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Post by Jerome H on Jul 10, 2016 21:36:22 GMT
Interestingly, last night I saw (on TV) a train where, when it stopped, a little platform emerged halfway between the passenger floor and track level. This was, of course, to produce a step to correctly interface between the two heights. However, it doesn't seem too difficult to imagine a similar system deployed on LU as a safety barrier. (I think that trying to produce something at (roughly) the same level as the carriage floor would be quite a technical challenge.) I believe these are known as "gap fillers" (not illogically). The idea is very simple, and for the most part the technology is pretty simple to implement. The problem is that they need to astoundingly reliable as if even one fails in the "out" position you can't move the train because by their very design the gap fillers are foul of gauge. If one fails in the "in" position then you have an increased risk of passengers falling into the unfilled gap as they are not expecting the gap to be there. The second issue can be mitigated by placing a member of staff at the affected doorway to warn specifically warn (and help) passengers about the gap, but only once the failure is known (so realistically likely from the second or third affected train only). Straying a bit from the topic, since new trains are being designed, it could be built into the system that the PED, Gap Filler, and Train Carriage Door are all in communication with each other so that if one fails neither of the three work if safety is the number one priority. |
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Chris M
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Post by Chris M on Jul 10, 2016 23:43:42 GMT
If a PED fails to open automatically then there is a manual override from the train side (I've had to use it once, I think it was Westminster) so a failure of a PED without a failure of the other two will not necessarily require the doorway to be OOU. What would definitely be useful though would be a way to display inside the train that the door/PED will not open and to use a different one. At Canary Wharf I once saw a member of staff stationed by a non-opening PED, I don't know the reason why it wasn't opening or how long the failure had been going on but all they could do was to gesture to the people trying to exit that they needed to use a different door.
If gap fillers are used there will definitely need to be some form of communication that all have been successfully fully retracted before movement authority is granted.
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Post by bassmike on Jul 11, 2016 10:34:24 GMT
bassmike, please have a look at some open air platforms. Your first suggestion would be hit by the trains. Otherwise you will see fairly large cables on hangers along the length of the platforms below an overhanging platform edge. That doesn't leave space for your alternative. In many cases there are voids under the slabs. The construction method was to support a platform not the weight of your proposed installation (or your 2" bored holes) I did give it thought which was based on more than 40 years of Underground experience. This includes working on the Jubilee Line Extension alongside the PED installers. Your comment about barrier hit by trains--- I did say move the platform edge back as necessary ans use the top of the barrier to restore the correct gap. Also I never said the weight was carried by the platform edge-it would be carried on a base plate at ground level interspersed with the lifting ram tubes. The whole thing is just an idea and would obviously need developing but is no more outlandish than many other schemes. |
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Post by snoggle on Jul 11, 2016 12:40:24 GMT
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Post by bassmike on Jul 11, 2016 17:47:51 GMT
I expect they're all impossible! Wire ropes might catch on the corners of trains!
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Post by philthetube on Jul 11, 2016 18:09:56 GMT
The first issue can also be mitiagted against, I imagine that this system would not allow the doors to open until the gap fillers were in position, but would you want the delays.
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