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| Banner repeaters and subsidiary signals 29/12/2013 at 18:50 #53386 | |
lazzer
635 posts |
An argument has broken out on social media among some drivers and signallers as to the behaviour of banner repeater signals where subsidiary signals (the "dots" are concerned.Someone asked if the banner shows a proceed indication (diagonal line) when a subsidiary signal associated with a main aspect signal comes off (the main aspect remaining red, of course). I say that they do NOT, as surely the banner repeats only the main aspect. Others are convinced that there are exceptions to this, and one person is convinced that the banner DOES show a proceed indication. So, who is right? And is it always the same with every main aspect signal with a subsidiary and banner repeater? Log in to reply |
| Banner repeaters and subsidiary signals 29/12/2013 at 18:54 #53387 | |
Firefly
521 posts |
You're correct. I'll try and find a reference. FF Log in to reply |
| Banner repeaters and subsidiary signals 29/12/2013 at 18:55 #53388 | |
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Late Turn
699 posts |
I can't give a definitive answer, I'm afraid, but surely it'd be a bad thing to lead a driver into thinking that the signal's cleared to a (main) proceed aspect only to find that it's the sub that's cleared for a lower speed (or occupied) route?
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| Banner repeaters and subsidiary signals 29/12/2013 at 18:56 #53389 | |
Peter Bennet
5402 posts |
Most subs linked to mains are approach released so linking a BR is probably pointless. As with everything railway related there are probably exceptions. Peter I identify as half man half biscuit - crumbs! Last edited: 29/12/2013 at 18:57 by Peter Bennet Log in to reply |
| Banner repeaters and subsidiary signals 29/12/2013 at 18:56 #53390 | |
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lazzer
635 posts |
" said:I can't give a definitive answer, I'm afraid, but surely it'd be a bad thing to lead a driver into thinking that the signal's cleared to a (main) proceed aspect only to find that it's the sub that's cleared for a lower speed (or occupied) route?Exactly. I wouldn't want to come round a corner, see a banner off, and then see a red, dots or not! Last edited: 29/12/2013 at 18:57 by lazzer Log in to reply |
| Banner repeaters and subsidiary signals 29/12/2013 at 19:53 #53393 | |
GeoffM
6376 posts |
Paddington platform 1 into the sidings: banner(s?) show off with shunt aspect displayed (at least in 2006 SSI data). However, you're obviously starting from a stand! I'm trying to think of some other examples proving either case, but as Peter notes, there are always exceptions. SimSig Boss Log in to reply |
| Banner repeaters and subsidiary signals 29/12/2013 at 20:05 #53394 | |
ozrail
197 posts |
I'd say you're right, but it's a good question.
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| Banner repeaters and subsidiary signals 29/12/2013 at 20:13 #53395 | |
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Firefly
521 posts |
I was about to suggest platform starters such as at Waterloo Plats 1 to 13. I've looked through the standards and all cases it states that a banner should display an 'Off" indication whenever it's associated signal is displaying an uncorrupted proceed aspect. A sub signal is a proceed aspect therefore according to the standards I've checked so far it's allowed. As Peter notes, a shunt or call on would have approach control. I can't imagine there will be many examples apart from the terminus platforms. Log in to reply |
| Banner repeaters and subsidiary signals 29/12/2013 at 20:41 #53398 | |
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JamesN
1608 posts |
SN1BR still displays an 'OFF' Indication with route into Royal Oak Sidings, hasn't changed since 2006 Geoff. Conversely, the Banner Repeater for the Up platform starter at Staines (I don't have the number to hand) shows an 'ON' indication even if the shunt route into Staines CHS has cleared. ((However the dispather's OFF indicator shows OFF in this situation, but the dispatch position doesn't afford a view of the platform starter so that's understandable) Log in to reply |
| Banner repeaters and subsidiary signals 29/12/2013 at 20:46 #53399 | |
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lazzer
635 posts |
" said:Paddington platform 1 into the sidings: banner(s?) show off with shunt aspect displayed (at least in 2006 SSI data). However, you're obviously starting from a stand!Now that's an interesting one, because the platform staff's indication that the signal is off (main aspect or shunt signal) are the banner repeaters on the platforms. If they had no indication they wouldn't be able to despatch even an ECS train. Having accepted the route a few times myself, the banner MUST come off for it or they'd not know it was safe to despatch me. You certainly can't see the signal from the platform, even on the front of an HST so you can't go by that. Log in to reply |
| Banner repeaters and subsidiary signals 29/12/2013 at 21:33 #53402 | |
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Late Turn
699 posts |
It might be worth looking at it the other way around - where a banner repeater is provided, is it permissible for the associated signal to clear for an approach controlled main route or a subsidiary route until an approaching train has passed the banner repeater? Unless a 'splitting' banner repeater is provided, the absence of any route indication might mislead the driver into thinking that the route's set for the highest speed route when it's not.
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| Banner repeaters and subsidiary signals 29/12/2013 at 22:56 #53406 | |
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Stephen Fulcher
2080 posts |
In the vast majority of cases where banner repeaters are deployed and the signal is not a terminal platform starter you would probably have gone passed the banner repeater before the subsidiary aspect would clear anyway. The whole purpose of conventional banners is so that a driver gets advance warning of a signal that the signtong of which would otherwise be inadequate. Nowadays, a separate track circuit is generally provided between the banner repeater and the signal to which it applies, and this track circuit will replace the banner repeater once the train has passed it. As it is normally (but not always) the last track circuit before a signal that will be in the approach release conditions for the subsidiary aspect, the train will normally have passed the banner repeater before there would be a chance of the signal clearing. Kevin, although a proceed for a banner is technically allowed by the standard, this does sound a little dangerous to me! I would be interested to know if there are any examples anywhere in practice. I presume that there are banners rather than (or possibly in addition to) Off indicators at Paddington because the Driver cannot see the signal from the cab either? In this case it is sensible for the banner to clear for a shunt route. Log in to reply |
| Banner repeaters and subsidiary signals 30/12/2013 at 01:23 #53408 | |
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vontrapp
210 posts |
BR's are for mainline signals. They show that the aspect of the signal ahead is either on or off, when the main aspect is obscured. Usually, cats-eyes, are used for slow moves but there are instances of where they prove that the points ahead are in the 'normal' position. This is a piccy of Macclesfield. On the TC-board is cats-eyes (47) to prove the mainline and a BR to prove the mainline signal:  CR:Dominic Beglin Post has attachments. Log in to view them. Last edited: 30/12/2013 at 01:33 by vontrapp Log in to reply |
| Banner repeaters and subsidiary signals 30/12/2013 at 01:49 #53409 | |
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Late Turn
699 posts |
47 is a limit of shunt indicator - how's that relevant?
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| Banner repeaters and subsidiary signals 30/12/2013 at 02:04 #53410 | |
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vontrapp
210 posts |
Sshh.
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| Banner repeaters and subsidiary signals 30/12/2013 at 02:08 #53411 | |
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vontrapp
210 posts |
41
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| Banner repeaters and subsidiary signals 30/12/2013 at 07:52 #53414 | |
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Late Turn
699 posts |
Thought so . 41, though, appears to be provided to allow shunts to drop behind it (having been signalled to 47, e.g. a loco running round its train). It's largely irrelevant to trains arriving on the Down - it'll precede 42-45, so should be cleared (as it's within the route) before a train is allowed to approach it. Presumably it will prove that the points in advance of it are still detected (but not necessarily normal??), but the main/calling-on routes from 42-45 would function equally well without it. To insert a hint of relevance, the banner repeater on the Down is shown as applying only to the main routes from the signal, not the calling-on routes that'll clear the sub! Last edited: 30/12/2013 at 07:53 by Late Turn Log in to reply |
| Banner repeaters and subsidiary signals 30/12/2013 at 10:52 #53416 | |
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AndyB
4 posts |
To be fair, I'm pretty sure that some subsidiary signals are not approach controlled eg approach to certain sidings etc. Due to the meaning of the subsidiary signal (proceed towards next signal of any sort including buffer stops prepared to stop on sight rather than line clear to next main signal) I would not want a Banner Repeater to show a proceed indication. As far as approach controlled subsidiary signals are concerned, it isn't an issue, as the driver will see the red before he gets the subsidiary signal anyway. On the exit from platforms, there are very few examples where a passenger train would be permitted to leave the platform on a subsidiary signal in the absence of special instructions (Belfast Central towards Bridge End was an example for a year or two when the layout was being changed and a new route was required over the Up line to the existing crossover and shunt signal at Bridge End pending resignalling and provision of proper bidirectional signalling and a new crossover - all routes from the north end of Central are now under full signals) - I think in all those cases, I would want the OFF indicator to remain extinguished and any platform staff providing assurance of the train being ready to proceed to check the actual signal. The rare occasions when a passenger train travels towards Great Victoria Street on the Down line from Great Victoria Street has to be done under subsidiary signals the whole way, and I would doubt any OFF indicator at Belfast Central is lit when the relevant sub signal is lit. Log in to reply |
| Banner repeaters and subsidiary signals 30/12/2013 at 11:02 #53417 | |
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Forest Pines
525 posts |
If 41 was actually separate levers for each route it could be used to "prove the points" to make the locking simpler - rather than have 43 and 45 locked/released directly by 39 and 37 you could have each one released by the relevant shunt signal lever - as it is I assume 43 and 45 must be released by 41. 41 wouldn't be there solely for that reason though - as LT said it's clearly there for the operational reason of reversing a train or loco that's been signalled to 47.
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| Banner repeaters and subsidiary signals 30/12/2013 at 15:15 #53434 | |
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Firefly
521 posts |
Quote:Kevin, although a proceed for a banner is technically allowed by the standard, this does sound a little dangerous to me! I would be interested to know if there are any examples anywhere in practice.I agree, there's no way I'd commission such an arrangement. I've never seen it in practice anywhere other than the terminus platform starters (Paddington, Waterloo etc). I was somewhat surprised that I can't find any mention of banners not applying to sub signals in either RGS or NR standards. The closest I have is that the design handbook (11201 ModB19 Section 1.6) states that the banner GR should be driven by the HR or a later repeat, ECPR and any intervening TPR. Banner repeaters don't have to have a replacement track circuit unless permissive moves are allowed, however if there is a track circuit between the banner and the signal that track circuit should be included in the banner controls. It's therefore theoretically possible for a sub signals approach control conditions to be satisfied prior to a train passing the banner signal. I think Late Turn probably hit the nail on the head because there is a standard that says a Banner should only apply to the highest speed route unless the diverging route is MAF (doesn't have approach control). But then a call on is not a diverging route! Quote: Well no, it's not allowed, however I'm aware of at least one place where the banner will clear for all routes, however the diverging routes have approach control and the timings were such that a train should of passed the banner before the signal releases. Of course if there was a track failure, or if the train was very slow it would see the banner off for a diverging route. In both cases the train is going slowly and will have time to react to the aspect and route indication on sighting the main signal. Macclesfield does indeed show that in that case the banner only apples to the main signal and not the sub. Last edited: 30/12/2013 at 20:52 by Firefly Log in to reply |
| Banner repeaters and subsidiary signals 30/12/2013 at 22:30 #53466 | |
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Forest Pines
525 posts |
" said:I'm aware of one location where the banner clears for all routes, the diverging route has approach control but the signal normally releases with the train in rear of but in sight of the banner! The signal in question is B235 at Narroways Hill Jn, Bristol. In nearly every case when a train is taking the diverging route there is a station stop at the signal in rear and a station stop between the banner and the signal; I suspect that the timing is such that if a train was not starting from a stand, the signal would not clear until the train had passed the banner. Incidentally, B235 did also have a subsidiary when it was commissioned, in 1970. Unfortunately I have no idea whether the sub also released the banner, but I suspect not, as it was worked from a ground frame. Log in to reply |
| Banner repeaters and subsidiary signals 30/12/2013 at 22:42 #53468 | |
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vontrapp
210 posts |
I'll go to Macclesfield SB and find out which cats-eyes are cleared for the DM route. I know they are 'off' for detection purposes. Or, I may ask a driver.
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| Banner repeaters and subsidiary signals 30/12/2013 at 23:23 #53470 | |
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Stephen Fulcher
2080 posts |
" said:" said:B235R seems to clear with 235HR (yellow relay) and 235GECR (lamp proving relay), so it will show 45 degrees every time B235 is called to display a main aspect, as long as B235 is lit.I'm aware of one location where the banner clears for all routes, the diverging route has approach control but the signal normally releases with the train in rear of but in sight of the banner! The signal in question is B235 at Narroways Hill Jn, Bristol. In nearly every case when a train is taking the diverging route there is a station stop at the signal in rear and a station stop between the banner and the signal; I suspect that the timing is such that if a train was not starting from a stand, the signal would not clear until the train had passed the banner. Whether or not the sub was worked from a ground frame would not make any difference, as most E10k panels would have had the ground frame slot the main panel anyway (ie both have to set the route for the signal to come off), and in any case the signal would still clear in the interlocking, which is where any banner controls would have been applied. I can see where the controls for the old "A" route have been erased off the diagrams for the HR and (S)GR circuits, but nothing on the banner repeater page of the diagrams, and there does not appear to be enough room for there to have ever been any controls which have subsequently removed. The route onto the branch requires KA track circuit occupied for 18 seconds before B235 will clear. This track circuit runs all the way back to Lawrence Hill Ground Frame (B538 signal), which is 670 yards from B235 so it is quite probable that most trains for Clifton Down would see the banner off, and even a wrong-routed non-stopping train might satisfy the approach clearing conditions for the route down the branch before passing the banner as well. I suspect this arrangement may not be allowed by the modern day standards. Last edited: 30/12/2013 at 23:24 by Stephen Fulcher Log in to reply The following user said thank you: Forest Pines |
| Banner repeaters and subsidiary signals 30/12/2013 at 23:55 #53471 | |
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Late Turn
699 posts |
" said:I'll go to Macclesfield SB and find out which cats-eyes are cleared for the DM route. I know they are 'off' for detection purposes. Or, I may ask a driver. My interpretation of the situation, without specific knowledge of the box, is as follows. The sub (41) will need to come off for any movement past it, whether running through from the main signal in rear or starting from a stand at 41. The cats eyes on 42-45 will come off when (amongst other conditions) the points in the route are detected and 41 is cleared. Loss of detection would replace 41 and (either directly or via 41?) 42-45 to danger. How could it be any different, and how's it relevant to the operation of the banner repeater anyway? Log in to reply |
| Banner repeaters and subsidiary signals 31/12/2013 at 00:00 #53472 | |
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vontrapp
210 posts |
When I saw it 'off', I was in the front-cab of a Pendelino. As for the BR, I am talking about the 2nd part of the forum title, as well.
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