Model railway signal box interior advice

Perhaps I’ve missed it in the discussion but what sort of era are you modelling? If it’s after the mid 1960s it is very likely that your single line sections would have been converted to Scottish region tokenless block.

This would mean a visually different type of block instrument - you can see a double ScR tokenless instrument in the photos of Dunkeld linked in other posts on this thread - and would usually require two levers to be used for Up and Down direction shunt keys. Although if space in the frame was tight, these were sometimes provided in slides on the block shelf adjacent to the instrument. Often when a box was converted to ScR tokenless a whole new frame was supplied from the regional S&T workshop at Irvine and these tended to have white traffolyte covers on the lever tops and catch handles, which are quite distinctive and would be visible on a model.

As this is a crossing point on a single line, what do people who wish to get on or off at the station do if their train is the second to arrive when crossing another train?

Distants could not be automated on a token system (but could be on the tokenless Ron notes) as 'distant(s) off' would be used to convey that the token was in the catcher for a collection at speed. Distant(s) on, stops off would mean a hand exchange.
Depending on layout, for a pass both trains could need to be stopped outside the loop.

Can you supply a photo of the traffolyte? The levers of Dunkled in Bill_gensheet's photo - https://www.flickr.com/photos/58534838@N05/5385033248/ - look normal to me.

Ron_J in post 159389 said:

As this is a crossing point on a single line, what do people who wish to get on or off at the station do if their train is the second to arrive when crossing another train?

Shunt and redock procedure. Train A arrives platform, then reverses back, then pulls forward to mainline. Train B runs to platform and continues, then Train A proceeds.

Ron_J in post 159389 said:

As this is a crossing point on a single line, what do people who wish to get on or off at the station do if their train is the second to arrive when crossing another train?

Shunt and redock procedure. Train A arrives platform, then reverses back, then pulls forward to mainline. Train B runs to platform and continues, then Train A proceeds.

I read somewhere that there's an alternative - less common but still found - where the signal levers are all put in the middle and the points etc. at the ends. If most moves are just straight through or just one or two lever pulls, there's much less walking around required.

Shunt and redock procedure.

Anothersignalman in post 159396 said:

Ron_J in post 159389 said:

As this is a crossing point on a single line, what do people who wish to get on or off at the station do if their train is the second to arrive when crossing another train?

Shunt and redock procedure. Train A arrives platform, then reverses back, then pulls forward to mainline. Train B runs to platform and continues, then Train A proceeds.

That method of operation at a crossing loop wouldn’t happen in Scotland, historically or today. Generally the station would have been built with either two platforms or an island platform. We might do fancy shunting like that with an overlength freight train but it wouldn’t be something that would happen as part of the day-to-day timetable with passenger trains. If there were, for some reason, only one platform at the station then it’s very likely that a passenger train wouldn’t be allowed to cross another passenger train at that location if both were booked to call there.

Ron_J in post 159397 said:

Anothersignalman in post 159396 said:

Ron_J in post 159389 said:

As this is a crossing point on a single line, what do people who wish to get on or off at the station do if their train is the second to arrive when crossing another train?

Shunt and redock procedure. Train A arrives platform, then reverses back, then pulls forward to mainline. Train B runs to platform and continues, then Train A proceeds.

That method of operation at a crossing loop wouldn’t happen in Scotland, historically or today. Generally the station would have been built with either two platforms or an island platform. We might do fancy shunting like that with an overlength freight train but it wouldn’t be something that would happen as part of the day-to-day timetable with passenger trains. If there were, for some reason, only one platform at the station then it’s very likely that a passenger train wouldn’t be allowed to cross another passenger train at that location if both were booked to call there.

Though there's somewhere in Ireland (Limerick Junction ??) where, until quite recently, every train from any of five directions had to reverse to get in the platform.

Here are a couple of photos of a frame with traffolyte covers from Flickr.

[shunt and redock] at a crossing loop wouldn’t happen in Scotland, historically or today.

Just an interesting note about how truly independent the development of Melbourne and Sydney railways were. The language used is totally different, for identical concepts.

There is also Penryn <sp?> on the Falmouth Branch in Cornwall, perhaps copied from Abergynolwyn on the Talyllyn Railway, where there's a double-length platform and the loop ends halfway along it, allowing both trains to call at the same platform without interfering with each other (apart from the little matter of overlaps - but let's not go there). Cambridge (as it was before the new platform was built on the Up side), of course, might be seen as the progenitor of both albeit that was part of a larger and busier layout.

Anothersignalman in post 159396 said:

Shunt and redock procedure.

Although everyone has understood what you meant, it's interesting to note (in my experience) that this is a specifically Victorian description of the move. There is no equivalent term for a 'dock' in Sydney, and I've not heard any of our British friends describe bringing a train from siding to platform in that way either. It may have come around as a consequence of Melbourne's failure to use any sort of train description system until quite late in the semaphore era.

Just an interesting note about how truly independent the development of Melbourne and Sydney railways were. The language used is totally different, for identical concepts. Victorian electric signalling systems used one switch or lever for all routes from a signal where NSW (usually) had one switch or lever per route.

Irrelevant to the post, sorry! As you were, gentlemen

flabberdacks in post 159402 said:

Anothersignalman in post 159396 said:

Shunt and redock procedure.

Although everyone has understood what you meant, it's interesting to note (in my experience) that this is a specifically Victorian description of the move. There is no equivalent term for a 'dock' in Sydney, and I've not heard any of our British friends describe bringing a train from siding to platform in that way either. It may have come around as a consequence of Melbourne's failure to use any sort of train description system until quite late in the semaphore era.

Just an interesting note about how truly independent the development of Melbourne and Sydney railways were. The language used is totally different, for identical concepts. Victorian electric signalling systems used one switch or lever for all routes from a signal where NSW (usually) had one switch or lever per route.

Irrelevant to the post, sorry! As you were, gentlemen

Oddly enough in Scotland we refer to ‘docking’ when talking about platforming and we often call platforms ‘docks’. That doesn’t seem to be the case anywhere else in the UK.

I've always known 'dock' as being a platform for goods traffic (usually a very short standalone structure in a goods yard, though sometimes tacked on to the main station), as in 'cattle dock', 'milk dock' and so on.

For the brown levers specifically, which paint colour/s would you recommend? I tend to use Humbrol red gloss 19, white gloss 22, blue gloss 48, black gloss 21. Same question for the yellow distant levers, though I'm guessing gloss 69 would be OK?

kbarber in post 159371 said:

Lever layouts

Victoria had a few different interlocking engineers over the decades with their own preferences, but generally speaking we'd have either all functions in geographic order left or right, or more commonly, arranged with all mainline up signals at one end of the frame, all mainline down signals at the other end of the frame, to minimise walking and pull-betweens. I'd guess that the former arrangement might have been more closely tied to rocker frames than tappets, because the older style might have needed to minimise the number and lengths of shafts in use - but I don't actually know if that's true or not.

We also had a mix of out-both-ways and in-both-ways lockbars, so there were quite a few instances where locks had to be put reverse, then throw the point, restore the lock, then pull the signal.

Given that the structure is probably a McKenzie-style, tappet-era frame, that would point towards the mainline-up, shunt/yard, mainline-down arrangement of levers?

kbarber in post 159371 said:

Number of levers
This could be dramatically affected by the lever spacing, which varied very widely. The Midland Railway's 'tumbler' frame had levers at 6" centres, necessary to fit the mechanism in. Later, a 'tappet' variant was developed, again initially with 6" centres, but the REC/LMS/LMR developments of that reduced them to 4.5" centres. If I recall rightly the GWR's 5-bar vertical tappet frame had levers down to 4.25" centres, though I think older models (the 'double-twist' for example) were a bit wider. The Springside kit is definitely GWR (though I've never measured the lever centres accurately enough to tell what the spacing is). The Peco example looks like an uneasy amalgam of GWR and McKenzie & Holland (the latter particularly in the level crossing wheel). The LNWR used 6" centres, presumably because it was impossible to get levers any closer with the stirrup catch handle; their later habit of signalling everything and (usually) operating a crossover from 2 levers not 1 led to them having some very large boxes.

Does the Peco signal box generally match the Peco lever frame kit? We won't be using the gate wheel parts anyway.

Are there other brands of OO scale lever frame kits you might recommend in lieu?

kbarber in post 159371 said:

Some companies left plenty of room at the ends of their frames. The GNR was a notable example; in their case it often meant new frames could be installed controlling extended layouts without having to build a new box. Others were more parsimonious.

I've done a sample statistical analysis which showed a correlation of 92% between number of six-pane windows and number of levers, but it's far from complete. Generally speaking, we can take the number of six-pane windows on the front of the box, subtract two panes (one either side), then multiply by five for the total levers. So a box with 7x6-panes would be (7-2)*5 = 25 levers, +/-5. Our rocker frames could be any size, but tappet frames were almost always multiples of five, plus gate wheels, minus mule plates if applicable. If that logic holds true, then the Peco box would have room for a maximum of 25 levers; and I'm not certain that's enough to work this sort of track layout, at least without considering mechanical selectors on the shunt signals. Was that a common practice in the UK? We had plenty of cases of two discs worked by a single lever, but home-or-disc combinations were mostly gone by the early 1900s, and cases of home-or-calling signals from a single lever were always controlled by track circuits.

kbarber in post 159371 said:

Some (the Midland and the LNWR for example) produced boxes and frames in standard sizes. The MR's were prefabricated at Derby and assembled like a big garden shed, using absolutely standard-sized 'flakes' delivered on a special wagon.

Off-topic, but that sounds really cool. Do you have any photos?

flabberdacks in post 159374 said:

Further to that, would normal working here involve shunting out onto the single line to get from one road to another? That would probably necessitate what NSW would call a starting signal. Something a reasonable distance down the single line that can be held at stop to control shunting movements but cleared to authorise a train to depart the area towards the next interlocking.

It depends on how you define station limits and shunting on the single line. The way the yard is presently built, there's a single set of push-button controls at either end for "out, stop, in" and "in, stop, out" with the station between them. The Up Arrival signal (treated as an Absolute, but dressed like a Permissive; applies to all roads) is placed about where the word "Down" is on the main diagram, and the Down Arrival signal (dressed as an Absolute with a single Stop/Proceed indication, no shunt or route indications, applies to all roads) is placed halfway between the words "Up end" and the rightmost level crossing. There are a set of Up departure signals at the right end of 1, 2 (lopsided bracket) and 3 (dwarf) roads, and a down departure signal between the trestle bridge and tunnel portal.

By those definitions, all shunting can be done inside the Yard Limits of the Arrival signals. Proper signalling is on my to-do list, but it could be years away. But the current project is to consider how the machine in the scale signal box might look, rather than reflecting the existing infrastructure.

Shunting between 1 and 3/4 roads at either end, or between 3 and 4 roads at the down end, does require use of the mainline. I think the answer there would be to put the Arrival Home signals as close as possible to the first turnouts from each end with Limit of Shunt boards provided further out, protected by Outer Home signals or, if those don't exist, the bell code 'Release Tablet or Staff for Shunting' or whatever the Scottish equivalent would be?

Anothersignalman in post 159381 said:

Were plunger locks a thing in the UK?

The GWR (and possibly others) went down that route, where the electric lock was released by pressing a plunger before moving the lever. On other frames, the lever catch was pulled and the lever moved a very short way (less then the depth of the lever), the lock released itself, and you then nudged it slightly back the way it had come before pulling it fully over. For power operated points, after doing the nudge routine, the lever is pulled 2/3 of the way over, until the points are detected in their new position, at which point it can be brought fully over.

Perhaps another thread is a better place for such etymological analyses

Anothersignalman in post 159373 said:

...the Peco box would have room for a maximum of 25 levers; and I'm not certain that's enough to work this sort of track layout, at least without considering mechanical selectors on the shunt signals. Was that a common practice in the UK? We had plenty of cases of two discs worked by a single lever, but home-or-disc combinations were mostly gone by the early 1900s, and cases of home-or-calling signals from a single lever were always controlled by track circuits.

Selection wasn't that common, for the most part. I have an idea it might have been seen more on the LSWR, who became expert at shoehorning far too many functions into an old frame rather than replacing a box, but that's not an area I know much about. But I have just started Graham Bowring's huge book on the subject, so I suspect my education is about to be completed!

Of course UK Electric Token regs allowed shunting into an occupied section provided the train in section was going away from you. In that situation, if the train arrived at the other end before the shunt was withdrawn you were required to immediately block back outside (3-3 bell signal) and these were the only circumstances where the other box was not permitted to refuse the block back. So advanced staring and outer home signals were quite often not provided, particularly on more lightly trafficked lines where such instances might be fairly rare.

There was, if I recall rightly, a 'release token' bell signal: 5-2, I think, if you needed to shunt and there was no train around; token was restored (again, if memory doesn't fail me) with a 2-5 signal.

Anothersignalman in post 159381 said:

Were plunger locks a thing in the UK?

The GWR (and possibly others) went down that route, where the electric lock was released by pressing a plunger before moving the lever.

kbarber in post 159412 said:

Anothersignalman in post 159373 said:

...the Peco box would have room for a maximum of 25 levers; and I'm not certain that's enough to work this sort of track layout, at least without considering mechanical selectors on the shunt signals. Was that a common practice in the UK? We had plenty of cases of two discs worked by a single lever, but home-or-disc combinations were mostly gone by the early 1900s, and cases of home-or-calling signals from a single lever were always controlled by track circuits.

Selection wasn't that common, for the most part. I have an idea it might have been seen more on the LSWR, who became expert at shoehorning far too many functions into an old frame rather than replacing a box, but that's not an area I know much about. But I have just started Graham Bowring's huge book on the subject, so I suspect my education is about to be completed!

This one? https://strathwood.co.uk/products/signalling-along-the-south-western-the-lswr-through-to-southern-and-br-periods

I don't really need that book in my personal collection, but I can ask if the club librarian can organise a copy. In the meantime, I look forward to your conclusions.

kbarber in post 159413 said:

Of course UK Electric Token regs allowed shunting into an occupied section provided the train in section was going away from you. In that situation, if the train arrived at the other end before the shunt was withdrawn you were required to immediately block back outside (3-3 bell signal) and these were the only circumstances where the other box was not permitted to refuse the block back. So advanced staring and outer home signals were quite often not provided, particularly on more lightly trafficked lines where such instances might be fairly rare.

There was, if I recall rightly, a 'release token' bell signal: 5-2, I think, if you needed to shunt and there was no train around; token was restored (again, if memory doesn't fail me) with a 2-5 signal.

I don't know if we permitted shunting into an occupied section or not (I'd guess that the gradient would also play a role, e.g. the handle trains dividing), but we did have the 5-2 / 2-5 codes. I've attached the official bell codes for the Victorian Railways. We use the simpler ones from this series at the model train club (1, 2, 3, 3-1, 4, 1-4, 4-1, 5, 2-2, 3-5; rarely 1-2-2, 2-3, 3-3-3 or 3-4-3) plus "1-3" for short passenger consists e.g. railmotors that will fit in dock platforms.

Steamer in post 159384 said:

Anothersignalman in post 159381 said:

Were plunger locks a thing in the UK?

The GWR (and possibly others) went down that route, where the electric lock was released by pressing a plunger before moving the lever.

Different type of plunger, might be a local terminology thing. I meant the hand-worked plunger lock that was fitted to mainline turnouts at non-interlocked locations, where home signals were mechanically detected and worked by any one of a series of quadrant levers. This system is still in use at Emerald and Cockatoo on the Puffing Billy line, and was used on the suburban terminus Hurstbridge until maybe a decade ago.
Examples:
https://railgallery.wongm.com/signalling/E116_7181.jpg.html
https://railgallery.wongm.com/victorian-goldfields-railway/F133_5753.jpg.html
https://railgallery.wongm.com/south-gippsland-railway/F139_6684.jpg.html
https://railgallery.wongm.com/signalling/E105_0810.jpg.html

There was, if I recall rightly, a 'release token' bell signal: 5-2, I think, if you needed to shunt and there was no train around; token was restored (again, if memory doesn't fail me) with a 2-5 signal.

Steamer in post 159384 said:

Anothersignalman in post 159381 said:

Were plunger locks a thing in the UK?

The GWR (and possibly others) went down that route, where the electric lock was released by pressing a plunger before moving the lever. On other frames, the lever catch was pulled and the lever moved a very short way (less then the depth of the lever), the lock released itself, and you then nudged it slightly back the way it had come before pulling it fully over. For power operated points, after doing the nudge routine, the lever is pulled 2/3 of the way over, until the points are detected in their new position, at which point it can be brought fully over.

Some companies, in some boxes, had a foot-operated plunger in the footboard just in front of the frame. I recall (just-about, I was less than 5 years old at the time!) such plungers in use at Spalding No. 1, which was a GNR box dating from 1921.

The purpose of the plunger was to avoid having to keep the lock energised for long periods. Steamer is describing a combined lock/economiser (I believe Westinghouse did them and the Southern certainly used them, but I haven't seen them much elsewhere). LNWR frames might have a contact box just above the catch block and Derby tappet frames (based on the MR design) had a contact box behind the frame, worked by the movement of the tappet.

It was also possible to find FPLs that locked something either way. Bewdley South on the Severn Valley Railway has one like that, with FPL 12 locking Xover 10 when normal and Xover 13 when reverse (it was also, with 13 N, part of a bit of point-to-point locking that gave route locking and - should the bobby play fast & loose with the rules - sectional route release, but that's by the by).

clive in post 159379 said:

I've just found an interesting layout at Leamside (https://signalbox.org/~SBdiagram.php/?id=%201519). There's 55 levers, of which 35 are spares. The through moves, with no points movements, are 3,4,2, on the Up and 53, 52, 51, 55 on the Down. But if a train is reversing Up to Down, the move out of the Up platform is points 10, 8 and then signals 16, 51, which will be a long walk!

Locally, we'd most likely have 51 as an automatic permissive signal with a note on the pull chart to the effect of, "51 need only be put normal when 5 or 6 is required". Was that an option in the UK?
Note the bottom-left of the pull chart here: https://vicsig.net/photo/12912

Anothersignalman in post 159396 said:

Ron_J in post 159389 said:

As this is a crossing point on a single line, what do people who wish to get on or off at the station do if their train is the second to arrive when crossing another train?

Shunt and redock procedure. Train A arrives platform, then reverses back, then pulls forward to mainline. Train B runs to platform and continues, then Train A proceeds.

Where single platform passing loops existed in the UK, it would be arranged never to cross two stopping passenger trains.
Loop for goods or through only.
(Abercairney, Mound, Saffron Walden)

<snip>

Highley (Severn Valley Railway) is an example that remains to the present day. In fact, unless the loop was signalled to passenger standards, it would be illegal to accept two trains simultaneously from the box in rear, as the clearing points would overlap each other. (Certainly Highley may not, unless I missed something when I read the SBSIs, accept from both directions simultaneously.) So to cross trains you'd need to wait until the first one you'd accepted had arrived and (either) been put 'in clear' in the loop, or had tipped out and been shunted into the loop, before you could even accept from the other direction.

If the loop was signalled to passenger standards, the relevant clearing point would be the fouling point at the opposite end of the loop - but both approaching trains would need to be brought quite or nearly to a stand, then each admitted in turn (not allowable to run them both in simultaneously).

kbarber in post 159455 said:

Highley (Severn Valley Railway) is an example that remains to the present day. In fact, unless the loop was signalled to passenger standards, it would be illegal to accept two trains simultaneously from the box in rear, as the clearing points would overlap each other. (Certainly Highley may not, unless I missed something when I read the SBSIs, accept from both directions simultaneously.) So to cross trains you'd need to wait until the first one you'd accepted had arrived and (either) been put 'in clear' in the loop, or had tipped out and been shunted into the loop, before you could even accept from the other direction.

If the loop was signalled to passenger standards, the relevant clearing point would be the fouling point at the opposite end of the loop - but both approaching trains would need to be brought quite or nearly to a stand, then each admitted in turn (not allowable to run them both in simultaneously).

Is that the sort of scenario where you'd use the bell code 1-5 (or UK equivalent), "Section Clear but Station or Junction Blocked"? As I understand it this would require the second approaching train to have been stopped at the prior location and advised verbally to expect this condition on arrival.

Come to think of it, I vaguely recall that a much earlier version of our rule book (c.1900s) which said that a train approaching a distant at caution then observing the first home signal at proceed was supposed to assume that the distant had been frozen on and to expect the remaining home and starting signals to also be at proceed; and that for this reason, the arrival home signals had to be held at stop until the train had passed the distant-at-caution. Pretty sure that if this ever was a thing, it was deleted pretty quickly. Definitely pre-dated the use of yellow distants, if it was a thing.

That wouldn't be used on single lines, as the clearing point would extend into the loop, there's just a specific ban on both trains entering the loop itself simultaneously, as any minor overrun could result in a collision. Not necessarily a requirement if there's a sufficient distance between the signal and the points, but as passing loop layouts are typically quite compact it would be rare to have that much space.

On double (or more) track lines worked under Absolute Block, the UK code is 3-5-5 and works much the same as you describe, the train would be cautioned at the previous signalbox (either verbally or via a green flag held out of the window) before entering the section. The 'Warning' could be upgraded to a full line clear by 3-3-5 if the full clearing point subsequently became available prior to the train entering the section.

Semaphore stop signals must be held at danger until the train is almost at a stand at them unless all signals to which the preceding distant signal applies can be cleared. While technically a driver passing a distant at caution could infer from an already-clear home signal that the signaller had since been able to clear everything, drivers would generally proceed in the expectation of each stop signal being at red. There were various unofficial 'hurry up' signals given by signalmen in the past to reassure the driver that they had the road and could open up a bit.