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#31
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Graeme Wall wrote:
On 14/11/2015 13:26, Someone Somewhere wrote: On 14/11/2015 10:26, Recliner wrote: In any case, the old escalator was wood-panelled, which wouldn't have affected the weight of the moving parts. They could have fitted a second escalator in the same space, but that wouldn't help people in wheel chairs. As it is, the able-bodied will be able to ascend using the other escalator, but are expected to walk down the stairs when arriving at the station. These inclined lifts are apparently much cheaper than conventional lifts, and are a cost-effective way of providing step-free access in stations that have multiple staircases but no convenient place for a vertical lift shaft. I have to say that it cannot be beyond the wit of man to come up with some kind of "carriage" that fits on an escalator that allows wheelchairs to be conveyed up and down with minimal interruption to the journeys of others. You need a flat platform for the wheelchair to roll on to, some kind of mechanism like they have on stretchers to go into ambulances but with a graduated rather than step mechanism, some kind of braking and some self levelling. The user and their wheelchair could be loaded on to the carriage someway away from the top or bottom of the escalator and then the thing could be maneuvered (or act like a roomba - a bit of vacuuming of a lot of stations wouldn't go amiss either) onto the esclator. Sounds horrendously complicated, it would have to have a self-contained power source to drive the self-levelling mechanism. The stretcher mehacnism doesn't have to cope with a support that is moving away from it while the leg are being adjusted. If the pivoted leg tucks under the base then it would only work on the uphill section. I accept it may require a "helper" of some description but given the closure of ticket offices, there are meant to be TfL employees out in the wild who could help. Even if such a thing cost £100k per station that's a shedload cheaper than a new lift... Is it? How much was the lift at Greenford? Around £2m. But that's instead, not on top, of the cost of a new escalator. |
#32
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Basil Jet wrote:
On 2015\11\14 09:09, Recliner wrote: Chris J Dixon wrote: Basil Jet wrote: https://www.youtube.com/watch?v=sxScXvX1Dv4 I'm a little surprised that they claim it uses less power than a conventional lift. If you have to raise a given mass through a given vertical distance, shouldn't the answer be the same? Yes, I agree about the *energy* consumption. But perhaps it gets away with a less powerful motor, as it's slower than a normal lift. I assume it has a counterbalance like a normal lift? I'll see if I can tell when I go to see it on Monday. Of course, the balance weight may be hidden, as it is with many normal lifts. It is yellow and clearly visible in the video above at 1:21. Yes, well spotted. According to the feasibility study, it would weigh 1.9 tonnes, though the one in the video doesn't look large enough. Maybe they also reduced the size of the cabin (it was proposed as a 10 person, 1 tonne capacity). |
#33
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On 2015\11\14 10:29, Mark Goodge wrote:
On Sat, 14 Nov 2015 09:36:51 +0000, Clive D. W. Feather put finger to keyboard and typed: In message -sept ember.org, Recliner wrote: I'm a little surprised that they claim it uses less power than a conventional lift. If you have to raise a given mass through a given vertical distance, shouldn't the answer be the same? That assumes 100% efficiency in the mechanism. Not a safe assumption. Yes, I agree about the *energy* consumption. But perhaps it gets away with a less powerful motor, as it's slower than a normal lift. In addition, the fact it's sliding down rails rather than hanging in free space may alter the efficiency of the mechanism. Yes. A simple thought experiment works here. It clearly requires less energy to push a wheeled object horizontally than it does to lift it vertically. So there's clearly also a continuum between 0 degrees = least energy and 90 degrees (from the horizontal) = most energy, and therefore something like 45 degrees = somewhere in between the two. Your basic task is to get someone from ground level to platform level. You have to compare doing it vertically with doing it in a LONGER diagonal shaft. Comparing 10 metres vertical with 10 metres at an angle is meaningless. There is a counterbalance, but I imagine that matches the weight of a half-laden cabin, so there will still be weight to be moved most of the time. I imagine the friction in an angled lift will massively exceed the friction in a vertical lift. The lift is ridiculously over-engineered. A platform with shoulder height gates would have done the job, instead of this cuboid with electronic displays all over it and lights in the ceiling. Lifts are cuboids because if something snaps, you don't want it crashing down on the heads of the people. There is nothing above an inclinator to snap and land on people, so no roof necessary, and no lights required either. Typical public sector largesse... no private company would have done this. |
#34
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In message , at 15:36:27 on Sat, 14 Nov
2015, Basil Jet remarked: The lift is ridiculously over-engineered. A platform with shoulder height gates would have done the job, instead of this cuboid with electronic displays all over it and lights in the ceiling. Lifts are cuboids because if something snaps, you don't want it crashing down on the heads of the people. There is nothing above an inclinator to snap and land on people, so no roof necessary, and no lights required either. Typical public sector largesse... no private company would have done this. Earlier this year I went in one of the scariest lifts I've encountered for a long time. It consisted only of a floor which went up and down inside a lined square tube; rather slowly. The lack of a roof, in particular, gave me very bad vertigo, even at ground level. -- Roland Perry |
#35
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On 14.11.15 1:56, Recliner wrote:
Basil Jet wrote: https://www.youtube.com/watch?v=sxScXvX1Dv4 Thanks, I had already planned to go and have a look at it next week. It's been ages in construction. Only a very few years ago, Greenford was a station with semaphore signals and a wooden panelled escalator. Now they've both gone, but it's still one of the very few stations with cross-platform interchange between DMUs and automatic Tube trains. Is there any place on the Greenford Branch Line London, or anywhere else in London, that continue to use semaphores? |
#36
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Robin9 wrote:
'Recliner[_3_ Wrote: ;151728']Basil Jet wrote:- https://www.youtube.com/watch?v=sxScXvX1Dv4 - Thanks, I had already planned to go and have a look at it next week. It's been ages in construction. Please let us know if Greenford Station still has posters heralding the imminent start of 24 hours tube sevice. They were there on the platforms last time I was at Greenford. I'll check. I also notice that my local Tube station, which isn't even scheduled to get the Night Tube when it does eventually start, already has the Night Owl logo on its Tube map, not covered with a sticker. |
#37
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On Sat, 14 Nov 2015 15:56:24 +0000, Roland Perry
wrote: In message , at 15:36:27 on Sat, 14 Nov 2015, Basil Jet remarked: The lift is ridiculously over-engineered. A platform with shoulder height gates would have done the job, Assuming that there is nothing within reach that can be touched and that clearance can be assured at all times in the future. instead of this cuboid A box performs that function in all directions. with electronic displays all over it and lights in the ceiling. Lifts are cuboids because if something snaps, you don't want it crashing down on the heads of the people. There is nothing above an inclinator to snap and land on people, so no roof necessary, and no lights required either. Typical public sector largesse... no private company would have done this. Earlier this year I went in one of the scariest lifts I've encountered for a long time. It consisted only of a floor which went up and down inside a lined square tube; rather slowly. The lack of a roof, in particular, gave me very bad vertigo, even at ground level. |
#38
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Basil Jet wrote:
On 2015\11\14 10:29, Mark Goodge wrote: On Sat, 14 Nov 2015 09:36:51 +0000, Clive D. W. Feather put finger to keyboard and typed: In message -sept ember.org, Recliner wrote: I'm a little surprised that they claim it uses less power than a conventional lift. If you have to raise a given mass through a given vertical distance, shouldn't the answer be the same? That assumes 100% efficiency in the mechanism. Not a safe assumption. Yes, I agree about the *energy* consumption. But perhaps it gets away with a less powerful motor, as it's slower than a normal lift. In addition, the fact it's sliding down rails rather than hanging in free space may alter the efficiency of the mechanism. Yes. A simple thought experiment works here. It clearly requires less energy to push a wheeled object horizontally than it does to lift it vertically. So there's clearly also a continuum between 0 degrees = least energy and 90 degrees (from the horizontal) = most energy, and therefore something like 45 degrees = somewhere in between the two. Your basic task is to get someone from ground level to platform level. You have to compare doing it vertically with doing it in a LONGER diagonal shaft. Comparing 10 metres vertical with 10 metres at an angle is meaningless. There is a counterbalance, but I imagine that matches the weight of a half-laden cabin, so there will still be weight to be moved most of the time. I imagine the friction in an angled lift will massively exceed the friction in a vertical lift. The lift is ridiculously over-engineered. A platform with shoulder height gates would have done the job, instead of this cuboid with electronic displays all over it and lights in the ceiling. Lifts are cuboids because if something snaps, you don't want it crashing down on the heads of the people. There is nothing above an inclinator to snap and land on people, so no roof necessary, and no lights required either. Typical public sector largesse... no private company would have done this. Given that it has electric doors on both sides, you need something to support them. I can't imagine that the roof adds much weight or cost, and it at least stops the pigeons from decorating the insides of the box. It also stops the local yobs climbing out and getting on to the lift mechanism, or throwing stuff on to it. |
#39
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Only ➘ ➙ ➚ ➛ ➜ ➝ ➞.
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#40
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