Graeme Wall wrote:
On 14/11/2015 09:03, 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?


More efficient and I suspect the actual lift body weighs less than a
wooden escalator.

He was comparing it to a conventional lift, not an escalator. I think it
needs a less powerful motor than a vertical lift as the rate at which the
weight is lifted vertically is less.

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.

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.

Mark
--
Insert random witticism here
http://www.markgoodge.com

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.

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.

If you ignore friction, it takes zero net energy to move an object at a
fixed speed horizontally, and a fixed amount to lift it a particular
distance. But the *power* will be less if you lift it more slowly, which
the inclined lift does, compared to a typical vertical lift. Of course,
friction isn't zero, and will be more, the shallower the angle. But if the
lift box runs on wheels on rails, the friction will be low.

In message e.net, at
10:29:44 on Sat, 14 Nov 2015, Mark Goodge
remarked:
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.

If it's the same weight, and with the same frictional losses as a
conventional lift, it would take the same energy to make the journey
[gaining potential energy in the process].

If the journey takes longer, the *power* (energy/time) would be less.

But it's complicated by the presence (or absence) of a counterweight,
which transfers its energy to the lift (and vice versa).

What the chap in the video is probably saying is that (without having
really thought about the physics himself) that the wattage plate on the
motor is less than you'd expect to find on a lift motor.
--
Roland Perry

Do you remember the guy who died after descending Mount Everest on an aluminium teatray? They buried him where the teatray stopped, near Dagenham East.

On Saturday, 14 November 2015 09:43:09 UTC, Recliner wrote:
Offramp wrote:
On Saturday, 14 November 2015 01:39:32 UTC, Basil Jet wrote:
https://www.youtube.com/watch?v=sxScXvX1Dv4

Why is it not called a funicular?

Good question. Maybe because it's indoors? I assume it also doesn't run on
railway-style tracks.

Indoor funiculars are called testiculars.

In message
-sept
ember.org, Recliner wrote:
In addition, the fact it's sliding down rails rather than hanging in
free space may alter the efficiency of the mechanism.

I assume it runs on rollers or guide wheels, rather than sliding.

Bad wording on my part.

It's at
quite a shallow angle.

With a few exceptions, LU escalators are at 30 degrees, so presumably
this is as well.

--
Clive D.W. Feather | Home:
Mobile: +44 7973 377646 | Web: http://www.davros.org
Please reply to the Reply-To address, which is:

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.

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...

On Saturday, 14 November 2015 11:54:02 UTC, Offramp wrote:

Indoor funiculars are called testiculars.

Think you will find that is b*llocks...

(I'll get my coat...)