GWR Signalling for Terminus

[bordercollie]

 

Hi

 

I am hoping for some advice on signalling of my track plan. I have based my plan loosely on Bodmin General. The starter signals at Bodmin were placed to the left of the loop due to lack of space between track work. I am not sure if my plan can be signalled properly as it may be un-prototypical, mainly in regards to a branch line entering into the loop so close to station (see rough diagram below)

 

My thoughts so are as follows:

Home Signals

a) Bracket signal with a arms from the mainline into the terminus platform and into loop and also Mineral lines into platform road and loop.

 

Starter Signals

b) Platform Starter

 

c) Main starter with signals for mainline, mainline to Mineral line 2 and for loop to mineral line 2

 

d) Advanced Starter with shunting signal below the main line signal and a branch line signal. Could advanced starter be dispensed with, with the shunt signal and a signal for the Mineral Branch 1 on the main starter signal? I labeled both mineral lines as 2 on my diagram. No 1 is the first branch i.e. the one furthest from the terminus.

 

How would the exit from goods yard be handled in the case of 1) proceeding on to the loop to shunt into head-shunt and also through the crossover to the mainline and 2) how to signal a train from goods yard directly onto mineral line 2.

 

I assume any turnouts in goods yard are worked by ground levers so don’t need ground signals here. A ground signal controls entry to engine and carriage sidings and loco release crossover. Also exit from engine shed controlled by ground signals. A ground signal controls the other crossover from loop. There was only a ground signal for exiting the loop but not one on the mainline in the other direction.

 

I have indicated ground signals by black ovals. I am not sure of 6. It is meant to protect the crossover. When its off I assume that the driver would know he can proceed into crossover. However if it is on how does the driver know he can proceed into head-shunt.

 

Best Wishes

 

[The Stationmaster]

In order to answer your questions the answers to some other questions are needed -

 

1. What era are you portraying? GWR signalling practice changed over the years (and in some cases, just to be awkward, at some places it didn't change when it was supposed to have changed).

 

2.  Very importantly is how will the two mineral lines be served?   Will there simply be occasional shunts to exchange traffic or will there be specific movements of trains or parts of trains?  This will affect the track layout - especially the connection to Mineral Line 2.

 

3.  The siting of signals depends very much on topography and other factors - what happened at Bodmin isn't a particular guide to what happened at many other places for example.  Signal C for instance is to a very unusual form while D is in the wrong place while ground disc 6 is peculiar because it carries out part of the function of a signal which isn't there.

 

I will ask for this post to be transferred to the correct part of the forum which deals with infrastructure and signalling

[bordercollie]

Mike

The period I am modelling is the Summer of 1929. The terminus only has one platform. All signals have to be to the left of the loop as there would not have been enough clearance if placed in between the track.

My idea with the mineral(clay) lines is that they service two separate facilities in this case two China clay dries. They both enter the terminus station to be shunted. At Bodmin the branch from Wenford could only bring 6 loaded clay wagons towards Bodmin due to gradients. As I understand it a few trips to Wenford were needed so that longer trains could be made up to be taken to the main line and on-wards. In my fictitious history I have designed two mineral lines to add  more operational interest but with same premise of limited train lengths. The trains will come into the Station and wagons shunted as required. They will be timetabled trains coming from or going to the fictitious locations at some imaginary distances from the terminus for empties to be loaded.

Yes with signal (c) I took a guess at what may or may not have happened in a similar situation. My thinking was that the tall signal was for the main line from terminus platform and first lower level signal to the left was for the terminus platform to mineral line 2. The second lower level signal to the far left was for the loop road to mineral line 2.

Signal (d) was meant to signal the terminus platform for the mainline and that to mineral line 1(i.e the branch at RHS of diagram not mineral line 2 as the diagram indicates). I placed it here as there maybe clearance issues with branch line 2 if placed further to LHS.  I thought that I couldn't place it any further to RHS as it wouldn't have been far enough from the junction.  The smaller signal is a shunting signal

In relation to ground signal 6 it is meant to signal a train on the loop to proceed onto the main line. From what I understand there wasn't a ground signal for main line to loop. All shunting on main line was  was done by hand signals. 

Best wishes

Graham

 

[Stephen Freeman]

1929, the posts should be of the timber variety. Signal C, as I see it, has 2 possibilities:

1) A bracket signal with the main starter on the central post with smaller arms on posts either side

2) A single post with the main starter and 2 very small brackets, one either side with small arms (centre balance type)

 

It just depends, I think on whether or not the mineral lines would have rated option 1.

[Stephen Freeman]

1929, the posts should be of the timber variety. Signal C, as I see it, has 2 possibilities:

1) A bracket signal with the main starter on the central post with smaller arms on posts either side

2) A single post with the main starter and 2 very small brackets, one either side with small arms (centre balance type)

 

It just depends, I think on whether or not the mineral lines would have rated option 1. Or, a cash register signal might have been used.

 

[The Stationmaster]

The first thing to consider is the position of the signal box.  the platform starting signal at Bodmin was where it was because the presence of the signal box didn't allow it to be put in the correct place at the platform end.  But on your track layout placing it there would move it away from the major centre of pointwork but lineside features and the overbridge prevented it from being sited in the ideal position at Bodmin.  As I said you do need to consider the topography before anything else as that will help decide the position of the signal box and the siting of various signals.  Bodmin signal box had 26 levers in the 1916 frame and your frame will probably be longer once we sort various signals - I've already got it up to 35 with very simple ground disc provision so you will have a bigger signal box than at Bodmin and it probably won't fit where the Bodmin box was sited.

 

So at this stage i think the first thing you need to do is sort your topography to settle on the signal box site.  Once we know that we can sort the signals but I am inclined to take a lead from Bodmin to fit your planned date and assume that the lever fram had been renewed ina manner which allowed simpler signalling (otherwise it will probably be more like 40 levers than 35).   Generally the bracket structures (except possibly for the Home Signal) will only have the main post plus a single doll for a divergence but that really also depends on the distance between the connections from the 'main' line to the two mineral lines because there is a risk of finishing up with a forest of signals which could over-power teh whole scene.

[bordercollie]

Hi

Thanks for help. It has taken me hours to find out how to place this rough hand drawn plan. I tried to to get a plan directly off Templot but I couldn't work out how to do it.

I had not initially given much thought to the signal box. In my mind I was going to place it at the platform end as was the case at Bodmin. The Modelex GWR signal box that I have is much bigger than that at Bodmin. I think it may be better to place it between the entry to goods yard and Mineral Branch 2. I have in mind that the topography will consist of a reasonably deep cutting starting at around where I may place the signal box. Branch 2 will cut through this cutting if you see what I mean. Probably not that prototypical though. The negative is that the signal box will towards the front of layout. I have drawn a rough freehand diagram of my plan. I have moved platform starter to  the end of the platform. I have assumed that all the home signals were the same as shown on the diagram

I have been pondering a few things all day:

 a) How would the trains exiting from loop to main line or onto Branch 1 be signalled? Could it be a double ground signal?

 b) I am pretty sure the home and platform are correct. Actually the Bodmin home signals had a third arm directing train directly into goods yard, but I think I can do without it as I read a comment that this usually would not have been possible due to congestion in the yard.

So far I have come with the need for the following:

     i) 5 levers for ground signals (possibly 6)

     ii) 2 levers for catch points.

     iii) 4 levers for FPLs

     iv) 1 lever each for the two crossovers

      v) 2 levers for cross over with single compound,

      vi) 4 levers for turnouts

      vii) 6 levers for home signals

      viii) 1 lever for platform starter.

I am not sure how many will be required for the main starter and maybe an advance starter. Can anyone tell me if I am on the right track? What starter signalling would be needed? Could I assume that the exit from goods yard would be under the control of the appropriate person using hand hand signals etc.? I have marked a possible signals for loop to branch, main line to branch and mainline to RHS of the signal box.(The black rectangle)

I have been thinking about point rodding but that will have to wait as it is now past my bedtime.

Best wishes

 

 

 

 

[Nearholmer]

I know nothing about the GWR, but I do wonder why you’ve put the starter at the platform end, rather than much to the left, just before the divergence to the mineral line, which would allow greater freedom of length/position of trains ‘inside’ it.

 

Also, what is the virtue in having mineral line 2 able to access the platform road? I think I’d be looking to deal with all the mineral train movements in the loop, although I guess if you want to be able to bring two mineral trains on-scene simultaneously the flexibility to use either road for either branch might help.

[bordercollie]

I have just done this diagram to show possible runs of point, FBL and catch point rodding. It may be a bit hard to see. I have exaggerated the distance between the loop and main line for a bit of clarity. I have  colour coded the various runs. Is this a feasible diagram? I will need to position signal box to make the runs as uncomplicated as possible. My plan does not involve the the same lever controlling the crossover with the slip. I wasn't sure if this is possible as one lever is controlling the two stretcher bars on the compound I have 2 catch points, 4 FBL and 7 point runs.

Best wishes

 

 

 

 

[bordercollie]

Hi Nearholmer

At Bodmin General the platform starter was on the outside of the loop. Stationmaster informed me that was due to the location of the signal box at the end of the platform making the operation of this signal difficult. Placing it between loop and main line was not possible due the clearance problems.

I take your point about running from branch to mainline but like you say there would times when loop would already be occupied and it will add some operational interest

Best wishes

 

 

[martin_wynne]

6 hours ago, bordercollie said:

I tried to to get a plan directly off Templot but I couldn't work out how to do it.

 

Hi Graham,

 

If you mean get an historic map into Templot, see: https://85a.uk/templot/club/index.php?threads/changes-in-templot-version-227.180/post-1548

 

To get a screenshot of your track plan, click:

 

 

cheers,

 

Martin.

[The Stationmaster]

On 25/10/2021 at 05:21, bordercollie said:

Hi

Thanks for help. It has taken me hours to find out how to place this rough hand drawn plan. I tried to to get a plan directly off Templot but I couldn't work out how to do it.

I had not initially given much thought to the signal box. In my mind I was going to place it at the platform end as was the case at Bodmin. The Modelex GWR signal box that I have is much bigger than that at Bodmin. I think it may be better to place it between the entry to goods yard and Mineral Branch 2. I have in mind that the topography will consist of a reasonably deep cutting starting at around where I may place the signal box. Branch 2 will cut through this cutting if you see what I mean. Probably not that prototypical though. The negative is that the signal box will towards the front of layout. I have drawn a rough freehand diagram of my plan. I have moved platform starter to  the end of the platform. I have assumed that all the home signals were the same as shown on the diagram

I have been pondering a few things all day:

 a) How would the trains exiting from loop to main line or onto Branch 1 be signalled? Could it be a double ground signal?

You could use a double ground signal but at the toe of the slip connection leading from the loop to N Mineral Line 2 which is currently not signalled and then use eiether a siding signal ora ground disc at the connection from the loop into the branch.

On 25/10/2021 at 05:21, bordercollie said:

 b) I am pretty sure the home and platform are correct. Actually the Bodmin home signals had a third arm directing train directly into goods yard, but I think I can do without it as I read a comment that this usually would not have been possible due to congestion in the yard.

You could arrange the Home Signals (Branch and Mineral Line 1) in one of two possible ways and I think that in terms of a model you have chosen the better of the two as it helsp reduces the forest of signal effect.

 

However you have now got some signals missing.  there is no splitting signal for the Branch to Mineral Line 2 nor is there one (at the toe of the relevant points) for the Branch to Mineral Line 1 turnout and both of these will have to be signalled.  To suit the period you are modelling - and to mitigate the 'forest of signals' effect  - the ideal signal format to use in both cases is like the signal at Bugle shown on Page 4 of this thread.  this form would be perfectly ok for the period you are modelling although technically on obsolescent by then but plenty of such signals were still around at that time -

 

On 25/10/2021 at 05:21, bordercollie said:

So far I have come with the need for the following:

     i) 5 levers for ground signals (possibly 6)

     ii) 2 levers for catch points.

     iii) 4 levers for FPLs

     iv) 1 lever each for the two crossovers

      v) 2 levers for cross over with single compound,

      vi) 4 levers for turnouts

      vii) 6 levers for home signals

      viii) 1 lever for platform starter.

I am not sure how many will be required for the main starter and maybe an advance starter. Can anyone tell me if I am on the right track? What starter signalling would be needed? Could I assume that the exit from goods yard would be under the control of the appropriate person using hand hand signals etc.? I have marked a possible signals for loop to branch, main line to branch and mainline to RHS of the signal box.(The black rectangle)

I have been thinking about point rodding but that will have to wait as it is now past my bedtime.

 

Best wishes

 

 

 

 

 

Edited October 27, 2021 by The Stationmaster

[Nearholmer]

1 minute ago, The Stationmaster said:

However you have now got some signals missing.  there is no splitting signal for the Branch to Mineral Line 2

This is the signal that I can see the need for, and I imagine it being fairly close to the turnout. The one I struggle with a bit is the platform starter. Why can’t this splitter serve the starter function too? If there was room to shunt in and out of the loco shed area beyond the starter, I might get it, but I don’t think there is.

[The Stationmaster]

Sorry but for some reason a major part of my reply has vanished so I'll have to redo it which will take some time as I have various other things to get on with.

[The Stationmaster]

1 minute ago, Nearholmer said:

This is the signal that I can see the need for, and I imagine it being fairly close to the turnout. The one I struggle with a bit is the platform starter. Why can’t this splitter serve the starter function too? If there was room to shunt in and out of the loco shed area beyond the starter, I might get it, but I don’t think there is.

Not the way the GWR did it would be my immediate answer but from a practical viewpoint there is the immediate problem of a locking bar for the facing point leading to mineral line 2 - so the signal needs to be at the toe of that point.   If the splitting signal is on the platfrm end there would be a very real risk of that signal being returned to dange before the mn movement reached the facing points leading to the two mineral lines. 

[Nearholmer]

I am itching to do it the other way round: have only this splitting signal at the toe of the points, and nothing at the end of the platform.

[Grovenor]

There are three sets of facing points for a passenger train leaving the platform, all need FPLs and lock bars and as SM says the signals need to be close to the lock bar end, so you are looking at 3 signals really. I would make branch 2 access the loop only reducing to two facing points and two signals.

[Nearholmer]

OK, I get it.

[The Stationmaster]

3 hours ago, Grovenor said:

There are three sets of facing points for a passenger train leaving the platform, all need FPLs and lock bars and as SM says the signals need to be close to the lock bar end, so you are looking at 3 signals really. I would make branch 2 access the loop only reducing to two facing points and two signals.

Removing the access to mineral line 2 from the running line would have quite an impact on both what can be seen  (as it would reduce the forest of signals) and on the size of the frame taking out two black levers, one blue FPL lever, and (the way various signals need to be arranged) 6  red levers as the connection from the loop could legitimately be reduced to a hand point.

 

some thought needs to be given to signalling the connections on the loop and i would suggest a double disc at the loop end toe of the connection to mineral line 2 and a siding signal at the exit of the loop onto the running line - this situation is reflected in the number of levers I have noted below. (and in the number of levers which would be saved if mineral line 2 is connected solely to the loop by means of a hand point

 

Going back to my 'lost post' items and sticking for a moment with my comments above regarding splitting signals for the connections to the two mineral lines that would give the following for the frame -

6 point levers (assuming the point between the shed road and carriage siding were to be a hand point - it would be 7 point levers if that is on the frame (7 used in the total below).

4 Facing point Lock (FPL)/locking bar levers - there would be no FPL on the platform line end of the engine release crossover in accordance with usual GWR practice.

7 levers working ground discs (although one of them could be a points indicator thereby saving one lever)

6 levers working the various inbound Home Signals.  I think the signals reading from the two mineral lines should be siding signals with two arms mounted one above the other and not bracket structures.

The amount of movement two/from the mineral lines might create a need for an Outer Home Signal

5 levers working outbound running line stop signals - excluding the possible addition of an Outer Advanced Starting Signal possibly with a Shunt Ahead subsidiary arm

 

Ths gives 29 working levers plus two spares or spaces.   Provision of an Outer Home would add one lever while the Outer Advanced Starting Signal with subsidiary would add 3 more working levers.

 

[bordercollie]

 

I have now found time to digest all of the input on this topic. I suspect my diagram may have been misleading. I had marked the main starter next to the signal box and I left the possible advanced stater off the diagram until I got further information. I have attached a line drawing from my plan off Templot with the location of signal box ( outlined in blue ) location of signals small squares ( Red outline). The black square next to the signal box was the location for Mineral line 2 and Branch/Main line. I wasn’t sure what configuration to use. I have now placed the Advanced starter(?)  at a more appropriate location (?) I was thinking that any further in advance would mean that there may have very little space for shunting up to the home signal. I am having trouble downloading my Templot trackplan so I will send post how before I accidentally delete everything. I will try to sort out the problem.

 I think I will need to use modeller's licence with this. I did some maths and I think the size of box I have could have had approx. 34 levers.

 

 

On 23/10/2021 at 20:25, The Stationmaster said:

Generally the bracket structures (except possibly for the Home Signal) will only have the main post plus a single doll for a divergence

Do you mean that the bracket signal (c) in my original diagram would not be correct? If so would a splitting main starter with two arms  and a separate single post signal be placed somewhere near the main starter to signal train from loop to mineral branch 2?

 

I think that I may a better idea of the operation of the ground signals now. If I am correct the ground signal in the "off" position would allow train to exit the loop. If the signal was "on" the train could proceed onto the siding. At Bodmin for reasons I can't understand a ground signal wasn't installed at the crossover in the down direction. Rather some sort of hand, voice signal was used

On 27/10/2021 at 18:24, The Stationmaster said:

the ideal signal format to use in both cases is like the signal at Bugle shown on Page 4 of this thread.  this form would be perfectly ok for the period you are modelling although technically on obsolescent by then but plenty of such signals were still around at that time -

The signal you refer to is a backing signal I think. Where would you place them? If I understand correctly the backing signal was used for "wrong direction" movements so I suppose at a situation such as my plan at terminus in some sense all movements are right and wrong direction movements. 

My head is spinning a bit trying to understand everything. I think there are two options i)  A bracket signal with 3 arms 1 for mainline, 1 for mainline to mineral branch and 1 for loop to mineral line  or b) A bracket signal with 2 arms for main line and mail line to mineral line and a separate signal post for the loop to branch line. How would the backing signals fit to this situation?

I think I would still need the splitting advanced starter for mineral 1 and main line. Correct or not?  Would the shunt ahead signal below main line signal still be appropriate?

On 27/10/2021 at 22:52, The Stationmaster said:

6 point levers (assuming the point between the shed road and carriage siding were to be a hand point - it would be 7 point levers if that is on the frame (7 used in the total below).

4 Facing point Lock (FPL)/locking bar levers - there would be no FPL on the platform line end of the engine release crossover in accordance with usual GWR practice.

7 levers working ground discs (although one of them could be a points indicator thereby saving one lever)

6 levers working the various inbound Home Signals.  I think the signals reading from the two mineral lines should be siding signals with two arms mounted one above the other and not bracket structures.

The amount of movement two/from the mineral lines might create a need for an Outer Home Signal

5 levers working outbound running line stop signals - excluding the possible addition of an Outer Advanced Starting Signal possibly with a Shunt Ahead subsidiary arm

In my tentative diagram I only have 6 ground signals i.e. 2 at loco release crossover, 1 for entry to engine shed/ carriage sidings , 1 each for carriage and engine shed exits and 1 for the other crossover. Assuming that the main line to loop is my hand or other system. Where would you place the 7th? I was thinking that the mineral line 1 could potentially have a workmen's passenger train working so not strictly a goods only branch thus siding signals would not be possible. I would be interested in comments on the need for advanced starter. I think that this would be necessary as signals for main line to mineral branch 1 could not/ would not have been signaled on main starter. I will need a least two trap points.

 

Regards

Graham

[The Stationmaster]

I'll try to knock up a sketch for you showing a suitable way of doing it for the period you are modelling taking into account the points I've made above.  The signal ar t Bugle was very definitely not a backing signal as it had no g holes in the arm and was signalling a move from the running line to a looped siding and was the standard way of signalling such an arrangement.  if you look elsewhere in that thread you will find photos of a Backing Arm at Newquay and a very unusual Backing Signal at St Dennis Jcn (unusual in being so tall and using a full size arm).  there would be no Backing Signals on your track layout because it is, as you say, basically single lines.

 

Siding Signals would definitely be used in your period from the mineral lines and there were plenty of freight only lines where Workmen's trains could be found with either those signals or no fixed signals at all.

 

Actually allying normal GWR stop signal nomenclature the Advanced Starting Signal would be the one signalling the divergence of mineral line 1 from the the main branch line and the Outer advanced starting signal would of course be on the branch line itself - potentially with a Shunt Ahead subsidiary arm if traffic needs so dictated.

[The Stationmaster]

Right hopefully this will come up ok and it is a rather rough sketch but hopefully it captures everything.  I am assuming the track layout remains as originally drawn with the connection from the main platform line to mineral line 2 via slip connect in the turnout from the loop to that mineral line.

 

The signalling is slightly reduced - as  mentioned previously to avoid teh appearance of a forest of signal where the loop diverges from the incoming main line (that makes no difference to the number of levers.  However in the outbound direction I have provided splitting signals at both the running lines divergences in view of the distance between them,  in both cases the main line to mineral line signals use the 'to siding' arms as seen in the Bugle picture but I have used a more modern (in contemporaneous terms)  bracket arrangement for the 'main line' Home Signal.   As was the norm at that period on the GWR I have kept the number of bracket signal structures to an absolute minimum 

 

the provision of the Outer Advanced Starting Signal (with or without Shunt Ahead subsidiary arm) does provide a limiting point for shunts made out onto the 'main line' and would probably have been provided if the frequency of such shunts made it a sensible addition.  On a relatively quiet line such as this I doubt if an additional (outer) Home Signal would have been provided - such a luxury was clearly not considered necessary at Bodmin for example.

 

There is some flexibility for minor changes within the plan -

The double disc at the toe of the loop to mineral line 2 points could just as easily be a single disc if the lever frame had been renewed with 3 bar VT locking,

The exit signal from the loop could as readily be a siding signal as a ground disc and a siding signal would offer better sighting.

The point leading to either the engine shed or carriage siding (once clear of the running line( could be a hand point and the two exit discs could be worked by a single lever with or without that change (it's unusual, for the period when the new frame was installed, that they were worked by different levers at Bodmin but there might not have been sufficient safe ground space for a selector).

 

[bordercollie]

Thanks for diagram. Having studied it, I now have some follow-up questions.

 

I think I had misunderstood function of the advanced starter. As I understand it now it is used to extend the station limits where required. The shunt ahead being used where shunting may be needed beyond the station limits and that that advanced starter must be visible from signal box

 

I understand your thinking on using siding entry 3’ centre pivot type arms. However, on a practical note I don’t know if anyone currently makes this type of arm. MSE on one of their etches has a 3’ restricted clearance arm and boss so this could what I am after. However, if I can’t buy or adapt something would the use of standard arms and normal brackets be possible/prototypical whilst accepting that it may add to the “forest of signals” effect.

 

In relation to these siding/loop entry signals am I correct in thinking that freight only lines were regarded as long sidings?

 

Am I correct in thinking that at my time period ground signals could display a white or red aspect when on? The first being used where a ground signal could be passed when the signal is on and the second being where a train could only progress when green was showing? Therefore would ground signals to engine shed, crossover from loop to main line and loco release crossover show white light and the engine shed and carriage siding exits have red lights?

 

How would the double ground signal system operate? Would they both have red aspect when in on position? I don’t have the understanding of the 3 bar vertical locking system. But am I correct in thinking that with only one ground signal it would display white in the on and the system of interlocking would mean that signal couldn’t show green unless the slip had been correctly set for mineral line 1?

 

From the diagram I understand that siding exit signals where mounted on a single post.

 

Best wishes

Graham

 

 

[5BarVT]

Hi Graham,

 

56 minutes ago, bordercollie said:

I don’t have the understanding of the 3 bar vertical locking system.

Then you won’t understand 5 bar VT either :-)

 

1 hour ago, bordercollie said:

Am I correct in thinking that at my time period ground signals could display a white or red aspect when on? The first being used where a ground signal could be passed when the signal is on and the second being where a train could only progress when green was showing? Therefore would ground signals to engine shed, crossover from loop to main line and loco release crossover show white light and the engine shed and carriage siding exits have red lights?

Frame types preceding the 3 bar design couldn’t do ‘OR’ locking (this might be a bit of an oversimplification as I think they could do a simple both ways lock).  So taking the loco release crossover, with the crossover reverse each disc signal should lock the other, but with the points normal they don’t.  The ‘get out’ with an older frame was to lock the discs against each other always and put in a white light to allow them to be passed with the points normal.  On a 3 bar or 5 bar frame the conditional (‘OR’) locking could be provided and the discs would have red lights.  These are the only two disc signals where a white light might be needed, all others can be red.

 

1 hour ago, bordercollie said:

How would the double ground signal system operate? Would they both have red aspect when in on position?

Yes, as would any disc signal with a main arm (3’ or 4’).

 

1 hour ago, bordercollie said:

But am I correct in thinking that with only one ground signal it would display white in the on and the system of interlocking would mean that signal couldn’t show green unless the slip had been correctly set for mineral line 1?

I think you mean Mineral Line 2!

If it was on old style frame, it would be a double disc, both with red light.  If a 3 or 5 bar, it could be a single disc reading both ways but still a red light.

 

1 hour ago, bordercollie said:

I understand your thinking on using siding entry 3’ centre pivot type arms. However, on a practical note I don’t know if anyone currently makes this type of arm. MSE on one of their etches has a 3’ restricted clearance arm and boss so this could what I am after. However, if I can’t buy or adapt something would the use of standard arms and normal brackets be possible/prototypical whilst accepting that it may add to the “forest of signals” effect.

Technically a 3’ arm isn’t ‘restricted clearance’, it just happens to be shorter so can fit closer#.  Etch 3 on the MSE kit SOO15/1 is a 3’ steel arm which would be used for signals into sidings and goods loops.  However centre pivot arms (which are restricted clearance) as far as I know are (still) wooden.  MSE kit SOO14 has centre pivot arms on the right hand side, the 3’ arm is top right corner.

For an idea of what one looks like see Droitwich Spa.  They are 4’ arms but the 3’ version is just shorter at each end.

 

Hope this helps,

Paul.

 

# Although (on another railway) Dundee station north had very short signals that weren’t much more than the size of the spectacle plate due to very limited space but still counted as the equivalent of 4’ arms!

[The Stationmaster]

1 hour ago, bordercollie said:

Thanks for diagram. Having studied it, I now have some follow-up questions.

 

I think I had misunderstood function of the advanced starter. As I understand it now it is used to extend the station limits where required. The shunt ahead being used where shunting may be needed beyond the station limits and that that advanced starter must be visible from signal box

You need to ignore Station Limits to some extent when it comes to shunting into single line sections as the critical signal is the Home Signal (applicable to trains arriving from the single line).  The use of an Advanced or Outer Advanced Starting Signal out in the single line section was comparatively uncommon and it basically served as a very visible limiting point for any shunts onto the single line (and was useful in some instances where gradients were involved.  Thus such signals would only be provided where a lot of regular shunts outside the Home Signal onto the single line took place.  the shunt Ahead subsidiary is only there to cater for shunting long rafts and v because teh signal is so far from the signal box.    Thus the signal is not essential and really amounts to a 'might like to have' if traffic conditions justify it.

1 hour ago, bordercollie said:

 

I understand your thinking on using siding entry 3’ centre pivot type arms. However, on a practical note I don’t know if anyone currently makes this type of arm. MSE on one of their etches has a 3’ restricted clearance arm and boss so this could what I am after. However, if I can’t buy or adapt something would the use of standard arms and normal brackets be possible/prototypical whilst accepting that it may add to the “forest of signals” effect.

I'm not sure what is currently available or if the previous Colin Waite etch of GWR signal arms is still around.  others might know?

1 hour ago, bordercollie said:

 

In relation to these siding/loop entry signals am I correct in thinking that freight only lines were regarded as long sidings?

Not exactly and things changed over the years as well as being dependent on the exact status of the line and who was in charge of it.  Taking your proposed track layout in order for the Signalman to clear the relevant signal for a train to run to it he would first have to a seek permission from/agree the move with the person in charge of that line (although equally he could himself be in charge of it - that would be made clear in the Local Instructions or the Signal Box Special Instructions if the normal Rule(s) did not apply.

 

For moves to the mineral lines there would also most likely have been some sort of procedure for somebody (who might not be the signalman) to obtain permission to make a movement onto a line owned by someone else.  But if the lines were railway company owned then the Signalman would clear the relevant fixed signal y to authorise a movment onto that line.  A lot depends on where the private ownership starts and where the gate is sited.

1 hour ago, bordercollie said:

 

Am I correct in thinking that at my time period ground signals could display a white or red aspect when on? The first being used where a ground signal could be passed when the signal is on and the second being where a train could only progress when green was showing? Therefore would ground signals to engine shed, crossover from loop to main line and loco release crossover show white light and the engine shed and carriage siding exits have red lights?

You are correct regarding red or white lights in ground signals in the 'on' position.  The GWR introduced the white light (to replace a red light) in certain ground signals from c.the 1890s onwards and they remained in some places in older signals well into the 1970s if nota bit later - the reason for it was because the interlocking used back then did not allow for 'conditional' releases but when Vertical Tappet locking was introduced in the early 20th century conditional locking became possible and technically there was no need for the white light although many hundreds remained.

 

The ground signal to shed would havea white, the release crossover ground signal from the platform would probably have a red light (which sounds odd but most I know of did have a red light.  The signal reading along the loop from the yard end would have a white light because that was the only way a move could pass it towards the stop block on the loop.   All the rest would have red lights with the exception of the exit signal from the loop to the branch provided that there was also a spur (some might call it a headshunt, the GWR called it a spur).

1 hour ago, bordercollie said:

 

How would the double ground signal system operate? Would they both have red aspect when in on position? I don’t have the understanding of the 3 bar vertical locking system. But am I correct in thinking that with only one ground signal it would display white in the on and the system of interlocking would mean that signal couldn’t show green unless the slip had been correctly set for mineral line 1?

With VT locking there would be no technical need for a double disc but operationally it could be considered desirable - something for the operators to consider carefully when looking at the proposed signalling.  This disc (double or single) has to have a red light(s) as it protects a potential conflicting movement from the platform line to the mineral line.

1 hour ago, bordercollie said:

 

From the diagram I understand that siding exit signals where mounted on a single post.

Exactly so - no messing about with bracket structures is needed, too expensive and mno justifcation where we are talking about very low speed movements.

 

Hope all this has helped.

 

Regards,

 

Mike

1 hour ago, bordercollie said:

 

Best wishes

Graham