In article ,
(Recliner) wrote:

On Thu, 3 Mar 2016 17:05:17 +0000, Roland Perry
wrote:

In message

-septembe
r.org, at 16:05:51 on Thu, 3 Mar 2016, Recliner
remarked:
Roland Perry wrote:
In message , at 15:07:19
on Thu, 3 Mar 2016, Recliner remarked:

People also complain about the earlier Victoria-Picc connection.
There must be something in the way to stop it dropping down
halfway along.


http://husk.org/www.geocities.com/at.../ltgreenpk.gif

I think the 'thing' is the expensive buildings north of Piccadilly.
It's much easier, cheaper and safer to build station tunnels under
a (literally) green park than large buildings.

The Piccadilly Line platforms will be under the road, so the "thing"
is also under the road, towards the western end of the platforms.

No, the issue is that the current station building is linked by
single long escalators to Piccadilly line platforms that used to be
under a different surface building directly above the line, linked by
lifts.

** see below

So the Picc platforms are under the road, but well to the east of the
current station building.

The Victoria line came next, at approximately right angles to the
east-west Piccadilly line, and the platforms were placed just south
of the road, for ease of construction. The escalators link to the
platforms about a third of the way along (which is better than
connecting to the extreme ends of the platforms, which is what
happens with the Piccadilly line).

The subsequent Jubilee line platforms are below and just to the east
of the Victoria platforms. Of course, if they'd known then about the
later change of route, with the new line not needing to swing so far
east, the Jubilee line might have had a very different configuration
at Green Park, with the platforms parallel to the Victoria line. They
might even have delivered cross-platform interchange with the
Victoria line, as at, say Baker Street.

But the Picc platforms are so far to the east of the station, that
there's no good way of connecting new north-south platforms to both
the station building and the Piccadilly platforms to the east.

None of that explains why...

But they could nevertheless have started the passage between them
further to the western end of the Piccadilly line platforms.

...the passages from the two new stations don't head for the bottom of
the Piccadilly escalators, rather than the eastern ends of the
platforms which is what creates the excessively long walks.

I wonder if that was to avoid congestion on the platforms, which also
have to act as the route to the escalators? This way, people heading to
the passage to the Victoria line aren't mixed in with people heading for
the exit.

Such matters don't appear to bother the designers of other stations.

But... ** the "thing" might be the old lift shafts, the space taken
up by which, for some reason, they declined to re-use.

No, the old Dover Street station lift shafts will be over the Piccadilly
platforms

The "thing" I'm trying to identify is also above the Piccadilly
platforms.

Not exactly. See below.

-- you can work out where they must be from the location of the
old station at Dover St.

The space occupied by the "thing" is very likely under the junction
between Dover St and Piccadilly (which makes a lift shaft less likely).

But I presume that the Piccadilly line escalator
motor rooms must be below the line, so the Victoria line needed to run
further to the west, to be well clear of the escalators and their
equipment. It was probably easier to build the new line to run almost
directly under the existing station building. That minimised the length
of escalators, and meant that the station construction activity wasn't
directly under someone else's property.

You are still fixated upon the position of the Victoria Line. What I'm
interested in is why the passageway from the Victoria to Piccadilly
doesn't emerge at the western end of the latter's platforms. And later,
the same for the Jubilee.

Another thought strikes me: I wonder if the Picc platform exits and
stairs to the long passages to the Victoria and Jubilee lines are the
re-used original exits and stairs to the old Dover St station lower
lift landing? They seem to be in the right place for that, and
re-using them would have saved disruption to the Piccadilly line
platforms when the station was extended for the new lines.

I suspect the geocities diagram tends to confirm that, judging by the Dover
Street substation location shown. The Piccadilly lifts can't have been
directly above the platform tunnels because they are under the road.

--
Colin Rosenstiel