Reversing in Royston

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Re: Reversing in Royston 08/11/2011 at 23:27 #22619
maxand
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Thanks mfcooper for answering many of my unasked questions in one post. Apologies if you found some of my comments offensive - I was just expressing newbie frustration. Royston might be a good place to start learning SimSig, but its sparsely written manual does not make it a beginner's sim.

So that little "comma thingie" is really a Catch and has nothing to do with LK246, even though it's abeam of it? Thank you. Looked everywhere to find its meaning. It's difficult to identify what a symbol does when you don't know its name, so you don't even know where to begin looking. Maybe one of us should start a Symbols Used page in the Wiki (hey, there's an idea). Thanks Steamer for the Wikipedia reference. I had no idea there were so many types of Catch points and Trap points in operation.

Does the S in "ROYSTON S K977/245 (Reverse)" stand for Station or Shunt?

I would not have attempted to squeeze 6E55 into the LOS area between LK246 and K977 had I been able to compare the length available with the length of the train. In Train Dispatcher one can turn on block length display for any block and decide ahead whether or not to shunt into a particular siding. If there is an equivalent function in SimSig, I have not been able to find it. Is there one? Neither the Royston Manual nor the Signalling Diagram (PDF) mention block lengths.

Last edited: 09/11/2011 at 01:39 by maxand
Reason: "LK246 and K246" should have read "LK246 and K977"

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Re: Reversing in Royston 09/11/2011 at 00:25 #22623
UKTrainMan
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" said:
Maybe one of us should start a Symbols Used page in the Wiki (hey, there's an idea).

http://www.SimSig.co.uk/dokuwiki/doku.php?id=usertrack:ssrun:signalling_display

" said:
Does the S in "ROYSTON S K977/245 (Reverse)" stand for Station or Shunt?

Probably South.

" said:
I would not have attempted to squeeze 6E55 into the LOS area between LK246 and K246 had I been able to compare the length available with the length of the train. In Train Dispatcher one can turn on block length display for any block and decide ahead whether or not to shunt into a particular siding. If there is an equivalent function in SimSig, I have not been able to find it. Is there one? Neither the Royston Manual nor the Signalling Diagram (PDF) mention block lengths.

SimSig is a highly realistic simulation of real-world signalling in the UK. I do not know of anything better than it in terms of realism. I'm pretty certain that at no signal boxes the signallers have such information displayed right in-front of them. But perhaps it is available via documentation within the 'box?!

Of interest though is you've sent a train to a LOS signal. LOS stands for Limit of Shunt, so surely it is only meant for passenger trains to shunt up to so they can switch to a different line or platform and not a freight train (which is usually far longer than passenger trains).

Any views and / or opinions expressed by myself are from me personally and do not represent those of any company I either work for or am a consultant for.
Last edited: 09/11/2011 at 00:27 by UKTrainMan
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Re: Reversing in Royston 09/11/2011 at 01:10 #22625
maxand
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Thanks UKTrainMan. I have added Catch point to the Wiki Symbols page.

Quote:
Of interest though is you've sent a train to a LOS signal. LOS stands for Limit of Shunt, so surely it is only meant for passenger trains to shunt up to so they can switch to a different line or platform and not a freight train (which is usually far longer than passenger trains).
I don't recall reading anywhere in SimSig that LOS signals are to be used only by passenger trains. The Glossary states:

Quote:
LoS - Limit of Shunt Signal

A Limit of shunt is the limit beyond which a shunting movement is not permitted to pass, and hence no route is available to be be set beyond it. Physically this may consist of a ground shunt signal showing two red lights, or an illuminated sign indicating the limit of shunt (wording varies).

Normally found at reversing locations on main lines and occasionally loops.
This makes no distinction between passenger and freight trains, although your point is a valid one. All the Royston manual says is

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The LOS on the Down line is closer to signal 977 than you might think. Long trains won't fit in there and need to be reversed on the Up.
Clearly the writer intended this as no more than a hint for experienced players, but as a newbie it passed right over my head. Long passenger trains? Even after going off to read up what LOS means, I had no clue how to go about "reversing on the Up". Newbies take things literally and the wording even suggests that reversing is a task for the signalman, not the driver, something the player should not attempt to do here.

Quote:
SimSig is a highly realistic simulation of real-world signalling in the UK. I do not know of anything better than it in terms of realism. I'm pretty certain that at no signal boxes the signallers have such information displayed right in-front of them. But perhaps it is available via documentation within the 'box?!
Well then, who knows in the UK whether a train will fit in a siding? The driver? The signalman? Surely both must know, or at least the signalman! IMO the very least that can be done is to include in the sim manual, (or, better, on the signalling map) the lengths of key blocks used by trains that appear in the timetable. I find it baffling that I can look up a train length but not a block length. Not every block need be shown, only key ones in shunting and sidings. This does not have to be completely authentic; the sim developer could make up lengths to suit the situation.

For example, if I knew in advance that the distance between LK246 (the LOS signal) and K977 is only, say, 100m (long enough for the longest EMU (82m) but way too short for 6E55, a freight train 250m long, I wouldn't even have considered trying to squeeze it in there!

Last edited: 09/11/2011 at 02:06 by maxand
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Re: Reversing in Royston 09/11/2011 at 07:35 #22630
Late Turn
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Just a few thoughts and corrections. Firstly, as others have suggested, Simsig is a very good simulation of the real thing - so perhaps the real thing is the place to start looking for some of the answers? There's plenty of resources out there (not sure whether there's a list of links available on the Wiki or elsewhere - happy to contribute if there is!), and you'll be a better position to understand Simsig if you've got a decent understanding - if only at a basic level - of the real thing.

Limit of shunt signals - as the name implies, it's the limit of a shunt move, so wouldn't normally be used for passenger trains in service (which shouldn't normally be signalled via a shunt route). Obviously in this case there's not enough space for a full-length freight either, so it's only going to be useful for a passenger train shunting empty (perhaps this is what UKTS meant) or a loco running round its train. Some of the pages on the Wiki list the lengths of key sidings and loops, but obviously not Royston at this point in time.

I think Matt's answered (well) most of the other questions, but I note at one point you're puzzled by the 'ghost train' appearing in the Down Loop. Perhaps something else not obvious to newcomers to signalling - there's often a difference between the positions of trains (indicated by track circuit occupancy - the red sections) and the train descriptions (which will 'step' automatically to the next 'berth' position as soon as a train leaves the first 'berth'). In this case, as soon as the train has passed 245 signal and occupied the track circuit in advance, the TD has tried to step from the berth at 245 signal - since this berth was empty (6E55's description was at the auto signal at the other end!), the software automatically enters **** just as the real thing would. In this situation, some sims would automatically step 6E55's description from the auto signal to 245 signal as soon as a route was set from the latter (so that it would in turn step into the Down Loop) - I don't know whether the omission of this from Royston is deliberate (if it doesn't appear on the real thing) or in error, or even if there's a berth at 245 in reality (shunt signals often don't have TD berths, and they often won't step automatically from them).

I'll try and explain that in simpler terms if I've gone on a bit.

Finally, in your first situation, it might be worth trying running 6R02 into the Down Loop to reverse at 244 signal - as you note, there's a passenger 'on the block' behind, and the shunt on either running line is going to further delay that. Looking again at reality for a moment, the platforms are almost certainly authorised for "permissive passenger" working only - which means that you're allowed to signal a second train in on top of one, but only if both trains are Class 1, 2, 3 or 5 (and, without checking, 9 and 0??). So although Simsig won't penalise you for it, it's something else that'll maybe make more sense with a bit of an understanding of how the real thing would do it.

Hope that helps at least a little bit - happy to explain further if necessary!

Tom

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Re: Reversing in Royston 09/11/2011 at 12:59 #22644
clive
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Okay, as the sim author it probably behoves me to reply to these comments. You might want to note that this is the first sim I ever wrote, so things aren't always as clear as in later sims.

Reversing 6R02

Quote:
there doesn't appear to be a Down-facing signal ... where we can hold 6R02 to prevent it crashing into 1R52
Trains in Simsig never crash into one another. Note that when you set the route from signal 977, it changed to a calling-on aspect, not a main aspect. That tells the driver that there's another train ahead and to drive cautiously as a result.

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6R02 managed to stop ... Who would have anticipated that?
If you'd clicked on the 6R02 description, or looked at the timetable, you'd have seen that it has "Royston S K246 (reverse)" at its next location. Since signal 246 faces the other way, this is a pretty strong hint that the driver is planning to stop his train so that he can reverse at signal 246.

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you might not have known 6R02 would reverse here automatically on stopping
Trains always reverse automatically in order to obey their timetable. The driver knows he's going into Sherriff's (because it's in his timetable), so he knows he has to reverse direction. The only time you have to tell the driver to reverse (unless there's a bug in the sim) is if you want him to do something outwith his timetabled instructions.

I know signallers often have a very low opinion of drivers (and vice versa), but the simulated drivers do know how to read a timetable.

Reversing 6E55

Quote:
"ROYSTON S K977/245 (REVE 15:10 15:16". What in blazes does this mean?
Okay, let's dissect this. "ROYSTON S" is "Royston South" - i.e. the area immediately south of Royston station. "K977/245" means "either signal 977 or signal 245". It's usual to use a slash to mean "or", with a dash meaning "to". "(REVE" is "(REVERSE)" truncated to fit, indicating that this location is intended for use by reversing trains (this affects what timetables you can write, but isn't of itself an instruction to reverse. The two times are the timetabled arrival and departure times.

It probably helps to know that this area is actually controlled from King's Cross PSB in real life, so the signals all have K prefixes (apart from a few at the north end which are Cambridge signals with a CA prefix). The reason for this is historical: the original King's Cross simulation was too big to fit, so the author cut it off just north of Hitchin on the main line and Baldock on the branch. The bit north of Hitchin got included in SimSig Peterborough even though it's not controlled by Peterborough PSB, and the Royston bit looked like a good place for me to learn how to write simulations (it's also included in SimSig Cambridge).

Why is this location given with two signals? The answer is that it means that you can choose which one to use and the driver won't complain that he'd been given a wrong route. If these had been made two different locations, you wouldn't have the flexibility of choosing which line to store a train on. Of course, as you've discovered, this flexibility doesn't always help.

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Since no other lines have a LOS signal, this confirms that we're on the right track
Actually, that's not so. A LOS signal indicates the point at which the line stops being bidirectional - more precisely the point at which you're not allowed to go any further in that direction. There isn't one on the Up line because you can go for many many miles (but you can only reverse if you stop immediately).

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that little annoying thingie
As others have pointed out, that's a catch point. Yes, we could probably do with a "non-railway-worker's guide to basic signalling symbols" somewhere on the Wiki. In this case it isn't a problem because it sorts itself out when a route is set over it, it can't move while a train is sitting on it, and if you let the rear of the train go past it before deciding to reverse it, you're just out of luck.

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6E55 not only stopped but reversed ... without any help from us
See the bit about drivers above.

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So why mention 977 at all on the timetable?
As I said, it's to offer flexibility. That doesn't mean that you can always use that flexibility.

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The ghost soon vanishes of its own accord and our remaining task is to Cancel the 6E55 berth.
I thought the description automatically stepped back to 245 signal when it cleared. There may be a bug there. Someone else has explained the rest of what's going on there.

Quote:
block length display for any block
Real signallers don't have such a facility, so we don't provide it in SimSig. Yes, that length perhaps ought to be in the manual but, as I said, it was my first sim. I'm not writing this at home som I can't check the actual distance. But if I've correctly identified it on Google Earth it's just over 150m.

I don't know where this idea that only passenger trains are involved comes from. LOS signals are used by goods trains, and the comment in the manual was intended to refer to all trains, not just passenger ones (which is why it doesn't use the word "passenger").

Finally, the longest EMU unit in Royston is 82m, but you get 2-unit (8-car) trains (and since I wrote that timetable you now get 3-unit trains).

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Re: Reversing in Royston 09/11/2011 at 13:05 #22645
clive
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While someone's updating the signalling symbols page, you might want to add "wide to gauge" points. There's an example in Wembley Suburban.
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Re: Reversing in Royston 09/11/2011 at 16:34 #22661
clive
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The standing room behind signal 977 is 173 metres, though trains will probably insist on having some clearance from the signal so you can't quite get that much in there.
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