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Post by xtmw on Feb 19, 2024 14:03:27 GMT
I've seen this happening 3 times today, what sounds like the train applying an emergency brake. The first time between Stratford and Mile End, train came to a stop, then a few seconds later there was the sound of air coming out from the train, then we were moving moments later.
It happened again between Holland Park and Shepherd's Bush, sound of air being released etc.
Then as we pulled into Shepherds Bush, we came to another stop! All on 3 separate trains! Is the signalling system playing up or is it stock related?
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class411
Operations: Normal
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Post by class411 on Feb 19, 2024 17:56:11 GMT
Was there a very high rate of deceleration?
When I was on a train that emergency braked, there was no doubt as to what happened.
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Post by xtmw on Feb 19, 2024 18:03:05 GMT
Yes, higher then normal - you could really feel the train coming to a stop. Just before it stopped you could really feel (and hear) the train jolt. I can only assume there was some problem with the signalling as it happened once in the Stratford area, and twice in the Shepherd's Bush/White City area.
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Chris M
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Post by Chris M on Feb 20, 2024 4:56:26 GMT
It could also have been the train losing the pilot light, for example due to people leaning on the doors.
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Post by xtmw on Feb 20, 2024 10:31:07 GMT
That's what I thought - the train was pretty quiet but it seems like the only logical explanation. Thanks Chris!
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gefw
Gone - but still interested
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Post by gefw on Feb 20, 2024 16:21:50 GMT
It could also have been the train losing the pilot light, for example due to people leaning on the doors. I believe the loss of passenger door proving only automatically cuts traction - it is then down to Train Operator to decide whether to "actively stop" or not. An exception may be if any part train is still within the platform area. There is a Remote Condition Monitoring and trend analysis/report system on the central line trains which should pick out any pattern of regular occurrences of faults such as this at a location or with certain trains. Otherwise there are acknowledged "random occurances" related to the system design (eg code stepping/ripple and code gaps at track boundaries) which are not economically resolvable |
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Post by aslefshrugged on Feb 21, 2024 14:06:21 GMT
It could be a number of things
We do get an occasional "invalid target speed" between Stratford and Mile End on the westbound that activates the emergency brake. The sound of air was most likely the driver getting a brake release after switching to Coded Manual.
Other possibilities are ATP failure or low adhesion (mostly in open section although not unknown in tunnel section). There's a lot can go wrong with 1992ts
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Post by xtmw on Feb 21, 2024 20:17:20 GMT
We do get an occasional "invalid target speed" between Stratford and Mile End on the westbound that activates the emergency brake Is this common on the 92s? |
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gefw
Gone - but still interested
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Post by gefw on Feb 21, 2024 21:31:43 GMT
We do get an occasional "invalid target speed" between Stratford and Mile End on the westbound that activates the emergency brake Is this common on the 92s? Yes this is quite common at sites where relays are used to perform the code changes and is caused by dirty/protracted code stepping. The trainborne ATP kit is basically complaining that the code signal from track circuit is indistinct/corrupt/illogical for too long and the ATP fails safe. |
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Post by londonboi1985 on Feb 24, 2024 4:45:44 GMT
It could also have been the train losing the pilot light, for example due to people leaning on the doors. I believe the loss of passenger door proving only automatically cuts traction - it is then down to Train Operator to decide whether to "actively stop" or not.An exception may be if any part train is still within the platform area. There is a Remote Condition Monitoring and trend analysis/report system on the central line trains which should pick out any pattern of regular occurrences of faults such as this at a location or with certain trains. Otherwise there are acknowledged "random occurances" related to the system design (eg code stepping/ripple and code gaps at track boundaries) which are not economically resolvable There is no deciding about it loss of pilot light/doors closed visual you STOP the train. |
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class411
Operations: Normal
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Post by class411 on Feb 24, 2024 4:57:06 GMT
I believe the loss of passenger door proving only automatically cuts traction - it is then down to Train Operator to decide whether to "actively stop" or not.An exception may be if any part train is still within the platform area. There is a Remote Condition Monitoring and trend analysis/report system on the central line trains which should pick out any pattern of regular occurrences of faults such as this at a location or with certain trains. Otherwise there are acknowledged "random occurances" related to the system design (eg code stepping/ripple and code gaps at track boundaries) which are not economically resolvable There is no deciding about it loss of pilot light/doors closed visual you STOP the train. If you have time, presumably. With a passenger leaning on a door, would you have time to react? |
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Post by spsmiler on Feb 24, 2024 19:06:33 GMT
I wish that train drivers would announce more often about the need to not lean on the doors - its quite irksome when trains trying to depart from stations constantly perform 'kangaroo' hops.
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