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Some specific signals 17/11/2011 at 01:10 #23104 | |
dmaze
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76 (on the down main line, departing Highbridge and Burnham): should this be an automatic signal? If not, should it have an "A" button? What's the deal with shunt signal 612 anyways? SA38R (the repeater leaving Severn Beach): always seems to be yellow, even if the home signal SA38 shows green. Is this prototypical? (The repeater/distant signal distinction always seemed a little odd to me.) Similarly, is there a reason most of the signals on the Avonmouth line don't seem to show green? UB106A (first signal on the up Badminton line past Westerleigh Junction): shows red if the points at Westerleigh are set for the up Charfield line; why? DT2 (last signal on the down Trowbridge line before the repeater/home signals for Bathampton Junction): should it have an "E" button, if someone calls in and the signaller needs to protect the Claverton LC? 538 (reversing shunt signal on the up Filton line at Lawrence Hill GF): wrong-line running seems to be permitted from here to signal 540 at Dr. Day's Junction; why here but not in general? Log in to reply |
Re: Some specific signals 17/11/2011 at 01:42 #23106 | |
jc92
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signals are only automatic, or supplied with an auto button as per the real box so 76 shouldn't be manual. i cant explain the purpose of 612 routing from 538 only allows wrong road running as far as barton hill depot, so presumably is signalled with position lights to keep speed down. "We don't stop camborne wednesdays" Log in to reply |
Re: Some specific signals 17/11/2011 at 02:00 #23109 | |
AndyG
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Signal 76 is manual, as I understand it used to protect the entrance line to a MoD depot. The line and points may well have gone, but the button is left 'as is' on cost grounds no doubt.
I can only help one person a day. Today's not your day. Tomorrow doesn't look too good either. Log in to reply |
Re: Some specific signals 17/11/2011 at 06:06 #23113 | |
pilotman
![]() 189 posts |
I don't know this sim, but usually signals are held at a restrictive aspect because of Approach Control (do they still call it that?) See Clive's excellent web pages for a full explanation Ray Log in to reply |
Re: Some specific signals 17/11/2011 at 07:17 #23114 | |
Late Turn
![]() 697 posts |
" said:SA38R (the repeater leaving Severn Beach): always seems to be yellow, even if the home signal SA38 shows green. Is this prototypical? (The repeater/distant signal distinction always seemed a little odd to me.) Similarly, is there a reason most of the signals on the Avonmouth line don't seem to show green? Distant signals fixed at caution (as SA38R appears to be) aren't all that uncommon - they're usually provided where there's no great benefit to providing a working distant, generally where the linespeed's low. In this case, all I can think is that SA38 signal generally won't be cleared until the train occupies the berth track circuit (otherwise how do you know it's left Severn Beach?) to avoid tying up the junction beyond, by which time it will already have passed the distant anyway. There's not really a distinction between distant and repeater (I believe they're all formally referred to as distant signals nowadays?) - the main thing is that neither is capable of displaying a red aspect! Quote: UB106A (first signal on the up Badminton line past Westerleigh Junction): shows red if the points at Westerleigh are set for the up Charfield line; why? I seem to remember this is to do with preventing a Driver approaching 115 signal (in rear of Westerleigh Jn) and 'reading through' to UB106A signal. Not sure why this is only a concern when the points have been swung towards Charfield - perhaps because of the possible the consequences of a SPAD at 115 signal (and thus over the low speed connection to the Up Charfield)? Quote: 538 (reversing shunt signal on the up Filton line at Lawrence Hill GF): wrong-line running seems to be permitted from here to signal 540 at Dr. Day's Junction; why here but not in general? Presumably at the design stage, the need for a (relatively short) signalled wrong-direction movement (only a shunt route too) was identified, and the benefit of providing this outweighed the cost. Obviously this wasn't the case for full bi-directional signalling throughout the scheme! Log in to reply |
Re: Some specific signals 17/11/2011 at 10:12 #23123 | |
headshot119
![]() 4869 posts |
" said:" said:The major difference is that a distant tells you that all signals are cleared for your train through an Absolute Block section. A repeater only indicates the aspect of the next signal.SA38R (the repeater leaving Severn Beach): always seems to be yellow, even if the home signal SA38 shows green. Is this prototypical? (The repeater/distant signal distinction always seemed a little odd to me.) Similarly, is there a reason most of the signals on the Avonmouth line don't seem to show green? "Passengers for New Lane, should be seated in the rear coach of the train " - Opinions are my own and not those of my employer Log in to reply |
Re: Some specific signals 17/11/2011 at 10:20 #23124 | |
Late Turn
![]() 697 posts |
I think they're all referred to as distant signals nowadays, irrespective of whether it's associated with a single stop signal in a TCB area or four stop signals on the approach to a mechanical box - happy to be corrected if necessary. To be pedantic, a distant signal indicates that all associated signals are cleared - in a semaphore signalled AB area, this usually means all signals through station limits reading into the next block section.
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Re: Some specific signals 17/11/2011 at 10:27 #23125 | |
y10g9
![]() 895 posts |
I'll start from the begining and hopefully tie what everyone has said together Signal 76, As andy said there used to be some sidings there. These have infact been lifted, and it just happens that its been found easier or cheaper to not put an auto on that signal. it also does give the weston pannel operator something to do. SA38R, i can offer no better explination to what Late Turn has said. haven't managed to get out to severn beach via train so i haven't had a look at whether the repeater has once aspect, or 2 or even is its not a signal board at all but rather a fixed stopping board. UB106A, you will prob find that this signal able to be clearly sited from westerleigh jn. Having been over that junction a few times before, i do remember that the badminton lines are on an embankment at that point and the charfield lines make a rather large 90 degree turn (if not more) with the lines dropping down the hill. The auto signal will turn to red to prevent the driver from misreading a green signal which doesn't apply to him. DT2. the simple answer is no. emergency buttons aren't for protecting a crossing. they are simply for emergency use only. However if your saying that DT2 should have one, then surely DT5 (Avoncliff), UT3 (between youngs and fishers crossings), uc114 and dc113 (signals either side of charfield hall farm crossing), um 129 (near yatton), and um148 and um147 (between bridgewater and highbridge) should all have emergency indicators as these are all auto signals that could protect crossings? That one could of been thought through a bit better before asking it. 538 routing wrong line. yeah thats fine. its seen as an official signalled move. If you play the 2009 tt by noisynoel you will have to use that route. there did used to be crossovers at that point back in the 1980s but therse wer obviously ripped out (as not shown on the map) but it was ound a route was needed here. it does mean that Light engines coming out of there to go to either kingsland road or barton hill or even further afield don't have to go via filton abbey wood. siganl 538 is only 200 meters or so away from the platform of lawrence hill so it is only about a 300m worng line move. not like hes going 10 miles on the wrong line. Log in to reply |
Re: Some specific signals 17/11/2011 at 10:56 #23127 | |
jc92
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the term repeater HAS been removed from the rulebook and replaced with distant again quite a few years ago. many signals still have R or RR suffixes, simply becuase its too expensive to bother re plating them, the current correct symbol is a white triangle on a black plate. the definition now of a distant signal is a signal which cannot display a stop aspect irrespective of method of working. this taken from my evening mutual improvement class notes from york "We don't stop camborne wednesdays" Log in to reply |
Re: Some specific signals 17/11/2011 at 11:24 #23128 | |
clive
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I know this isn't the official definition, but I always viewed the distinction as: "Repeater - an automatic signal that can't show red." "Distant - a signal that can't show red and which can be controlled to its most restrictive aspect by the signaller." In both cases the actual aspect shown is determined by the aspects of one or more associated signals and/or by track circuits. The current official definition on the big railway is in GK/GN0802 issue 1 (April 2004): Distant Signal: A Signal (not itself a Stop Signal) capable of displaying a Cautionary Aspect that informs the driver of the state of the Signals or Level Crossing ahead. Repeater Signal: A Signal (not itself a Stop Signal) capable of displaying a Cautionary Aspect, that informs the driver about the state of the next stop Signal ahead. Non-preferred term for a Distant Signal. The previous definition was in GK/RT0002 issue 1 (July 1995): DISTANT SIGNAL: A SIGNAL (not itself a STOP SIGNAL) capable of displaying a CAUTIONARY ASPECT and controlled by a SIGNALMAN, that informs the driver about the state of the signals ahead, usually on the APPROACH TO a STOP SIGNAL. REPEATER SIGNAL: A SIGNAL (not itself a STOP SIGNAL) capable of displaying a CAUTIONARY ASPECT, that informs the driver about the state of the next stop signal ahead. Log in to reply |
Re: Some specific signals 17/11/2011 at 15:12 #23145 | |
Forest Pines
![]() 525 posts |
" said:I also don't know about the specific signal in question, but there is at least one other distant signal on the Bristol sim that is actually a board: the first signal seen by trains coming from Portbury Dock and approaching the Ashton Gate level crossing. Its location is just south of the old Clifton Bridge station platforms - somewhere I have a photo but it's of utterly awful quality. Log in to reply |
Re: Some specific signals 17/11/2011 at 15:23 #23147 | |
Stephen Fulcher
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" said:I'll start from the begining and hopefully tie what everyone has said togetherAnother issue to consider here is that generally speaking, emergency replacement switches on 1960s Western Region interlockings cannot be relied upon. I cannot remember 100% why but I think it has something to do with there not being a direct indication back to the box or something similar. Firefly or Geoff will no doubt know the total reason. As this is the case, the use of these signals to protect a crossing would not be allowed anyway, and in reality the Signalmen would just use the previous controlled signal. Modern SSI interlockings have replacement facilities which can be relied upon, and as such are often used to protect crossings. Log in to reply |
Re: Some specific signals 18/11/2011 at 23:56 #23257 | |
dmaze
![]() 88 posts |
" said:DT2. the simple answer is no. emergency buttons aren't for protecting a crossing. they are simply for emergency use only.What's the right way in general to manage level crossings, then? Set a reminder at the nearest preceding controlled signal? In this specific case, do I need to BLOK the down Trowbridge line from Westbury? (Thanks to everyone for the other answers, this is pretty informative!) Log in to reply |
Re: Some specific signals 19/11/2011 at 05:40 #23261 | |
Firefly
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Quote:Another issue to consider here is that generally speaking, emergency replacement switches on 1960s Western Region interlockings cannot be relied upon. I cannot remember 100% why but I think it has something to do with there not being a direct indication back to the box or something similar. Firefly or Geoff will no doubt know the total reason. As this is the case, the use of these signals to protect a crossing would not be allowed anyway, and in reality the Signalmen would just use the previous controlled signal.In order for a signal replacement to be relied upon it must be proved to be alight and exhibiting a red a aspect. Prior to SSI this would mean sending an ON proving indication circuit back to the control point and it was rarely done due to the costs involved. Secondly a lot of signal replacement controls were transmitted over non-vital FDM systems which could in theory fail "wrong side". FF Last edited: 19/11/2011 at 05:41 by Firefly Log in to reply |
Re: Some specific signals 19/11/2011 at 11:31 #23269 | |
Steamer
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" said:That's up to your conscience! I suppose the 'correct' answer is, replace and place a reminder (collar) on the nearest controlled signals. I would also recomend collaring the crossing (you can place a reminder on the RAI-WKG-FAI lights of an AHB, or the TEL/MWL text) as an extra reminder. Or you could use the emergency buttons, which will always work correctly in SimSig. In the specific case you mentioned, BLOK doesn't work, however provided nothing has entered at Bradford Junction when you give permission to cross, the crossing will be clear by the time the train gets there. "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) Log in to reply |