Hello, I was recently doing some research for (hopefully) a route project and when trying to study the signals, I came across something that I find very weird and would like to get it explained. Basically it's about the reduced braking distance and German Ks signals imposing speed limits under specific conditions. As you can see from the video starting at time 23:40, the first signal is showing "40 km/h expect stop at reduced distance" to warn about a red signal that is just 505 meters away (the route has a 120km/h speed limit so that's very short). Once our train gets to it and before the signal turns to green, it momentarily flashes to "80 km/h expect stop at reduced distance" (next signal is 815 meters away). The setting of a route in 2 parts isn't anything unusual but the speed restrictions absolutely are. It's also worth noting that for a passthrough on the exact same track, all of them show clear with no speed restrictions. Is there any place where I could read about this kind of signailing and more importantly, how the speed restrictions are determined and what even classifies as a reduced distance? I also have another example where the first signal shows "90 km/h, expect 60 km/h at reduced distance", the second one shows "60km/h, expect stop at reduced distance" and the one at the platform is red. Here starting from 24:00. Still following along? Ok. Second thing that I would like to know is that when departing straight from the platform, there is a second signal (just 200 meters away) that shows a single white light when the departure route is set (otherwise it's red as you would expect). I couldn't find anything about this being a valid aspect, let alone what is it's intended use. Does anyone know? I hope I didn't boil a few heads with this and also hope that there is someone more knowledgeable in this than I am.
I'm not sure how exactly the speed restrictions for "expect stop at reduced distance" are calculated, but signal A's 40 km/h for 500 m doesn't feel unusual to me. The different speed restrictions for the same route from ZR31 are probably for a different reason: the speed at which you are allowed to approach a red signal depends on the length of the overlap behind that signal. A 100 m overlap gets you 60 km/h, 200 m allows for >60 km/h. So I'd assume the two videos show the same path from ZR31 to N1, but with different overlaps behind N1 - straight ahead towards N51 for the freight, or immediately right after N1 for the regional. The single white light on N51 is "Kennlicht", which is not an aspect as such. It means that the signal is intentionally turned off and can be ignored. When setting the path from ZR31, the dispatcher can choose to either set a "short entry" to N1 (in which case, once a new path onward is set, N1 will display a proceed aspect and N51 Kennlicht), or a "long entry" to N51 (with N1 showing Kennlicht while that path is active).
So, basically the speed restriction is determined based on the position of the switch behind N1 and therefore based on the amount of room available behind it? Thanks for pointing that one out. Safe to say that TSW isn't going to simulate any of that and will happily give a yellow on N1 and then red on N51 (massive SPAD generator) so that would probably mean changing up the station a bit. And yeah, I didn't mean that it's unusual according to the German railway rules but it is for someone who generally deals with Czech signaling, which has very different working principles. Like not considering overlaps and very different logic for reduced braking distance.
Yes, exactly. I think it could be possible to get this right in TSW. There are signals that show Kennlicht in a similar kind of situation at Frankfurt Hbf - perhaps take a look at how these are configured for some pointers.
Sorry but you know this isn't Germany and those are not KS signals... Or do i understanding something wrong?
The station is Bad Schandau just south of Dresden and the route has a mix of Hl and Ks signals so nothing wrong about that. Maybe it's just the camera causing the lights to flicker really quickly?
Elbtalbahn Dresden Hbf Bad Schandau Schöna Bodenbach (Decin). Think of that as the international section of the existing Nahverkehr Dresden & Tharandter Rampe Bahnstrecke Dresden Chemnitz Werdau. Which was actually said in a live stream about it 2-3 years ago towards the Czech Republic former Czechoslovakia.
I think its okay that the signal 67A is placed in this distance, because it acts as a distant signal repeater ("Vorsignalwiederholer") to one of the signals before, which also emit "40 km/h expect stop at reduced distance" to the signal(s) before. The driver should already be aware of the aspect as such. If you take a closer look at the video at 25:14, you see there is a cut/jump in the video after the driver moves the camera a little. Then when the video continues, the aspect has changed to "80 km/h expect stop at reduced distance", but we actually don't even know what happened exactly in the time between, which has been not recorded or cut out. My assumption is that the driver contacted the dispatcher via the remote radio for some reason. One thing to note, before the cut in the video, you actually can see a train on platform 2 in Bad Schandau ahead, which however disappeared thereafter. Maybe this had an impact on signalling or pathing, so speed restrictions changed in an unusual way. tf-ausbildung.de is a good place to know more about german signals, aspects and speed restrictions. The domain name basically translates to "driver-apprenticeship.de"; TF is the abbreviation for "Triebfahrzeugführer" (driver). The site is even a helpful source for drivers in real life. You should be able to translate the pages via a translator addon if necessary. But as a side note, learning signalling for such special cases isn't really necessary for building a route as we haven't much influence on the dispatcher blueprint in the core, unlike you want to create your own. However, knowing the paths to related signals is important since (although pathing is done automatically), we might need to change or at least check pathing is set correctly for certain situations. For the flickers that go really quick, yes. These should be constant in reality.
No, it does not act as a repeater. A signal can't "act as" a repeater, it either is one or it isn't. The distant signal announcing 67A is visible at 21:45 minutes, showing "expect clear at 40 km/h". This is followed, because of the platform at Krippen, and the curvature of the track, by two repeaters, then 67A itself, a combined main/distant signal showing "clear at 40 km/h, expect stop". A few minutes of waiting, which doesn't make for great entertainment in video form, I would assume. I certainly don't see any reason why the signal might have displayed any other aspects or anything in the meantime... I mean, in the simplest form, it definitely did, in that the train ahead needed to leave the section before 67A could display a proceed aspect. In every other way, no. It is a great source for the "how does the driver need to react to different signal aspects" part of "signalling". The questions that Tomas had, falling into the "how does a signalling planner decide which aspects to display for which routes" part of "signalling", are well out of the scope of that website. Sadly there aren't a lot of sources on this available online, let alone in English. There are some German-language books I could recommend, but those probably won't be too helpful for you? Yes it is, if you want to do it correctly. The dispatcher just decides which route to set, but which routes are available and which signal aspects to display for them, is something you do have quite a bit of influence over as a route builder. I'm also just generally not quite sure why you went to the effort of answering several questions incorrectly which I had already answered correctly almost a whole week ago? Sorry, I somehow missed this question originally! The regular distance between a distant signal and its main signal (also applies to combined distant/main signals of course) is 1000 m, or 700m, for main lines with a top speed of >100 km/h, or <=100 km/h respectively, or 400 m for secondary lines with <=80 km/h top speed. The actual distance may be up to 50% longer, or 5% shorter than the "regular distance" which applies. So for a main line like Schöna--Dresden, anything below 1000m * 0,95 = 950 m would be a "reduced distance" and require the white light (and most likely some fun multi-block speed signalling).
Excuse my wording. The word "act" relied on the white light above, which shall signify a repeater. I have no clue if this actually can be turned off so that the signal is used for a different purpose. My assumption is that the driver called the dispatcher. Therefore they turned the capture off since audio were recording and it probably isn't allowed to record and publish internal talk about the railway infrastructure on YouTube. The conversation might had helped to know what is going on. We just don't if the aspect changed to something different in the meantime. I thought about maybe the dispatcher and driver had a conversation to path the loco over the other platform, granting them access to platform not intended to use for this train by its purpose. But then the other train moved and cleared the platform ahead. What I meant is that we can't access or edit the dispatcher system blueprint 'DispatcherAIV3' set up in the timetable to change it to any special kinds of speed restriction, if not yet built into it. We can place individual signals and set up their paths, but even for these, there is no need to reinvent the wheel and change functional (not visual) components, which do work fine as in DTG DLCs. This was never intended to be a competive answer to the main question(s), actually. I just wanted to give a bit of side information and discussion, which weren't covered before.
Signal A isn't a repeater. It is a combined main/distant signal. A repeater, in the Ks system, has its white light on the bottom left. Forgive me for quoting myself, but: --- I mean, I can't prove it since I happen to be there at the moment the video was recorded, but there is no reason for it to have displayed any other aspects. The switch behind N1 is in the overlap, so it has to be set and locked before ZR31 can display a proceed aspect towards N1. Therefore, N1 must always have had the long overlap (towards N51) behind it and as soon as the previous train has cleared the section, you can immediately allow the next train to approach N1 at 80 km/h. The driver and dispatcher may well have discussed whether or not a different path through the station, without waiting for the previous train to leave, would have been possible. A discussion over GSM-R, however, cannot "have an impact on signalling or pathing, so speed restrictions changed in an unusual way". Of course you don't need to re-write the dispatcher from scratch, or completely re-do DTG's signal scripting. But you do need to set up the routes, and make sure the correct aspects are displayed, for which you need to know what the correct aspect would be in real life. The reason why I "didn't cover" most of what you said was because it wasn't actually true.
Ok. time to add to this I guess. 67A is an entry signal to the station so it's a main signal (can show a red) combined with a distant signal (can show a yellow). A repeater would indeed show the aspect of the previous distant signal (placed at regular distance) with an added white dot (because it's closer) but this is a very different case. Also main signals, distant signals and repeaters have different post plates so that's how you can instantly tell them apart. Many cabview videos cut out stations and other stops because it's not interesting. Nothing special about that and the train at the platform leaving is what allowed the signal to go from red to yellow (setting a route to the platform). Then the dispatcher set the departure route as well, which turned the signal green. Nothing too special about that one and you can see that often in the real world as well. Especiall if the station has multiple dispatchers (doubt that in this case) where they have to handover the trains. I think it absolutely is because when making the signal rules, you are going one level deeper compared to what the driver can see. Basically you have to do the job of a signaling engineer. As a driver using the line, you just have to follow what is presented to you and everything will be fine however if you are designing the line, you have to make sure that everything makes sense so that it can be followed properly. You know what I mean? Of course you can just copy all non-changable signs the way you see them without much thoughs but for changable light signals, you have to know stuff unless you somehow have access to the original routing tables. Whether or not you can represent your findings in TSW is a whole other question though. Thanks for this one and yeah, it seems pretty normal. One more thing that could be useful though (and surely is related) is how far does the speed reduction warning board (Lf 6 aka the orange triangle) need to be. From what I know, it has to be at least a set number of meters for every 10 km/h of speed reduction. If you don't know the German norm, I will look through SŽ D1 (the Czech rulebook) and go from there.
I've been curious about this one since your original post, but I'm afraid I haven't found an answer yet. Sadly, this part of the Rulebook isn't public.
Ok, I looked at the Czech stuff (since the D1 is fully public) and damn. Minimum distances: 400 meters for lines with top speed up to 60 km/h 700 meters for lines with top speed up to 100 km/h 1000 meters for lines with top speed up to 120 km/h and for lines with top speed up to 160 km/h if the speed reduction is lower than 50 km/h 1550 meters for lines with top speed up to 160 km/h if the speed reduction is higher than 50 km/h They must also be visible from the distance of 12 seconds at maximum line speed (can be calculated as 10V/3 where V is speed in km/h and result is distance in meters) and they don't need to be installed for 10 km/h speed reductions if the original line speed is 120 km/h or lower. Curious thing is also that you can't have 2 of them in a row (can't announce a second speed reduction before the first one takes effect), which I believe have seen done in TSW so maybe it's legal in Germany. There's also a nice picture for that. And that's about it.
