, oops! I can't believe did that.

 

The distance in wagons between 13 and 16 should be 5 or 6 wagons which I was hoping would be representative of the maximum normal cut for a station like this.

 

Re signals 9 and 10, I think your suggestion of 9 reading 'shunt to up main or good yard' and 10 reading 'set back onto down main', is better than my original idea so I'll go with that.

 

I'm going to have to shoehorn this layout into a less than ideal space but I'm hoping I can fit 5 or 6 wagons in between signals 15 and 17, and when I put 17 and 3 there I was thinking of the fouling point for trains held at those signals.

 

With signal 22 I was thinking I needed a signal to bring trains to a halt at the correct position to begin shunting.

 

For the time period and company I was thinking of late thirties and an independent cross country route which was absorbed by the Southern at grouping. Not sure how feasible that Idea is but I wanted a background story which would allow as wide a variety of engines and rolling stock as possible, also a wide variety of signalling equipment as the pre grouping company was careful with its money and bought from whoever was offering the best deal at the time.

 

Chris,

For the time period and company I was thinking of late thirties and an independent cross country route which was absorbed by the Southern at grouping. Not sure how feasible that Idea is but I wanted a background story which would allow as wide a variety of engines and rolling stock as possible, also a wide variety of signalling equipment as the pre grouping company was careful with its money and bought from whoever was offering the best deal at the time.

 

 

 

The numbering of levers around the cross over and slip was really a bit of a guess. I tried to work with the idea that levers associated with a particular move would be grouped as close as possible to save the signalman running backwards and forwards along the frame.

 

 

 

Levers 4.5 and 19.20 are arranged this way because I thought for signalling through trains all the necessary levers would be together. However looking at it again maybe 20 would be more relevant to up trains and lever 5 to down trains.

 

 

Bécasse,

The plan was something I dreamt up and is coincidentally very similar to a number of stations on the DNS. When I noticed this I looked at the layout for places like Burghclere and Whitchurch but they seemed to be noticeably less complex than my plan leading me to think that maybe the diagrams I found didn't have everything in them. However from the comments it looks like mine has too much in it. 

 

 

Ian,

If I'm honest, one of the reasons for signal 17 is that I really like the look of the old "S" type shunt ahead signals so I was trying hard to find a reason to include one, but also I was thinking that "up" trains would have to be held clear of the fouling point if the section ahead was occupied by an approaching down train so I put signal 3 in.

 

 

Chris, Nick,

I put lever 8 in as I've bought some Scalefour lever frame kits to use, so I would have to use a lever in one of them to control that point in order to avoid the "great hand from the sky" but now you mention it I think you're right that it shouldn't be number 8. Perhaps an un numbered one at one end of the frame?

 

 

 

Thanks everyone for the responses, I can now make some improvements which should make things more believable. If I've made further errors in my answers please let me know, otherwise I'll post every now and again to show progress.

 

 

 

Steve

 

[RailWest]

>>>Re signals 9 and 10, I think your suggestion of 9 reading 'shunt to up main or good yard' and 10 reading 'set back onto down main', is better than my original idea so I'll go with that....

 

I would suggest that a "back along down main" signal would not normally have been provided, and if it had then a LOS board would have been needed just before the movement got to the entry to the loop. Better IMHO either to have just one disc there or else make the top one read into the yard and the lower one read to the Up loop.