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| Re: Do they turn signals off to save power? 16/12/2011 at 10:36 #25649 | |
Firefly
521 posts |
I believe you're correct Ron. I know that numerous panels used to have dim/bright switches for panel indications. (western E10K panels had them)  The attached shows 2 switches on an E10K Panel On the left: Panel Bright / Dim On the Right: Point Indications Off / On At that back of my mind I had the vaguest memory of shunt signals at one time having different intensities but I wouldn't swear to it. I'm not aware of any mainline signals ever having a bright/dim function (but that doesn't mean its never happened). Knowing how signals are wired and controlled it would be a large expense to provide a bright/dim function on all signals within a box area and also it's a huge risk. If the signaller forgets to turn the switch to bright in daylight hours and a train SPAD's a dim signal there would be a lot of explaining to do. Secondly if you have a red signal which is dim because it's controlled by signal box A, and further down the line you have a Yellow or Green signal which is bright because it's controlled by signal box B, an optical illusion will cause the Yellow/Green to appear closer than the Red and it would have a massive read-thru risk. I'd eat my keyboard if there's any working examples of this on the mainline. (and by working I mean that it's allowed to be used) FF Post has attachments. Log in to view them. Last edited: 16/12/2011 at 10:38 by Firefly Log in to reply |
| Re: Do they turn signals off to save power? 16/12/2011 at 12:00 #25651 | |
Peter Bennet
5360 posts |
" said:I'd eat my keyboard if there's any working examples of this on the mainline. (and by working I mean that it's allowed to be used)http://www.wired.com/gadgetlab/2008/01/chocolate-keybo/ Peter I identify as half man half biscuit - crumbs! Log in to reply |
| Re: Do they turn signals off to save power? 16/12/2011 at 15:31 #25653 | |
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kbarber
1712 posts |
" said:I believe you're correct Ron. All the examples I was ever aware of (the LTS basically) have now been superseded. I don't know whether the facility was provided at the big OCS panels at York & Newcastle, or the 1949 installations between Liverpool St & Shenfield; of course they, too, have now gone. Euston definitely had bright/dim facilities on the shunt signals - Clive's transcript of the BR "Instructions to..." make it clear that they were supposed to be switched to "dim" at night but I don't know how long that went on for, or indeed whether/when the switches were ever removed. Again, the installation has now gone. But I wonder if New Street (approx same vintage) might've had the same. " said: Knowing how signals are wired and controlled it would be a large expense to provide a bright/dim function on all signals within a box area Sure. In the immediate aftermath of WWII, when large parts of our cities had been razed by aerial bombing, the cost might well have been seen as a very sensible investment. Remember even Euston & New Street were opened just about 20yr after the end of that war; I suspect memories were still fresh in those days. " said: and also it's a huge risk. Remember we're talking about days of yore, when drivers were expected to know the road and obey signals, when many signals were still oil-lighted semaphores (even on 100mph main lines) and, TBH, when many minor SPADs were "squared" with no-one being any the wiser. " said: I'd eat my keyboard if there's any working examples of this on the mainline. (and by working I mean that it's allowed to be used) I think your keyboard is safe. As I say they're pretty much all gone now and I really don't see any that remain continuing in use. But whether the circuits (and perhaps the switches) are still lurking... Log in to reply |
| Re: Do they turn signals off to save power? 16/12/2011 at 16:39 #25655 | |
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button_pusher
56 posts |
" said:SSI = Solid State InterlockingThanks Firefly! Forgot that non-S&T chaps won't have a clue about our super-secret nomenclature! Log in to reply |
| Re: Do they turn signals off to save power? 16/12/2011 at 17:27 #25657 | |
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eddy
45 posts |
KBarber is quite correct New st panel did have bright and dim switches for both the panel and the shunt signals. both disabled now. But Wolverhampton does have bright and dim switch for the Panel and it still works the bright and dim for the shunt signals is disabled don't know what effect it would have with the installation of LED signals.
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| Re: Do they turn signals off to save power? 16/12/2011 at 22:06 #25672 | |
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MrBitsy
121 posts |
I used to drive Piccadilly line underground trains in London. Between Terminal 4 and Heathrow central there was a long straight with a signal at the end just before a curve. The signal was lit if green, but if red it was turned off to stop drivers braking too early. It would light up to red with enough time for the approaching train to stop.
TVSC Link 4 signaller - Temple Meads, Bath & Stoke Gifford Log in to reply |