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Speed signalling 17/12/2014 at 23:27 #66775 | |
Finger
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BTW, could SimSig handle areas with speed signalling?
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Speed signalling 18/12/2014 at 00:19 #66777 | |
maxand
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Please try to stay on-topic. This deserves its own thread.
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Speed signalling 18/12/2014 at 02:02 #66779 | |
GeoffM
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" said:BTW, could SimSig handle areas with speed signalling?Yes, to a certain degree. It could handle a handful of different speeds but not a wide range. Again, to a certain degree, US and (US-style) Australian signalling. SimSig Boss Last edited: 18/12/2014 at 12:21 by Peter Bennet Log in to reply |
Speed signalling 18/12/2014 at 11:43 #66782 | |
maxand
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As a non-professional, I for one, having made an effort to learn the Route Signalling system used in the UK in order to play SimSig, find Speed Signalling confusing, even though a variant of it is used in my home state of Victoria in Australia. So some explanation seems in order. Quote: Route signalling and speed signallingIf it were as simple as that, it would not be too difficult to add an extra set of icons when simulating American or Australian layouts. However: Quote: There are two main types of signaling aspect systems found in North America, Speed Signaling and Weak Route Signaling.[2] Speed signaling transmits information regarding how fast the train must be going in the upcoming segment of track, weak route signaling transmits information related to the route a train will be taking through a junction and it is incumbent upon the engineer to govern the train's speed accordingly. Weak Route Signaling is applied with the term "Weak" because some speed signal aspects may be used in the system and also because exact route information is not typically conveyed, only the fact of a diverging or straight route, each having a predictable range of known speeds.Here are two other useful links on US conditions: Railway Technical Web Pages Primer On American Railroad Signals In Australia it varies from state to state. Again, Wikipedia describes this very well. For example, in my home state: Quote: The railways of Victoria use a mix of railway signalling practices: British route signalling with home and distant signals (2 position signalling) and American speed signalling (3 position signalling)... (Wikipedia - Australian railway signalling)John Hinson, known for his website The Signal Box, wrote an amusing account of Melbourne speed signalling as seen through UK eyes, titled Speed Signalling on the suburban lines of Melbourne After reading these articles it becomes clear to me that to simulate North American and Australian routes accurately would require an immense amount of preparatory coding by SimSig's developers, almost a complete rewrite of the core code, which would execute slower and be harder to debug. Since there are many more signalling icons required, implementing this might require much higher screen resolution and completely new graphics, whereas the present system using simple icons faithfully reproduces the real life simple VDU display as used all over the UK. I think it would also make writing timetables more difficult because in speed signalling the onus is now on the driver to adhere to the new speeds. If and when the UK finally adopts speed signalling or changes to moving-block technology it will be time to consider upgrading SimSig. In the meantime I think most of us have our hands full just coping with what we have. Last edited: 18/12/2014 at 11:46 by maxand Log in to reply |
Speed signalling 18/12/2014 at 13:59 #66789 | |
Muzer
![]() 718 posts |
I've always wondered - presumably in speed signalling, the signallers have to be even more careful of a wrong route, as it's much more likely for a driver to accept a wrong route. What additional mitigation, if any, against wrong routes do they have?
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Speed signalling 18/12/2014 at 19:37 #66803 | |
GeoffM
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" said:I've always wondered - presumably in speed signalling, the signallers have to be even more careful of a wrong route, as it's much more likely for a driver to accept a wrong route. What additional mitigation, if any, against wrong routes do they have?Talking of US signalling, drivers would have some idea of a wrong route if there were only 2-3 possible choices. This is because a "straight" route would get one aspect, let's say green over red, while a diverging route would get a different aspect, let's say red over green. Some have two diverging speeds, medium and slow (?), which again would be a different aspect. SimSig Boss Log in to reply |
Speed signalling 18/12/2014 at 20:05 #66805 | |
metcontrol
![]() 217 posts |
Thank you for the explanation of what is being discussed here. For a time there I thought perhaps this was a discussion regarding certain areas already available being enabled for super-quick mouse clicks or similar, for those with nimble enough reflexes to set routes with the sim running on the fastest setting. :doh Log in to reply |
Speed signalling 18/12/2014 at 20:05 #66806 | |
Finger
![]() 220 posts |
" said:" said:BTW, could SimSig handle areas with speed signalling?Yes, to a certain degree. It could handle a handful of different speeds but not a wide range. Again, to a certain degree, US and (US-style) Australian signalling. So, no German or East European (OSShD*) signalling is possible? The biggest problem with speed signaling is that you don't set speed profile according to the track, but, depending on the circumstances, you might get quite different aspects leading to the same track, resulting in different permissible speeds. It can mean you'll get a 40 kmh restriction even for straight route, which is lifted once route forward (or second route forward, or third...) is set. " said: I've always wondered - presumably in speed signalling, the signallers have to be even more careful of a wrong routeBasically, you've said it. It isn't much of a problem, because the driver will stop anyway when routed somewhere he's not supposed to go. It can be pernicious, however, when the signaler accidentally sets route to a shorter track than normally expected by drivers. There have even been accidents on this account, under quite intriguing circumstances. *) personally I think it should be written OSZhD, but nevermind Last edited: 18/12/2014 at 20:16 by Finger Log in to reply |
Speed signalling 18/12/2014 at 20:07 #66807 | |
Finger
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" said:Thank you for the explanation of what is being discussed here. Thanks! That made my day ![]() Log in to reply |
Speed signalling 18/12/2014 at 20:27 #66810 | |
GeoffM
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" said:So, no German or East European (OSShD*) signalling is possible?As I said, to a certain degree. SimSig Boss Log in to reply |
Speed signalling 19/12/2014 at 20:45 #66848 | |
Forest Pines
![]() 525 posts |
I suspect you could probably simulate the West German signalling system, which is still widely used, by using the defensive driving rules, as the West German system only really has "line speed" or "restricted" speeds. The East German system is much more complex, and the modern German "combined aspect" system is in many ways the British four aspects with arbitrary speed indications on top! Incidentally I've read that in Germany theatre indicators showing letters are used at major junctions to refuce the risk of a driver taking a wrong route.. Log in to reply |
Speed signalling 19/12/2014 at 21:44 #66852 | |
Jan
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" said:I suspect you could probably simulate the West German signalling system, which is still widely used, by using the defensive driving rules, as the West German system only really has "line speed" or "restricted" speeds.I wouldn't say so. Yes, there is a dedicated aspect for restricted speed (40 km/h), but with the help of theatre indicators any other speed (as long as it's a multiple of ten) can be shown as well. In that regard it is actually even more flexible than the OSShD derived signalling systems, including the East German variety, which can only show a certain number of fixed speed steps and don't use any theatre indicators at all. Additionally, in Germany you have a distinction between the station area and the plain line, which is important when having to decide how long a speed limit is valid, and there is a slightly weird rule about what happens within a station when an intermediate/exit signal is showing a higher speed limit than the entrance signal - basically after a scheduled stop at the ordinary stopping position the train can accelerate immediately, while in all other cases the complete train needs to pass the signal before the driver is allowed to accelerate. And that's just covering the signalling-driver interface, if you actually want to simulate a signal box you'll find lots of other differences as well... Two million people attempt to use Birmingham's magnificent rail network every year, with just over a million of them managing to get further than Smethwick. Log in to reply |
Speed signalling 19/12/2014 at 22:39 #66854 | |
Forest Pines
![]() 525 posts |
" said:" said:The West German signalling system - the "Hp" system, which distinguished stop signals and distant signals by head shape - didn't include theatre indicators as far as I'm aware. You're thinking of the post-reunification "Ks" signalling system which I also mentioned in my post - it has four aspects that are very similar in meaning to British signalling, but with additional white and yellow theatre indicators to display maximum speeds at the current or next signal.I suspect you could probably simulate the West German signalling system, which is still widely used, by using the defensive driving rules, as the West German system only really has "line speed" or "restricted" speeds.I wouldn't say so. Yes, there is a dedicated aspect for restricted speed (40 km/h), but with the help of theatre indicators any other speed (as long as it's a multiple of ten) can be shown as well. In that regard it is actually even more flexible than the OSShD derived signalling systems, including the East German variety, which can only show a certain number of fixed speed steps and don't use any theatre indicators at all. You're right about the problems that would be involved in simulating the "points zone" - I'm not sure if that could be done in SimSig at present. Last edited: 19/12/2014 at 22:39 by Forest Pines Log in to reply |
Speed signalling 20/12/2014 at 11:59 #66858 | |
Jan
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" said:The West German signalling system - the "Hp" system, which distinguished stop signals and distant signals by head shape - didn't include theatre indicators as far as I'm aware.Well now you can say that you are aware ;) Here with fixed indicators (in combination with mechanical signalling sometimes even a moveable variety is used): ![]() ... and with theatre indicators. For speeds up to 60 km/h, the "proceed slowly" aspect (Hp2 and Vr2) is used, for speeds above that the normal "proceed" (Hp1 and Vr1) aspect is shown. In this case, we have a distant signal repeater (the German equivalent of a banner repeater) as indicated by the additional white light and the missing distant signal plate, therefore the advanced speed warning - displayed with yellow digits - gets repeated as well. ![]() This signal is also exhibiting the Zs2 direction indicator you mentioned, in this case it is displaying 'R' for - I think - Rheintalbahn. ![]() Alternatively, as long as all sets of points allow higher speeds than the standard 40 km/h, it is possible to simply redefine the meaning of the "proceed slowly" aspect at all entrance/intermediate/exit and/or block signals of a certain location and direction to 50 or 60 km/h via the working timetable. Two million people attempt to use Birmingham's magnificent rail network every year, with just over a million of them managing to get further than Smethwick. Last edited: 20/12/2014 at 12:00 by Jan Log in to reply The following user said thank you: Forest Pines |