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Opinions sought on using a leverframe to control my layout


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I love everything about the idea but my brain just refuses to compute it. Any time I feel like I start to understand, it all falls apart.

 

For a lever to move, the block that is holding it must have a 45 degree corner, rather than a 90 degree one (such that the block is forced across by pulling it), and that block must have room to be displaced. I.e. 1 and 16 both have a single block with a 45 degree corner. This means, they are able to displace that block - however there is no room for it unless 2 and 15 are also pulled.

 

That's about as far as I get before I end up in a spiral of questions - if block 1 engages with lever 2 with a square edge and lever 3 with a point. So, the distant can only be reversed if both 3 and 2 are also reversed. Makes lots of sense - but straight after that it gets into a right tangle. How do you mentally arrange the locking and releasing of each lever to get from your second picture/table to the actual levers?

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Nothing wrong with using electrical interlocking on a system based only on switches, as that is what the real thing has to do with a One Control Switch (OCS) panel which use a switch wherever you would have a lever in a mechanical box.  Throw a switch that is equivalent to a mechanically locked lever and nowt happens.  When you notice the signal doesn't move, you have to put the switch back to the on position and set the points correctly before trying again. 

 

As for Facing Point Locks, they don't have to be on separate levers.  The Midland Railway used "Economical" FPLs which threw the point and FPL on the same lever, and the same happens with motor points.  If you want to keep the cost of levers to a minimum, you can use "selected" signals, that is at a junction instead of using separate levers for the signal to the main and signal(s) to the branch(es), the one lever operates whichever is appropriate to the way the points lie.  IBS Home and DIstant Signals are usually colour lights and worked off a single leeer

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Another fan of operating (steam age) layouts by use of lever frames a la signalbox here.

 

If you have the space / time / inclination then a fully mechanically interlocked lever frame, exactly replicating how the real thing was, including all the things mentioned liked facing point locks, sequential locking, etc can be very satisfying

 

HOWEVER(!)

 

Some element of compromise / pragmatism might be required.

 

On my exhibition layout 'Grantham - the Streamliner Years', I was determined to build in the signalling arrangements to the control of layout right from the start and make it look (to the viewer) like it was traditionally worked. However, the very fact that it's transportable meant I had to go down the electrics route, rather than mechanical, due to the sheer size and complexity of the location.

 

DSC01486.jpg.74fadd96871a97ff69049e55643c9710.jpg

 

I've used Peco equipment (point motors with passing contact levers, arranged in lever frame blocks). There are three sets of these, to correspond to the three signalboxes at the location and they are arranged so that they are on view to the public - in the photo above you can see two of them adjacent to each other. The third (Grantham South) is situated 10 feet away to the right.

 

The real compromise is on the number of levers. The real Grantham North had over 100 levers in the frame; as you can see, the model version has 30. They ARE interlocked - but not mechanically. So if you pull the wrong lever there is silence rather than a 'click' (bit like Michael describes above). All the 'clever' stuff is done by relay panels, hidden inside the control panel box. It's complex - but logical. The relays perform four operational functions:

1. Interlocking

2. Switching power to the track

3. Raising / lowering the correct arm on a multi-arm (junction) signal - this is where the compromise  comes in. The relay logic knows which route is set so only one lever is needed. NOT prototypical (for a mechanical box) but to the watching public it looks 'correct' and is simpler for the operator

4. 'Auto' distant operation. You'll notice no yellow levers. All (yellow) distant arms are operated automatically - as the signalboxes are close together, there are distant and stop arms on the same post. So the relay logic is used to detect when both the relevant stop arms are 'pulled off' and then the distant arm operates. Put either of the stop arms back and the distant goes back too. Again, to the viewing public it all operates 'correctly'.

 

That might not tick many - or any? - of your boxes but perhaps a few ideas for you there nonetheless.

Edited by LNER4479
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Another vote here for a lever frame. My own “lever frame” is a bank of toggle switches that input into an Arduino - 15A5121A-1E05-438C-8BE5-429B38E1BC2A.jpeg.2343d806dda3d54283c693c50c3ff37d.jpeg

 

The Arduino does the interlocking, switches power to the track (no separate isolating switches required), and operates the point and signal motors. Like @LNER4479 I’ve made compromises for convenience; e.g. the distant is fixed, FPLs are economic, certain ground signals have multiple routes off a single lever. One signal lever has a “selector”, so that the correct arm is lowered depending on the lie of the points. 

 

(In case anyone was wondering, the “spare” lever in the photo actually operates the “hand-worked” yard points)

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On 22/09/2020 at 10:28, Titanius Anglesmith said:

Another vote here for a lever frame. My own “lever frame” is a bank of toggle switches that input into an Arduino - e.g. the distant is fixed, FPLs are economic, certain ground signals have multiple routes off a single lever. One signal lever has a “selector”, so that the correct arm is lowered depending on the lie of the points. 

 

All those are of course perfectly valid prototype features!

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It's worth investigating text books on signalling such as those by H Raynar Wilson who was signal superintendent for the L&YR - "Mechanical Railway Signalling" and "Power Railway Signalling".  These were republished 'recently' (1990s?) and, although possibly out of print, are readily available.

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Lots of replies that I will read through carefully. 

 

My apologies for the delay in posting a track layout sketch.  There are a couple of areas where I'm still considering the arrangement of pointwork, and I don't want to waste peoples time getting advice on a specific track arrangement if I then go and change it. Of course I will still be happy to alter the track arrangement if feedback says it's not right. 

 

One specific question has arisen , on starter signal placement. To get the longest platform length it would be useful if engines be held next to the signal box, almost at the end of the run round loop. This poses a problem of where the starter signal should be?

 

  It could be next to the loop track , but I was considering having a separate starter on the loop for mineral trains. 

 

  It could be  a short distance past the loop pointwork, but I'm not sure if that's 'legal' since an engine might be allowed to run up to the signal awaiting it being pulled off, and would meanwhile be standing right on the pointwork which might not be set for it.

 

Perhaps the is some possibility that the engine could wait until flagged to proceed by the signalman, but I get the impression that this was for little used moves, and so unlikely to be used for starting regular passenger trains. 

 

I know a sketch will help to illustrate this question, and again I am working on providing one.

 

Thanks all.

Ian

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Ok, here is a very poor sketch of the proposed track plan. The good bits are courtesy Iain Rice ( Varteg Hill ) and the bad bits are mine.

 

Based on Iain's plan, I have added two exchange sidings at the left hand side. These slope down 1:100 away from the station, so I am hoping I can dispense with trap points for them?

 

The line to the colliery climbs at 1:30 and i have allowed for a trap point to protect the big railway.

 

At the right hand side I have dedicated one track for local goods, probably just with a loading bank I have provided a trap point since it connects to the platform line. Below the goods line is the short siding for running round. I might add a water crane on here and maybe a coaling stage. If I have a loco coal wagon on the end of this track I guess it will need its own trap point ?  or would the point for the loop protect the platform road?

 

The sorting sidings are primarily for shunting coal wagons, and I'm assuming ( maybe incorrectly ) that the point for the engineering siding protects any wagons going astray here.

 

The engineering siding is mainly there as a suitable place for various permanent way wagons I have.

 

Signals ( Those of a nervous disposition beware...  I have probably broken all kinds of rules here )

 

I have put a junction signal on the approach to the station, with the more important arm for the platform. I am intending that mineral trains will run directly into the loop line. ( I hope that's sensible )

 

I have indicated a starter on the loop line for goods/mineral  trains. This is partly to avoid having coal trains run almost off the visible part of the layout to shunt back into the platform road to await permission to start.  I haven't shown the starter for the platform road since, as I mentioned previously, I'm really not sure where it should go. If I put it inside the loop I'm going to lose a fair bit of usable platform length, after allowing clearance for overhang for long vehicles.

 

The colliery line will have a gate to separate it from the big railway. The access via a single slip prevents colliery trains running into the platform road.  I'm not sure how engines would be signalled to run onto the colliery line and its exchange sidings. Maybe by a ground signal ?

 

I haven't indicated any ground signals because  I'm not sure what would be required. I guess there would be ground signals protecting the exit from the goods siding,  from the sorting sidings, and the engineering siding... ?

 

Any comments and advice are very welcome.  Hopefully  not 'start again ' .

 

Ian

 

Edited to add:  I realise I haven't indicated any signal to allow colliery engines to cross the single slip into the loop line.  Not sure if a ground signal is appropriate here . I was thinking colliery engines would be made to wait until specifically flagged by the signalman, hence why the signal box is located right by the crossing.

 

1370725215_trackplan1.jpg.3ac8fdd16cdc0c3e1c5b67ba39288e3a.jpg

Edited by Bucket of Steam
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I'd suggest adding a headshunt to the colliery line in place of trap 'A', running behind the box and platform, then move the points accessing the exchange sidings to behind that (or use a double slip) - then the colliery engine can run into the headshunt and propel into the sidings, without encroaching onto BR metals - it'd then run back into the headshunt and the BR engine would run in from the station to swap wagons.

 

If there's no room for the platform starter, you could move the signalbox to the other side of the line, to the left of the word 'loop'.

 

As for shunt signals, I'd suggest the following: single line to platform/loop (either one signal or two depending on your prototype), loop to exchange sidings/single line (again either one or two), exchange sidings to loop, platform to goods yard/headshunt, goods yard to platform, headshunt to loop.

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Thanks Nick,

 

I am aware that ideally the colliery engine shouldn't need to run into the loop. I had looked at doing something similar to what you suggested, which I think I mentioned in my third post. Space considerations mean doing that would have the following consequences:-

 

The curves at the left side of the layout would be tighter, and/or the gradients would be steeper in order to allow the bridge where the colliery line crosses over the single line to remain where it is while the platform road moves further forward to accommodate the colliery headshunt and exchange sidings.

 

There would be very little space between the backscene and the colliery headshunt and its exchange sidings. 

 

My thinking at the moment is that  these factors would compromise the visual impression of the layout more than allowing the colliery engine into the loop line, ..... but I'll look at it again. The trackwork will be mainly Peco but I'm not happy with the small radius of their slips, so the single slip will be Tillig. Their single slip looks reasonable but the double slip has a peculiar solid chunk in the middle of it, so I really want to stick with the single slip. 

 

The shunt signals I will think about what you have written and try to visualise it.

 

Best Regards

Ian

 

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Take a look at my thread (in the bottom) as Long Marton is run that way.

 

I went with a combination of electric and mechanical interlocking- the original ideas I had schemed out used mostly electrical interlocking, but because Modratrac make the kits for interlocking, it became practical for me to make a mechanical box, which then interfaces with the electrics.  

I'd be happy to discuss what I have been taught, and learned, with doing Long Marton. 

 

James

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This view illustrates the two left hand boards laid on my dining room floor, with the single slip in approximate position  and shows that there is not much space available behind the slip ( or above the slip if you are looking at the sketch ).

 

Please excuse my rough and ready  woodwork. Carpentry is not my strong suit. The boards do fit neatly together but I have left a small gap for this photo, so that the position of the board join is clear. I will start a proper thread in the layout forum for the layout in due course.

 

boards1bsm.jpg.87aa9a46eda2d5ea276c3bdafdb7b1e2.jpg

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A quick question - what company origin are we looking at - one of the local Welsh lines, GWR, or LNWR (or even MR)?  It will affect the signalling.  

 

But whichever the two colliery exchange sidings need a trap point because they will be worked by an engine which could pass a signal at danger, and/or run through the gate into collision with a passenger train.  Incidentally there is no reason why a colliery engine could not be examined and 'plated' to operate over the railway company's lines as far as a specified location although in a location like this a proper shunting spur on the colliery's railway would be far more likely because of the amount of shunting involved to get/from the exchange sidings.

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Mike,  thanks for your reply,

 

It will be GWR 1930's   ex Taff Vale.

I'm looking again at if there is any way to provide a proper shunting spur  as Nick and yourself have suggested. Currently every option I try looks very awkward and 'train set' like, but i will continue trying.

 

Thanks very much for the advice on the trap on the exchange sidings, I will fit a trap, or move the exchange sidings behind the proposed 'Trap A' on the sketch.

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Another possible suggestion - how about swapping the platform and loop roads, so the platform is at the front of the layout, which would allow room for a headshunt, and avoid the colliery traffic crossing the passenger traffic? It'd mean a little rearranging at the sorting sidings end though.

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25 minutes ago, Bucket of Steam said:

Mike,  thanks for your reply,

 

It will be GWR 1930's   ex Taff Vale.

I'm looking again at if there is any way to provide a proper shunting spur  as Nick and yourself have suggested. Currently every option I try looks very awkward and 'train set' like, but i will continue trying.

 

Thanks very much for the advice on the trap on the exchange sidings, I will fit a trap, or move the exchange sidings behind the proposed 'Trap A' on the sketch.

It would only be a single tongue trap so wouldn't take up much room if you did it as a dummy using a piece of rail - but a shunting spur would be better if you can fit it.

 

As far as the signalling is concerned all pretty straightforward as by the 1930s the GWR would probably have got their methods into play where things weren't up to their standards.  There would probably be a semaphore signal (of TVR origin so a somersault signal) guarding the trap points in the sidings or the connection from the shunting spur towards the gate.  The platform starting signal will inevitably be between the platform end - or even on the platform/platform ramp  itself -  it can't really go anywhere else although it could be on the side of the loop furthest from the platform adjacent to the loop starter.

 

The far end of the platform is where choices will exist - the trap point from the goods siding would most likely have a rotating lamp unit point indicator worked off the point and the GWR wouldn't bother to alter it.  There would be a ground disc at the facing point at the platform end to read to towards the runround spur - and that would be that because I very much doubt any sort of signal would be provided for the point end coming out of the run round spur.

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Nick,

Hmm moving the platform to the front is a major change, but it would I will have a look at how practicable it is, bearing in mind  the boards are already built. I'll have to think long and hard on that option.

 

Mike,

Dam, I was hoping you wouldn't mention somersault signals, but I guess it was bound to happen  . haha.

 

I will study what you have both written. Meanwhile  I made this 'trap point' for a earlier layout, which had to be scrapped. Hopefully something similar will do for the traps on the new layout ( it needs a dummy  actuating mechanism ).

 

trap1.jpg.ba17a0d76730caf9a3c216a50698e8f2.jpg

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3 hours ago, Bucket of Steam said:

Nick,

Hmm moving the platform to the front is a major change, but it would I will have a look at how practicable it is, bearing in mind  the boards are already built. I'll have to think long and hard on that option.

 

Mike,

Dam, I was hoping you wouldn't mention somersault signals, but I guess it was bound to happen  . haha.

 

I will study what you have both written. Meanwhile  I made this 'trap point' for a earlier layout, which had to be scrapped. Hopefully something similar will do for the traps on the new layout ( it needs a dummy  actuating mechanism ).

 

trap1.jpg.ba17a0d76730caf9a3c216a50698e8f2.jpg

That would be perfectly ok (visually) as a single tongue trap.

 

As far as the somersault signals are concerned you could of course adopt the line that they were all in poor condition and the GWR quickly replaced them.  Quite a lot of Pre-Group signals in South Wales had gone by the mid 1930s but on the other hand plenty survived into the 1950s/early '60s and a few (but no somersaults on BR lines) made it into the 1970s.

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Thanks Mike,

 

I'm happy that a simple trap like that will do the job. I was looking at photos today, and traps seem to vary in complexity. Some being almost a complete turnout with a frog,  some as per the photo above, but with switch rails on both sides ( but no frog ).

 

Regarding the somersault signal.   If I can make one that works then I will, but I think initially I will use an 'off the shelf' one. A somersault one would certainly add character though.

Edited by Bucket of Steam
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17 hours ago, Bucket of Steam said:

Thanks Mike,

 

I'm happy that a simple trap like that will do the job. I was looking at photos today, and traps seem to vary in complexity. Some being almost a complete turnout with a frog,  some as per the photo above, but with switch rails on both sides ( but no frog ).

 

Regarding the somersault signal.   If I can make one that works then I will, but I think initially I will use an 'off the shelf' one. A somersault one would certainly add character though.

Worry not about the complexity of the trap points - the Western commonly used single tongue traps in situations like those of your planned layout.   After all for it to do its job you only needed the one switch rail although adding another reduced damage to sleepers and with an added crossing (aka 'Frog') made a far more positive job of where any errant vehicles were likely to end up, but also cost a lot more..

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Thanks Mike,

I'm currently sanding down the firewood which I bought from a well known DIY store for legs on the layout ( never seen so many knots), but I'm still trying to resolve the colliery headshunt issue.

 

Where you wrote

On 25/09/2020 at 11:44, The Stationmaster said:

The platform starting signal will inevitably be between the platform end - or even on the platform/platform ramp  itself -  it can't really go anywhere else although it could be on the side of the loop furthest from the platform adjacent to the loop starter.

 

If I put the platform starter adjacent to the loop starter, how would the loco crews know which signal to obey?  ( In the event that a mineral train and a passenger train are standing in the loop and platform roads respectively, and then one of those starter signals is cleared )  would this be covered by some local instruction, or is there some indication on the signals themselves?   I kind of imagining a red faced mineral engine crew saying "well there was a lot of smoke and steam from the two engines, I saw a starter cleared to my left...., and well that's how we ended up on the ballast...."

Edited by Bucket of Steam
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