RMweb Gold The Stationmaster Posted November 29, 2015 RMweb Gold Share Posted November 29, 2015 Travelling back from the Warley show yesterday with a former colleague we passed a recently installed banner repeater a good couple of hundred yards in rear of the signal to which it applies and which is presumably been added (to a signal which has been there for 50 years) because ohle masts will interfere with distant sighting of the signal. My former colleague passed a comment about the increasing use of banner repeaters and wondered if the folk installing actually understand their purpose - which causes me to ask the following question. On a stretch of ma signalled route there are two successive signals which I'll call A & B, the signals are at least linespeed/mixed traffic braking curve braking distance apart (in fact probably more) which leads me to the following question - a train passes signal A at green and is running at its maximum permissible speed with the controller barely partway open in order to maintain momentum, the line is as good as level as makes no difference. The Driver sees the banner repeater for B, the next signal in advance, to be showing a proceed aspect indication but it is not green (it being a banner which he knows can show green). What should the Driver's action be on first sighting the banner repeater, does he - A. Partially close the controller? or B. Completely close the controller? or C. Close the controller and commence a brake application? or D. Wait until he sights the signal before taking action appropriate to the aspect it is displaying. We should assume that he has what he considers a wholly effective brake in relation to trainload and braking distances and has excellent knowledge of the road. Link to post Share on other sites More sharing options...
RMweb Gold big jim Posted November 29, 2015 RMweb Gold Share Posted November 29, 2015 I'd say It all depends on the route and speed at the time of siting the banner Speaking from experience, north of norton bridge there is a green banner on the up fast, a pendolino driver would upon spotting it would be shutting off power and beginning to brake before siting the signal it applies to whereas if i were on say a NR train at 90mph would be shutting off power and be preparing to brake when i site the signal (which would be a double yellow at a minimum) and further down the food chain if i werr on a freight at 60mph id probably not shut off til passing the associated signal In many locations the modern banner is now seen as an extra aspect Link to post Share on other sites More sharing options...
johnb Posted November 29, 2015 Share Posted November 29, 2015 I've noticed recently on the WCML between Euston and Rugby that banner repeaters capable of showing green have proliferated, particularly on the fast lines. I wonder of the signal spacing along the WCML is, in places, just that bit tight for Pendos running at max speed, whilst the thing would be stopped within the distance, it could well be somewhat abrupt. A 'soup-in-laps' scenario comes vividly to mind John Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted November 29, 2015 Author RMweb Gold Share Posted November 29, 2015 I've noticed recently on the WCML between Euston and Rugby that banner repeaters capable of showing green have proliferated, particularly on the fast lines. I wonder of the signal spacing along the WCML is, in places, just that bit tight for Pendos running at max speed, whilst the thing would be stopped within the distance, it could well be somewhat abrupt. A 'soup-in-laps' scenario comes vividly to mind John That shouldn't be the case as that is not the purpose of a banner repeater (which is how the conversation with my former colleague started yesterday). In simple terms - and don't forget the WCML was allegedly upgraded ready for introduction of the Pendolinos - if signals are underbraked either they should be moved or line speeds should be reduced to suit the braking distance available from the signalling. Link to post Share on other sites More sharing options...
APOLLO Posted November 29, 2015 Share Posted November 29, 2015 Some interesting banner signals on the down fast line through Rugby on this Youtube clip https://www.youtube.com/watch?v=M_YnD0O8Ku0 Note some are green when "off", and a bit further north they are white when "on or off" (at the junction signal). The white arrow on the first green banner one is interesting. I presume it means the repeated signal (ahead) is clear for the straight (main) route. There is also an interesting illuminated arrow on its own 13 secs into the clip - and its on the right hand side of the line, presumably for high speed sighting. A Pendolino driver needs to be fully alert when cruising through Rugby !. Brit15 Link to post Share on other sites More sharing options...
Supaned Posted November 29, 2015 Share Posted November 29, 2015 Green banners are generally used when there is a higher linespeed (such as EPS and HST differential speeds) , although some used in the new Reading scheme fly in the face of this. My understanding was that they were originally used where the braking was a bit "tight" when running at the higher speeds to give drivers an additional few seconds warning - bear in mind that HSTs were introduced to do 125 under conventional signalling due to their higher performing brake rate , and this trend continued with 220/221/390 et al. I was told that the one approaching Norton Bridge on the up fast was a bit of a tight section if running at EPS speeds and the signal was two yellows , so the green banner was presumably a cheaper fix than a complete re-signal. As to how I drive , it all depends on the linespeed and rail conditions. If I am doing 125 and the green banner shows white , I will start braking as the associated signal will be two yellows. If I am pottering along at lower speed there may not be an immediate need to brake , and in the case of those around Reading , they are more useful for knowing how far the route is set in advance. Link to post Share on other sites More sharing options...
AberdeenBill Posted November 29, 2015 Share Posted November 29, 2015 Some interesting banner signals on the down fast line through Rugby on this Youtube clip https://www.youtube.com/watch?v=M_YnD0O8Ku0 Note some are green when "off", and a bit further north they are white when "on or off" (at the junction signal). The white arrow on the first green banner one is interesting. I presume it means the repeated signal (ahead) is clear for the straight (main) route. There is also an interesting illuminated arrow on its own 13 secs into the clip - and its on the right hand side of the line, presumably for high speed sighting. A Pendolino driver needs to be fully alert when cruising through Rugby !. Brit15 Impressive stuff. Just out of interest, what was the speed limit at Rugby in steam days?? Bill Link to post Share on other sites More sharing options...
RMweb Gold big jim Posted November 29, 2015 RMweb Gold Share Posted November 29, 2015 Some interesting banner signals on the down fast line through Rugby on this Youtube clip https://www.youtube.com/watch?v=M_YnD0O8Ku0 Note some are green when "off", and a bit further north they are white when "on or off" (at the junction signal). The white arrow on the first green banner one is interesting. I presume it means the repeated signal (ahead) is clear for the straight (main) route. There is also an interesting illuminated arrow on its own 13 secs into the clip - and its on the right hand side of the line, presumably for high speed sighting. A Pendolino driver needs to be fully alert when cruising through Rugby !. Brit15 the arrow on its own (13 secs) is the PRI (preliminary route indicator) to tell the driver he is going straight on rather than diverging to the left or right into a platform similarly the green banner witht eh PRI arrow is telling him hes also going straight on and the next signal is green, if it was a double yellow on the same route the banner would be white but still with the arrow lit, if the train was going to birmingham the banner could still be green but the PRI arrrow will point to the left instead PRI's basically allow a faster aproach to a diverging junction, platform etc without the need for the train to be 'bought down' on restrictive aspects or indeed flashing aspects Link to post Share on other sites More sharing options...
SM42 Posted November 29, 2015 Share Posted November 29, 2015 The green arrow is I believe a preliminary route indicator to give the driver a clue as to what route they are going to take at the junction ahead and whether they need to think about slowing down or keep the power on. Andy Ah! I see we crossed in the post Jim but a far better explanation by far. Thanks. Link to post Share on other sites More sharing options...
Edwin_m Posted November 30, 2015 Share Posted November 30, 2015 Isn't the PRI only used when there is no significant speed difference between the routes, but the driver might need to know which route is set for some other reason such as lack of electrification/clearance/route availability? If there is a speed difference, or more than 10mph IIRC, then the driver is warned by flashing aspects or approach control, supported by AWS/TPWS, to ensure compliance with the relevant junction speed restriction. Link to post Share on other sites More sharing options...
RMweb Gold big jim Posted November 30, 2015 RMweb Gold Share Posted November 30, 2015 i dont think thats the case, for example birmingham international has them, straight through the middle platform (straight ahead arrow) is 75mph but the diverging route (left hand arrow) into a back platform across 'high speed' points is 40mph, however to cross over via the 30mph crossover from the down to the up (and vice versa) you are bought down on restrictive aspects (aproach release) to the junction signal similarly aynho jn, its 90mph aproaching it from banbury on the up line and 90mph onto the chilterns, you get a green with no 1 route indicator at the jn with the associated PRI before it pointing left, the main line towards oxford is 75mph at the junction and you get a green on its own the associated PRI showing the 'straight on' arrow if you are going that way, that set up replaced 'flashing yellows' for the chiltern line from when the junction was 60mph Link to post Share on other sites More sharing options...
RMweb Premium HillsideDepot Posted November 30, 2015 RMweb Premium Share Posted November 30, 2015 Some interesting banner signals on the down fast line through Rugby on this Youtube clip https://www.youtube.com/watch?v=M_YnD0O8Ku0 Note some are green when "off", and a bit further north they are white when "on or off" (at the junction signal). The white arrow on the first green banner one is interesting. I presume it means the repeated signal (ahead) is clear for the straight (main) route. There is also an interesting illuminated arrow on its own 13 secs into the clip - and its on the right hand side of the line, presumably for high speed sighting. A Pendolino driver needs to be fully alert when cruising through Rugby !. Brit15 That clip certainly shows why a driver needs route knowledge! Did else anyone notice that the Freightliner 90 (1:54) appeared to have its marker lights illuminated on the trailing end? Link to post Share on other sites More sharing options...
RMweb Gold The Stationmaster Posted November 30, 2015 Author RMweb Gold Share Posted November 30, 2015 The whole purpose of PRIs has evolved since the first one appeared a bit over 20 years ago. The main idea - as Jim explained in his first post - is to allow junction divergence speeds to be exploited to the maximum by letting the Driver know in advance which way his train will be going in a situation when the aspect control sequence (and hence aspects he receives) might otherwise require him to reduce speed below the junction turnout speed. The situation with banner repeaters seems to have got thoroughly confused or misunderstood - the whole purpose of a banner repeater is to inform a Driver that an awkwardly sited signal is showing a proceed aspect as he brakes towards it expecting to find it at danger. Thus the addition of the green makes sense because it tells a Driver that not only is the signal displaying a proceed aspect but that it is displaying a green instead of a more restrictive aspect. The purpose of a banner repeater is therefore not so much intended as an aid to braking (in anticipation of a succession of more restrictive aspects) but as an aid to acceleration (when approaching a signal which could reasonably have expected to be at danger from the aspect displayed by the signal in rear). If Drivers are starting to rely on banner repeaters as an advance indication of the need to start braking, or at least to reduce power, then there is something wrong with the spacing of the signal which is being repeated as that is its purpose. Link to post Share on other sites More sharing options...
RMweb Gold beast66606 Posted November 30, 2015 RMweb Gold Share Posted November 30, 2015 A green banner demonstrating it's use (for those not already in the know) Link to post Share on other sites More sharing options...
RMweb Premium Richard E Posted November 30, 2015 RMweb Premium Share Posted November 30, 2015 When Peterborough was updated last year and the platforms extended it seems it was found that the up starter on platform 3 (which is also used for high speed through running with a 100mph limit) could not be seen for a sufficient distance from the north. There is, therefore, a banner repeater at the north end of the platform exactly like that pictured by Beast in his post above. The diverging routes from the north through platforms 1, 2, 4, 5, 6 and 7 are not so equipped as they have much more restrictive speed limits and are not used for through running at speed. Link to post Share on other sites More sharing options...
Mike Storey Posted November 30, 2015 Share Posted November 30, 2015 If anyone is looking to model these, St Simon is producing a couple of versions on his Shapeways 3D site. Link to post Share on other sites More sharing options...
Rugd1022 Posted November 30, 2015 Share Posted November 30, 2015 The new green banner repeaters are certainly a Godsend from a Driver's point of view, there are dozens of them on my route card now, none of which I can fault in their placement or intent. Approaching Watford Tunnel on the Up Slow before the new banner was installed was often a little hairy if you were following an Up stopper with a very heavy train, I'd always anicipate receiving two yellows just round the corner out of sight before entering the tunnel, but now, with the green banner in place it means I'm not braking too soon and not having to waste (expensive) fuel to regain my momentum. At night, the extra 'green glow' on the rails where you'd previously see only a 'white glow' is certainly very welcome. For us lowly freight type chappies there is still an element of 'hanging back' in certain locations but these new banners are all about keeping the job moving where a bottleneck might otherwise prevail. There is one on the Down Fast just south of Flitwick which when I first saw it thought that's an odd place to put one', but on the rare occasions I'm on the fast line with a freight it has been very much appreciated! Link to post Share on other sites More sharing options...
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