Chris M
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Post by Chris M on Jul 21, 2017 17:06:40 GMT
Pushback certainly isn't always effective in preventing a dragging, partly because people generally don't know about it and partly because it requires some physical force to be exerted on the door. I think pushback only operates on one door leaf per doorway. If that's the leading door you need to push forwards faster than you are moving relative to the door. If you are inside the train that's fairly easy as your relative motion is roughly zero, but if you are outside you have to move faster than the speed of the train, which is essentially impossible after the first few seconds. |
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Deleted
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Post by Deleted on Jul 21, 2017 19:38:46 GMT
Emergency stop plungers along the platform as used on the Victoria and Central Lines, supplemented by duplicates in the Control Room too, would have prevented this accident. I an surprised that the Jubilee and Northern Lines had them omitted in order to save money. (a false economy).
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North End
Beneath Newington Causeway
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Post by North End on Jul 21, 2017 19:59:09 GMT
Pushback certainly isn't always effective in preventing a dragging, partly because people generally don't know about it and partly because it requires some physical force to be exerted on the door. I think pushback only operates on one door leaf per doorway. If that's the leading door you need to push forwards faster than you are moving relative to the door. If you are inside the train that's fairly easy as your relative motion is roughly zero, but if you are outside you have to move faster than the speed of the train, which is essentially impossible after the first few seconds. Correct. On something like a 95/96 stock the pushback side can be identified as the door with the slightly thicker rubber seal. I think the idea is that anything would be freed before the train starts moving, which as you say doesn't always happen in reality. If one can push the door open and break the interlock in time then that may in itself prevent the train picking up too much speed, although this would depend on gradient and whether the driver notices there's something amiss. The main gist is don't try to enter or leave a train when the doors are closing, which is unfortunately a lesson a lot of people need to learn, and IMO something LU could try harder when it comes to educating people. Some drivers do quite 'informative' announcements targeted at individuals, however generally this isn't really encouraged by the company. |
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North End
Beneath Newington Causeway
Posts: 1,769
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Post by North End on Jul 21, 2017 20:02:08 GMT
Emergency stop plungers along the platform as used on the Victoria and Central Lines, supplemented by duplicates in the Control Room too, would have prevented this accident. I an surprised that the Jubilee and Northern Lines had them omitted in order to save money. (a false economy). Yes and no. I suspect in most cases by the time the plunger would be operated it may well be too late, and all this has to be balanced against the risk of misuse. |
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