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Post by Deleted on Feb 9, 2011 11:01:43 GMT
Disclaimer: I'm new to reading signal diagrams and hope what I'm saying is not daft - thanks for your patience!I've been looking at the fascinating Earl's Court diagram.. www.trainweb.org/districtdave/Earls_Court_Diag.jpg to try to get a better understanding of some operations at this fascinating station. From what I can tell crossover 17 to the east of Earl's Court is the one used for early morning reversers (from eb platform 2 back into westbound platform 3), presumably then awaiting green at EC13 to indicate (among other things) that the points are correctly set for that westbound crossover manoeuver. Recently I saw that a westbound train had terminated at ECT, its dot-matrix was showing Dagenham East and the train was beginning to head eastbound in darkness/out of service (not sure of the appropriate acronym for this!) just as my train left pfm4, so I wasn't able to see whether that train was using crossover 17 (I presumed it couldn't go further east without doing so). I wondered whether it would continue to Gloucester Rd to begin service there or would be stopping and reversing into pfm2 to start eastbound service at ECT (this seemed unlikely given that it would require stepping back twice - and I wasn't sure whether EC13 could even indicate a route set back into pfm2). However from the diagram I imagined EC16 may be used to indicate whether the crossover is set for west-east use. Am I right? Thanks for any guidance. karona
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Post by Dstock7080 on Feb 9, 2011 11:11:16 GMT
Earl's Court 'yard' (as it's called locally) is the ability to do a main-line shunt. (in the diagram it's limits are between EC13 to the east, and EC18 to the west)
From the yard you can go back WB only into pfm3 using shunt signal EC18.
What you saw was a WB train reversing to the EB main via coloured light signal EC16. It would have continued to Gloucester Road and could actually carry passengers, although they rarely do.
The "EC13" you are probably referring to is actually fog repeater FREC13 - which faces EB trains departing pfm2 (repeating the aspect of EC13).
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Post by Deleted on Feb 9, 2011 15:03:10 GMT
Great stuff Dstock7080 - that's instantly cleared up a number things. For a start I hadn't realised what the "FR" prefix meant! Now I just need to find out what that "ECX"(697) is all about So technically EC16 would be termed a "station starter" to head eastbound via that crossover? Since it is a coloured light signal without the usual 3-light route indicator, I presume a green aspect shown there must imply that the train will always cross to that eastbound track and never continue on the same track that arrives in pfm3. I imaging there would be a lit symbol or other signage there which tells drivers that, unless that type of thing is just a known characteristic of the line. This may not be the right forum to address such a thing, but I had been curious how a shunt signal can exist in the contraflow to a normal line use and not confuse the safety systems with every train that passes. Earl's Court is endlessly fascinating - and I was so pleased to find that layout image to answer questions such as "how did two Wimbledon-bound trains simultaneously leave from pfm3 & 4 and trundle along together for a while before one appeared to give up!?" (I now know). Thanks again
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Post by railtechnician on Feb 9, 2011 15:57:34 GMT
Great stuff Dstock7080 - that's instantly cleared up a number things. For a start I hadn't realised what the "FR" prefix meant! Now I just need to find out what that "ECX"(697) is all about So technically EC16 would be termed a "station starter" to head eastbound via that crossover? Since it is a coloured light signal without the usual 3-light route indicator, I presume a green aspect shown there must imply that the train will always cross to that eastbound track and never continue on the same track that arrives in pfm3. I imaging there would be a lit symbol or other signage there which tells drivers that, unless that type of thing is just a known characteristic of the line. This may not be the right forum to address such a thing, but I had been curious how a shunt signal can exist in the contraflow to a normal line use and not confuse the safety systems with every train that passes. Earl's Court is endlessly fascinating - and I was so pleased to find that layout image to answer questions such as "how did two Wimbledon-bound trains simultaneously leave from pfm3 & 4 and trundle along together for a while before one appeared to give up!?" (I now know). Thanks again EC16 is a 'wrong road starter' having only one route as you correctly deduce and as it is a 'running signal' allows the carriage of passengers. Were EC16 to be a shunt signal passengers could not be carried over 17W. The move from EC16 is a 'known' so no additional signage or indication to tell the driver he is making a 'reverse' move.
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Post by Deleted on Feb 9, 2011 16:39:21 GMT
EC denotes the signal control area, IMR, signalbox, whatever it be. The X in a signal number represents semi-automatic, and cannot be passed under the driver's own authority, as it can be held at danger for many reasons; they are in a 'controlled area' normally around points and/or have other triggers, such as floodgates and surface stock detectors.
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Post by railtechnician on Feb 9, 2011 17:16:44 GMT
EC denotes the signal control area, IMR, signalbox, whatever it be. The X in a signal number represents semi-automatic, and cannot be passed under the driver's own authority, as it can be held at danger for many reasons; they are in a 'controlled area' normally around points and/or have other triggers, such as floodgates and surface stock detectors. The X does not mean semi-automatic, every signal on that diagram is in the controlled area and all are semi-automatic! An X signal does indicate approach to something! A plain X signal i.e. X855 indicates outer approach to a computer controlled area. Floodgate signals will be prefixed e.g. FPX for Piccadilly or FNX for Northern etc and possesion signals will be prefixed PNX. ECX697 indicates approach to the draw up signal EC600.
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Post by Deleted on Feb 9, 2011 17:55:29 GMT
Hmm, need to brush up on signal IDs by the sound of it, I was rather sure on that.
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Post by Deleted on Feb 9, 2011 18:21:20 GMT
A simple X signal (such as the ECX one mentioned) is an Automatic signal that MUST be treated as a semi automatic from a Rules point of view.
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Post by Deleted on Feb 9, 2011 22:08:07 GMT
Thank you so much for those explanations.
Final query if I may (I hope no-one minds this, but since the answers are coming so quickly, this is clearly the place to ask) - and again these things are going to be obvious to the professionals here.
I found it difficult to see the purpose of EC10 which appears to be just past crossover 5 but before ECT pfm2. I had initially imagined it was used as a "last resort" to stop a SPADing train, but then with EC9a & b before it - and it being _after_ the crossover on that diagram, I guessed that wouldn't help much since a train that wasn't supposed to be there might have already gone across the points.
a) Is a train coming from West Brompton ever deliberately held at EC10? I had imagined 9a or 9b would be the normal stopping point. b) Would a train from Olympia/West Ken ever be held in that crossover if the platform ahead is occupied? Or does EC4 before it only clear when EC10 is clear?
If trains are never held at EC10 for either of those approach routes, then I had wondered whether even the repeaters on both lines approaching the crossover are at all useful since surely the signal prior (EC4, or 9b depending on origin) would already give the same indication each time - unless EC10 is just useful for telling you that the platform has cleared and so you'll soon be on the move?
Ok - that's a multi-part query but after this that's probably everything I had ever wondered about the signalling around that area! Thanks again.
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Post by Dstock7080 on Feb 9, 2011 22:50:41 GMT
Going back to your original query, of the 'yard' - if a train was being held at either EC13 or waiting to come WB via shunt signal EC16, it would not be advisable to allow the train to approach pfm2 and EC11 at full speed!
Therefore, EC10 is used to protect a train held in the 'yard'.
Yes, approaching from EC4 and EC9B you can get held at EC10.
To pre-empt a further question about this area!! EC250, EC300 and EC330 (indeed EC280 and EC600 too) should clear when an approaching train is proved to be travelling slow enough.
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mrfs42
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Post by mrfs42 on Feb 10, 2011 1:27:41 GMT
EC 10 will also allow a quicker approach [1] into platform 2 as it only requires TCs clear to the block joint in advance of EC 18 and that 12 A, 19 and 17 B are normal. I think the majority of its function is to allow trains to close up on the approach. [1]I think [2] if it wasn't there things would be tied up as far back as EC 9 B and EC 4 until a train had trundled past EC 7 or EC 13. [2]It is a bit early in the morning to think about such things!
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Post by Deleted on Feb 10, 2011 6:47:20 GMT
It is a bit early in the morning to think about such things! You're not wrong! Thanks again for this wonderful insight - what a superb forum.
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Post by kingdinger on Feb 10, 2011 16:14:29 GMT
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Post by Deleted on Feb 10, 2011 17:01:06 GMT
My my - that diagram is very interesting! A few things there that I don't understand (such as what "19" would be for) but it does make the junctions a lot clearer. I had never seen one of these and I can see there are a whole load more of these covering other parts of the line, but it's presumably from a training book rather than something available to the public. I'm very grateful for that info.
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Post by Deleted on Feb 10, 2011 17:45:09 GMT
My my - that diagram is very interesting! A few things there that I don't understand (such as what "19" would be for) but it does make the junctions a lot clearer. I had never seen one of these and I can see there are a whole load more of these covering other parts of the line, but it's presumably from a training book rather than something available to the public. I'm very grateful for that info. 19 points are part of the wide gauge points, the go back to platform 3
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Post by Deleted on Feb 16, 2011 7:43:31 GMT
There's another interesting little "glitch" with the signalling in this area, that if a train is supposed to be reversing in the yard but (either in error, or by the programme machine) EC13 is cleared, a release cannot be taken to clear the shunt instead and the train HAS to be worked EB to Gloucester Road.
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Post by Deleted on Feb 17, 2011 18:07:16 GMT
My my - that diagram is very interesting! A few things there that I don't understand (such as what "19" would be for) but it does make the junctions a lot clearer. I had never seen one of these and I can see there are a whole load more of these covering other parts of the line, but it's presumably from a training book rather than something available to the public. I'm very grateful for that info. this is the site diagram for the programme machines aetearlscourt.fotopic.net/p15106346.htmlalso the wide to gauge points are 17b and 19 (2 single chairlock units)
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