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Post by harbour on Apr 28, 2017 16:34:38 GMT
Today when commuting into Victoria on the District Line I twice noticed a light blue board with a white "6" on, trackside, and if my memory is correct they were sited before Gloucester Rd station and after South Ken. Are these the train length markers that were mentioned on an old thread I found when searching "blue". Are they new along that stretch of the SSL, they looked clean and shiny to me. Or am I just unobservant apart from today?!
Thanks for any input
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Dstock7080
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Post by Dstock7080 on Apr 28, 2017 16:59:33 GMT
Called 'countdown' or 'count-up' markers, they were installed on Lines when the PEA Passenger Emergency Alarms were altered so they give an emergency brake and an alarm to the driver. If PEA is operated departing a station and the driver sees a car marker (of any number) he should allow the train to stop with the already activated emergency brakes. If no count-up marker is seen, the driver should allow the train to stop, use the talk-back facility to passengers, (if available) then continue on to the next station, after over-riding the emergency brake.
On the Metropolitan, Circle, Hammersmith & City and District Lines these markers are now redundant, as S Stock do not use them.
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class411
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Post by class411 on Apr 28, 2017 17:36:03 GMT
So the train still stops when the emergency alarm is operated?
I, and a lot of other people were under the impression that that function had been abandoned (it comes up for discussion even amongst non-underground fans because people wonder what would happen if someone was stuck half out of the carriage and the train moved off).
I must say I'm quite relieved to know that in such a (albeit extraordinarily rare) situation it is actually possible to stop the train.
I'm sure the wording I have seen is misleading because I've never known anyone suggest this was how it now worked.
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Deleted
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Post by Deleted on Apr 28, 2017 18:21:27 GMT
So the train still stops when the emergency alarm is operated? I, and a lot of other people were under the impression that that function had been abandoned (it comes up for discussion even amongst non-underground fans because people wonder what would happen if someone was stuck half out of the carriage and the train moved off). I must say I'm quite relieved to know that in such a (albeit extraordinarily rare) situation it is actually possible to stop the train. I'm sure the wording I have seen is misleading because I've never known anyone suggest this was how it now worked. Train wouldn't move full stop because a doors close visual or pilot light would not be gained this would not let the motors energise to enable the train to move.
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Deleted
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Post by Deleted on Apr 28, 2017 18:56:41 GMT
Train wouldn't move full stop because a doors close visual or pilot light would not be gained this would not let the motors energise to enable the train to move. Wrong. Operating a PEA doesn't break the door interlock circuit. On any stock.
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Post by phoenixcronin on Apr 28, 2017 19:17:05 GMT
Should the driver still apply the brake even at, for example, the 6 car marker on a 6 car train? Surely by the time the train stops the last car will be beyond the end of the platform?
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Post by MoreToJack on Apr 28, 2017 19:26:42 GMT
Train wouldn't move full stop because a doors close visual or pilot light would not be gained this would not let the motors energise to enable the train to move. Wrong. Operating a PEA doesn't break the door interlock circuit. On any stock. But an obstruction in the doors would, which is the part of class411's post ("what would happen if someone was stuck half out of the carriage and the train moved off") that @aetearlscourt was referring to (I think).
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Deleted
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Post by Deleted on Apr 28, 2017 19:29:05 GMT
Should the driver still apply the brake even at, for example, the 6 car marker on a 6 car train? Surely by the time the train stops the last car will be beyond the end of the platform? In that scenario the brake has already been automatically applied due to the PEA being operated. The correct procedure is for the train to be allowed to come to a stand and the PEA investigated immediately. It is nothing to do with the train's proximity to the platform when it stops, but the possibility that it has been operated due to a PTI (platform/train interface) incident.
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Post by phoenixcronin on Apr 28, 2017 19:36:05 GMT
Should the driver still apply the brake even at, for example, the 6 car marker on a 6 car train? Surely by the time the train stops the last car will be beyond the end of the platform? In that scenario the brake has already been automatically applied due to the PEA being operated. The correct procedure is for the train to be allowed to come to a stand and the PEA investigated immediately. It is nothing to do with the train's proximity to the platform when it stops, but the possibility that it has been operated due to a PTI (platform/train interface) incident. Ah, I see
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Deleted
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Post by Deleted on Apr 28, 2017 19:46:30 GMT
Train wouldn't move full stop because a doors close visual or pilot light would not be gained this would not let the motors energise to enable the train to move. Wrong. Operating a PEA doesn't break the door interlock circuit. On any stock. I was referring to before the train even set off
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Deleted
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Post by Deleted on Apr 28, 2017 20:51:40 GMT
On closer inspection, you should see a string of six markers, labelled 1-2-3-4-5 and then 6, on each of the relevant platform departure zones, i.e. the area just beyond the platform in the direction of running.
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class411
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Post by class411 on Apr 29, 2017 7:38:08 GMT
Train wouldn't move full stop because a doors close visual or pilot light would not be gained this would not let the motors energise to enable the train to move. And yet they do. Many years ago I used to occasionally (oh, all right, quite often) drink at a pub, after work, and one of the regulars there (whom I didn't know) got his arm caught in the door at Great Portland Street, and the train departed and travelled some distance in the tunnel before someone activated the emergency stop. I saw the chap in the pub a few days later with his arm in plaster. At the time the papers said that it was a myth that trains would not move with a door open (which seemed to be putting it a bit strongly, to me). However, as with any other piece of equipment, a door safety mechanism can fail - even if it is supposedly fail safe, as this event proved.
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