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| L.E.D signal heads 26/07/2010 at 22:50 #1506 | |
Simdmuk
155 posts |
I was down in Devon the other day and noticed that a number of signal heads have been replaced with L.E.D heads. Normally a 3 aspect signal head would be replaced by a single lens "L.E.D" version (search light style)which seems to be the norm for most of the network,however a number of the replacements I observed were "like for like" i.e a 3 lens head replaced by 3 L.E.D lens. Any one know why they haven't replaced the heads with a single L.E.D lens ? 
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| L.E.D signal heads 26/07/2010 at 22:50 #10241 | |
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Simdmuk
155 posts |
I was down in Devon the other day and noticed that a number of signal heads have been replaced with L.E.D heads. Normally a 3 aspect signal head would be replaced by a single lens "L.E.D" version (search light style)which seems to be the norm for most of the network,however a number of the replacements I observed were "like for like" i.e a 3 lens head replaced by 3 L.E.D lens. Any one know why they haven't replaced the heads with a single L.E.D lens ?
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| L.E.D signal heads 27/07/2010 at 09:17 #10249 | |
kbarber
1742 posts |
Although some LED signals use just one aperture to show 3 aspects , I believe there's at least one design that shows each colour through a separate aperture. Perhaps it depends who's got kit on special offer when you're buying 
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| L.E.D signal heads 27/07/2010 at 18:35 #10267 | |
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UKTrainMan
1803 posts |
Simdmuk said:Any one know why they haven't replaced the heads with a single L.E.D lens ?Is it a possibility that the reason a 3-aspect(?) LED signal was used is something to do with the location, i.e: a location specific reason. I would imagine someone turned up there (looks like just beyond Dawlish Warren station and just before Langstone Rock) sometime before the work was due to happen, carried out an assessment and it was decided that for some reason, perhaps for signal sighting purposes, a 3-aspect signal would be better than one. Then again, I am aware that there is a permanent red signal on the down platform at Dawlish Warren at the London-end and they may have chosen to use a 3-aspect LED signal to distinguish between it and the permanent red signal. Just a few possible reasons, although they are only rough guesses. (P.S: Not sure if 'aspect' is the correct terminology to used, but it'll suffice.) 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 |
| L.E.D signal heads 27/07/2010 at 18:42 #10269 | |
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Danny252
1461 posts |
UKTrainMan said:(P.S: Not sure if 'aspect' is the correct terminology to used, but it'll suffice.)2-, 3- and 4-aspect are the normal terminology. Log in to reply |
| L.E.D signal heads 28/07/2010 at 18:46 #10296 | |
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Simdmuk
155 posts |
Thanks for the replies guys. UKTM......... The pic is actually the Down gantry near Spray Point (Between Holcombe and Teignmouth) . Its just odd because two signals on the Up Main approaching Teignmouth are 3 aspect,single lens L.E.D and the approach signal on the Up Main at Dawlish Warren  (formally a 4 aspect)was replaced a year or so ago with a two lens, 4 aspect L.E.D head. Yet those pictured together with a couple on the Up Main at Starcross are new L.E.D heads but multi lens (3 aspect with 3 lens). So like you say it may be sighting or kit providers !Worth noting that the recent renewal of signal heads in the Trent Junction area , all are either single lens L.E.D (3 aspect) or twin lens L.E.D (4 aspect) , so the mix and match in Devon seems odd. Log in to reply |
| L.E.D signal heads 31/07/2010 at 05:50 #10352 | |
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oldman
37 posts |
The ability for a signal to show a double yellow will have an input in to the type of signal head chosen.
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| L.E.D signal heads 08/08/2010 at 23:44 #10595 | |
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Stephen Fulcher
2078 posts |
ME1 signal at London Marylebone is also a 3-aspect LED signal like the one in your pic here, and has been for several years now.
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| L.E.D signal heads 09/08/2010 at 00:10 #10596 | |
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Danny252
1461 posts |
Stephen Fulcher said:ME1 signal at London Marylebone is also a 3-aspect LED signal like the one in your pic here, and has been for several years now.Depending on how often Simdmuk visits Starcross (e.g. monthly or once every 5 years), could it be the case that the 3-head LEDs are just an older style, since abandoned in favour of the 1-heads, and that the installation at Starcross (and Marylebone) was put in/contracted before the 1-head came into fashion, with Dawlish being part of a later project? Log in to reply |
| L.E.D signal heads 10/08/2010 at 00:08 #10609 | |
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Simdmuk
155 posts |
I'm a regular visitor (ex resident) to Dawlish and district. The signal heads in question DM206 E276 etc have been replaced in the last six months whereas E21 was replaced about 18 months ago.As I stated, up here in Nottingham (now my residence)when the Trent Jn area was recently resignalled, 3 aspect heads were replaced by single lens L.E.D heads which seems to be the norm around the country ,likewise 4 aspect heads being replaced by 2 lens L.E.D heads. So what is strange is that the heads replaced recently along the sea wall area (noted as far as Starcross) have been replaced like for like in terms of lens(with the exception E21 and on the up approaches to Teignmouth ).
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| L.E.D signal heads 10/08/2010 at 02:28 #10611 | |
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UKTrainMan
1803 posts |
I have just recalled something a look-out once said to me in relation to the positioning of the aspects on old-style signals and why the red aspect is positioned as it is (at the bottom, something to do with snow?!!) and this just got me thinking if the replacement of the signals in the Dawlish/Teignmouth area had anything to do with the closeness to the sea? Long shot, perhaps but who knows....maybe?!! Danny252 said: UKTrainMan said:I said that as I wasn't sure if 2-, 3- or 4-aspect is correct terminology to use for LED signalling.(P.S: Not sure if 'aspect' is the correct terminology to used, but it'll suffice.)2-, 3- and 4-aspect are the normal terminology. 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 |
| L.E.D signal heads 10/08/2010 at 03:18 #10612 | |
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lpeters
160 posts |
LEDs are the way of the future. Much brighter, much more reliable and use much less energy.
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| L.E.D signal heads 10/08/2010 at 16:31 #10629 | |
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Danny252
1461 posts |
lpeters said:LEDs are the way of the future. Much brighter, much more reliable and use much less energy.A comment somewhat out of the blue there... Log in to reply |
| L.E.D signal heads 10/08/2010 at 19:25 #10631 | |
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Osprey
35 posts |
Danny252 said:lpeters said:LEDs are the way of the future. Much brighter, much more reliable and use much less energy.A comment somewhat out of the blue there... Out of the blue I personally don't like them at all,especially where they are mixed with semaphores as they completely outshine them and in the rain if your wipers aren't spot on the "splash" from them diffuses over the screen making seeing where you are going difficult.Lot of people like them though. Log in to reply |
| L.E.D signal heads 10/08/2010 at 20:14 #10633 | |
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lpeters
160 posts |
My LED comment was suggesting that the word aspect will probably include LED lights because they will likely replace most normal bulbs as they are brighter, clearer, more durable and cheaper to run. The word aspect is only to indicate the colour of the signal anyway so shouldn't make a difference if it's made with red torches, red bulbs or red LEDs for a red aspect.
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| L.E.D signal heads 10/08/2010 at 20:44 #10634 | |
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Osprey
35 posts |
The other things I dont like about them is the yellow and green aspects are slightly different shades to the older colour lights,more traffic light shades.
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| L.E.D signal heads 11/08/2010 at 12:56 #10644 | |
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clive
2789 posts |
There are strict restrictions, in the Rail Group Standards, about what colour a signal light can be. These are in turn derived from the CIE chromaticy diagram. Thus there are a range of colours that fit the criterion "signal red category C" and all red signals, whether oil lamp, incandescant bulb, halogen bulb, or LED have to meet that criterion. Incidentally, the same applies to road traffic signals, but the colour limits are rather wider. Log in to reply |
| L.E.D signal heads 12/08/2010 at 14:48 #10678 | |
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clive
2789 posts |
UKTrainMan said:I have just recalled something a look-out once said to me in relation to the positioning of the aspects on old-style signals and why the red aspect is positioned as it is (at the bottom, something to do with snow?!!) and this just got me thinking if the replacement of the signals in the Dawlish/Teignmouth area had anything to do with the closeness to the sea?Red is normally at the bottom for two reasons. Most important is to make it closest to the driver's eye, so it's less likely to be overlooked if there's a phantom aspect in another aspect. Secondly is that there's no lens hood underneath it for snow to build up on. When signals are mounted on the ground red is usually put at the top because of the first reason, even though the second reason would suggest putting it at the bottom. Instead the signal is tilted or sheltered in some way to reduce the snow risk. Log in to reply |
| L.E.D signal heads 15/08/2010 at 20:13 #10743 | |
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Osprey
35 posts |
There may be parameters that the colours have to be within but I find the green on LED signals are "greener" than older signals that are a yellow lamp shining through a shade of blue lens to give the green.The yellow I find is closer to a street lamp yellow but the red isnt much different in shade.
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| L.E.D signal heads 18/08/2010 at 16:28 #10799 | |
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Woodhead Signalman
64 posts |
Just remembering something from my past days as a signalman on the old S&LR/GCR Woodhead Route, I and my colleagues on that line would often talk of giving a train 'a line or row of blues' when referring to clearing the route on all greens for a train. The signalheads that I remember seeing when sometimes I used to walk my 'patch' as it were, (especially at night-time) did look more blue than green!
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