class411
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Post by class411 on Jul 10, 2017 12:54:04 GMT
Safety will always take priority over speed and doors opening before the train has fully stopped would increase the chance of accidents. There have been faults on some trains, particularly D Stock, that meant that doors could be opened before the train had stopped but any driver caught pressing the "door open" buttons before they had stopped could be in serious trouble. No Train Operating Company would be stupid enough to suggest it as they'd never get it past the ORR and even if they did they'd never get it past the insurers who'd hike the public liability premiums into infinity. Which is why it would be good if the train could start the open process as it came to rest so that the doors parted a few milliseconds after a full stop. Whether the instrumentation fitted is up to measuring the very slow speeds that it would need to, in order to implement this, is another matter. Almost certainly not on older stock. It may be able to on ATO capable stock as it may be necessary to accurately and quickly calculate breaking capability and, perhaps, for wheel spin protection.
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Post by aslefshrugged on Jul 10, 2017 13:35:03 GMT
I certainly wouldn't recommend it on the 1992ts, sometimes in ATO they slow almost to the point of stopping less than a cars length short of the stopping mark then speed up for the remaining distance. As the 1992ts will be replaced with the new driverless trains which will have self opening doors (And PEDs) there's not much point of an expensive upgrade plus you'd also have to get the unions to agree to self opening doors, if memory serves there was a bit of a kerfuffle over that a few years ago.
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class411
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Post by class411 on Jul 10, 2017 13:59:39 GMT
I certainly wouldn't recommend it on the 1992ts, sometimes in ATO they slow almost to the point of stopping less than a cars length short of the stopping mark then speed up for the remaining distance. As the 1992ts will be replaced with the new driverless trains which will have self opening doors (And PEDs) there's not much point of an expensive upgrade plus you'd also have to get the unions to agree to self opening doors, if memory serves there was a bit of a kerfuffle over that a few years ago. I wasn't suggesting any upgrading. Just musing about future possibilities with whatever the stock could manage (safely).
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Post by brigham on Jul 10, 2017 15:14:02 GMT
Otis automatic lifts do this, and have done for years. I suppose if it had just been thought-of, a major examination of the idea would need to take place.
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North End
Beneath Newington Causeway
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Post by North End on Jul 10, 2017 15:18:44 GMT
I certainly wouldn't recommend it on the 1992ts, sometimes in ATO they slow almost to the point of stopping less than a cars length short of the stopping mark then speed up for the remaining distance. As the 1992ts will be replaced with the new driverless trains which will have self opening doors (And PEDs) there's not much point of an expensive upgrade plus you'd also have to get the unions to agree to self opening doors, if memory serves there was a bit of a kerfuffle over that a few years ago. I've certainly seen paperwork hinting that LU would love to utilise the self-open function that comes with TBTC. It seems to be mainly ER rather than technical capability which stands in the way. TBTC is a pain because there is a significant delay between the train stopping and the doors being able to be opened. The Victoria Line managed to avoid this. It's definitely something that needs working on with TBTC as it amounts to a lot of wasted dwell time.
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Post by stapler on Jul 10, 2017 17:29:12 GMT
D stock?....and what a failure that was, and how soon abandoned!
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class411
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Post by class411 on Jul 10, 2017 18:48:04 GMT
I certainly wouldn't recommend it on the 1992ts, sometimes in ATO they slow almost to the point of stopping less than a cars length short of the stopping mark then speed up for the remaining distance. As the 1992ts will be replaced with the new driverless trains which will have self opening doors (And PEDs) there's not much point of an expensive upgrade plus you'd also have to get the unions to agree to self opening doors, if memory serves there was a bit of a kerfuffle over that a few years ago. I've certainly seen paperwork hinting that LU would love to utilise the self-open function that comes with TBTC. It seems to be mainly ER rather than technical capability which stands in the way. TBTC is a pain because there is a significant delay between the train stopping and the doors being able to be opened. The Victoria Line managed to avoid this. It's definitely something that needs working on with TBTC as it amounts to a lot of wasted dwell time. What is TBTC?
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Rich32
Staff Emeritus
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Post by Rich32 on Jul 10, 2017 18:55:11 GMT
Transmission-Based Train Control This is used on the Jubilee and Northern lines. The SSR will use the upgraded version CBTC - Communications-based Train Control
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Deleted
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Post by Deleted on Jul 10, 2017 21:22:53 GMT
LUL have coped with self-opening doors on almost all its passenger lifts for many decades at least. The lift car arrives at the landing, stops and the doors open. perhaps this proven LUL technology could be extended to its trains???
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Post by brigham on Jul 11, 2017 7:23:02 GMT
LUL have coped with self-opening doors on almost all its passenger lifts for many decades at least. The lift car arrives at the landing, stops and the doors open. perhaps this proven LUL technology could be extended to its trains??? The point about Otis lifts is that the doors commence opening prior to the lift arriving at the landing, at which it then subsequently stops.
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Deleted
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Post by Deleted on Jul 11, 2017 12:02:33 GMT
Safety will always take priority over speed and doors opening before the train has fully stopped would increase the chance of accidents. There have been faults on some trains, particularly D Stock, that meant that doors could be opened before the train had stopped but any driver caught pressing the "door open" buttons before they had stopped could be in serious trouble. No Train Operating Company would be stupid enough to suggest it as they'd never get it past the ORR and even if they did they'd never get it past the insurers who'd hike the public liability premiums into infinity. Paris Metro train drivers have been doing this for years.
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cso
Posts: 1,043
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Post by cso on Jul 11, 2017 12:20:42 GMT
Bakerloo Line trains seem to do that too to a degree whether by design or not.
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Post by AndrewPSSP on Jul 11, 2017 12:25:33 GMT
I've been on Piccadilly and Victoria line trains where the doors open before the train fully stops.
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Post by MoreToJack on Jul 11, 2017 13:46:59 GMT
It happens on a few lines and is possible due to the way that the Correct Side Door Enable (CSDE) equipment is set up.
However, it is frowned upon and is not an accepted practice; the train should be fully berthed with the CTBC/TBC/whatever else it's called in the appropriate braking/hold position (e.g. rheo 1 & hold on a 72TS) before the door buttons are operated.
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North End
Beneath Newington Causeway
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Post by North End on Jul 11, 2017 14:02:45 GMT
It happens on a few lines and is possible due to the way that the Correct Side Door Enable (CSDE) equipment is set up. However, it is frowned upon and is not an accepted practice; the train should be fully berthed with the CTBC/TBC/whatever else it's called in the appropriate braking/hold position (e.g. rheo 1 & hold on a 72TS) before the door buttons are operated. It can happen on the 72, 73, 92 and 09 stocks. It was also very common on the 95 stock - not sure about 96 stock as they had to have an accurate stop certainly at the PED stations at least. The combination of a CSDE 'zone' and the door buttons working on the basis of speed sensing (i.e. they are enabled below a set speed) allow it to happen. A common practice - indeed on the Northern Line it was a useful way of avoiding having to go through the CSDE override procedure if overrunning the stopping mark slightly. Never caused an incident to my knowledge, although certainly likely to be pulled up if observed in a CMS assessment or road test.
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Post by croxleyn on Jul 11, 2017 17:55:27 GMT
One of the differences to a lift is that in a crush hour train, one can be frequently pushed against the door, into the corner if decelerating. A possibility of injury if the door opens?
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Post by silenthunter on Jul 14, 2017 20:31:00 GMT
Way back when South Eastern still ran slam door trains and I commuted to London, I tended to travel at the front of a twelve carriage train (because it was less crowded there), and thus had to walk back along most of the platform at my destination. On most days I (or other passengers) would need to push at least one door closed as it had been left ajar, or partially latched by other passengers. During daylight hours this generally allowed the train to depart as it saved a porter (remember those) from having to make his way down the platform. At night, when the porters could not always see the open doors, it sometimes meant giving the door a kick whilst the train was accelerating from the station. I read a story about a member of BR staff who didn't manage to close the door of an InterCity train properly and the door ended up being ripped off the train when it entered a tunnel. Said door was delivered back to her depot wrapped up in something, but I can't remember what.
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