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| Bars on automatic signal stems 24/02/2012 at 12:33 #29884 | |
maxand
1637 posts |
Here are 2 pics from Wembley Sub:  Some automatic signals have bars on their stems, some don't. It doesn't seem to matter whether or not they have an Emergency button attached. I always thought that automatic signals without bars were controlled by some other signalbox, but 17 and 14, for example, are clearly within my area, so this shouldn't apply. What determines whether an automatic signal has a bar across its stem? Thanks. Log in to reply |
| Bars on automatic signal stems 24/02/2012 at 13:14 #29886 | |
postal
5263 posts |
For those who have better things to do with their lives than spend their time remembering what has been previously posted on the Forum, this subject was discussed at length in the later posts of this thread. Seems to answer the same question! “In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe Last edited: 24/02/2012 at 13:15 by postal Reason: Phrasing was accidentally confrontational Log in to reply |
| Bars on automatic signal stems 24/02/2012 at 14:11 #29888 | |
northroad
872 posts |
" said:For those who have better things to do with their livesProbably a case of information overload.....we all have them...now and again. Must admit I like the screen dump showing the signal numbers Geoff Log in to reply |
| Bars on automatic signal stems 24/02/2012 at 14:40 #29891 | |
Guts
604 posts |
Let me explain as i work there. A few years back when the Suburban was being updated, Network Rail were changing the way Line Blockages were being taken. They didn't want verbal, or informal blocks, they wanted paperwork so as to be able to scrutinise them and more for investigational purposes especially during incidents. If you've played Suburban, you'll see that there are not many gaps between trains, this made it increasingly hard to give blocks between trains, ALSO, the rules at the time said you were allowed to take certain blocks from Automatic signals. (The reason for this is a rule which allows trains to pass an automatic signal at danger if they have completely no communication from the controlling signalbox/powerbox) On the original Panel a block on the Down DC through Kensal Green tunnel (KG Tunnel), the block had to be taken from WS11 at Queens Park. This would cause major delays to the service, so they re-plated certain signals, to facilitate smaller sections to allow block, as the line could have fallen into disrepair without these blocks being done. So they work as controlled signals but are capable of being held at danger to protect blockages of the line AND trains are unable to pass them at danger on their own cognition as they would with an automatic one. Log in to reply |
| Bars on automatic signal stems 24/02/2012 at 17:16 #29901 | |
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Firefly
521 posts |
Guts Just correcting a couple of bits here. If you can edit yours I'll delete this post. FF Quote: ALSO, the rules at the time said you were allowed to take certain blocks from Automatic signals.should read:- ALSO, the rules at the time said you were NOT allowed to take certain blocks from Automatic signals. Quote: So they work as controlled signals but are capable of being held at danger to protect blockages of the line AND trains are unable to pass them at danger on their own cognition as they would with an automatic one.So they work as Log in to reply |
| Bars on automatic signal stems 24/02/2012 at 23:13 #29917 | |
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maxand
1637 posts |
Thanks postal for referring me back to my earlier thread. I remembered it as a good general discussion of what constitutes an automatic signal, though didn't understand everything that was said at the time and this also applies to barred signals. I'll re-read it and hopefully all will be clear.
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| Bars on automatic signal stems 25/02/2012 at 01:03 #29919 | |
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maxand
1637 posts |
Quote:For those who have better things to do with their lives than spend their time remembering what has been previously posted on the Forum, this subject was discussed at length in the later posts of this thread. Thanks postal, your tactfulness shines through as always, but I appreciate the link you posted - to an earlier thread of mine! I must admit that although I thought I understood what Clive and others were driving at, I now see a lot of it was over my head at the time. Marvellous what difference a bit more experience makes. For anyone who missed it, Clive's post #19 contained not only an excellent explanation of the different types of automatic signal but also a link to a set of 4 pictures of the Cambridge signal box that clearly explains all parts of a panel. I must have overlooked it somehow at the time and it fills in so many details. Thanks Clive. Re-reading the posts in that thread and what Guts and Firefly said here, I think the answers to my original question are as follows: 1.) Clive: Quote: The first distinction is between "passable" and "non-passable". A passable signal is one that a driver may pass at danger on his own authority under certain circumstances (usually because both the radio and the phones are broken). Passable signals are indicated by a white plate with a black horizontal bar on it. The "passable" bar is usually drawn on the signalling panel so that the signaller knows about it. So (referring to my pics in the original post here), even though 47, 14 and 17 are automatic signals within my own area, they are shown unbarred because they are unpassable by the driver, though the automatic signals on either side are passable. The Emergency buttons associated with them are controlled by the signaller. And note, one can only display whether or not an automatic signal has bars by checking "Show automatic signal posts" in the sim. 2.) Whether or not an automatic signal is displayed barred or not, it's also important to know whether they are part of your area or someone else's (aka external signals). Ways of ascertaining this include: a) They are usually located on the fringe of your area and are probably there just to let the signaller know they exist and what their number IDs are. b) With Display > Panel signals unchecked and Show automatic signal aspects checked, automatic signals within your area should display "what the driver sees" aspects (red, yellow, green, etc.). Those that remain grey belong to someone else's box, e.g., WM902, WM903, WM904. c) Their IDs include a prefix, and their numbers differ from the adjacent ones in your area. E.g., WM902, WM903, WM904 are controlled by Cambridge. However, this only applies to automatic signals; elsewhere in Wesley Sub there are controlled signals with a WJ (Watford Junction) prefix. 3.) The type of automatic signal stem (barred/unbarred) displayed is governed more by reality than logic, and even then the sim designer may need to choose between varying versions. Clive again: Quote: As I said, on WembleySub the bars reflect reality. Well, one version of it: I'm looking at a photo of the signaller's screen with no crossbar on 63, 66, and 67, and also a drivers' route learning guide that does have them! I've gone with the former. 4) This is all probably unrealistic now. As ralphjwchadkirk wrote: Quote: Not anymore I'm afraid. From tomorrow, that rule is being withdrawn and drivers now cannot pass automatic or semi-automatic signals on their own authority. Page 56 module AM. Last edited: 25/02/2012 at 01:06 by maxand Log in to reply The following user said thank you: postal |
| Bars on automatic signal stems 25/02/2012 at 01:27 #29921 | |
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maxand
1637 posts |
Following on from item #4 in the previous post: Quote: This is all probably unrealistic now If that's the case, unchecking Show automatic signal posts should bring the sim up to present-day reality, since there is no further need for drivers (or signallers) to distinguish barred from unbarred automatic signals. However, this raises its own problems. If Show automatic signal aspects is checked and Show automatic signal posts and Panel lights are unchecked, automatic signals are now undistinguishable from controlled signals. I must say I often prefer to play with Panel lights unchecked, as the varying signal aspects in front of a train help me to gauge its speed better without needing to refer to the F2 Train List. If what the driver sees ahead is yellow instead of the panel's green, he will need to slow down. I find this easier than counting the number of greens ahead of the train. If controlled and automatic signals both show aspects but are otherwise undistinguishable, and we have no signal ID numbers to tell them apart, it makes setting routes much more difficult as one is prone to try setting a route from an automatic signal. Thus we would need a special new symbol (maybe a diamond instead of a round head?*) to distinguish all automatic signals from all controlled signals. Since this is a SimSig-specific problem (real panels are only two-aspect, and these only for controlled signals), I wonder what the developers have in mind? :) *We could, I suppose, display all automatic signals in SimSig with bars, but (a) this would depart from reality; (b) bars are no longer applicable. Besides which, when you think of it, just like ARS colours, bars are easily misinterpreted by the non-initiated. Taken at their face value, they might seem to indicate that it's the barred automatic signals that the driver is (was) not permitted to pass on his own initiative, not the other way round. But then again, if it wasn't for the human brain turning things the right way up, we would see everything as the human eye sees it, just like a pinhole camera, upside down... The simplest solution, as always, will be to leave things as they are, to comply with the requirements of authenticity, not to stress out over their interpretation but simply to ignore them and go on living life until, in the distant future, in the fullness of time and budget, all the plates with bars on automatic signals are removed and something else takes their place on the IECC panel which needs to be faithfully replicated in SimSig. 
Last edited: 25/02/2012 at 04:43 by maxand Log in to reply |
| Bars on automatic signal stems 25/02/2012 at 01:43 #29923 | |
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postal
5263 posts |
" said:I must say I often prefer to play with Panel lights unchecked, as the varying signal aspects in front of a train help me to gauge its speed better without needing to refer to the F2 Train List. If what the driver sees ahead is yellow instead of the panel's green, he will need to slow down. I find this easier than counting the number of greens ahead of the train.Max Don't forget that the line speeds are set by the need for a train to stop within the limits of the signal spacing. So, for example a Class 1 running at full line speed should stop before reaching a red signal if it reaches (not sights) the first caution signal at full speed (i.e at the YY in 4-aspect signalling and the Y in 3-aspect). This has to be the case because the train might be running in conditions of reduced visibility. The practical result is that slower trains can proceed at their full speed until a lot nearer the red signal. If you watch class 6 and 7 trains on the F2 screen, they often maintain their normal speed while passing YY and Y and only start slowing not far short of the red signal. “In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe Log in to reply The following user said thank you: maxand |
| Bars on automatic signal stems 25/02/2012 at 02:04 #29925 | |
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maxand
1637 posts |
postal: Quote: the line speeds are set by the need for a train to stop within the limits of the signal spacing. Did you mean the maximum line speed for that route segment, or the maximum line speed for a particular train? Quote: So, for example a Class 1 running at full line speed should stop before reaching a red signal if it reaches (not sights) the first caution signal at full speed I always thought trains were supposed to slow down and finally stop at a red signal?? It's where the phone box is! (Not trying to be smart here, just curious.) I've been watching train speeds on F2 Train List as well as watching full signal aspects by turning Panel Signals off, as I think jc92 or Steamer suggested elsewhere, to "get the feel of the sim", and although all the extra information was a bit of an overload at first, once I was able to distinguish automatic signals from controlled ones (mainly because of barred stems), it not only seemed more realistic (except maybe to a signaller accustomed to two-aspect display) but helped me look further ahead of each train. I must return to one with numerous freight trains and see whether their speeds change as they progress through all signals showing a proceed aspect. Having Panel Signals off has also made me much more aware of when there is a risk of causing ACOA by cancelling a route, e.g., when the train has reached its last green, so any route cancellation ahead might turn it yellow (or double yellow). Last edited: 25/02/2012 at 02:06 by maxand Log in to reply |
| Bars on automatic signal stems 25/02/2012 at 03:28 #29927 | |
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AndyG
1842 posts |
My rule of thumb whilst I've been 'pro'-testing simulation at a certain company in Bradford-on-Avon is that most automatic signals that are NOT plated and thus the driver is not authorised to pass at danger in ANY circumstances are: i) protecting signals to LCs, including AHBs and other crossings where the signaller may be holding the crossing open for a particular reason; ii) signals prior to a tunnel. In case i), you wouldn't want a driver to usurp the signaller's authority in those circumstances, and in case ii) a driver cannot proceed and be able to stop short of any obstruction cos it's too dark to see. Doesn't explain every last one, but seems to cover a lot of them. I can only help one person a day. Today's not your day. Tomorrow doesn't look too good either. Log in to reply The following user said thank you: maxand |
| Bars on automatic signal stems 25/02/2012 at 09:10 #29931 | |
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postal
5263 posts |
" said:postal:As a general rule, a section of line will have a maximum speed limit which all trains must obey (although in reality lots of them will be unable to reach that speed anyway). There are some sections of line which now have two (or even three) different speed limits depending on the class of train; on these sections a passenger train will normally have a higher allowed speed than a freight. This is due to engineering constraints (the effect of higher axle loads, total train weight and the like) so strictly speaking my original point should have been that one of the reasons for setting a speed limit is the signal spacing. Quote: Quote:The driver will normally run up to the signal before stopping, but the absolute safety requirement is that the train should stop before reaching the red signal. If the train does not, it is a SPAD and everyone has the chance to fill in a form.So, for example a Class 1 running at full line speed should stop before reaching a red signal if it reaches (not sights) the first caution signal at full speed “In life, there is always someone out there, who won’t like you, for whatever reason, don’t let the insecurities in their lives affect yours.” – Rashida Rowe Log in to reply The following user said thank you: maxand |
| Bars on automatic signal stems 25/02/2012 at 10:52 #29933 | |
GeoffM
6376 posts |
" said:I always thought trains were supposed to slow down and finally stop at a red signal?? It's where the phone box is! (Not trying to be smart here, just curious.)There is a lot of margin for error built in to the spacing. I think a rule of thumb is that the distance from passing the first caution signal to the signal at danger is 25%-35% more distance than a typical train will need to stop. If you're driving a train at 125mph, you don't want to have a standard brake application bring you to a stand exactly in front of the red signal! You want to decrease your speed in stages. In the last 10 years or so, defensive driving has been a big thing. This includes things such as stopping 20m before a red signal and freight trains doing no more than 15mph when passing over the AWS magnet (200yds before the signal). As already noted, differential speeds apply if a different type of train would be unable to stop in that distance - the speed can be lowered to fit the distance. SimSig Boss Log in to reply The following user said thank you: maxand |
| Re: Bars on automatic signal stems 26/02/2012 at 15:43 #30043 | |
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kbarber
1742 posts |
" said:" said:I always thought trains were supposed to slow down and finally stop at a red signal?? It's where the phone box is! (Not trying to be smart here, just curious.)There is a lot of margin for error built in to the spacing. I think a rule of thumb is that the distance from passing the first caution signal to the signal at danger is 25%-35% more distance than a typical train will need to stop. If you're driving a train at 125mph, you don't want to have a standard brake application bring you to a stand exactly in front of the red signal! You want to decrease your speed in stages. But time was when a driver was trusted to use his professional skill & ability, together with route knowledge and awareness of conditions. Braking distances are calculated to allow for average braking performance of the worst types of train (of their class) on potentially greasy rails (well OK, normal levels of greasiness - there is no way you can calculate for the leaf fall season). Hence the standard driving method I was used to in certain areas - pass YY with controller wide open, pass Y with controller wide open, somewhere a bit further along shut off power, drop the (bake) handle once (only) & stop a couple of yards short of the red! Log in to reply The following user said thank you: maxand |