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| Do they turn signals off to save power? 13/12/2011 at 13:21 #25082 | |
maxand
1637 posts |
I know this may sound ridiculous, but... Last week a single light signal along a double-track suburban line seemed to be working OK, but today it seemed as dead as a doornail and the driver just ignored it. There's a TC box next to it (break in the rail too). No sign of conduit box forced open with miles of copper wire missing. Just wonder if authorities ever turn non-essential signals off like this to save money? Signals further down the track at a crossover seemed to be working OK. Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 13:33 #25085 | |
headshot119
4869 posts |
In the UK signals are not turned of to save power. The only case I can think of is signals that are "approach lit" usually found in goods loops, they don't light until a route is set towards them, or from them. This is to prevent drivers reading the signal as though it was on the main route. An example of this is signal 121 on Gloucester, in the Up Goods Loop at Haresfield. "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: Do they turn signals off to save power? 13/12/2011 at 13:41 #25090 | |
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clive
2789 posts |
There are approach-lit signals in some places in the UK, though it's not to save power, it's to prevent a driver being confused by a red signal in an awkward place. In the US automatic signals in remote areas used to only light up if either a train was approaching or they would show not-green; this was purely to save battery life. Are you sure the signal you're referring to applied to the track your train was on? If so, then it's puzzling. The most likely explanation is that the signal has been decommissioned. In the UK that would involve a big white X over the head until they got round to removing it, but perhaps the rules are different over there. I certainly wouldn't expect the rule to be "treat this signal as green when unlit" because of the obvious risks. I suggest you ask a driver. Related to this, though, is the South African ghost signal: "Just before Virginia, where the Glen Harmony branch reaches the main-line, all trains come to a halt at a 'spooksinjaal'. Drivers have to contact Virginia cabin on the radio and they give him authority to pass this signal at danger. The thing is there is no signal here any more! Only the concrete foundation rings remain! We were told that this signal went AWOL a while back and has never been replaced. It is still regarded as a red signal though." Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 15:46 #25163 | |
GeoffM
6376 posts |
" said:In the US automatic signals in remote areas used to only light up if either a train was approaching or they would show not-green; this was purely to save battery life.Not just remote areas and not just auto signals. I remember standing at a station in metro Chicago with four tracks running through, 3-lamp signals (I forget the name) so 12 lamps in total. All dark until a train passed the previous signal (you could see it approach) and then the whole array lights up - mostly red in this case, except for the train itself. Like a billboard made of lamps. All tracks are required to light to ensure the driver knows which is his. Obviously no lamp proving from the previous signal in this case. [Point of interest: dispatched from 825 miles away] Another, slightly more rural example was a double track ending just before a short platform, then double track again. Signal at end of double track and end of single track, but under 100m apart and the second signal is clearly visible whilst looking at the first. Again, the second signal only lit when the train passed the first signal which can be a little unnerving if you're not used to it. SimSig Boss Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 17:19 #25171 | |
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kbarber
1742 posts |
Historically, the LNER installed approach-lighted signals north of York in the 1920s or 30s, but I believe they were all superseded by continuously-lit signals by the end of the '30s (I have a copy of a report, somewhere, on the opening of the OCS panel at Northallerton - which was September 3rd 1939 - and I think it was there that I saw a reference to the replacement of the last approach-lit signals). I believe the original motivation for their installation was indeed saving of power, although it was considered an advantage that they suddenly became illuminated after the train passed the preceding signal, as the sudden appearance was considered to grab the driver's attention. Since then, as Clive and Headshot119 say, they've only been provided where they mitigate a risk of read-through.
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| Re: Do they turn signals off to save power? 13/12/2011 at 18:31 #25178 | |
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TomOF
452 posts |
Yoker has one (YF149 I think) and so does Paisley. The former is on a passenger line and will illuminate when either a route is set towards it or the approaching tracks become occupied for any other reason.
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| Re: Do they turn signals off to save power? 13/12/2011 at 18:36 #25180 | |
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Sam Tugwell
494 posts |
Could Approach lighting be implemented into Simsig?
"Signalman Exeter" Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 18:43 #25181 | |
jc92
3685 posts |
it has been- on gloucester?
"We don't stop camborne wednesdays" Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 18:58 #25182 | |
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Sam Tugwell
494 posts |
Note to self. Read all of thread before posting 
"Signalman Exeter" Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 19:14 #25186 | |
Peter Bennet
5402 posts |
And a few in Edinburgh, Inverkeithing Fife line UP loop for one. Peter I identify as half man half biscuit - crumbs! Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 19:18 #25188 | |
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jc92
3685 posts |
not all semaphores are backlit 24/7 if this counts towards conversation.... also brancliffe east had approach lit distant signals before it was resignalled under worksops control... i havent a clue why. "We don't stop camborne wednesdays" Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 19:36 #25191 | |
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UKTrainMan
1803 posts |
On the subject of this thread, by chance I was just thinking about signal failures today and in the case of lamp failures I'm wondering if leaving the signals lit almost all of the time (except during any works where they need to be turned off or disconnected, etc.) is part of the cause of a lamp failure because it wears down/out the filaments? Just wondering.
Any views and / or opinions expressed by myself are from me personally and do not represent those of any company I either work for or am a consultant for. Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 19:42 #25194 | |
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Stephen Fulcher
2078 posts 
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It is indeed, however there are two points worth noting here: 1. Lamp failures are disproportionately common in SimSig 2. There is a backup filament to generally prevent WSFs on signals, and an alarm is activated (either to the Signalman or Technician depending on individual installation) whenever a "First Filament Failure" occurs, and the Technician will replace the lamp before the Auxiliary filament has had a chance to fail. Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 20:33 #25205 | |
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stuartpalmer
14 posts |
We have a passing loop at Carrbridge where the signals are switched off when the loop is "switched out" - not quite "to save power" as the original poster discussed, but nevertheless an interesting curiosity at a passenger platform. Whether or not the loop signals are turned on is also a valuable guide to which platform your train might be using, as both are used in both directions. It's rather odd watching the train you have just alighted from depart - the green signal turning red as the train passes and then turning off as it clears the loop points. Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 20:54 #25217 | |
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Peter Bennet
5402 posts |
" said:We have a passing loop at Carrbridge where the signals are switched off when the loop is "switched out" - not quite "to save power" as the original poster discussed, but nevertheless an interesting curiosity at a passenger platform. Whether or not the loop signals are turned on is also a valuable guide to which platform your train might be using, as both are used in both directions.Sounds like it's an approach lit signal. Peter I identify as half man half biscuit - crumbs! Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 21:05 #25228 | |
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Peter Bennet
5402 posts |
" said:" said:Hmm the loop signals at Kincraig, Slochd, Tomatin and Moy are noted as Approach lit but not Carrbridge.We have a passing loop at Carrbridge where the signals are switched off when the loop is "switched out" - not quite "to save power" as the original poster discussed, but nevertheless an interesting curiosity at a passenger platform. Whether or not the loop signals are turned on is also a valuable guide to which platform your train might be using, as both are used in both directions.Sounds like it's an approach lit signal. Peter I identify as half man half biscuit - crumbs! Log in to reply |
| Re: Do they turn signals off to save power? 13/12/2011 at 22:59 #25328 | |
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maxand
1637 posts |
Thanks for your interest in this. I rang Metro Trains to see what they had to say, but as their supervisor had difficulty getting through they gave me a job number and promised to get back to me. I'll let you know if I hear from them.
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| Re: Do they turn signals off to save power? 14/12/2011 at 10:12 #25442 | |
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kbarber
1742 posts |
One further variant: a number of early panels had bright/dim switches so the signal light intensity could be reduced when required at night. Barking (1960ish) was certainly one. The signalman demonstrated it but I must admit I could see no difference in brightness and I believe by that time (1978) it was pretty much out of use; it was suspected it was provided in case of war, to reduce the visibility of the signals to potential enemy bombers (remember those schemes were being designed within 10 years of the end of WWII and in many cases covered areas that had suffered in the Blitz).
Last edited: 14/12/2011 at 10:13 by kbarber Log in to reply The following user said thank you: maxand |
| Re: Do they turn signals off to save power? 14/12/2011 at 18:26 #25494 | |
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stuartpalmer
14 posts |
" said:The difference possibly being that Carrbridge is an active station (although for how much longer we sometimes ask!) and the signallers do try to get the trains into the loop (which serves the platform nearer the road) for passenger convenience when they can, even if there's no crossing traffic. Waiting for a train to arrive, you can sometimes see the signals being switched on and off as the signaller tries to make up his mind! Unless the approaching train is doing something very odd, I don't think it's a simple approach lit situation. Log in to reply |
| Re: Do they turn signals off to save power? 14/12/2011 at 18:54 #25499 | |
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Firefly
521 posts |
Approach Lit signals light up when a route is set towards them. Therefore you are correct that it's the signaller making up his/her mind that causes the signal to light and extinguish. Quote: I don't think it's a simple approach lit situation.This is the simple approach lit situation :) FF Log in to reply |
| Re: Do they turn signals off to save power? 14/12/2011 at 21:21 #25571 | |
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button_pusher
56 posts |
Regarding FFFs: On SSI areas, FFF should automatically be reported by the interlocking and recorded on a print-out at the techs. terminal. On older installations they sometimes grouped signals into 4 e.g. 101, 102, 103 and 104. There is then a panel placed in the main relay room (usually under the controlling signal box OR when the S&T spend most of their time). When a FFF is detected then it drops the group relay out (EKR/ECPR dependent on the area). This then lights up the group on the board. The technician then either watches trains through on the panel with someone resetting the FFF board (usually on cold winter days!) or goes out to site and watches the EKR/ECPR relay whilst trains pass (a nice way to spend a summers day!). Dependant upon local instruction as well, the main aspect (i.e. the one that is normally lit green in an auto section/red in a controlled section) is sometimes replaced on the annual service. Log in to reply |
| Re: Do they turn signals off to save power? 15/12/2011 at 07:15 #25582 | |
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maxand
1637 posts |
Gee that reminds me of a poem that appeared in The Bulletin, a Sydney weekly magazine, many years ago, complete with accompanying cartoon. Australian wheat is FAQ Australian bread is NBG When given to pigs they BOQ Or if they don't it's RIP. BTW, I got a call from them on the Al Capone to say E333 was U/S and not reported, so they were sending someone round to have a butcher's.
Last edited: 15/12/2011 at 07:27 by maxand Log in to reply |
| Re: Do they turn signals off to save power? 15/12/2011 at 07:27 #25583 | |
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stuartpalmer
14 posts |
" said:Approach Lit signals light up when a route is set towards them.Thanks for clarifying that - I had taken it from the earlier discussion that "approach lit" meant they somehow detected the approach of a train (like "approach controlled"). Route setting makes far more sense and yes - I now think we have approach lit signals at Carrbridge! Log in to reply |
| Re: Do they turn signals off to save power? 15/12/2011 at 14:19 #25599 | |
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Firefly
521 posts |
SSI = Solid State Interlocking FFF = First Filament Failure EKR = Lamp Indicating Relay ECPR = Lamp Proving Repeat Relay
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| Re: Do they turn signals off to save power? 15/12/2011 at 20:29 #25613 | |
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Ron_J
331 posts |
" said:One further variant: a number of early panels had bright/dim switches so the signal light intensity could be reduced when required at night. Barking (1960ish) was certainly one. The signalman demonstrated it but I must admit I could see no difference in brightness and I believe by that time (1978) it was pretty much out of use; it was suspected it was provided in case of war, to reduce the visibility of the signals to potential enemy bombers (remember those schemes were being designed within 10 years of the end of WWII and in many cases covered areas that had suffered in the Blitz).Was this not just for the panel indications? I seem to remember that Perth (a 1961 SGE push/turn NX panel) has such a switch which only affects the indications. Log in to reply |