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| Cornwall SimSig 28/04/2014 at 13:06 #59676 | |
lazzer
604 posts |
" said:" said:So far as my driving is concerned, Lostwithiel is an absolute block signalbox, and if the distant is on, I'm going to be going slowly until I'm past what I define as the section signal." said:While technically correct, at the end of the day lazzer is a driver, where the AB regulations start/terminate affects his driving. He has been taught LL10 is the section signal and therefore it'd be irresponsible for us to speculate or suggest otherwise.Regardless of whether there is an AB section in advance of LL10, I simply cannot believe that LL10 is not an absolute block section signal. If it isn't, then no one has ever told me or any of the drivers at my depot who regularly drive trains through Lostwithiel. But I am now intrigued enough by the Sectional Appendix's stating that AB and TCB appear to have a boundary at the signalbox to go and talk to the signaller to find out how THEY define the area. Log in to reply |
| Cornwall SimSig 28/04/2014 at 13:25 #59682 | |
headshot119
4869 posts |
I think some confusion is being drawn between AB/TCB vs Semaphore/Colourlight. As has been stated above a Semaphore stop signal, or a two aspect colour light stop signal, will not normally be cleared if the signal a head is at danger unless the train has come nearly to a stand at it (There are exceptions to this across the country, and usually stated in the SBSIs for the box concerned). Whether it's AB, TCB, EKT, OTW, or any other method of working does not change this. The SBSIs for Lostwithiel clearly say that "The Down and Up lines between THIS signal box and Liskeard, are worked in accordance with Track Circuit block regulations." Therefore I can only conclude that the change to TCB does indeed occur where the SA says it does. I'll reinforce again, passing a distant signal at caution on approach to semaphore signals, or two aspect colour lights should always be taken as those signals being at danger (From a drivers perspective) For those wondering the signal sequence in the Up direction is as follows: LL1 (Colour Light Distant) [Y/G] LL2 (Semaphore) [R/G] TPWS LL3 (Semaphore) [R/G] LL5 (Semaphore) [R/G] TPWS LL6 (Semaphore - Bracket short arm for goods loop) [S/R/G] TPWS LL8 (Semaphore) [R/G] LL10 (Colour Light) [R/G] TPWS As for the aspect sequence I haven't got that information to hand though as it's effectively all semaphore signals I would take a guess that LL1 can only be cleared if all the following signals are off. I'm sure our resident Cornish expert Stephen Fulcher could confirm this. "Passengers for New Lane, should be seated in the rear coach of the train " - Opinions are my own and not those of my employer Last edited: 28/04/2014 at 13:48 by headshot119 Log in to reply |
| Cornwall SimSig 28/04/2014 at 16:05 #59692 | |
Stephen Fulcher
2025 posts |
LL1 will only clear with LL2, LL3, LL5, LL6, LL8 and LL10 off. The line between these signals is not continuously track circuited, but the bit from LL5 onwards is (LL5 is on the end of the platform). Lostwithiel works Absolute Block to Par, and Track Circuit Block to Liskeard, using bells for descriptions. The only conditions for clearing LL10 are that the track circuits and axle counters are clear upto the overlap of LL1028 signal at Largin are clear, LL1028 and LL1028R are lit and that Bodmin Parkway GF is detected normal with the key in. The next signal is controlled by Lostwithiel on an NX panel for Largin, which is an SSI interlocking located at Par. Liskeard is also TCB throughout on the main lines, even though all stop signals are semaphore. From an S&T perspective, LL10 is not a section signal because it is neither locked by the block (as none exists), nor leads into an Intermediate Block Section. How it is referred to by drivers is anyones guess,and as long as they stop at it when it is at red it doesn't really matter. The change in operating regulations AB to TCB isn't something that has any real bearing on how the signalling system works. Log in to reply |
| Cornwall SimSig 28/04/2014 at 16:11 #59694 | |
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Zoe
251 posts |
" said:all stop signals are semaphore. Except LD4 on the Up Main. Last edited: 28/04/2014 at 16:34 by Zoe Log in to reply The following user said thank you: Stephen Fulcher |
| Cornwall SimSig 28/04/2014 at 17:32 #59698 | |
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Late Turn
696 posts |
Until very recently, at a fringe box between AB and TCB, the signalling regs stated that AB applied as far as the home signal (out of the AB section) and from the section signal in the other direction. This is now specified in the SBSIs in all cases rather than by exception, but I'd suggest that it's unlikely that the box in question deviates from this (but I could be wrong!). Either way, there's no way that LL10 can be termed the 'section signal' - that's defined as the signal controlling entry into an Absolute Block section, which LL10 doesn't. None of the above has any bearing whatsoever on the working of the semaphore signals, which will be in accordance with the general signalling regs (and thus equally applicable anywhere) unless exempted in the Sectional Appendix. The same goes for the distant signal, which still relates to all applicable stop signals even if some of them aren't under AB regs. Log in to reply |
| Cornwall SimSig 29/04/2014 at 10:17 #59726 | |
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kbarber
1712 posts |
My twopennorth from an older perspective. In AB signalling it used to be (presumably still is?) the case that the stretch of line between the first stop signal (the home, outer home, first home or similar description) and the signal worked by the same box governing entry to the section ahead was regarded as 'station limits'. Within that stretch, it was permissible to do all sorts of things (wrong direction moves or unsignalled shunts, for example) that would not be permitted in a block section. (There might sometimes be a need to apply one or other block reg, and the stretch between a section signal and an Intermediate Block signal worked from the same box was specifically defined as outside station limits, but hopefully you get the general principle.) In TCB, each 'section' consists of the stretch of track between one signal and the next. (I suspect it's a matter for debate whether the overlap is technically part of the rear section or whether the 'control length' (I believe that's an LT term) and the signal section might be different but to the signalman it's a complete irrelevance, we need both section and overlap clear before the signal governing entry can clear.) The concept of station limits is therefore largely obsolete, although it used to be the case that certain locations (I recall Derby being one) would have 'station limits' specifically defined in the Sectional Appendix, with similar relaxations on what kind of movements were permissible. As others have observed, there is no such thing as a 'section signal' in the TCB regs; in my view that's because every signal would technically have to be regarded as a section signal so the description is superfluous. From the descriptions people have given, it appears to me that Lostwithiel station limits stretch from LL2 to LL10. That implies that, strictly, TCB working commences at LL10 and not at the signalbox itself. In that respect it's no different to the situation in a box that works AB all round; the SBSIs would read along the lines of 'the Absolute Block regulations apply between this box and...' but it would be clearly understood by all concerned that the distance between the box and the section signal (and indeed between the first home signal and the box) was station limits and that the section itself commenced at the section signal. Again, I agree that working of signals has nothing to do with which particular set of block regulations applies. If a signal has three aspects and full braking distance to the next signal, it may be cleared as soon as the control length is clear; if there is less than full braking distance it must be held at danger until the train is closely approaching it (regardless of whether it's semaphore or not) and of course that restriction applies by definition if it's a semaphore as it can't display the caution aspect. This is true regardless of which set of regulations apply. One question in my mind: in practical terms, what would be the difference between applying AB regs and applying TCB regs between Lostwithiel box and signal LL10? And I do mean practical terms here; I'm sure it would be possible to point to all sorts of theoretical differences but I'd expect a practical railwayman to apply the regs in a commonsense way. (The first possible example that occurs to me is communication with the signalman. I suspect, nowadays, all references in relation to TCB state or imply that a signal post telephone or some kind of cab secure radio must be used. But I also suspect most signals at Lostwithiel don't have SPTs and there's no CSR of any kind. But I can't imagine that anyone would refuse to communicate with the bobby direct if he were leaning out of the box window just because the requisite phone or radio wasn't provided - or if they did I'd anticipate a well-aimed 'please explain'.) But of course I've been out of the industry for some time, so there may be differences nowadays that would have a practical impact. (And of course there might also be a generation of managers who'd insist on the letter of the law, even if it meant a driver refusing to speak to the signalman who's shouting out of the window at him; if the railway's in those sort of hands I really do despair!) Log in to reply |
| Cornwall SimSig 29/04/2014 at 14:24 #59734 | |
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Stephen Fulcher
2025 posts |
Further complicated Keith by the next signal after LL10 being controlled by the same box. There are fixed telephones dotted around, although not at every signal. All trains in the area are now fitted with GSMR radio and this is what drivers tend to use. There are a few shunts that happen down that end of the station, but they are all signalled moves. Log in to reply The following user said thank you: kbarber |
| Cornwall SimSig 29/04/2014 at 20:10 #59767 | |
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Late Turn
696 posts |
Over time, of course, such terms change - 'station limits' is probably one such example, which doesn't even exist any more! In their most recent form, though, it was clearly stated that they didn't normally apply at an AB/TCB fringe box. As Keith suggests, though, it's largely irrelevant in practice - the 'specific' regs (i.e. AB and TCB) are most relevant to movements in the section itself, and between signal boxes, rather than within what was once called station limits. How often is the method of signalling referred to in the rules applicable to drivers? The rest of it is contained in the general signalling regs, applicable everywhere. TCB or AB, I'd much rather speak to a driver in person than by any form of radio or telephone - it's much easier, I think, to come to a clear understanding when talking face-to-face. There's certainly nothing in the rules and regs to stop us doing that - perhaps the only reason would be the desire to have everything recorded, but no-one's yet objected to me taking the former approach... Log in to reply |
| Cornwall SimSig 03/05/2014 at 02:48 #59953 | |
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Muzer
718 posts |
My opinion on the original topic - I wouldn't mind having a Cornwall sim, it would be an interesting addition with quite different operation to normal. Assuming it was simulated all the way up to the fringe with Exeter, it could also add an interesting extra sim to the Great Western chain. However, given the difficulty in making the sim due to all the absolute block working and the general fact that it's not really what SimSig was designed for, I won't be surprised if it never makes it past mock-ups. I'm hopeful, though.
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| Cornwall SimSig 03/05/2014 at 09:23 #59959 | |
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lazzer
604 posts |
" said:However, given the difficulty in making the sim due to all the absolute block working and the general fact that it's not really what SimSig was designed for, I won't be surprised if it never makes it past mock-ups. I'm hopeful, though.Do you mean AB such as it is in Cornwall, or AB in general? Don't forget about the Scottish sims, Worksop, and North Wales - they've managed to simulate it quite effectively. Log in to reply The following user said thank you: guidomcc |
| Cornwall SimSig 03/05/2014 at 14:59 #59988 | |
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Muzer
718 posts |
I must admit, I haven't tried any of those sims yet. I've played Aston which has a limited amount of AB, but not on such a large scale as Cornwall. Do these other sims have a lot of AB?
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| Cornwall SimSig 03/05/2014 at 15:15 #59989 | |
Steamer
3921 posts |
" said:I must admit, I haven't tried any of those sims yet. I've played Aston which has a limited amount of AB, but not on such a large scale as Cornwall. Do these other sims have a lot of AB?Worksop has 4 AB sections (I'm counting double track as 1 section), using the same method as Aston. NEScot has absolutely loads- 25 boxes simulated, almost all of which work AB to at least 1 other box. The AB is optional and can only really be used in multiplayer. AB is implemented in a different way to Aston and NEScot. NWC has 16 boxes, all of which work AB to at least 1 other box. AB is simulated in a different way to the others, and is manageable on single player. "Don't stress/ relax/ let life roll off your backs./ Except for death and paying taxes/ everything in life.../ is only for now." (Avenue Q) Last edited: 03/05/2014 at 15:15 by Steamer Log in to reply |
| Cornwall SimSig 03/05/2014 at 15:30 #59990 | |
jc92
3629 posts |
" said:" said:Cscot can be added to that list - it simulates an AB area, but without actual block instruments, although all other principles and practice are there. you could add the Hope Valley line on Sheffield to the equation as well, not forgetting South Humberside, and also stratford panel on Saltley. those all simulate an AB area which convert's nicely onto the SimSig platform.I must admit, I haven't tried any of those sims yet. I've played Aston which has a limited amount of AB, but not on such a large scale as Cornwall. Do these other sims have a lot of AB?Worksop has 4 AB sections (I'm counting double track as 1 section), using the same method as Aston. NEScot has absolutely loads- 25 boxes simulated, almost all of which work AB to at least 1 other box. The AB is optional and can only really be used in multiplayer. AB is implemented in a different way to Aston and NEScot. NWC has 16 boxes, all of which work AB to at least 1 other box. AB is simulated in a different way to the others, and is manageable on single player. "We don't stop camborne wednesdays" Log in to reply |
| Cornwall SimSig 03/05/2014 at 21:38 #60011 | |
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john_s
31 posts |
I appreciate that Simsig was designed for something other than Absolute Block, but there is at least one workstation in real life which works AB to an adjacent box (as far as I know). I realise there must be a block bell in this case, but I wonder if the indications on the screen are (essentially) the same as in Simsig - I've never seen a picture.
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| Cornwall SimSig 24/07/2014 at 16:38 #63088 | |
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Bagnall2067
17 posts |
At Barnham (NX Panel) the AB 'instrument' (including bell plungers) for the Bognor branch is integrated into the panel, in a similar manner to that depicted by Simsig. It does retain the old SR block bell from the old signalbox, perched on top of the panel. Next time I'm up there I'll make sure to get some pictures.
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| Cornwall SimSig 25/07/2014 at 09:06 #63118 | |
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tjfrancis
358 posts |
just had a look in my track atlas if it Cornwall SimSig goes ahead may be it can link up with exter at totnes/marley tunnels from that point to penzance they is 9 different boxes but this was back in 2012 so it may of changed
I am dyslexic so please consider this when reading my posts Log in to reply |