Connecting a freight-only line without using signals

[47137]

This is a mock-up of my layout project. The siding B is a terminus for a passenger shuttle service, this runs from B through A to the rest of the layout:

 

The route from C to A carries only freight. The coffee tin represents a bulk storage tank and is a view blocker hiding the exit. The "wing" of the scene is also the backscene of the section of layout to the left, beyond point A.

 

I am wondering, what is the installation of signals I should provide for this turnout? I am especially concerned, a bracket signal for trains approaching from A will clash with the backscene, and maybe I should instead be representing a distant signal here.

 

- Richard.

Edited June 9, 2020 by 47137
Change of topic title (was "Signalling where a passenger line diverges from a freight-only route")

[ikcdab]

If the line only carries freight, how is there a passenger service?

Otherwise normal signalling would apply

Edited June 6, 2020 by ikcdab

[Compound2632]

I would think in terms of a freight-only route diverging from a passenger line. But perhaps it's just a question of perspective.

[Grovenor]

There should be a trap point on C protecting the A-B route from any errant move. Then a Ground frame to operate the points and facing point lock. The Ground frame released by the train staff or token. No need for any signals. If passenger trains are to arrive and depart whilea freight is inside the industry, then a small hut with a 'No-signalman' key token instrument inside is needed.

In order to enter the single line at the far end the train must have the staff/token. The points will be locked for B. A passenger can arrive and depart on the authority of the staff/token. A freight on arrival uses the key attached to the staff or token to reverse the points and enter the industry. If you provide the 'No signalman' instrument, then after moving into the industry the crew can lock up the ground frame again set for B and put the token in the instrument, which will allow the signalman at the other end to obtain a token for another train.

[47137]

9 hours ago, Compound2632 said:

I would think in terms of a freight-only route diverging from a passenger line. But perhaps it's just a question of perspective.

 

Yes - it's only perspective. There will be more freight trains than passenger trains. Freight is at the root of this railway; it happens to run a passenger service but this is very much an incidental thing. In fact, historically it is most likely the railway has added the passenger service in recent years. It is indeed a freight-only route diverging from a passenger line, but somehow operationally I don't especially see it like this. Thanks.

 

9 hours ago, Grovenor said:

There should be a trap point on C protecting the A-B route from any errant move. Then a Ground frame to operate the points and facing point lock. The Ground frame released by the train staff or token. No need for any signals. If passenger trains are to arrive and depart while a freight is inside the industry, then a small hut with a 'No-signalman' key token instrument inside is needed.

In order to enter the single line at the far end the train must have the staff/token. The points will be locked for B. A passenger can arrive and depart on the authority of the staff/token. A freight on arrival uses the key attached to the staff or token to reverse the points and enter the industry. If you provide the 'No signalman' instrument, then after moving into the industry the crew can lock up the ground frame again set for B and put the token in the instrument, which will allow the signalman at the other end to obtain a token for another train.

 

I could not ask for a better answer. I'm so glad there are folk on the RMweb who know about their subjects and can explain them so clearly. I'm off to find a photo of a suitable hut.

 

- Richard.

[47137]

I have been studying the description of No-Signalman Token Remote (NSTR) at "Railway Signs and Signals of Great Britain" (this illustrates a hut) and also an account of the Oban line using a "no signalman" key token instrument.

 

I am imagining, my key token instrument can hold multiple copies of the token. Perhaps six tokens maximum. My railway is a self-contained operation with a finite number of engines. Every engine has to make a return journey sooner or later, regardless of which end it entered the block section. Therefore the quantity of tokens stored at each end of the block section will always work itself back to an equilibrium, unless the railway starts double-heading its trains in one direction.

 

So I imagine this will work .

 

The account of Oban explains, the 2-lever ground frame for the oil depot was replaced by a 3-lever version, but doesn't explain why. Could this be, to have separate levers for the points for the main line and for the trap points? I am starting to think about how to build my model. I favour mechanical operation for all of the points on the layout. There might be scope to build a representation of this ground frame, with physical keys to unlock it. Such things hanging over the buffers of a train. Or perhaps an electric push button to represent inserting a physical key unlocking the levers. I am rather thinking out loud here, but I am sure there is merit in placing the levers to emulate this ground frame away from the levers for the other points on the layout.

 

So - I'm wondering if there an over-riding rule on deciding whether to have two or three levers in this ground frame?

 

- Richard.

[TheSignalEngineer]

4 minutes ago, 47137 said:

So - I'm wondering if there an over-riding rule on deciding whether to have two or three levers in this ground frame?

What provision would be made would depend on a number of issues such as date it was put in, region etc.

Is B the end of the line? Can a loco be 'Shut inside' either B or C whilst another loco comes into the other line?

[The Stationmaster]

There is quite a difference between No Signalman Key Token  (NSKT) and No Signalman Key Token Remote (NSTR).  What it boils down to in your layout situation is this - if the line is NSKT there will be a signal box at one end of it (beyond A on your layout) but with NSTR there could be, and usually is, a succession of token sections wholly supervised remotely, and with a very different arrangement at passing stations because there would be no signal box at them.

 

What you basically have is a stub branch line so normally it would be NSKT operation exactly as described above by 'Grovenor'.   Once a train has arrived at C it is no longer in the NSKT section but is in sidings where, depending on the track layout, it might be possible to accommodate more than one train at a time.  Or, as you have mentioned, a train could arrive with two engines which could then depart working two separate trains.

 

As to exact equipment fit in respect of things like huts and signs etc, and even the arrangement of the ground frame, this sort of detail varied between the BR Regions and also over the years as - for example - new types of signage were introduced.  Thus what you do need to do if you want to be really accurate in such minor details is decide which BR Region, or when, any changes were carried out in the backstory to your layout.

[47137]

1 hour ago, TheSignalEngineer said:

What provision would be made would depend on a number of issues such as date it was put in, region etc.

Is B the end of the line? Can a loco be 'Shut inside' either B or C whilst another loco comes into the other line?

 

A loco can be "shut inside" either B or C. In fact, the train for passengers will spend much of its time in the platform road (the stub branch line as described by Mike) here. I envisage passenger operations to be a bit like the Sudbury branch, where the train reverses immediately when it reaches Sudbury, and waits at Marks Tey between trips.

 

I need to firm up on what I am trying to represent before I start to make the model. Studying Mike's post immediately above, I think I want No Signalman Key Token (NSKT), not No Signalman Key Token Remote (NSTR). If there is to an overriding reason for this, it is the seven feet of model track extending from location A to the rest of the layout connects to the fiddle yard, and trains go from there to the rest of the layout. I am much happier to imagine a signal box somewhere in the system than a succession of NSTR sections. Indeed, I might build a model signal box one day!

 

The plan of the layout is here, and the turnout under discussion is at the bottom right hand corner of the  plan, in the area shaded yellow. The plan shows "tram terminus" and indeed the passenger train is currently a Flexity 2 tram. Using NSKT, the tram driver can be carrying a token when he runs along the block, and indeed the tram would not need modification to work with a radio signalling system. This ties in with my back story, of the line having the tram on loan from Blackpool Corporation.

 

I do hope I can still continue with the advice of 'Grovenor' because the lack of signals will reduce clutter.

 

- Richard.

 

 

 

 

Edited June 7, 2020 by 47137

[Grovenor]

With the descibed arrangement trains can be shut inside C to release the line for another train. However you can't shut inside B because there is no protection of the passenger train from another train approaching. B is essentially part of the single line. With special instructions you could allow a departure from C while B is occupied but not an arrival. I think you are best arranging for the passenger to come and go between freight moves.

So far as ground frame levers go 2 is enough but some engineers would use 3. I would just go with 2, why add unneccessary things. Lever 1 would be released by the key token and when pulled would unbolt the facing point lock. that would then release lever 2 to change the points. When both levers were put back then the key token could be removed to leave everything locked. The only reason to have 3 levers would be if you wanted to bolt the points when set for C. Then you need to seperate the release lever from the facing point lock lever.

[47137]

2 hours ago, Grovenor said:

However you can't shut inside B because there is no protection of the passenger train from another train approaching. B is essentially part of the single line. With special instructions you could allow a departure from C while B is occupied but not an arrival. I think you are best arranging for the passenger to come and go between freight moves.

...

 

This little spur is useful because it gets the passenger train out of the way; it is too long to store in the fiddle yard. Supposing I explain: this is a light railway with a 20 mph speed limit; and passengers are only allowed to be on board their train on the stub branch when the driver has a token for the block ... would these be enough mitigation to let me keep the passenger train here between trips?

 

I feel, if I cannot do this then the stub branch has little value. I might as well make it a PW siding or discard it altogether, and put the passenger platform on the main line.

 

I'm happy with two levers in the ground frame.

 

- Richard.

[Grovenor]

There is always Rule 1. And you seem to be using it very effectively anyway so you may as well use it here.

[The Stationmaster]

5 minutes ago, 47137 said:

 

This little spur is useful because it gets the passenger train out of the way; it is too long to store in the fiddle yard. Supposing I explain: this is a light railway with a 20 mph speed limit; and passengers are only allowed to be on board their train on the stub branch when the driver has a token for the block ... would these be enough mitigation to let me keep the passenger train here between trips?

 

I feel, if I cannot do this then the stub branch has little value. I might as well make it a PW siding or discard it altogether, and put the passenger platform on the main line.

 

I'm happy with two levers in the ground frame.

 

- Richard.a

I've been rattling my brain to try to think of a way of doing it to suit what you seem to be after and I can't think of one unless you create an additional shut-in facility for B.  But if you do that you can't guarantee its operational security for an arriving trains because the station platform would no longer be in the NSKT section - as Grovenor has already explained.  The only way in which it could be done is to create a siding beyond the station platform where a train could be shut in and thus it wouldn't be part of the NSKT section as the siding entrance would be a trap point worked by a ground frame released by the token.   That leaves the platform within the NSKT section, where it operationally has to be, but allows you to shut in the passenger train by taking it beyond the platform into a ground frame controlled siding.  The train shuts in there and the token can be placed in an instrument thus allowing another token to be withdrawn.

 

There are a number of. 'real world' examples of a siding like this although I don't know if any of them have ever been provided or used to lock in an empty passenger train not that I can see any reason for not doing it.  But the station platform has to be in the NSKT section .  Whether you have actually got enough space to extend the passenger station line is something only you will know

[47137]

2 hours ago, The Stationmaster said:

...

There are a number of. 'real world' examples of a siding like this although I don't know if any of them have ever been provided or used to lock in an empty passenger train not that I can see any reason for not doing it.  But the station platform has to be in the NSKT section .  Whether you have actually got enough space to extend the passenger station line is something only you will know

 

Needless to say I'm using all the space I have got, there is no room for a siding to shut in a passenger train beyond the platform on the stub branch.

 

Suppose I relocate the passenger platform from B to A and remove the stub branch from the NSKT section ... this would seem to keep passenger-carrying movements within the NSKT section, and let the passenger train be stabled out of the way in the stub branch.

 

Clearly this removes passenger facilities from this part of my system (the part shaded yellow in the plan) ... but would this approach have a better chance of complying with the rules?

 

- Richard.

[47137]

2 hours ago, Grovenor said:

There is always Rule 1. And you seem to be using it very effectively anyway so you may as well use it here.

 

I'm not a great fan of rule 1. I think a freelance system needs to be plausible. Indeed, the need to observe rules for matters like signalling  is probably more important than for a model of a prototype, where the modeller can simply explain his layout is 'simplified'.

 

- Richard.

[RailWest]

If you were to move the platform to the left of the letter 'A', then 'A' could be become the limit of passenger working and the NSKT section. There would need to be a trap point just to the right of A, facing to trains coming from R to L, in order to protect the NSKT section. There would then be no need for a FPL, just one lever for the point, unlocked by the token. Passenger train could arrive at the platform, everyone get off, unlock GF, drive forward into spur, re-lock GF and replace token in NSKT instrument, leaving section clear for freight. No need for any signals at all.

 

In very simple form, rather similar to places like Fairford or Looe or the current version of Coombe Jcn, putting all non-passenger stuff off to one end of the layout.

[simon b]

Looking at what your planning to do, the operation seems very similar to how the Aylesbury - Calvert line used to be worked.

 

That line was freight only worked by token machines, but did see regular once a day passenger workings at weekends to Quainton road. The sidings at Calvert, Aylesbury north, (and presumably the line to Grendon underwood) were accessed by ground frames. 

 

A good description of how this worked, and an interesting read in general is this RAIB report: LINK.

Edited June 7, 2020 by simon b

[47137]

1 hour ago, RailWest said:

If you were to move the platform to the left of the letter 'A', then 'A' could be become the limit of passenger working and the NSKT section. There would need to be a trap point just to the right of A, facing to trains coming from R to L, in order to protect the NSKT section. There would then be no need for a FPL, just one lever for the point, unlocked by the token. Passenger train could arrive at the platform, everyone get off, unlock GF, drive forward into spur, re-lock GF and replace token in NSKT instrument, leaving section clear for freight. No need for any signals at all.

 

In very simple form, rather similar to places like Fairford or Looe or the current version of Coombe Jcn, putting all non-passenger stuff off to one end of the layout.

 

I don't know about Fairford or Looe, but if I am understanding your advice correctly I think I need a ground frame with one lever, connected to both the point to the stub branch and the trap point, and unlocked by the block token. So the model would look like this:

 

There is no FPL.

 

This has been a pleasant and instructive diversion for a Sunday. In the arrangement I've sketched here (as @RailWest has prompted me) the driver of the passenger train takes his empty train out of the block and into a safe place before putting his token into the NSKT instrument in the bothy. And obtains a token from the same instrument before being able to take his train back into the block and collect his new passengers.

 

Please, does this sketch look ok?

 

I will study the RAIB report for the Quainton Road line tomorrow.

 

- Richard.

 

[RailWest]

Not quite.....:-)

 

The platform needs to be further to the left away from the point for the 'stub'. The trap should be between the end of the platform and that that point. Then everything to the right of the trap is non-passenger, so the point for the stub could be just a hand-point and no need to connect it to the GF. The 'stub' become in effect just another siding.

[47137]

31 minutes ago, RailWest said:

Not quite.....:-)

 

The platform needs to be further to the left away from the point for the 'stub'. The trap should be between the end of the platform and that that point. Then everything to the right of the trap is non-passenger, so the point for the stub could be just a hand-point and no need to connect it to the GF. The 'stub' become in effect just another siding.

 

I knew I was still guessing.

 

My plan now looks like this. The GF controls only the trap point. I've moved the label 'A' so it can mark the location of a board reading "stop - obtain token". There will be a complementary sign to the left of the trap too:

 

 

To sum up what I think is going to happen:

1. For trains arriving from the left, the train stops at the platform, the trainman operates the ground frame, operates the points as needed, passes to B or C, operates the ground frame again and stows the token in the apparatus in the bothy.

2. The trainman arriving from the right pauses at B or C, sets the points as needed, collects a token, operates the GF, pauses at the platform, operates the ground frame again, and keeps the token in their possession as they proceed into the block section.

 

I actually feel I am beginning to understand the principles behind this. It also simplifies the present layout project, because everything to the left of the bothy is on the baseboard of my next project. Indeed the bothy can go onto the this baseboard.

 

All I need to do for the time being is to stop all trains to represent the activity on the ground; and my present project (the area shaded yellow on my plan) becomes a wholly freight-only operation.

 

Am I there yet? :-)

 

- Richard.

[RailWest]

Actually, if the point connecting the two sidings is simply a hand point and not worked from the GF, then no need for trains coming from R to L to stop at B or C, as they can trail the point - just stop at A.

[47137]

27 minutes ago, RailWest said:

Actually, if the point connecting the two sidings is simply a hand point and not worked from the GF, then no need for trains coming from R to L to stop at B or C, as they can trail the point - just stop at A.

 

Yes. Trains from R to L only need to stop at B or C if the point is set against them. Given the short walking distance, they could stop at B or C instead of at A to collect their token and proceed into the block.

 

I think the fundamental thing here is, we have a physical feature on the track - the trap point - to define and protect the end of the block. Without the trap point, a train could simply run through in either direction without stopping. The mechanism here makes sure, a train in the block always has the token. It cannot get into the block without the token.

 

I suppose a L-R train could disappear into the freight-only section leaving the token in the GF, but I guess such practice would be detected in the signalbox promptly.

 

I must read the RAIB report Simon linked for me.

 

- Richard.

Edited June 8, 2020 by 47137

[RailWest]

57 minutes ago, 47137 said:

 

>> Trains from R to L only need to stop at B or C if the point is set against them. .....

 

Not necessary IMHO, as normal hand-points can be trailed quite safely if wrongly set, tho' it might be preferred to change them anyway.

 

>>>>I suppose a L-R train could disappear into the freight-only section leaving the token in the GF, but I guess such practice would be detected in the signalbox promptly.....

 

Unless the whole line was track-circuited, which would rather defeat the object of having NSKT and be far too expensive to fit, the signalman at the 'far end' would have no means of knowing exactly were the train was. All he would know was that the key-token had not been returned to the instrument.

[47137]

3 hours ago, RailWest said:

>> Trains from R to L only need to stop at B or C if the point is set against them. .....

 

Not necessary IMHO, as normal hand-points can be trailed quite safely if wrongly set, tho' it might be preferred to change them anyway.

 

>>>>I suppose a L-R train could disappear into the freight-only section leaving the token in the GF, but I guess such practice would be detected in the signalbox promptly.....

 

Unless the whole line was track-circuited, which would rather defeat the object of having NSKT and be far too expensive to fit, the signalman at the 'far end' would have no means of knowing exactly were the train was. All he would know was that the key-token had not been returned to the instrument.

 

Yes. Do remember, my opinions and ideas are more humble than yours. I have been studying the railway since I my late Mum held me up to the kitchen window and pointed out an anonymous black thing belching smoke and pulling a few wagons along, and I still know next to nothing about the railway sufficient to create a design I could recommend to anyone else.

 

In my last post, I was imagining the signalman can see the block is unoccupied and the GF is unlocked, and he can see how long this condition persists. But realistically, trying to work through abnormal scenarios won't change the design features a jot.

 

I do see my model railway layout ready to represent signalling technology developed since the 19th century, which will be a first for me. I've changed the title of this topic (it was "Signalling where a passenger line diverges from a freight-only route") to help anyone else looking for what I wanted.

 

- Richard.