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Post by antharro on Jul 19, 2008 0:17:14 GMT
Are fog repeaters still on full time? If so, I have a few questions.
- If a "regular" signal bulb fails, I understand there's a procedure for dealing with that so the train can continue. If a repeater bulb fails, I assume the t/op doesn't need to carry out any specific procedure, just look out for the signal it's repeating in advance in case it's red?
Thing that got me thinking was; I was on an EB H&C to Hammersmith this afternoon, and happened to see that the repeater for A121 (WB) wasn't showing an aspect. (The main signal was showing green).
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Post by ruislip on Jul 19, 2008 0:40:47 GMT
Are fog repeaters still on full time? If so, I have a few questions. - If a "regular" signal bulb fails, I understand there's a procedure for dealing with that so the train can continue. If a repeater bulb fails, I assume the t/op doesn't need to carry out any specific procedure, just look out for the signal it's repeating in advance in case it's red? Thing that got me thinking was; I was on an EB H&C to Hammersmith this afternoon, and happened to see that the repeater for A121 (WB) wasn't showing an aspect. (The main signal was showing green). What is the purpose of a "Fog Repeater"? |
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Post by antharro on Jul 19, 2008 1:52:40 GMT
Repeats the aspect of a signal that hasn't been reached yet so that the t/op can see what that signal shows in advance. Initially used in poor conditions where the main signal cannot be seen (hence "FOG" repeater), but now used all the time as an anti-SPAD measure.
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Colin
Advisor
My preserved fire engine!
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Post by Colin on Jul 19, 2008 17:01:06 GMT
As you say, they're now on all the time as an additional SPAD mitigation measure.
There are no special procedures if one has no aspect; they are treated exactly the same as any other repeater - basically, be aware that the signal being repeated may actually be at danger.
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Tom
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Signalfel?
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Post by Tom on Jul 19, 2008 19:52:16 GMT
As you say, they're now on all the time as an additional SPAD mitigation measure. Which on one particular signal has increased the risk of a SPAD, such that they now want the Fog Repeater hooded! (As a point aside, Fog Repeaters never have hoods because you need the wide beam the give out in conditions of fog.) |
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Deleted
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Post by Deleted on Jul 21, 2008 9:43:48 GMT
As you say, they're now on all the time as an additional SPAD mitigation measure. Which on one particular signal has increased the risk of a SPAD, such that they now want the Fog Repeater hooded! How can that be the case? Surely it results only in it being clear that the signal it is repeating is at danger. If it would be visible in such a way as to show clear when another signal. also visible, is at danger, then surely it should go out - I know FRAC1 does. Unless, of course, the signal is in the opposite direction, when I don't know how it could be handled. |
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Tom
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Post by Tom on Jul 21, 2008 19:53:08 GMT
It's on a curve in a four track section - the concern is that T/Ops could read over to the Fog Repeater on the other road and think it's their own.
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