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"Run out of valid track" explained?

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Re: "Run out of valid track" explained? 08/12/2011 at 06:35 #24689
clive
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" said:
Can't set the second leg of that from 59 to 24.
Those face in opposite directions. Of course you can't set a route between them.

Quote:
However, when the loco stops and automatically reverses, it's now not against 59 (as I expected) but against 24.
That is, it's standing at a signal facing in the direction it wants to go. Why on earth is that a surprise?

Quote:
I was kinda hoping to set the next route 24-MS1 directly, as 24 is a running signal with a subsidiary shunt, but no such luck, for luck it seems to be.
Rubbish. MS1 is an un-track-circuited area. So the route into it is going to be a shunt route, not a main one. Shunt routes rarely (there are exceptions) have intermediate "preset" signals, so you should expect to have to set the route from shunt signal to shunt signal.

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That in this situation there isn't just one signal that can be called "Bristol East Junction" - there are at least two, possibly more that satisfy this requirement.
Um, is this the same Max who was complaining that a location in Royston named both the signals you could reverse at? Do you not pay attention to your own rants?

Quote:
Also that the actual signal at which a train reverses (24) need not be the one (59) to which it's routed. The reversing signal has to face the way the train will face AFTER it automatically reverses.

Truly mind-bending stuff.
Let's see: a train stops at the signal controlling the action it wants to take, rather than driving half a mile down the line only to drive back again. What a surprise!

You know, some of your comments have been quite sensible and thought-provoking, but this one is just stupid.

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Re: "Run out of valid track" explained? 08/12/2011 at 06:42 #24691
clive
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" said:
If the driver didn't have some kind of handbook saying "If you are cleared forward through signals 59 to 65, you must know to stop at signal 24 and reverse." I can't believe that a vague directive such as "Bristol East Jn Reverse" would be considered adequate for both driver and signaller. In other words, one of them has to know if this sim is to be considered authentic. I imagine that what would happen in real life is that the signaller would call the driver, saying "I've cleared you to signal 65 along the main, please reverse at 24."
No, at the most he'd say "please reverse at 24". But if this is a timetabled move, he probably wouldn't speak to the driver at all. The driver would see "BRISTOL EAST JN, RM" in his working timetable ("RM" meaning "reversing move"), see the road clear towards 65, and know that 24 is where he's booked to reverse. He knows this from his training.

Quote:
IMO, to run out of valid track unexpectedly in this situation should not be blamed on the sim player who honestly believed he had correctly identified the signal at which to reverse. It's just situations like this in real life which cause real accidents.
You've been told before that trains will reverse themselves when they're at the correct reversing point. You reversed that train at the wrong place, so you should accept responsibility for what happened.

(And in real life the driver isn't going to panic when running out of track. He'll know he's heading for a buffer stop and will stop his train accordingly.)

Quote:
but as discussed elsewhere on the forum, the potential to run out of valid track is not well signposted in this game and not entirely bug-free, either.
Excuse me? What bug in my code are you referring to?

Last edited: 08/12/2011 at 06:43 by clive
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Re: "Run out of valid track" explained? 08/12/2011 at 06:46 #24693
clive
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" said:
You've put your finger on it! Instead of "Waiting at red signal 59" we need something less cryptic to indicate the reversing signal has not been reached yet.
The code doesn't contain the level of artifical intelligence necessary to do that.

Quote:
but the last thing a tired, overtaxed sim player needs is to have to hang up a game he probably forgot to save when the going was good, just to puzzle out another missing bit of information.
The F3 controls include an option to automatically save the game at regular intervals, which can be as low as 5 (simulated) minutes.

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Re: "Run out of valid track" explained? 08/12/2011 at 06:49 #24695
clive
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" said:

If the train is briefly listed through F2 as "Waiting at (unspecified) red signal", before changing status to "Run out of valid track": Could this be the red lights conventionally affixed to buffer stops (at the end of bay platforms), being considered as a signal? (Albeit one that never changes aspect, is not shown on panels; nor assigned a number*?)
That is, roughly, what is happening in the code.

The message "run out of valid track" has been removed from all future simulations, replaced by a range of more expressive messages and phone calls, such as "at buffer stops".

(Oh, and that change was made a week or so ago and has been on my list for a while; it's not a reaction to this thread.)

Last edited: 08/12/2011 at 07:06 by clive
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Re: "Run out of valid track" explained? 08/12/2011 at 07:27 #24700
maxand
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Clive:
Quote:
You've been told before that trains will reverse themselves when they're at the correct reversing point. You reversed that train at the wrong place, so you should accept responsibility for what happened.

Hindsight is a wonderful thing.

Quote:
Excuse me? What bug in my code are you referring to?

It was in either some Southampton yard or at Sherriff's siding at Royston, similar to alvinhochun's experience in post #9. The train ran out of valid track, I lost the train, finally removed it via the Train List and was convinced it was a bug. However, as I just now went back to see if I could duplicate it, it all worked properly, so whatever it was, I am managing to avoid it. Apologies.

Quote:
The message "run out of valid track" has been removed from all future simulations, replaced by a range of more expressive messages and phone calls, such as "at buffer stops".

Best news I've heard for weeks. Hope it can be made retrospective as I've got a lot of catching up to do before I get to the future.

Your other comments were educational and are appreciated.

Last edited: 08/12/2011 at 07:31 by maxand
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Re: "Run out of valid track" explained? 08/12/2011 at 10:56 #24706
kbarber
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" said:
Moreover, I just can't believe that any signaller (or driver) responsible for an area such as Bristol, given the limited amount of information in the accompanying manual, would know instinctively what routes to set, nor that he would not confer with the driver (or his Controller) in such a situation. In the above example we see at least two possible reversing routes for this loco driver to take. If the driver didn't have some kind of handbook saying "If you are cleared forward through signals 59 to 65, you must know to stop at signal 24 and reverse." I can't believe that a vague directive such as "Bristol East Jn Reverse" would be considered adequate for both driver and signaller. In other words, one of them has to know if this sim is to be considered authentic. I imagine that what would happen in real life is that the signaller would call the driver, saying "I've cleared you to signal 65 along the main, please reverse at 24."

IRL this is the kind of thing that is dealt with as people learn their areas.

A friend used to be signalman at Euston in the mid-1980s. I have an idea there was some kind of authority to drive from the rear cab when shunting out into the throat, in order to return either to one of the loco holding locations or to another platform. Drivers were taught that they should keep going as far as the outlet signal authorised them to go unless & until they saw a shunt signal clear to let them back in (in SimSig terms signals 28 - 47). That way, if the bobby wanted them to go all the way out, they would get there without additional instructions or risk of misunderstanding. If he could let them in from one of the inner shunt signals, he'd set the route as soon as it became available (and with electropneumatic points machines it would set very quickly). If the driver saw it he could immediately stop & reverse. If he didn't the loco would carry on until it got beyond the next shunt signal, at which point the bobby would set the route back (again hoping it'd be seen and the driver come back in straightaway). In the end, the loco would come back in anyway, without any need for further instructions. (IIRC that behaviour can't be fully replicated in SimSig - if a loco is shown to reverse at 28 - 47 it'll go all the way out there even if it can be let in sooner.)

The point is that every driver is required to "learn the road" before he can be considered competent, and to do that he has to learn the location and meaning of every signal, as well as the ways of working at every location on that route. Routelearning would probably take several weeks for a driver working out of Euston to become useful, although the first segments could probably be signed in a week or so. As well as travelling over the line every day (and probably having some kind of route manual showing signals etc, either privately produced in the depot or sometimes an official local publication), he'd be accompanying experienced drivers and/or travelling with a traction inspector/routelearning instructor who could tell him all these things. Likewise every signalman has to learn his 'box; I'd expect an absolute minimum of six weeks learning at Euston (a week on each of the three shifts for each of the two panels) - and of course he'd be working with experienced men who already knew the box and all its little foibles.

We have to learn these jobs for ourselves without the sort of help the real railway offers its staff. That people here are able to master complex & demanding areas as quickly as they do - and I'm including you in this Max - says a great deal for the enthusiasm and railway nous that exists here; for most signalmen, Euston PSB or Bristol Panel would've been a place they aspired to some 20 years into a lifelong railway career, by which time you can be sure they'd be well-steeped in railway lore!

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Re: "Run out of valid track" explained? 08/12/2011 at 11:53 #24708
kbarber
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I think one of the issues driving this thread is just how much real-life intelligence ("commonsense"we can expect from a simulated (artificial intelligence) train driver.

In many cases there will be no working timetable at all to cover shunt moves. At Bristol I guess there's relatively few shunting moves of the kind that kicked off this discussion; even before the advent of DMU-type trains (Cl 253/254 from the mid-1970s, virtually everything these days) many trains would have passed through.

Euston before the introduction of push-pull working is probably a better illustration. (I hope you'll forgive a description of the relevant bits of Station Yard working.) Most of this would have applied as much in the days of steam as during the electric era BTW.

When a train arrived, the incoming loco would be uncoupled. There were then three possibilities for the driver:
1 he would be relieved, either by the crew for the next working or by a man allocated to shunting locos in the station (or perhaps by a ferry set who would take the loco to Willesden Depot for maintenance);
2 he would be booked to stay with the loco & take it out on the next working (or perhaps light to depot), in which case he'd wait for the next move (perhaps nipping off to mash a can of tea in the interim - it would take a while for the train to be ready to go);
3 he would screw the loco down and leave it (it's pretty irrelevant to us whether it would be to take another train out immediately, to have his PNB (Physical Needs Break) or to go off duty), in which case the loco would (preferably) have to be manned before the train on top departed.

When the train departed - and assuming the incoming loco was manned - it was required to follow the train "closely" (undefined - that's the word in the regulations and interpretation is a matter of discretion) as far as the signal at the platform end (which you'll often hear referred to as the "starter" or sometimes "platform starter"). It is an absolute requirement that it waits at the starter until it has been returned to danger (automatic, of course, in any power signalling installation) and again cleared.

If for any reason the loco didn't closely follow the outgoing train, the driver was required to obtain the signalman's permission before moving. (The reason for that is that, as soon as the departing train is clear, the bobby could signal another train in - with rather unfortunate consequences if it meets a loco tardily dragging itself up to the starter!)

When the starter cleared again, the loco would move out (as described in my previous post) until signalled back. If the man who took over was the outgoing driver, he'd know where he was going (probably including the most likely platform even). In the other cases he'd just go where the signals directed him, either to another platform (there presumably to hook on to a waiting train) or to one of the loco holding sidings around the place (the "back of the box" behind 48 or the parcels dock behind 16 in earlier eras, or sidings A - D in the 1990s). Only if the driver was the outgoing man would he have a "working timetable" (perhaps a note on his diagram) - and in fact probably not then - referring to the move; most likely he'd just have been told by the Train Crew Supervisor he was to move/take the loco on platform X.

Professional games programmers working full-time might (or perhaps might not, I don't know) be able to recreate those sorts of behaviours, though probably at a cost in terms of processor & memory usage as well as time & effort. Even if SimSig programmers could, I think there's probably other things that have priority, particularly as it's (supposedly) a hobby for them (though, if we the users aren't careful, one that may end up devouring them). So there are some things that aren't quite "as IRL" that we just have to accept, in order to have the benefit of this otherwise stunningly realistic sim. With every release of core code they get less and the "real life" features are extended; personally I'm prepared to say that's good enough for me. (But of course if anyone wants to programme some "realistic" driver - and other staff - behaviour - including voice-recognition and a vast range of possible messages & responses - so calls from drivers held at signals, for instance, can be more realistic, I'm sure Geoff & Clive would consider how the result might be integrated. Perhaps the people who play Trent would appreciate the facility to tell Toton Supervisor to get off his backside & give them the slot they'd requested hours before )

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Re: "Run out of valid track" explained? 08/12/2011 at 12:48 #24712
maxand
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Thanks Keith. As usual, your description is so vivid I can practically hear it all happening as I read. There is absolutely no substitute for this kind of memoir. Please give us the benefit of your experience any time you feel like writing.

From a programmer's viewpoint, you're quite right about the exponentially greater amount of hours of programming needed to turn your memories into reality. One only has to look at current attempts to simulate train driving sims to realize how artificial it all looks. On the other hand, by replicating the elements of real control panels which are themselves computer interfaces, SimSig doesn't need to bother with 3D graphics to achieve the unique advantage that it has.

The activities you relate are those of well trained individuals who understand what each man has to do. The whole functions as a well oiled system with little or no guesswork. This is the real interface that SimSig is trying to emulate, not just the signalling part of it.

My approach to making it more realistic than it is today would be to build into the core code the ability to create shorter but more intricately detailed scenarios. I'm sure Clive and Geoff have already considered this at length and are waiting to find the spare time needed.

Scenarios are not new; you find them in commercial games and particularly in any rail driving simulator where you might have to drop goods off and pick up others, etc. Everyone likes the idea of becoming involved in this type of interaction. But it does require significantly greater documentation than is currently provided, to capture the essential atmosphere.

This should be be the province of the timetable creator, not the sim developers, whose task is to provide timetablers with the ability to intersperse pedestrian timetables with more imagination and good writing. I see more intricate and interactive timetables as the path SimSig should take, if it can.

24 hour timetables covering large territories are fun, but if the scene becomes more detailed, the scope and duration of the scenario will necessarily shrink. I like the Euston shunt scenario you described. I don't think a scenario requires a great deal of extra AI, at least nothing that can't be written in Object Delphi. It would be fun to test the limits of the timetable envelope in this way.

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Re: "Run out of valid track" explained? 08/12/2011 at 17:16 #24731
Steamer
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My approach to making it more realistic than it is today would be to build into the core code the ability to create shorter but more intricately detailed scenarios.
By scenario, do you mean an event that alters how you have to play the game? If so, SimSig already simulates random Track Circuit, Signal and Point failures, as well as options on start-up which close either specific sections of track (fast lines between location X and location Y, for example), or more random sections (usually a random platform). These will force you to alter the way you play in the way you described. Don't dismiss 24-hour TTs so quickly- the 0000-0500 period is generally quiet, allowing the player to learn the Sim before passenger traffic starts, and provide varying levels of difficulty- night, rush hour, daytime, rush hour again, then evening. Also, trains will ring in saying that they are delayed at X location. I (think) everything described at Euston is already possible- set the loco departure time to 00:00 and the loco will depart as soon as the passenger and the signal has cleared. If the signal doesn't clear, the loco will ring in before moving.

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Re: "Run out of valid track" explained? 08/12/2011 at 17:47 #24733
Late Turn
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Although, as explained above, a shunt move will continue to its booked reversing location regardless of your efforts to get the Driver to see an 'earlier' signal come off to get him back into the station - you can of course quickly and easily edit the train's timetable so that it stops behind the signal you want it to stop at. Whilst battling with Bristol, Max could have changed the shunt move's timetable to substitute "Bristol East Junction (Reverse)" with "BTM East Reverse (B558/560/562)" ("Bristol TM East Inner Reverse" wouldn't do - the move would stop behind 574, which isn't far enough out to get back to the middle sidings).

Not convinced by talk of 'scenarios' - the timetable defines what needs to happen during the course of the simulated day, and you can implement infrastructure failures manually, through predefined scenarios or randomly. Perhaps the only thing that you can't do on a predetermined or random basis is a train failure - and I'm not sure how you'd simulate that randomly in a realistic manner.

Tom

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Re: "Run out of valid track" explained? 08/12/2011 at 19:45 #24739
clive
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" said:
Quote:
The message "run out of valid track" has been removed from all future simulations, replaced by a range of more expressive messages and phone calls, such as "at buffer stops".

Best news I've heard for weeks. Hope it can be made retrospective as I've got a lot of catching up to do before I get to the future.
It will happen in all new sim builds and refreshes. Old sims can only have new features like this added by doing a refresh (like the Royston refresh last month).

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Re: "Run out of valid track" explained? 08/12/2011 at 19:48 #24740
clive
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" said:
it was required to follow the train "closely" (undefined - that's the word in the regulations and interpretation is a matter of discretion) as far as the signal at the platform end (which you'll often hear referred to as the "starter" or sometimes "platform starter"). It is an absolute requirement that it waits at the starter until it has been returned to danger (automatic, of course, in any power signalling installation) and again cleared.
Automatic, yes, but it's worth noting that the platform starters at Euston were "last wheel replace" (so as not to upset drivers doing propelling moves).

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Re: "Run out of valid track" explained? 08/12/2011 at 19:52 #24742
jc92
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" said:

It will happen in all new sim builds and refreshes. Old sims can only have new features like this added by doing a refresh (like the Royston refresh last month).
how complicated are refreshes. not in terms of removing bugs etc, just in terms of bringing the sim up to date with core code features?

"We don't stop camborne wednesdays"
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Re: "Run out of valid track" explained? 08/12/2011 at 20:50 #24749
Firefly
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I've joined this thread rather late.

Firstly

Bobby = Signaller (Due to the fact that policeman used to carry out the job of signaller)
Dolly = Shunt Signal

Surprised neither have been asked yet.

Max
Quote:
That in this situation there isn't just one signal that can be called "Bristol East Junction" - there are at least two, possibly more that satisfy this requirement.
Bristol East Junction is a location, not a signal. There are many signals at Bristol East Junction. The train reverses at that location, it's not important which signal it uses.

Quote:
I just can't believe that any signaller (or driver) responsible for an area such as Bristol, given the limited amount of information in the accompanying manual, would know instinctively what routes to set, nor that he would not confer with the driver (or his Controller) in such a situation. In the above example we see at least two possible reversing routes for this loco driver to take. If the driver didn't have some kind of handbook saying "If you are cleared forward through signals 59 to 65, you must know to stop at signal 24 and reverse." I can't believe that a vague directive such as "Bristol East Jn Reverse" would be considered adequate for both driver and signaller. In other words, one of them has to know if this sim is to be considered authentic. I imagine that what would happen in real life is that the signaller would call the driver, saying "I've cleared you to signal 65 along the main, please reverse at 24."
Drivers and signallers receive on the Job training, they don't learn shunting moves from a manual. There's no manual at Bristol Power Box specifying a prescribed route for trains between the yard and the sidings. There will be special box instructions which may or may not give the signaller information on which shunt moves are allowable. If a move is allowable a signaller can use it to achieve the required result. There is very unlikely to be any conversation between the driver and the signaller, they just know their jobs.

The thing that you're lacking is on the job training. If,like a real trainee you had someone sat next to you in order to show you what to do and answer your questions immediately I'm sure you'd have a lot less misery.

I do like the scenario idea, some of the people hosting games try to simulate scenarios with varying degrees of success.

The problem is that most real life scenarios involve telephones. The reality of a signallers job is that they spend a lot of time on the phone.

Scenarios could include:-

The Lengthman phones up and reports a track defect. Signaller has to caution trains unit the emergency speed restriction can be set up.

Possessions. - Possessions don't just appear, they involve a number of communications between PICOP and signaller. Signal Protection must be provided and reminder appliances applied.

Line Blockages - S & T phoning up for a line blockage between trains. S & T asking you to swing points N or R, or asking for a particular signal to display a particular aspect to take a voltage reading

S & T working on a set points or track circuit between trains, you have to enable them the access without delaying any trains.

Driver reports a trespasser, you must stop all trains and inform your control in order to get the police in.

Train Describer failure or a planned switch off for a data change

Single Line Working using pilotman

The trouble with all these scenarios (except the TD failure) is that it requires a certain amount of dialogue with the relevent parties.

FF

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Re: "Run out of valid track" explained? 08/12/2011 at 20:55 #24752
ralphjwchadkirk
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And about 50 pages of paperwork for each one of the items in Firefly's list!
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Re: "Run out of valid track" explained? 08/12/2011 at 21:07 #24756
Peter Bennet
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" said:
" said:

It will happen in all new sim builds and refreshes. Old sims can only have new features like this added by doing a refresh (like the Royston refresh last month).
how complicated are refreshes. not in terms of removing bugs etc, just in terms of bringing the sim up to date with core code features?
Depends on what's changed. If it's just new features that don't require data modification then not long but if data requires modification then it's anyone's guess.

Peter

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Re: "Run out of valid track" explained? 09/12/2011 at 09:01 #24773
clive
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" said:

how complicated are refreshes. not in terms of removing bugs etc, just in terms of bringing the sim up to date with core code features?
If the sim only uses the standard features intended for development, then it should just be a matter of rebuilding it and running some tests - for Royston and Drain that was an hour or two each. If it's got a lot of custom code in it then that might have to be revisited or completely rewritten.

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Re: "Run out of valid track" explained? 09/12/2011 at 12:20 #24781
kbarber
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" said:
And about 50 pages of paperwork for each one of the items in Firefly's list!

Well it may these days... always remember 'twas not always thus, and if you play a 1980s timetable you can legitimately do all sorts of things that aren't allowed these days (as well, I suspect, as being barred from several things that would be regarded as normal nowadays). There's always been a certain amount of paperwork (25kV OHLE isolations were probably the most involved) but I get the impression it's mushroomed rather impressively since I left - probably the quickest-growing activity on the entire railway

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Re: "Run out of valid track" explained? 15/12/2011 at 23:55 #25621
maxand
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Thanks to all, particularly Firefly, who posted extra comments since I last visited this thread.

Rather than start a new thread, I'd like to draw attention to the fact posted earlier that in the Bristol sim, to set a route from 24 to MS1/MS2 I have to set the route 24-560-566-MS1/MS2.

However, if I wish to set a route from 26 to Platform 1, I can do it in one step, even though it passes through 562 and 568. Why the difference?


Last edited: 16/12/2011 at 00:07 by maxand
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Re: "Run out of valid track" explained? 16/12/2011 at 00:04 #25622
Late Turn
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The difference is that a 'main' class route is available into Platform 1 (that'll allow signal 26 to clear to a single yellow). Such routes, which are used for most 'running' movements as opposed to shunts, are only set from main signal to main signal - they indicate to the Driver that the line is clear at least to the next main signal

The routes into MS1 and MS2 are only 'shunt' class routes, which are generally only used for shunt moves and only indicate that the route is set to the next signal, giving no guarantee that the line is clear that far. No doubt on some installations you'd be able to set the shunt route from 26 to MS1 in one go (just as you can set the 'calling on' routes from 26 into any occupied platform), but not here.

Edit: apologies if that makes no sense - it's late, and I'm trying to keep it easy to understand, and that doesn't seem to be a good combination!

Last edited: 16/12/2011 at 00:06 by Late Turn
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Re: "Run out of valid track" explained? 16/12/2011 at 00:09 #25623
maxand
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Makes very good sense, and thanks for the quick reply!
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Re: "Run out of valid track" explained? 16/12/2011 at 00:24 #25624
Late Turn
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No problem! Perhaps I should have added (but probably didn't need to) that you can't set the main routes via the intermediate shunt signals - as I think you've already found, that would instead set a series of shunt routes, causing the entry signal to stay at Danger and the 'sub' to come off instead (without route indication!), which a passenger train shouldn't accept (in reality). Incidentally, that's different to setting a calling-on route (in one go) into an occupied platform. In that case, you'll just get the 'sub' off, but with route indication (not shown in Simsig or on the panel in reality).
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Re: "Run out of valid track" explained? 16/12/2011 at 01:44 #25627
maxand
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"sub" = subsidiary shunt signal?
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Re: "Run out of valid track" explained? 16/12/2011 at 15:42 #25654
kbarber
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" said:
"sub" = subsidiary shunt signal?

Yep. Sometimes referred to as "catseyes", or at least they used to be in the days when colloquialisms weren't a hanging offence.

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