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Dungrange

Colour Light Signalling and Operating Critique Required

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Rather than, yet again, post my developing layout plan on Simon Paley's thread about his book on Colour Light Signalling for Railway Modellers, I think it's time I start a new thread for my questions.   The layout below represents nowhere in particular, but is intended to represent somewhere in Central Scotland in the early 21st Century (principally in the period from around 2006 to 2009).

 

image.png.eb805b11cd409642d38c0f1a1a932f2a.png

 

The Up and Down lines are fairly self explanatory and effectively just provide the opportunity to watch the trains go by. There is a single track branch line (probably freight only) which diverges from the Down Main and a short Loop in the Down direction, which serves three purposes:

  1. It provides access to the Oil Sidings and allows shunting of these to take place off the mainline.  These will be operated similar to my understanding of the operation of the sidings at Dalston in Cumbria.  I'm assuming there is a Marshalling Yard in the Up direction (to the right of the diagram) and TEA wagons are tripped to the Down Loop in short cuts of five or six wagons.  Once the loaded train is locked into the Down Loop (crossover 304 returned to Normal) the Subsidiary Signal on LP108 will be pulled Off and the full wagons are shunted into the top siding.  Collecting the Annett's key, the Ground Frame can then be unlocked and point 303 worked locally, with the empty TEA wagons being removed from the unloading facilities and then coupled to the loaded wagons to allow the loaded wagons to then be shunted into place for unloading.  During this part of the operation, it will be necessary for the locomotive to pass LP105 (because it will have ten or twelve bogies in tow), with the Subsidiary Signal giving authority to proceed to LP 206 (which will act as a Limit of Shunt to minimise the impact on the capacity of the branch).  With the empty tanks sitting in the Down Loop, the locomotive will run round, wrong line running on the Down Main as far as LP201 Limit of Shunt Signal, before coupling up to its train in the Down Loop and proceeding back to the Marshalling Yard via the Up Main. 
  2. The Down Loop will also provide access to the Yard on the Up side, with trip workings from the off-scene Marshalling Yard arriving in the Down Loop. The locomotive would uncouple, run round as above, and then once coupled up to the other end of the train it would proceed from LP108 to LP102 and then set back into the yard.  Departing trains would then proceed back to the Marshalling Yard via the Up Main.
  3. The Down Loop will also be used by some 'Short' Down Freight trains heading for the branch, so that they can be held off the mainline whilst waiting for an Up Freight to come off the branch.  However, many of the Branch Freight trains will be too long to fit in the loop and will therefore stay on the Down Main and use crossover 308 to access the branch.

 

So, is there anything that I've omitted from the plan above or anything that looks non-prototypical?  I'll only be modelling the section between the bridges.

 

I guess my principal remaining questions are how does the driver of the locomotives using the Down Loop and running round communicate with the signalman to request authority to shunt beyond Signal LP105 and to inform the signalman that they are ready to depart from Signal LP108 and cross onto the Up Main?  Would this just be undertaken by use of a telephone on each of these signals?

 

My other question is how does a signalman know whether a train has come to a stop?  For example, LP101 can't be pulled off to permit a train to approach Signal LP103 if there is an Up train coming off the Branch (because the LP103 Overlap wouldn't be clear), but I'm assuming that if a train is already stationary at Signal LP103 and LP103 is On (ie showing red), it would be permissible for LP112 to be pulled off and allow an Up train to cross onto the Up Main.  However, I'm assuming that this can only be permitted when there is no prospect of the train on the Down Main passing LP103 at danger.  That therefore prompts the question, how would this be detected?

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13 minutes ago, Dungrange said:

Rather than, yet again, post my developing layout plan on Simon Paley's thread about his book on Colour Light Signalling for Railway Modellers, I think it's time I start a new thread for my questions.   The layout below represents nowhere in particular, but is intended to represent somewhere in Central Scotland in the early 21st Century (principally in the period from around 2006 to 2009).

 

image.png.eb805b11cd409642d38c0f1a1a932f2a.png

 

The Up and Down lines are fairly self explanatory and effectively just provide the opportunity to watch the trains go by. There is a single track branch line (probably freight only) which diverges from the Down Main and a short Loop in the Down direction, which serves three purposes:

  1. It provides access to the Oil Sidings and allows shunting of these to take place off the mainline.  These will be operated similar to my understanding of the operation of the sidings at Dalston in Cumbria.  I'm assuming there is a Marshalling Yard in the Up direction (to the right of the diagram) and TEA wagons are tripped to the Down Loop in short cuts of five or six wagons.  Once the loaded train is locked into the Down Loop (crossover 304 returned to Normal) the Subsidiary Signal on LP108 will be pulled Off and the full wagons are shunted into the top siding.  Collecting the Annett's key, the Ground Frame can then be unlocked and point 303 worked locally, with the empty TEA wagons being removed from the unloading facilities and then coupled to the loaded wagons to allow the loaded wagons to then be shunted into place for unloading.  During this part of the operation, it will be necessary for the locomotive to pass LP105 (because it will have ten or twelve bogies in tow), with the Subsidiary Signal giving authority to proceed to LP 206 (which will act as a Limit of Shunt to minimise the impact on the capacity of the branch).  With the empty tanks sitting in the Down Loop, the locomotive will run round, wrong line running on the Down Main as far as LP201 Limit of Shunt Signal, before coupling up to its train in the Down Loop and proceeding back to the Marshalling Yard via the Up Main. 
  2. The Down Loop will also provide access to the Yard on the Up side, with trip workings from the off-scene Marshalling Yard arriving in the Down Loop. The locomotive would uncouple, run round as above, and then once coupled up to the other end of the train it would proceed from LP108 to LP102 and then set back into the yard.  Departing trains would then proceed back to the Marshalling Yard via the Up Main.
  3. The Down Loop will also be used by some 'Short' Down Freight trains heading for the branch, so that they can be held off the mainline whilst waiting for an Up Freight to come off the branch.  However, many of the Branch Freight trains will be too long to fit in the loop and will therefore stay on the Down Main and use crossover 308 to access the branch.

 

So, is there anything that I've omitted from the plan above or anything that looks non-prototypical?  I'll only be modelling the section between the bridges.

 

I guess my principal remaining questions are how does the driver of the locomotives using the Down Loop and running round communicate with the signalman to request authority to shunt beyond Signal LP105 and to inform the signalman that they are ready to depart from Signal LP108 and cross onto the Up Main?  Would this just be undertaken by use of a telephone on each of these signals?

 

My other question is how does a signalman know whether a train has come to a stop?  For example, LP101 can't be pulled off to permit a train to approach Signal LP103 if there is an Up train coming off the Branch (because the LP103 Overlap wouldn't be clear), but I'm assuming that if a train is already stationary at Signal LP103 and LP103 is On (ie showing red), it would be permissible for LP112 to be pulled off and allow an Up train to cross onto the Up Main.  However, I'm assuming that this can only be permitted when there is no prospect of the train on the Down Main passing LP103 at danger.  That therefore prompts the question, how would this be detected?

For the Down Loop to be considered a "Loop", shouldn't it be capable of a direct route back to the Down Main? Also, should  trap points be provided ahead of signal 112?

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24 minutes ago, iands said:

For the Down Loop to be considered a "Loop", shouldn't it be capable of a direct route back to the Down Main? 

 

If a loop is required for refuge purposes (ie to allow slower moving trains to be overtaken by faster moving trains that are following), then obviously a direct re-connection would be essential, but is that a requirement to be called a "Loop"?   If it is, do you know how my 'Down Loop' should be referred to?

 

I actually started with the idea of refuge loops off the Up and Down Mainlines for the purpose holding freight trains.  Unfortunately, it quickly became apparent that I couldn't fit sufficiently long loops into the space that I have available, which is why the track plan morphed into the format presented above.

 

24 minutes ago, iands said:

Also, should  trap points be provided ahead of signal 112?

 

What would the purpose of these trap points be?  The flank protection provided by crossovers 308 and 304 would stop any runaway on the branch from reaching the Down Main, which is where the passenger services will be.  As drawn, the branch should only be used by freight trains (which is how I think I will operate this).  If passenger trains are to be operated on the branch, then I'd need to add a trap point immediately in advance of Signal LP105 to avoid the possibility of stock in the 'Down Loop' rolling into the path of a passenger train negotiating crossover 308 when it's Reversed to permit a passenger movement on or off the branch.  If that's what you meant, thank's for pointing it out - I clearly need to be committed to a freight only branch before committing to laying the track or see if I can fit that trap point in. 

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2 hours ago, Dungrange said:

Rather than, yet again, post my developing layout plan on Simon Paley's thread about his book on Colour Light Signalling for Railway Modellers, I think it's time I start a new thread for my questions.   The layout below represents nowhere in particular, but is intended to represent somewhere in Central Scotland in the early 21st Century (principally in the period from around 2006 to 2009).

 

image.png.eb805b11cd409642d38c0f1a1a932f2a.png

 

The Up and Down lines are fairly self explanatory and effectively just provide the opportunity to watch the trains go by. There is a single track branch line (probably freight only) which diverges from the Down Main and a short Loop in the Down direction, which serves three purposes:

  1. It provides access to the Oil Sidings and allows shunting of these to take place off the mainline.  These will be operated similar to my understanding of the operation of the sidings at Dalston in Cumbria.  I'm assuming there is a Marshalling Yard in the Up direction (to the right of the diagram) and TEA wagons are tripped to the Down Loop in short cuts of five or six wagons.  Once the loaded train is locked into the Down Loop (crossover 304 returned to Normal) the Subsidiary Signal on LP108 will be pulled Off and the full wagons are shunted into the top siding.  Collecting the Annett's key, the Ground Frame can then be unlocked and point 303 worked locally, with the empty TEA wagons being removed from the unloading facilities and then coupled to the loaded wagons to allow the loaded wagons to then be shunted into place for unloading.  During this part of the operation, it will be necessary for the locomotive to pass LP105 (because it will have ten or twelve bogies in tow), with the Subsidiary Signal giving authority to proceed to LP 206 (which will act as a Limit of Shunt to minimise the impact on the capacity of the branch).  With the empty tanks sitting in the Down Loop, the locomotive will run round, wrong line running on the Down Main as far as LP201 Limit of Shunt Signal, before coupling up to its train in the Down Loop and proceeding back to the Marshalling Yard via the Up Main. 
  2. The Down Loop will also provide access to the Yard on the Up side, with trip workings from the off-scene Marshalling Yard arriving in the Down Loop. The locomotive would uncouple, run round as above, and then once coupled up to the other end of the train it would proceed from LP108 to LP102 and then set back into the yard.  Departing trains would then proceed back to the Marshalling Yard via the Up Main.
  3. The Down Loop will also be used by some 'Short' Down Freight trains heading for the branch, so that they can be held off the mainline whilst waiting for an Up Freight to come off the branch.  However, many of the Branch Freight trains will be too long to fit in the loop and will therefore stay on the Down Main and use crossover 308 to access the branch.

 

So, is there anything that I've omitted from the plan above or anything that looks non-prototypical?  I'll only be modelling the section between the bridges.

 

I guess my principal remaining questions are how does the driver of the locomotives using the Down Loop and running round communicate with the signalman to request authority to shunt beyond Signal LP105 and to inform the signalman that they are ready to depart from Signal LP108 and cross onto the Up Main?  Would this just be undertaken by use of a telephone on each of these signals?

 

My other question is how does a signalman know whether a train has come to a stop?  For example, LP101 can't be pulled off to permit a train to approach Signal LP103 if there is an Up train coming off the Branch (because the LP103 Overlap wouldn't be clear), but I'm assuming that if a train is already stationary at Signal LP103 and LP103 is On (ie showing red), it would be permissible for LP112 to be pulled off and allow an Up train to cross onto the Up Main.  However, I'm assuming that this can only be permitted when there is no prospect of the train on the Down Main passing LP103 at danger.  That therefore prompts the question, how would this be detected?

I don’t see the need for LP205 or LP206 as these would need to become ‘pre-set’ shunt signals within the main aspect routes and also when 103 could have a LOS up the branch replacing 206 and then the subsequent opposite direction would utilise 112 replacing 205.

 

In regards to your final question, if you had also designed in track circuits on your scheme plan, LP103 & 105 would have in place TER (timed electrical release) where their berth track circuits were occupied for say 30 seconds on their own with the tc of that berth in rear having been cleared for that time also to ‘demonstrate/prove’ that the train had been ‘electrically’ timed to a stand. Another way that we do this, is that  if we set a route from 101 to either 103 or 105 and the route from 103 or 105 is not already ‘pre-selected’, 101 signal becomes approach controlled from ‘red’ thus as belt and braces making the approaching train being at a speed of which the driver is prepared/ready to stop. This is a compromise in absolute approach locking as we nether have flank protection applied by existing S&C or by run offs. Once this down direction train was ‘electrically’ proved to a stop and UP direction service could be signalled off the branch.

 

Another way it could be done is that if first a train is signalled from 112 in the UP direction, the interlocking would have a ‘special control’ where if 112 was showing a proceed or had an overlap going past it, a proceed aspect could not be obtained on 101.

 

hope this helps

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45 minutes ago, thedman said:

I don’t see the need for LP205 or LP206 as these would need to become ‘pre-set’ shunt signals within the main aspect routes and also when 103 could have a LOS up the branch replacing 206 and then the subsequent opposite direction would utilise 112 replacing 205.

 

Yes, I'm envisaging that LP205 and LP206 would have to be pre-set shunt signals set by LP112 and either LP103 or LP105 depending on the lie of crossover 308, respectively.  My rational for the inclusion of these was that to accept an Up Freight train on the branch as far as LP112, the Overlap beyond that would have to be clear.  Therefore, to stop a locomotive making a run round move running into the Overlap in advance of Signal LP112 when an Up Freight is on the branch, I assume that I need to define the Limit in which the locomotive may move during the run round.  That was my rational for adding LP206 and it's placement is just outside of the Overlap - ie slightly more than 180 metres from LP112.  The driver of a locomotive sitting at that point would then need to know when crossover 308 had been thrown and they were permitted to run out onto the Down Main to undertake their run round.  That was my rational for adding LP205.  The distance between LP206 and LP205 would obviously have to be greater than the length of the locomotive.

 

Are you saying that the run round movement should actually be made from LP105 to a point that is past LP112, so that LP112 is the signal that gives permission for the driver to run wrong direction on the Down Main (instead of LP205)?

 

1 hour ago, thedman said:

In regards to your final question, if you had also designed in track circuits on your scheme plan, LP103 & 105 would have in place TER (timed electrical release) where their berth track circuits were occupied for say 30 seconds on their own with the tc of that berth in rear having been cleared for that time also to ‘demonstrate/prove’ that the train had been ‘electrically’ timed to a stand. 

 

That technically doesn't prove that a train has actually stopped, but I suppose if the track circuits are relatively short and the timing interval is relatively long, then it does prove that the locomotive is travelling at less than a very low speed and therefore may be presumed to be stationary.

 

To be honest, I'd think it was unlikely that a train would normally be held on the Down Main at Signal LP103 to allow an Up Freight to cross from the Branch to the Up Main, but I'm envisaging a station to the left of the plan (possibly at LP107) and therefore an incident that may result in an increased dwell time may mean that Signal LP103 can't be cleared and with an Up Freight already sitting at LP112, I'm assuming that the signaller may 'let it out' assuming there is a path on the Up Main.  Obviously under that scenario, the train would approach LP103 at red and therefore LP101 would have been displaying a cautionary aspect, so that the driver should have been able to stop.  It's just it seems obvious that a check should be made before LP112 can be pulled off.

 

Looking at Track Circuits is my next task.

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I think you need LP202 on the other side of 301A so it controls the entire reversing movement into either of the loops.  

 

Similarly LP204 would probably go to the fouling point on the other side of 301B, if there is still enough length for a loco to stand between it and LP201.  I'm not sure if this facilitates any other useful shunting moves but it feels wrong to be reversing on points.  

 

Moves from LP106 and LP108 to LP102 would be main aspect, but these signals still need their subsidiary aspects for shunting moves.  

 

The driver would phone from the relevant signal when ready to make a move, if the signaler hadn't cleared the signal already.  

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1 hour ago, Edwin_m said:

I think you need LP202 on the other side of 301A so it controls the entire reversing movement into either of the loops.   

 

I can't see a regular need to use crossover 301 to move from the Up Main to the Down Main but I can see that it would create additional operational flexibility.  Since I want to make the Down Loop as long as possible, I need to push crossover 301 as close to the over bridge that will provide the scenic break, so I'll move LP202 as you suggest.  As it will likely be under the bridge, I don't even need to make it work.

 

1 hour ago, Edwin_m said:

Similarly LP204 would probably go to the fouling point on the other side of 301B, if there is still enough length for a loco to stand between it and LP201.  I'm not sure if this facilitates any other useful shunting moves but it feels wrong to be reversing on points.  

 

Moving LP204 as you suggest, doesn't provide any additional operation flexibility, but if normal operating practise is to try and avoid reversing the direction of a locomotive when it's sitting on point work, then I'm happy to move that Signal too.  That means that it likely be under the bridge in line with LP202.  LP201 would have to be moved to the other side of the bridge (ie into my fiddle yard) and LP101 moved further up the line so that it's 180 metres from LP201, but since that's imaginary, it's easy enough to accommodate.

 

1 hour ago, Edwin_m said:

Moves from LP106 and LP108 to LP102 would be main aspect, but these signals still need their subsidiary aspects for shunting moves.  

 

Agreed and I've shown subsidiary aspects on both signals.  I think only LP105, LP106 and LP108 need subsidiary aspects.  What I haven't shown is the need for "Opposing Locking Omitted between LP106 and LP203".

 

1 hour ago, Edwin_m said:

The driver would phone from the relevant signal when ready to make a move, if the signaller hadn't cleared the signal already.  

 

I assumed that would be the case - I just need telephones at the relevant signals.  I assume that needs a separate telephone on a post adjacent to a ground signal.

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Not sure you really need a sub on 105 or need 205/6 - locos etc can run out and use 112 (which should have a feather) with a sub to return. I don't think limiting capacity on the branch is really an issue for an odd shunt, especially as the single line is occupied anyway.

 

As Edwin says 202 needs moving back and 204 is unnecessary as the main can be used for run rounds

 

A loop - by definition - would be a loop off a line, you don't have a (down) loop just a down running line

 

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6 hours ago, beast66606 said:

A loop - by definition - would be a loop off a line, you don't have a (down) loop just a down running line

 

On 01/02/2020 at 19:35, iands said:

For the Down Loop to be considered a "Loop", shouldn't it be capable of a direct route back to the Down Main? 

 

Okay, having dug out an old version of Quail Maps for Scotland (1987) I haven't been able to identify a single track arrangement that looks like I've drawn.  I had thought that the Up Goods Loop on the Edinburgh and Glasgow line at Greenhill Upper Junction only exited onto the route to Larbert (the branch), but it seems that there is also a connection back onto the Up line towards Edinburgh at that location.  The closest I can find is that the Up Passenger Loop at Law Junction is only accessible to trains from Wishaw (the branch) and not from Motherwell (the main).  That's sort of the reverse of what I've drawn.  However, at every location, a direct route back to the main seems to be provided.  I'll therefore add another crossover (309) between the Down Loop / Branch to the Down Main to facilitate all trains using the loop to be able to rejoin the Down Main.  The connection will be there in the approach track work in the fiddle yard just off stage, so I just need to add it to the signal plan.  

 

Unfortunately, that means that the branch will cut across the Down Loop, but thankfully I notice that there is a similar arrangement immediately east of Drem, where the North Berwick branch cuts through the end of the Up Passenger Loop.

 

6 hours ago, beast66606 said:

Not sure you really need a sub on 105 or need 205/6 - locos etc can run out and use 112 (which should have a feather) with a sub to return. I don't think limiting capacity on the branch is really an issue for an odd shunt, especially as the single line is occupied anyway.

 

As Edwin says 202 needs moving back and 204 is unnecessary as the main can be used for run rounds

 

So, if I understand what you're saying here, to run round, from the Down Loop, the driver would be shown a main aspect on LP105 and he would proceed down the branch past Signal LP112 and then change ends.  He will then be shown a Subsidiary Aspect on LP112 (Main Aspect implying Up Main and Main Aspect plus feather implying Down Loop).  The Subsidiary Aspect on LP112 gives him authority to proceed wrong line on the Down Main past LP103 and LP101 and once he's passed LP101 he would change ends.  I'm assuming that means that there needs to be a Subsidiary Signal on LP101 to provide the authority to return to the occupied Down Loop.

 

I had assumed that Position Light Signals would be provided to limit the length of time spent on both the Branch and Down Main during the run round, since at 20 mph it will take around 20 seconds to travel through a 180 metre Overlap.  However, thinking about it further, it will take longer for the driver to change ends, so I guess I just need to remember to allow sufficient time for the locomotive to be offstage - ie something like three or four minutes would be realistic.

 

So, of the Position Light Signals that I've shown, only LP202 and LP203 will actually be required and the others can be removed.

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13 hours ago, Dungrange said:

 

 

Okay, having dug out an old version of Quail Maps for Scotland (1987) I haven't been able to identify a single track arrangement that looks like I've drawn.  I had thought that the Up Goods Loop on the Edinburgh and Glasgow line at Greenhill Upper Junction only exited onto the route to Larbert (the branch), but it seems that there is also a connection back onto the Up line towards Edinburgh at that location.  The closest I can find is that the Up Passenger Loop at Law Junction is only accessible to trains from Wishaw (the branch) and not from Motherwell (the main).  That's sort of the reverse of what I've drawn.  However, at every location, a direct route back to the main seems to be provided.  I'll therefore add another crossover (309) between the Down Loop / Branch to the Down Main to facilitate all trains using the loop to be able to rejoin the Down Main.  The connection will be there in the approach track work in the fiddle yard just off stage, so I just need to add it to the signal plan.  

 

Unfortunately, that means that the branch will cut across the Down Loop, but thankfully I notice that there is a similar arrangement immediately east of Drem, where the North Berwick branch cuts through the end of the Up Passenger Loop.

 

 

So, if I understand what you're saying here, to run round, from the Down Loop, the driver would be shown a main aspect on LP105 and he would proceed down the branch past Signal LP112 and then change ends.  He will then be shown a Subsidiary Aspect on LP112 (Main Aspect implying Up Main and Main Aspect plus feather implying Down Loop).  The Subsidiary Aspect on LP112 gives him authority to proceed wrong line on the Down Main past LP103 and LP101 and once he's passed LP101 he would change ends.  I'm assuming that means that there needs to be a Subsidiary Signal on LP101 to provide the authority to return to the occupied Down Loop.

 

I had assumed that Position Light Signals would be provided to limit the length of time spent on both the Branch and Down Main during the run round, since at 20 mph it will take around 20 seconds to travel through a 180 metre Overlap.  However, thinking about it further, it will take longer for the driver to change ends, so I guess I just need to remember to allow sufficient time for the locomotive to be offstage - ie something like three or four minutes would be realistic.

 

So, of the Position Light Signals that I've shown, only LP202 and LP203 will actually be required and the others can be removed.

 

 

Regarding run round.

 

The driver would get a main (yellow) aspect at 105, run beyond 112, change ends then get a yellow / green (depending on 104) to run back to 104 which would show a yellow to run forward, change ends and when (the re-positioned) 202 clears set back onto the train.

 

The sub on 112 would be used if a loco wanted to drop onto something already in (your term) the down loop.

 

Yes, only 202 and 203 needed.

 

I would give 112 pos 1 and pos 4 feathers, so the driver never gets a straight aspect, only a feather with an aspect (or the sub of course) which emphasises (to the driver) that both routes (To Up Main or to Down Loop) are restricted speeds.

 

You will need an exit signal from the unloading facilties area, and I'm not sure what the GF controls as the points are numbered 303. I'd make 303 a trap point and change the siding points to be hand worked.

 

Thats my 0.02p - your layout of course.

 

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2 hours ago, beast66606 said:

The driver would get a main (yellow) aspect at 105, run beyond 112, change ends then get a yellow / green (depending on 104) to run back to 104 which would show a yellow to run forward, change ends and when (the re-positioned) 202 clears set back onto the train.

 

Okay, that makes sense.  I'd been assuming that the run round would be completed by running wrong direction on the Down Main to avoid the requirement to find a path on the Up Main, which was why I assumed that I'd need a Limit of Shunt Signal facing wrong way on the Down Main (ie Signal LP201).   However, what you describe makes sense.

 

2 hours ago, beast66606 said:

You will need an exit signal from the unloading facilities area, and I'm not sure what the GF controls as the points are numbered 303. I'd make 303 a trap point and change the siding points to be hand worked.

 

I'm assuming that the points numbered 303 are controlled by the Ground Frame rather than the Signalling Centre, but I numbered these, because I thought they would be included in the interlocking, although now I'm not so sure.   If my understanding of the operation of the Oil Sidings at Dalston is correct, the siding accessed from the Normal Lie of 303 is always empty apart from during the shunting movement.  Wagons are only left unattended in the siding accessed when 303 is Reversed.  Therefore, once the shunt is complete (before the run round), I'm assuming that 303 will have to be returned to Normal before the Annett's Key can be returned to permit crossover 304 being unlocked at the Signalling Centre.  However, thinking about this a bit more, the Signalling Centre interlock is with the Ground Frame rather than with the point.  Point 303 needs to be set to Normal to allow the Ground Frame to be locked.  The Ground Frame needs to be locked to unlock crossover 304 at the signalling centre. 

 

I'm assuming that means that I don't need to number points 303 (and similarly 305 and 306 which will be controlled by a separate Ground Frame).

 

I'd been assuming that there wasn't a need to trap the Oil Unloading Facilities because any wagon would need to roll over a set of points set against them.  However, I should maybe look at trapping this as well (assuming I can fit a separate trap point).  I didn't put a signal there because I'm not convinced that I can get a locomotive clear of the clearance point from crossover 304.  However, if one is required, then I'll look to fit it in.

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The closest track layouts off the top of my head to what your are trying to model is Barassie or Thornton North.

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Hi Dungrange,

 

The location you’re looking for is Craigendoran and the West Highland Loop: only accessible to/from WHL.  Your layout works fine if you name it the Branch Loop. 

Paul.

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Not quoting as replies are getting long !

 

Dalston is slightly different as the ground frame is released from Carlisle PSB but controls the trap, the connection to the sidings and the crossover.

 

For your layout I'd make the ground frame control the sub on 108, an exit GPLS, the trap and the points connecting to the down branch loop and make the siding / industrial point a hand worked one.

 

Personally I'd make the points in the up yard all hand worked and have permission to enter the yard (ie set the route) given by the local ground staff.

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1 hour ago, thedman said:

The closest track layouts off the top of my head to what your are trying to model is Barassie or Thornton North.

 

I've just had a look at these, but both seem to have a downstream connection back to the mainline, which is, I think, the point that's been made earlier.  In my case, a train being signalled into the Down Loop can't rejoin the Down Main, which seems to be an unusual arrangement.

 

However, I can see the similarity at Barassie insofar as the branch connects to the Down Loop and there is also a yard off the loop.  It is therefore a good enough location to look for a signal diagram for.

 

1 hour ago, 5BarVT said:

The location you’re looking for is Craigendoran and the West Highland Loop: only accessible to/from WHL.  Your layout works fine if you name it the Branch Loop. 

 

That loop is indeed only accessible for traffic to/from Crianlarich.  I overlooked that one because it's a single track line rather than double track.  I guess the issue with using that as inspiration is that I don't think it's used for anything other than two trains passing when they enter / exit the RETB section controlled from Banavie and both lines seem to be bi-directional, so it doesn't help with my signalling, but it does demonstrate that there is a prototype.

 

That said, I think I'll just add a downstream connection back to the Down Main (it's offstage anyway), since that's the layout at Drem and a similar arrangement existed to the east of Prestonpans, where 'the branch' was the access to the former Cockenzie Power Station.  As has been highlighted above, Barassie is another location where a branch line cuts through a Down loop to join / leave the up / down mainline.  It just means that I'd need to a Junction Indicator to Signal LP105.

 

1 hour ago, beast66606 said:

For your layout I'd make the ground frame control the sub on 108, an exit GPLS, the trap and the points connecting to the down branch loop and make the siding / industrial point a hand worked one.

 

Personally I'd make the points in the up yard all hand worked and have permission to enter the yard (ie set the route) given by the local ground staff.

 

When I started drawing this I had 304A and 304B labelled as being controlled separately, but if 304B is not operated by the Signal Centre then it's normal lie wouldn't provide what I understand is called flank protection (ie something rolling past LP108 would be directed towards the Down Main rather than into an empty siding.  That was the reason why I changed this to be half of a crossover.  However, I'm content that the rest could be operated from a Ground Frame as you suggest. I'd presumably need Opposing Locking Omitted between LP108 and the new GPLS

 

Up yard, I'd be happy to assume that's all hand operated, but I'll presumably still need LP106, LP203 and entry point 302B being motorised as part of the crossover controlled from the Signal Centre.

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9 hours ago, Dungrange said:

 

When I started drawing this I had 304A and 304B labelled as being controlled separately, but if 304B is not operated by the Signal Centre then it's normal lie wouldn't provide what I understand is called flank protection (ie something rolling past LP108 would be directed towards the Down Main rather than into an empty siding.  That was the reason why I changed this to be half of a crossover.  However, I'm content that the rest could be operated from a Ground Frame as you suggest. I'd presumably need Opposing Locking Omitted between LP108 and the new GPLS

 

Up yard, I'd be happy to assume that's all hand operated, but I'll presumably still need LP106, LP203 and entry point 302B being motorised as part of the crossover controlled from the Signal Centre.

 

Indeed - 106/302 still need to be controlled by the PSB/SCC and yes you could have normally off opposing signals but I wouldn't as that would mean shunts could occupy the down loop without positive permission.

304 should be worked as a pair, no gains if independant points.

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17 hours ago, Dungrange said:

 

However, I can see the similarity at Barassie insofar as the branch connects to the Down Loop and there is also a yard off the loop.  It is therefore a good enough location to look for a signal diagram for.

 

Have a look at page 8 of the attached link, I am unable to post up the M12

 

https://www.whatdotheyknow.com/request/293222/response/729672/attach/34/511578 SC039 Kilmarnock Barassie Jn May 15 Ver 1.5 020.pdf#page=8

 

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On 03/02/2020 at 14:17, Dungrange said:

I'd been assuming that there wasn't a need to trap the Oil Unloading Facilities because any wagon would need to roll over a set of points set against them.  However, I should maybe look at trapping this as well (assuming I can fit a separate trap point).  I didn't put a signal there because I'm not convinced that I can get a locomotive clear of the clearance point from crossover 304.  However, if one is required, then I'll look to fit it in.

 

Hi,

 

Agree with Beast that you need to trap the oil/unloading sidings from the down ‘loop’.

That point 303 is trailing to anything left in those sidings, and a run away could through them over.

 

You need a trap ‘facing’ to those sidings, between 303 and 304B, so that anything loose runs off the road and not down the branch!

If you don’t want to trap it there then you need to trap it (facing) after Signal 105, then remove GPS 204, locating the sub onto the mast of signal 101, and then remove the feather from 101 so that all down main to down loop moves from the right side come from the sub on 101.

 

Paul

Edited by bigP
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Thanks everyone for your comments.  I think that I have taken most of them on board and now have the revised plan below.

 

image.png.e6d63c8afda3838b727ce734b8ef5ad4.png

 

I've added in a new connection from the Down Loop to the Down Main, which means adding a Junction Indicator to LP105.  I've removed the Subsidiary Signal from LP105 (yellow main aspect used for run round) and added Subsidiary Signals on to LP101 and LP112 and removed all of the unnecessary Ground Signals, previously shown - relocating LP202 as suggested and adding in one at the Oil Sidings along with a trap point at the preferred location.  I've also removed point numbers from those that I'm assuming are worked from the ground frames. 

 

I'm therefore assuming that this is better.

 

1 hour ago, bigP said:

If you don’t want to trap it there then you need to trap it (facing) after Signal 105, then remove GPS 204, locating the sub onto the mast of signal 101, and then remove the feather from 101 so that all down main to down loop moves from the right side come from the sub on 101.

 

Just to clarify that I understand this correctly.  I can either have a Junction Indicator at LP 101 and no trap point in advance of LP105 (approach to Down Loop at normal line speed - as I've shown above) or I can remove the Junction Indicator at LP 101 and add a trap point in advance of LP105 (approach to Down Loop as a shunt manoeuvre from stop).   I'm assuming the former arrangement (Junction Indicator and no trap point) would make the Down Loop usable as a Down Passenger Loop, whereas the latter makes it a Down Goods Loop only.  Is that correct?

Edited by Dungrange

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2 hours ago, Dungrange said:

Just to clarify that I understand this correctly.  I can either have a Junction Indicator at LP 101 and no trap point in advance of LP105 (approach to Down Loop at normal line speed - as I've shown above) or I can remove the Junction Indicator at LP 101 and add a trap point in advance of LP105 (approach to Down Loop as a shunt manoeuvre from stop).   I'm assuming the former arrangement (Junction Indicator and no trap point) would make the Down Loop usable as a Down Passenger Loop, whereas the later makes it a Down Goods Loop only.  Is that correct?

 

Hi,

 

That  revised plan looks a lot 'nicer' to me.  In fact - I want to model that!

 

Apologies, I didn't mean to sound like an expert on signalling installations - I'm not, so I can't be authoritative and say something is an absolute never.  I sit at the front making the train move, not in an office scheming up how a piece of line will be laid, signaled and run.

 

That said, I can't think of anywhere I sign where I could be signaled into a 'loop' on a main aspect (green or yellow with JI) and there be a possibility of a non-trapped siding running into that loop also.

There are places where non trapped sidings run into loops, but in all those that I know of the main line signal giving access to said loop does so by use of position light mounted on the main post.

 

In effect, a main proceed aspect (yellow, double yellow, or green) is telling me the section ahead is clear.  Two white dots at 45 associated with a main red is a different story.

 

A generic diagram, but both of these 'situations' exist in real life.  Note the subtle differences .....

Dungrange.jpg.d6a378e699f954d98a72887faa4496eb.jpg

 

 

Paul

 

 

Edited by bigP

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The revised plan is pretty close to what I was going to suggest. 

I would probably forget the Shunters Acceptance and TRTS as the box wouldn't be able to signal in and needs to know the reporting number and destination of outward moves, so there is a need to phone anyway.

Leave LP101 as it is, assuming the loop is track circuited use a main aspect if loop clear or sub if occupied. 

I was going to suggest renaming the loop as part of the branch then you wouldn't necessarily need to have the outlet back to the main line. 

If you make the loop passenger and the branch is freight only you may need to consider a different arrangement at the LP105/LP112 interface

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I'm wondering about how a run-round move in the down loop would be signalled (though I'm not an expert!)

 

The train has arrived from the right, using 101(main loop). It's shunted the sidings using 108(sub). The loco then uncouples and runs forward using 105(branch) - this would require authority to enter the branch single line. Would there not be another signal in advance so that the loco could clear 112 without having to enter the section? It then presumably has to cross both lines to run along the up main until it passes 202 to be signalled back onto the train?

 

Also, wouldn't the siding trap and ground signal be controlled by the box? It'd certainly have to be detected normal to allow 101 to be cleared for the loop?

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Hi,

 

Hope you don't mind.  Extended the image a bit.

 

2014128743_Dungrange102.jpg.bff6146fc4202ad8d63263e130a45693.jpg

 

New Limit of Shunt on Down Main, Up direction, behind LP101.

New GPLS Down Main, Up direction behind 309B points.

LP105 - #1 Route Indicator for Branch.  Main aspect back to Down Main LP107 - same as for LP103!

New Two aspect Main on Branch - DB1.

 

To run round:

either;

LP105 Single Yellow only to LP107, to go behind LP205.

LP205 bang road to Limit of Shunt on Down Main, to go behind LP101.

LP101sub only to go back onto train in Down Loop.

 

or;

LP105 Single Yellow + #1RI for the Branch to DB1, to go behind LP112.

LP112 sub to go bang road to Limit of Shunt on Down Main, to go behind LP101.

LP101sub only to go back onto train in Down Loop.

 

In reality both could be provided for to give the Signaler options when busy - depends how busy the area is I suppose as to what signalling would be provided.

 

 

Paul.

 

P.S.  What do you use to draw these track plans - is it a bespoke program for this kind of stuff, or just your own graphics in a drawing program?  Looks good either way.

 

Edited by bigP
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2 hours ago, bigP said:

That  revised plan looks a lot 'nicer' to me.  In fact - I want to model that!

 

Go ahead.  My inspiration actually started with Mick Bryan's Newbryford (a layout that is about the same size as this will be), which models just part of a station and then I decided that the station was actually the least important part, so it got abandoned to try and fit in more space for freight trains.

 

2 hours ago, bigP said:

Apologies, I didn't mean to sound like an expert on signalling installations - I'm not, so I can't be authoritative and say something is an absolute never.  I sit at the front making the train move, not in an office scheming up how a piece of line will be laid, signalled and run.

 

But you are eminently more knowledgeable than the plebs like me who just look out the window, over the line side fence or at photographs taken by others.

 

44 minutes ago, TheSignalEngineer said:

The revised plan is pretty close to what I was going to suggest. 

I would probably forget the Shunters Acceptance and TRTS as the box wouldn't be able to signal in and needs to know the reporting number and destination of outward moves, so there is a need to phone anyway.

 

I'm happy to remove anything that's not required.  My assumption was that both of these were a form of interlocking.  That is, the box would only be able to throw crossover 302 and pull LP202 Off to allow entry to the yard if the track circuit between LP106 and LP203 was unoccupied and the Shunters Acceptance was 'On'.  That is, it provides the signalman with positive confirmation that the Shunter is ready to receive a train.

 

Similarly, my assumption was again, that for a departing train, the TRTS would have to be pressed (and the track circuit between LP106 and LP203 unoccupied) before the box would be able to throw crossover 302 and change the aspect on LP106 to anything other than red.  Therefore unless one or other of the Shunter's Acceptance or TRTS was pressed, then crossover 302 and the main aspects on Signal LP106 would be locked out.  However, I can see the need to phone to confirm the destination of the departing service and its reporting number.

 

1 hour ago, TheSignalEngineer said:

If you make the loop passenger and the branch is freight only you may need to consider a different arrangement at the LP105/LP112 interface.

 

Is this because if the branch is freight only, then there is a need for a trap point between LP112 and crossover 309?  I note that there were differences between the signalling at Drem and at Prestonpans, both of which have / had a similar layout.  At Drem the branch is a passenger line to North Berwick (and looks similar to what I've shown), but at Prestonpans, the branch is freight only (to the former Cockenzie Power Station) and access looks like it might have been controlled by an offset Subsidiary Signal from the signal on the loop (rather than a Junction Indicator).

 

I'm content to operate both passenger and freight trains on both the mainline and the branch if that's more straightforward and would allow me to use ready made signals.  My thinking is driven by the fact that based on the current iteration of my fiddle yard design, my longest loop (~14') and two of my next longest loops (~11') are only going to be accessible from the branch.  This therefore means that most of my longest trains will be assigned to these fiddle yard loops and therefore use the branch.  However, there is nothing to stop me sending the occasional passenger train down the branch as well.

 

15 minutes ago, Nick C said:

I'm wondering about how a run-round move in the down loop would be signalled (though I'm not an expert!)

 

The train has arrived from the right, using 101(main loop). It's shunted the sidings using 108(sub). The loco then uncouples and runs forward using 105(branch) - this would require authority to enter the branch single line. Would there not be another signal in advance so that the loco could clear 112 without having to enter the section? It then presumably has to cross both lines to run along the up main until it passes 202 to be signalled back onto the train?

 

Also, wouldn't the siding trap and ground signal be controlled by the box? It'd certainly have to be detected normal to allow 101 to be cleared for the loop?

 

As you can tell, I'm no expert either.  I think you're thinking is perhaps similar to mine, insofar as my first track / signalling plan tried to minimise encroachment onto the branch by using two ground signals (LP205 and LP206 in my first post).  However, I've taken Beast's advice from up thread so that the run round will now be conducted as follows.  LP105 showing Yellow Main Aspect + Position 1 JI is the authority to proceed onto the branch.  Once the driver is passed Signal LP112 he will stop, change ends and wait for Signal LP112 to display a Yellow or Green Main Aspect + Position 1 JI .  This is the authority to cross the Down Main and proceed on the Up Main as far as LP104 (Yellow) or LP102 (Green).  Once passed LP202, the driver will stop, change ends and wait for Ground Signal LP202 to be pulled Off, with the stencil indicator indicating that the route set is to the loop.

 

However, since receiving that advice, I have added in crossover 309, so I think it would also be possible to signal a route via that crossover that avoids the branch, if I were to add a new Ground Signal at the Clearance Point of 309B.  That is, LP105 showing Yellow Main Aspect but without the Junction Indicator lit is the authority to proceed onto the Down Main as far as LP107.  Once on the Down Main, clear of 309, the Ground Signal (not shown) could then provide the authority to run wrong line to beyond LP101.  The Subsidiary Signal on LP101 would then provide the authority to return to the loop to complete the run round. 

 

As for the trap and Ground Signal at the Oil Sidings, I think that would all be controlled by the Ground Frame, which would have four levers.  The Signal Box would route a train into the loop and when the rear of the train is clear of crossing 304, this would be returned to Normal and locked.  The Secondman on the oil train would then unlock the Ground Frame (which can only be done when crossover 304 is locked Normal), which would allow him to reverse the trap point and set the point in the oil siding correctly and control the Subsidiary Aspect on LP108 and the Ground signal  to control shunting.  Once shunting is complete, the shunter would have to set both the Subsidiary Aspect on LP108 and the Ground Signal to On, and the points to Normal before the Ground Frame can be locked again, and only once the Ground Frame is locked will the Signal Box regain control over crossing 304.  At least that is the way that I understand this to work.

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12 minutes ago, bigP said:

Hi,

 

Hope you don't mind.  Extended the image a bit.

 

2014128743_Dungrange102.jpg.bff6146fc4202ad8d63263e130a45693.jpg

 

 

LP105 - #1 Route Indicator for Branch.  

 

Apologies for being pedantic, but the signals such as 103, 105, 112 etc., are drawn with "junction" indicators not "route" indicators (sorry, but this was drummed into me when I was a trainee with the S&T way back when).

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