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Post by tube10 on Dec 17, 2007 22:43:09 GMT
Whatdevice is used for operating the doors on the underground?
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Post by edwin on Dec 17, 2007 23:13:25 GMT
A question about doors that i've always pondered about...
Why do Northern line drivers open their doors really quickly whereas Jubilee line drivers take yonks?
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Post by Tubeboy on Dec 17, 2007 23:13:45 GMT
Compressed air.
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Post by Tubeboy on Dec 17, 2007 23:14:57 GMT
A question about doors that i've always pondered about... Why do Northern line drivers open their doors really quickly whereas Jubilee line drivers take yonks? The PEDS I suppose, I find a lot of Northern T/ops miss the stopping mark slightly, and so have to use the door controls by the cab door to open the doors. |
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Post by c5 on Dec 17, 2007 23:16:00 GMT
A question about doors that i've always pondered about... Why do Northern line drivers open their doors really quickly whereas Jubilee line drivers take yonks? At a guess it may be that the Northern has larger Correct Side Door Enable zones (or that the Northern is better than the Jubilee ;D ;D) |
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towerman
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Post by towerman on Dec 18, 2007 19:11:11 GMT
Basically there are 2 door engines(for each door)a large one and a small one.When the doors are closed there is no air in the large engine and the small engine keeps the doors closed.When the open buttons are operated,the air is let into the large engine and this overcomes the pressure in the small engine and the doors open.When the close button is operated the air is released from the large engine and the doors close.
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Post by 100andthirty on Dec 18, 2007 20:32:51 GMT
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Post by edwin on Dec 18, 2007 23:35:03 GMT
A question about doors that i've always pondered about... Why do Northern line drivers open their doors really quickly whereas Jubilee line drivers take yonks? The PEDS I suppose, I find a lot of Northern T/ops miss the stopping mark slightly, and so have to use the door controls by the cab door to open the doors. It happens at stations without PEDs though, like at Kilburn the other day I waited over 10 seconds for the doors to open. When I was on the Northern line the doors opened as soon as the train stopped! Same for the Piccadilly/Victoria lines. |
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Post by Chris M on Dec 19, 2007 1:36:15 GMT
It took over a minute for the doors to open on the Central Line at Leytonstone the other day (although I think this might have been because driver was factionally too keen to end his shift/rounder and forgot to open the passenger doors  ). Even so, waits of 10 seconds are not uncommon. Compare this to the C stocks where the doors are half open as soon as the train has come to a stop. |
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Post by happybunny on Dec 19, 2007 10:18:27 GMT
I found on the Jubille it took quite a while for the accurate stop light to come on after stopping on some stations. The fastest was Baker St NB where it was instant. All the rest had a delay. So even if you stop exactly on the mark with you're fingers on the buttons just before u stop... you still have a delay of a few seconds before the doors open. Whereas once I was on the Northern (quite rare for me) and I was surprised that just as the train was stopping the doors opened (similar to as they do it on the Circle/Dist/Picc etc) which surprised me because I thought it had the same system as the Jubilee.. I think the new "accurate stop" system (or whatever its called) is not as good as the old CSDE system.
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towerman
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Post by towerman on Dec 19, 2007 19:15:53 GMT
May be quicker when TBTC is commissioned,opening of the doors is automatic.
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Post by edwin on Dec 30, 2007 3:24:10 GMT
What is TBTC?
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towerman
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Post by towerman on Dec 30, 2007 3:36:57 GMT
Transmission Based Train Control.
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Post by Deleted on Dec 30, 2007 13:34:19 GMT
on the video125 DEV at oval a 1995 stock train arrives and the doors open a fraction of a second berfore the train stops
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Post by edwin on Dec 30, 2007 21:19:16 GMT
Big deal? That always happens on the 67TS, 72TS, 73TS, 95TS, D and C Stock, never seen it on the 92TS or 96TS though.
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Post by Tubeboy on Dec 30, 2007 21:22:03 GMT
on the video125 DEV at oval a 1995 stock train arrives and the doors open a fraction of a second berfore the train stops Did Rob Curling mention this quirk of the 1995 stock's door mechanism.... in his incidentally informative commentary? |
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Post by tubeprune on Dec 31, 2007 12:54:13 GMT
In my view, it is a good idea to allow the doors to begin opening just before the train stops. This saves a second or two and gets people's attention for faster unloading. If the door open buttons are pressed at the right moment, the door engines will begin opening just as the wheels stop so they are open about 3 inches at the moment the train stops.
If the same approach is adopted for closing, i.e. just as the last passenger steps onto the car floor, the doors will close behind him immediately he clears the sill plate.
With these two smart operations, you can make about 4 seconds time saving on each station stop. If everyone did this you could get an extra train per hour through the line.
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Post by Deleted on Dec 31, 2007 21:01:33 GMT
it needs to be done on the JLE beacause the PEDS take a second or to extra to open
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Post by edb on Jan 9, 2008 12:58:17 GMT
I would have suspected that this would be due to the need to Align the trains in a more precise fashion before the doors and peds open, i also suspect the transmission time of this kind of data would affect the opening speeds.
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Post by version3point1 on Jan 9, 2008 19:10:18 GMT
it needs to be done on the JLE beacause the PEDS take a second or to extra to open In essence, edb is correct. You can press those door buttons all you like, but until that train is 1) aligned and 2) has come to a complete stop, all that button pushing isn't going to make a blind bit a difference. In any case, edb has it all summed up in a nutshell: In order for the PEDs to open, equipment on the train needs to communicate with the PED controlling equipment on the platform in order to engage both the electrical and mechanical outputs that results in the PEDs opening. This is why sometimes the train doors will open, but those PEDs will take forever to follow in quick succession. The train however needs to be aligned in a particular place however for all of this to happen, which is why you often find a lot of drivers slowing right down and coasting very gently to a stop as there is very little margin for error. Should the train's equipment fail to communicate with the PED controlling equipment, or equally, should the PED controlling equipment fail to communicate with the electrical supply in order to get the door motors running, you will end up with none of those PEDs opening up at all. Which is annoying! :@ The joys of technological advances!  |
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). Even so, waits of 10 seconds are not uncommon.
