"Basil Jet" wrote:

On 2011\05\13 11:43, wrote:

(Offramp) wrote:

One of the runsoff of fare evasion is that these two-step lifts are
thought necessary.

An in extremis example is at Westminster. There is no lift from the
street to the platforms; that would mean by-passing the ticket gates.
So there is a lift from the street to the ticket office level - one of
the shallowest lifts in London, I would think. It has the depth of
about a dozen steps. There is a similar sort of thing at the Borough
High St exit at London Bridge.

I suspect the Westminster height is more typical than you realise. From
street to ticket hall is a common lift requirement.

If the lift had doors on two sides and sensors to detect people within,
a single lift could link the street, the ticket hall and the platforms
without compromising the barrier line.


With doors opening alternate sides I suppose.

On 2011\05\13 12:54, Mizter T wrote:

"Basil Jet" wrote:

On 2011\05\13 11:43, wrote:

(Offramp) wrote:

One of the runsoff of fare evasion is that these two-step lifts are
thought necessary.

An in extremis example is at Westminster. There is no lift from the
street to the platforms; that would mean by-passing the ticket gates.
So there is a lift from the street to the ticket office level - one of
the shallowest lifts in London, I would think. It has the depth of
about a dozen steps. There is a similar sort of thing at the Borough
High St exit at London Bridge.

I suspect the Westminster height is more typical than you realise. From
street to ticket hall is a common lift requirement.

If the lift had doors on two sides and sensors to detect people
within, a single lift could link the street, the ticket hall and the
platforms without compromising the barrier line.


With doors opening alternate sides I suppose.

The lift would have two modes, streetside and airside, and could only
switch between the two when empty. On the ticket hall level the mode
would control which of the two doors opened.

In message , at 13:00:34 on
Fri, 13 May 2011, Basil Jet remarked:
If the lift had doors on two sides and sensors to detect people
within, a single lift could link the street, the ticket hall and the
platforms without compromising the barrier line.

With doors opening alternate sides I suppose.

The lift would have two modes, streetside and airside, and could only
switch between the two when empty. On the ticket hall level the mode
would control which of the two doors opened.

And I predict it would spend most of its time full of people wanting the
opposite mode to that which it was currently performing, and refusing to
get out.
--
Roland Perry

On 2011\05\13 13:30, Roland Perry wrote:
In message , at 13:00:34 on
Fri, 13 May 2011, Basil Jet remarked:
If the lift had doors on two sides and sensors to detect people
within, a single lift could link the street, the ticket hall and the
platforms without compromising the barrier line.

With doors opening alternate sides I suppose.

The lift would have two modes, streetside and airside, and could only
switch between the two when empty. On the ticket hall level the mode
would control which of the two doors opened.

And I predict it would spend most of its time full of people wanting the
opposite mode to that which it was currently performing, and refusing to
get out.

It's theoretically possible that one mode could hog the lift, but I
don't think any lift on LU is busy enough for that to happen, except at
the lift-only stations such as Covent Garden.

The other way to exploit one shaft and motor would be to attach two lift
cages on top of each other, with the top one streetside and the bottom
one airside. If the distance between the two cages was the same as the
distance from street to ticket hall, they could both load simultaneously
at the top, although they'd need to load separately at the bottom. That
way neither mode can hog the lift, but people would often be in a
stopped lift with the doors shut.

In message , at 14:29:52 on
Fri, 13 May 2011, Basil Jet remarked:

The other way to exploit one shaft and motor would be to attach two
lift cages on top of each other, with the top one streetside and the
bottom one airside. If the distance between the two cages was the same
as the distance from street to ticket hall, they could both load
simultaneously at the top, although they'd need to load separately at
the bottom.

I've never seen that lift configuration, possibly because one lift's
occupants will assume they are trapped when the lift stops without the
doors opening.
--
Roland Perry

On 2011\05\13 14:42, Roland Perry wrote:
In message , at 14:29:52 on
Fri, 13 May 2011, Basil Jet remarked:

The other way to exploit one shaft and motor would be to attach two
lift cages on top of each other, with the top one streetside and the
bottom one airside. If the distance between the two cages was the same
as the distance from street to ticket hall, they could both load
simultaneously at the top, although they'd need to load separately at
the bottom.

I've never seen that lift configuration, possibly because one lift's
occupants will assume they are trapped when the lift stops without the
doors opening.

If the motor had two different sized drums attached to the same axle,
with the cables for the two cars attached to the two drums, as the upper
lift moved one metre the lower lift could move ten metres. In theory
this should be cheaper than two lifts, but in practice it might not be
due to non-standard parts.

On Fri, 13 May 2011 15:03:19 +0100
Basil Jet wrote:
If the motor had two different sized drums attached to the same axle,
with the cables for the two cars attached to the two drums, as the upper
lift moved one metre the lower lift could move ten metres. In theory
this should be cheaper than two lifts, but in practice it might not be
due to non-standard parts.

There's probably a whole host of safety issues too.

B2003

In article , (Roland
Perry) wrote:

In message , at 13:00:34
on Fri, 13 May 2011, Basil Jet
remarked:
If the lift had doors on two sides and sensors to detect people
within, a single lift could link the street, the ticket hall and the
platforms without compromising the barrier line.

With doors opening alternate sides I suppose.

The lift would have two modes, streetside and airside, and could only
switch between the two when empty. On the ticket hall level the mode
would control which of the two doors opened.

And I predict it would spend most of its time full of people
wanting the opposite mode to that which it was currently
performing, and refusing to get out.

Never mind all the operating complexity, just think where the lifts go.
Those in Westminster are some way apart.

--
Colin Rosenstiel

On Fri, 13 May 2011, Roland Perry wrote:

In message , at 14:29:52 on Fri, 13
May 2011, Basil Jet remarked:

The other way to exploit one shaft and motor would be to attach two lift
cages on top of each other, with the top one streetside and the bottom one
airside. If the distance between the two cages was the same as the distance
from street to ticket hall, they could both load simultaneously at the top,
although they'd need to load separately at the bottom.

I've never seen that lift configuration, possibly because one lift's
occupants will assume they are trapped when the lift stops without the
doors opening.

You could have a sign outside the window saying DON'T WORRY, YOU ARE NOT
TRAPPED, perhaps. Or, if there was an intermediate level the same distance
below the ticket hall as that is below the street, the doors could open
there. You could even furnish such a level merely to prevent distress!

On double-decker lifts more generally:

http://en.wikipedia.org/wiki/Double-deck_elevator

tom

--
These spoiled youths forget that when they are shaven they look like
boiled potatoes. -- Tara Singh

On Sat, 14 May 2011 10:29:19 +0100, Tom Anderson
wrote:
TRAPPED, perhaps. Or, if there was an intermediate level the same
distance
below the ticket hall as that is below the street, the doors could
open
there. You could even furnish such a level merely to prevent
distress!

Some funiculars appear to have stations in the middle of nowhere for
that sort of purpose.

Neil

--
Neil Williams, Milton Keynes, UK