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| AWS and flashing greens 31/05/2017 at 20:27 #95536 | |
jc92
3629 posts |
Just a random question in relation to the flashing greens provided for 140mph running as seen on Pbro sim. Normally a green aspect wouldnt be considered restrictive so wouldnt trigger a warning horn with AWS. If flashing green becomes the least restrictive aspect did that mean drivers would get a warning horn for a steady green as in effect its a restrictive aspect or not? Id imagine its no longer in place anyway but just a curiosity. "We don't stop camborne wednesdays" Log in to reply |
| AWS and flashing greens 31/05/2017 at 20:41 #95537 | |
TUT
507 posts 
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The excellent Railway Signs and Signals of Great Britain website says that AWS gave a clear indication for both green and flashing green, but I can't find a primary source.
Last edited: 31/05/2017 at 20:42 by TUT Reason: None given Log in to reply |
| AWS and flashing greens 31/05/2017 at 22:01 #95538 | |
58050
2650 posts
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I'd certainly agree with what TUT says as a signal displaying a green aspect whether flashing or not would be interpreted as a proceed aspect as opposed to flashing or steady yellow aspects.
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| AWS and flashing greens 02/06/2017 at 09:16 #95570 | |
Ltbuckler
9 posts |
I have had a look at the AWS control circuits for P579 Signal at Little Bytham, which had the flashing green ability. The power to AWS electro magnet is directly controlled by the DR relay (Green control relay) and not the FDR (Flashing Green control relay). In order to energize the FDR relay you need to Have the DR energized first. So it is indeed the case that both a green aspect or a flashing green aspect would provide a bell/no sunflower indication to the driver. Please find the circuit diagrams attached 
Post has attachments. Log in to view them. Last edited: 02/06/2017 at 09:34 by Ltbuckler Reason: None given Log in to reply The following users said thank you: Stephen Fulcher, JamesN, Steamer, TUT, The Real Pieman, Forest Pines |
| AWS and flashing greens 02/06/2017 at 09:27 #95571 | |
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AndyG
1834 posts |
A steady green would have to give a 'clear' AWS indication otherwise all trains would be getting a caution warning at a green; the majority of the trains didn't require the 140mph feature.
I can only help one person a day. Today's not your day. Tomorrow doesn't look too good either. Log in to reply |
| AWS and flashing greens 02/06/2017 at 09:42 #95572 | |
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MarkC
1089 posts
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AndyG in post 95571 said:A steady green would have to give a 'clear' AWS indication otherwise all trains would be getting a caution warning at a green; the majority of the trains didn't require the 140mph feature.I have found this article from "The University of California Transportation Center" paper in 1992. See page 32 (PDF page 36) The article's web address is a web archive due to the age of it Log in to reply |
| AWS and flashing greens 08/06/2017 at 22:03 #95753 | |
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clive
2737 posts |
Ltbuckler in post 95570 said:Interesting that the DR is cut in there twice but the HHR not at all. If the HHR is deduced from the DR, why is the HR in there? Log in to reply The following user said thank you: Ltbuckler |
| AWS and flashing greens 08/06/2017 at 22:05 #95754 | |
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clive
2737 posts |
AndyG in post 95571 said:A steady green would have to give a 'clear' AWS indication otherwise all trains would be getting a caution warning at a green; the majority of the trains didn't require the 140mph feature.But those trains would still be getting the flashing greens; they're not train-specific. I know of one driver who used the presence or absence of a flashing green at a specific signal to give him a bit of extra warning whether or not to brake for a turnout (the diverging route was approach-controlled). And, as is replicated on the sim, all diverging routes in the flashing zone are restricted to displaying YY. Log in to reply |
| AWS and flashing greens 21/06/2017 at 11:49 #95946 | |
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Ltbuckler
9 posts |
clive in post 95753 said:That is quite a good point. I am not really sure why the HR has been cut in. A normal AWS control circuit contains only the double cutting of the lamp proving and DR relay. The only time today, you would include the HR or HHR within the control circuit is if there was some strange timing arrangement where it was possible for the DR to become energized before the HR/HHR. It might be the case that this is a relic from when the area contained the crossover and more complex aspect sequences. From looking at 579's DR circuits today and the current layout, we would not provide a HR/HHR contact in the circuit. Last edited: 21/06/2017 at 11:50 by Ltbuckler Reason: Quote Added Log in to reply |